Norman Lady Cargo Operating Manual

Issue: 2

Norman Lady Cargo Operating Manual Cargo Operating Manual

List of ContentsIssue and UpdateCargo Symbols and Colour Scheme Electrical and Instrument SymbolsIntroduction

Part 1: Design Concept of the Vessel

1.1 Principal Particulars1.1.1 Ship Principal Particulars 1.1.2 Principal Particulars of Cargo Machinery1.1.3 General Arrangement1.1.4 Tanks and Capacity Plan

1.2 Rules and Regulations

1.3 Cargo System Technology1.3.1 Cargo Containment System Principle 1.3.2 Kvaerner-Moss Cargo Containment1.3.3 Failure of Containment1.3.4 Void Spaces

1.4 Hazardous Areas and Zones

Illustrations1.1.3a General Arrangement1.1.3b Compressor Room Layout1.1.4a Tank Capacity Plan1.3.2a Construction of Containment System - Equatorial Ring and

Wedge Space1.3.2b Construction of Containment System - Rupture Discs1.3.2c Construction of Containment System - Dome and Tank Access1.3.2d Construction of Containment System - Insulation1.3.2e Construction of Containment System - Piping Insulation1.3.4a Void Spaces and Ventilation1.3.4b Relationship between Corrosion and Relative Humidity1.4a Hazardous Areas and Gas Dangerous Zones

Part 2: Properties of LNG

2.1 Physical Properties and Composition of LNG

2.2 Characteristics of LNG2.2.1 Flammability of Methane, Oxygen and Nitrogen Mixtures2.2.2 Supplementary Characteristics

2.3 Health Hazards

Illustrations2.1a Vapour Pressure Diagram of Liquid Cargoes2.1b Physical Properties of LNG2.1c Composition of LNG from Major Export Terminals (Mol%)

2.1d Relative Density of Methane and Air2.2.1a Flammability of Methane, Oxygen and Nitrogen Mixtures2.2.2a Structural Steel: Ductile to Brittle Transition Curve

Part 3: Distributed Control System (DCS)

3.1 Cargo Control Room (CCR) Arrangement

3.2 Vessel Control System 3.2.1 Damatic XD Distributed Control System (DCS) Overview3.2.2 Operator Stations3.2.3 Screen Displays3.2.4 Operation3.2.5 Mimics3.2.6 Cargo and Ballast Operations

Illustrations3.1a Cargo Control Room Layout 3.1b Cargo Control Room Console 3.2.1a Distributed Control System Overview3.2.2a Operator Station Keyboard3.2.3a Screen Display3.2.3b Operating Panel Display3.2.4a Operation3.2.5a Mimics3.2.6a Ballast Operating Display Screens

Part 4: Cargo and Ballast Systems

4.1 Cargo Containment and Monitoring Systems 4.1.1 Liquid Leakage Detection4.1.2 Temperature and Pressure Monitoring System4.1.3 High Level and Overfill Alarm System

4.2 Cargo Piping System4.2.1 Liquid Line4.2.2 Vapour Line4.2.3 Spray Line4.2.4 Fuel Gas Line4.2.5 Vent Masts 4.2.6 Inerting/Aeration Line

4.3 Cargo Pumps 4.3.1 Main Cargo Pumps4.3.2 Stripping/Spray Pumps

4.4 Gas Compressors4.4.1 High Duty Compressors4.4.2 Low Duty Compressor

4.5 Cargo Heaters

4.6 LNG Vaporisers

4.7 Void Space Systems

4.7.1 Inert Gas Generators 4.7.2 Nitrogen Generator 4.7.3 Void Space Dryers

4.8 Custody Transfer System4.8.1 Custody Transfer System (CTS)4.8.2 Float Level Gauges4.8.3 Loading Computer

4.9 Gas Detection Systems 4.9.1 Fixed Gas Detection Systems4.9.2 Portable Gas Detection Instruments

4.10 Valve Remote Control and Emergency Shutdown System 4.10.1 Cargo Valve Remote Control System4.10.2 Emergency Shutdown System4.10.3 Ship Shore Link

4.11 Relief Systems4.11.1 Cargo Tank Relief Valves4.11.2 Line Relief Valves4.11.3 Void Space Relief Valves

4.12 Ballast System4.12.1 Ballast Piping4.12.2 Ballast Control and Indicating System

Illustrations4.1.1a Leakage Pipes4.1.2a Temperature and Pressure Monitoring System4.1.3a High Level and Overfill Alarm System4.2a Cargo Piping System4.2b Manifold Arrangement4.2.3a Spray Pipes in the Cargo Tanks4.3.1a Main Cargo Pump4.3.1b Pump Arrangement in Cargo Tank4.3.2a Spray Pump4.4.1a High Duty Compressor4.4.1b High Duty Compressor Performance Curves4.4.2a Low Duty Compressor4.4.2b Low Duty Compressor Performance Curves4.5a Cargo Heater4.6a LNG Main Vaporiser4.7.1a Inert Gas System4.7.2a Nitrogen Generator4.7.2b Nitrogen System4.7.3a Void Space Dryers4.8.1a CTS Printout4.8.2a Whessoe Float Level Gauge 4.8.3a Loading Computer Screen4.9.1a Ballast and Void Spaces Gas Sampling System4.9.1b Boil Off Gas Pipe Vent Duct Gas Sampling System4.9.1c Cargo Areas Gas Sampling System4.9.2a Portable Gas Detectors

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Issue: 2

Norman Lady Cargo Operating Manual 4.10.1a Cargo Valve Remote Control System4.10.1b Cargo Gate Valve4.10.2a Fibre Optic Ship-Shore Link System and Pneumatic ESD

Circuit4.10.2b Emergency Shutdown Logic4.11.1a Cargo Tank Relief Valves4.11.3a Void Space Relief Valves4.11.3b Monitoring of Pressure Relatives (Tank-Void Space-Atmosphere)4.12.1a Ballast Piping System

Part 5: Cargo Auxiliary and Deck Systems

5.1 Fire Detection System

5.2 Fire Fighting Systems 5.2.1 Fire and Deck Wash System 5.2.2 Water Spray System 5.2.3 Forward Emergency Fire Pump System 5.2.4 Dry Powder Systems 5.2.5 CO2 System 5.2.6 Emergency Headquarters

5.3 Cargo Compressor Room Systems5.3.1 Cooling Water System5.3.2 Steam to Cargo Consumers

5.4 Deck Machinery and Systems5.4.1 Mooring Winches Windlasses and Deck Steam System5.4.2 Mooring Plan5.4.3 Pilot and Accommodation Ladders5.4.4 Deck Cranes

5.5 Safety Plan

Illustrations5.1a Fire Detection System5.2.1a Fire and Deck Wash System 5.2.2a Water Spray System 5.2.3a Forward Fire Pump System 5.2.4a Dry Powder Systems 5.2.4b Dry Powder Systems: Hose Boxes and Units5.2.5a CO2 System 5.3.1a Cargo Plant Water Cooling System5.3.2a Steam to Deck Consumers5.4.1a Mooring Winches and Deck Steam System5.4.1b Winch/Windlass5.4.2a Mooring Arrangement 5.4.3a Required Boarding Arrangement for Pilot5.4.3b Pilot and Accommodation Ladders5.4.4a Deck Cranes5.5.1a Fire Detection and Alarms Decks 1 and 25.5.1b Fire Detection and Alarms Decks 3 and 45.5.1c Fire Detection and Alarms Decks 5 and 65.5.1d Fire Detection and Alarms Upper Deck and Engine Room5.5.2a Fire Fighting Equipment Decks 1 and 2

5.5.2b Fire Fighting Equipment Decks 3 and 45.5.2c Fire Fighting Equipment Decks 5 and 65.5.2d Fire Fighting Equipment Upper Deck and Engine Room5.5.3a Lifesaving Equipment Decks 1 and 25.5.3b Lifesaving Equipment Decks 3 and 45.5.3c Lifesaving Equipment Decks 5 and 65.5.3d Lifesaving Equipment Upper Deck and Engine Room

Part 6: Cargo Operations

6.1 Operating Procedures Overview

6.2 Post Dry Dock Operation6.2.1 Drying Cargo Tanks and Void Spaces6.2.2 Inerting Cargo Tanks 6.2.3 Gassing Up Cargo Tanks 6.2.4 Cooling Down Cargo Tanks

6.3 Ballast Passage 6.3.1 Cooling Down Cargo Tanks Prior to Arrival

6.4 Loading 6.4.1 Preparations for Loading 6.4.2 Cargo Lines Cooldown 6.4.3 To Load Cargo with Vapour Return to Shore via the High

Duty Compressors6.4.4 Deballasting

6.5 Loaded Voyage With Boil-Off Gas Burning6.5.1 Loaded Voyage with Normal Boil-Off Gas Burning

6.6 Discharging with Gas Return to Shore6.6.1 Preparations for Discharging 6.6.2 Liquid Line Cooldown 6.6.3 Arm Cooldown Before Unloading 6.6.4 Discharging Cargo6.6.5 Ballasting

6.7 Pre Dry Dock Operations6.7.1 Stripping and Line Draining6.7.2 Tank Warm-Up 6.7.3 Inerting6.7.4 Aerating

Illustrations6.1a Operating Procedures Schedule6.2.1a Drying Cargo Tanks and Void Spaces6.2.2a Inerting Cargo Tanks 6.2.3a Gassing Up Cargo Tanks 6.2.4a Cargo Tanks Cooldown Rates6.2.4b Cooling Down Cargo Tanks During Loading6.3.1a Cooling Down Cargo Tanks Prior to Arrival6.4.1a Preparations for Loading6.4.2a Cargo Lines Cool Down

6.4.3a Cargo Loading with Vapour Return to Shore via the High Duty Compressors

6.4.3b Completing Loading 6.4.4a Deballasting6.5.1a Loaded Voyage with Normal Boil-Off Gas Burning6.6.1a Preparations for Discharging 6.6.2a Liquid Line Cooldown 6.6.3a Arm Cooldown Before Unloading 6.6.4a Discharging Cargo 6.6.4b Discharging 6.6.5a Ballasting 6.7.1a Stripping and Line Draining6.7.2a Tank Warm Up6.7.3a Inerting6.7.4a Aerating

Part 7: Emergency Procedures

7.1 LNG Vapour Leakage to Insulation Space

7.2 LNG Liquid Leakage to Insulation and Void Space 7.2.1 Use of Eductors for LNG removal

7.3 Water Leakage to Void Spaces 7.3.1 Use of Eductors for Water Removal

7.4 Failure of Cargo Pumps - Emergency Discharge

7.5 Fire and Emergency Breakaway

7.6 One Tank Operation7.6.1 One Tank Warm Up7.6.2 One Tank Gas Freeing7.6.3 One Tank Aerating

7.7 Ship to Ship Transfer7.7.1 General Safety7.7.2 Pre-Mooring Preparations7.7.3 Mooring7.7.4 Transfer Operations7.7.5 Unmooring

7.8 LNG Jettison

7.9 General Emergency Procedures

Illustrations7.1a Vapour Leakage to Insulation Space7.2.1a Use of Eductors for LNG Removal7.3.1a Use of Eductors for Water Removal7.4a Emergency Discharge 7.6.1a One Tank Warm Up7.6.2a One Tank Gas Freeing7.6.3a One Tank Aerating

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Issue: 2

Norman Lady Cargo Operating Manual

Front Matter - of 9

Issue and Update ControlThis manual is provided with a system of issue and updatecontrol. Controlling documents ensures that:

• Documents conform to a standard format;

• Amendments are carried out by relevant personnel;

• Each document or update to a document is approvedbefore issue;

• A history of updates is maintained;

• Updates are issued to all registered holders ofdocuments;

• Sections are removed from circulation when obsolete.

Document control is achieved by the use of the footerprovided on every page and the issue and update tablebelow.

In the right hand corner of each footer are details of thepages section number and title followed by the pagenumber of the section. In the left hand corner of eachfooter is the issue number.

Details of each section are given in the first column of theissue and update control table. The table thus forms amatrix into which the dates of issue of the originaldocument and any subsequent updated sections are located.

The information and guidance contained herein is producedfor the assistance of certificated officers who by virtue ofsuch certification are deemed competent to operate thevessel to which such information and guidance refers. Anyconflict arising between the information and guidanceprovided herein and the professional judgement of suchcompetent officers must be immediately resolved byreference to Höegh Fleet Shipping Co. Ltd TechnicalOperations Office.

This manual was produced by:

WORLDWIDE MARINE TECHNOLOGY LTD.

For any new issue or update contact:

The Technical DirectorWMT Technical OfficeThe Court House15 Glynne WayHawardenDeeside, FlintshireCH5 3NS, UK

E-Mail: [email protected]

Issue: 2


Issue 1 Issue 2 Issue 3 Issue 4List of ContentsCargo Symbols and Colour SchemeElectrical and Instrumentation SymbolsIntroduction

Text1.11.1.11.1.2 1.1.31.1.41.21.31.3.11.3.21.3.41.4

Illustrations1.1.3a1.1.3b1.1.4a1.3.2a1.3.2b1.3.2c1.3.2d1.3.2e1.3.4a1.3.4b1.4a

Text2.12.22.2.12.2.22.3

Illustrations2.1a2.1b2.1c2.1d2.2.1a2.2.2a

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Issue 1 Issue 2 Issue 3 Issue 4Text3.13.23.2.13.2.23.2.33.2.43.2.53.2.6

Illustrations3.1a3.1b3.2.1a3.2.2a3.2.3a3.2.3b3.2.4a3.2.5a3.2.6a

Text4.14.1.14.1.24.1.34.24.2.14.2.24.2.34.2.44.2.54.2.64.34.3.14.3.24.44.4.14.4.24.54.64.74.7.14.7.24.7.34.84.8.1

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Issue 1 Issue 2 Issue 3 Issue 44.8.24.8.34.94.9.14.9.24.104.10.14.10.24.10.34.114.11.14.11.24.11.34.124.12.14.12.2

Illustrations4.1.1a4.1.2a4.1.3a4.2a4.2b4.2.3a4.3.1a4.3.1b4.3.2a4.4.1a4.4.1b4.4.2a4.4.2b4.5a4.6a4.7.1a4.7.2a4.7.2b4.7.3a4.8.1a4.8.2a4.8.3a4.9.1a4.9.1b4.9.1c4.9.2a4.10.1a

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Issue 1 Issue 2 Issue 3 Issue 44.10.1b4.10.2a4.10.2b4.11.1a4.11.3a4.11.3b4.12.1a

Text5.15.25.2.15.2.25.2.35.2.45.2.55.2.65.35.3.15.3.25.45.4.15.4.25.4.35.4.45.5

Illustrations5.1a5.2.1a5.2.2a5.2.3a5.2.4a5.2.4b5.2.5a5.3.1a5.3.2a5.4.1a5.4.1b5.4.2a5.4.3a5.4.3b5.4.4a5.5.1a5.5.1b

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Issue 1 Issue 2 Issue 3 Issue 45.5.1c5.5.1d5.5.2a5.5.2b5.5.2c5.5.2d5.5.3a5.5.3b5.5.3c5.5.3d

Text6.16.26.2.16.2.26.2.36.2.46.36.3.16.46.4.16.4.26.4.36.4.46.56.5.16.66.6.16.6.26.6.36.6.46.6.56.76.7.16.7.26.7.36.7.4

Illustrations6.1a6.2.1a6.2.2a6.2.3a6.2.4a6.2.4b

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Issue 1 Issue 2 Issue 3 Issue 46.3.1a6.4.1a6.4.2a6.4.3a6.4.3b6.4.4a6.5.1a6.6.1a6.6.2a6.6.3a6.6.4a6.6.4b6.6.5a6.7.1a6.7.2a6.7.3a6.7.4a

Text7.17.27.2.17.37.3.17.47.57.67.6.17.6.27.6.37.77.7.17.7.27.7.37.7.47.7.57.87.9

Illustrations7.1a7.2.1a7.3.1a7.4a7.6.1a7.6.2a


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Condensate

Inert Gas

Dry Air

Moist Air

LNG Liquid

LNG Vapour

LNG Vapour (Warm)

Ballast/Sea Water

Nitrogen

Fresh Water

Lubricating Oil

Compressed Air

Bilge Water/Steam Exhaust

Fire Main/Wash/Spray Water

CO2 Smothering

Diesel Oil

Electrical Signal

Instrumentation

Steam

P2P1

H B

F B

P

H P

H

Discharge/Drain

Relief Valve

N.O or N.C

Magnetic Valve

Flow Control, Diaphragm

Type Valve

S

Deck Stand (Manual)

Deck Stand (Hydraulic)

Filter Regulating Valve

With Strainer

Surface Valve

Air Horn

Filter

Angled Screw Down

Non-Return Valve

Normally Open

or

Normally Closed

Fire Hose Box

Foam Box

Accumulator

Hand Operated

Hydraulic Operated

(Open/Shut)

Pneumatic Operated

(Open/Shut)

Intermediate Position

Control

Solenoid Actuator

Cylinder Piston Actuator

Spring

Weight

Float

Centrifugal Type Pump

Gear Type Pump

Screw Pump

Reciprocating Type Pump

Hand Pump

Eductor (Ejector)

Suction Bellmouth

Rose Box

Simplex Strainer

Y-Type Strainer

Hopper Without Cover

Vent Pipe

Vent Pipe with

Flame Screen

Steam Trap With Strainer

and Drain Cock

Sounding Head with

Filling Cap

Flow Meter

Observation Glass

Not Connected

Crossing Pipe

Connected Crossing Pipe

T Pipe

Blind (Blank) Flange

Orifice

Overboard Discharge

Flexible Hose Joint

Storm Valve

Stop Valve

Gate Valve

Butterfly Valve

Screw Down Non-Return

Valve

Lift Check Non-Return

Valve

Self-Closing Valve

Wire Quick-Closing Valve

Safety / Relief Valve

Swing Check Valve

3-Way Valve

Hose Valve

Pressure Reducing Valve

2-Way Cock (S-Type)

3-Way Cock

(L-Type / T-Type)

4-Way Cock

Thermostatic Temp.

Regulating Valve

Spectacle Flange

( Open, Shut)

Mud Box

Spool Piece

Mono Pump

PP

HH

Quick-Closing Valve

Quick-Closing Valve Hydraulic

Non-Return Ball Valve

Air Regulating Valve

Tank Penetration

3-Way Swing Valves

Auto Filter

Level Gauge

(Cylindrical Type)

Level Gauge

(Float Type)

FM Flow Meter

Flame Arrester

Cargo Symbols and Colour Scheme

Restrictor

Drain Trap

Colour Scheme

Pneumatic

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Governor Motor

Snap Switch

Making Contact

Breaking

Disconnection Switch

Battery

Diesel Generator

Transformer

Current to Press

Converter

Press to Current

Converter

XXXXXXX

P

I

I

P

AC Induction Motor

Zener Diode

M

DG

GM

Locally Mounted

Instrument

Remotely Mounted

Instrument

CP Compound Gauge

DPI Differential Pressure Indicator

DPS Differential Pressure Switch

DPT Differential Pressure Transmitter

FD Flow Detector

FS Flow Switch

FT Flow Transmitter

IL Indication Lamp

LAH Level Alarm High

LAL Level Alarm Low

LI Level Indicator

LIC Level Indicating Controller

LS Level Switch

LT Level Transmitter

PAH Pressure Alarm High

PAL Pressure Alarm Low

PI Pressure Indicator

PIC Pressure Indicating Controller

PIAH Pressure Indicator Alarm High

PIAL Pressure Indicator Alarm Low

PIAHL Pressure Indicator Alarm High Low

PS Pressure Switch

PT Pressure Transmitter

SAH Salinity Alarm High

TAH Temperature Alarm High

TAL Temperature Alarm Low

TI Temperature Indicator

TIC Temperature Indicating Controller

TIAH Temperature Indicator Alarm High

TIAL Temperature Indicator Alarm Low

TIAHL Temperature Indicator Alarm High Low

TS Temperature Switch

TT Temperature Transmitter

VAH Viscosity Alarm High

VAL Viscosity Alarm Low

VCA Vacuum Alarm

VCI Vacuum Indicator

VCT Vacuum Transmitter

VI Viscosity Indicator

VT Viscosity Transmitter

XS Auxiliary Unspecified Switch

ZI Position Indicator

ZS Limit Switch

Earth

Shield Wire

XXX

Electrical and Instrument Symbols

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Issue: 2


Introduction

GeneralAlthough the ship is supplied with shipbuilder’s plans and manufacturer’sinstruction books, there is no single handbook which gives guidance onoperating complete systems, as distinct from individual items of machinery.

The purpose of this manual is to fill some of the gaps and to provide the ship’sofficers with additional information not otherwise available on board. It isintended to be used in conjunction with the other plans and instruction booksalready on board and in no way replaces or supersedes them.

In addition to containing detailed information of the cargo equipment andrelated systems, the CARGO SYSTEM and OPERATING MANUAL containssafety procedures and procedures to be observed in emergencies and afteraccidents. Quick reference to the relevant information is assisted by divisionof the manual into parts and sections, detailed in the general list of contents onthe preceding pages. Reference is made in this book to appropriate plans orinstruction books.

In many cases the best operating practice can only be learned by experience.Where the information in this manual is found to be inadequate or incorrect,details should be sent to the Hoegh Fleet Services AS LNG Operations Officeso that revisions may be made to the manuals.

Safe OperationThe safety of the ship depends on the care and attention of all on board. Mostsafety precautions are a matter of common sense and good housekeeping andare detailed in the various manuals available onboard. However, records showthat even experienced operators sometimes neglect safety precautions throughover-familiarity and the following basic rules must be remembered at all times.

1 Never continue to operate any machine or equipment whichappears to be potentially unsafe or dangerous and always reportsuch a condition immediately.

2 Make a point of testing all safety equipment and devices regularly.Always test safety trips before starting any equipment. Inparticular, overspeed trips on auxiliary turbines must be testedbefore putting the unit into operation.

3 Never ignore any unusual or suspicious circumstances, no matterhow trivial. Small symptoms often appear before a major failureoccurs.

4 Never underestimate the fire hazard of petroleum products,whether fuel oil or cargo vapour.

In the design of equipment and machinery, devices are included to ensure that,as far as possible, in the event of a fault occurring, whether on the part of theequipment or the operator, the equipment concerned will cease to functionwithout danger to personnel or damage to the machine. If these safety devicesare neglected, the operation of any machine is potentially dangerous.

DescriptionThe concept of this Operating Manual is based on the presentation of operatingprocedures in the form of one general sequential chart (algorithm) which givesa step-by-step procedure for performing operations.

The manual consists of introductory sections which describe the systems andequipment fitted and their method of operation related to a schematic diagramwhere applicable. This is then followed where required by detailed operatingprocedures for the system or equipment involved.

The overview of machinery operations, as detailed in Section 1, consists of abasic operating algorithm which sets out the procedure for operations from pre-paring the plant for operation from dead ship condition, to shutting down theplant in readiness for dry dock. The relevant illustration and operation sectionnumber is located on the right hand side of each box.

Each machinery operation consists of a detailed introductory section whichdescribes the objectives and methods of performing the operation related to theappropriate flow sheet which shows pipelines in use and directions of flowwithin the pipelines.

Details of valves which are OPEN during the different operations are providedin-text for reference.

The valves and fittings identifications used in this manual are the same as thoseused by Höegh Fleet Services AS.

IllustrationsAll illustrations are referred to in the text and are located either in-text wheresufficiently small or above the text, so that both the text and illustration areaccessible when the manual is laid face up. When text concerning anillustration covers several pages the illustration is duplicated above each pageof text.

Where flows are detailed in an illustration these are shown in colour. A key ofall colours and line styles used in an illustration is provided on the illustration.Details of colour coding used in the illustrations are given in the colourscheme.

Symbols given in the manual adhere to international standards and keys to thesymbols used throughout the manual are given on the following pages.

NoticesThe following notices occur throughout this manual:

WARNINGWarnings are given to draw reader’s attention to operation whereDANGER TO LIFE OR LIMB MAY OCCUR.

CAUTIONCautions are given to draw reader’s attention to operations whereDAMAGE TO EQUIPMENT MAY OCCUR.

(Note: Notes are given to draw reader’s attention to points of interest or tosupply supplementary information.)

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Part 1Design Concept of the Vessel

Part 1 Design Concept of the Vessel

1.1 Principal Particulars

1.1.1 Ship Principal Particulars

Shipbuilder: Rosenberg Verft a.s.Stavanger Norway

Yard number: 196Ship name: Norman LadyYear built: 1973Flag: NorwegianIMO number: 7320344MMSI: 259 903 000Port of registration: OsloCall sign: LAGX5

Type of ship: Steam driven LNG carrierType of cargo: LNG/LPGCargo tanks: 5 Moss type independent sphericalStem: Bulbous bow and raked soft-nosed stemStern: Transom

Classification: Det Norske Veritas1A.1, Tanker for LNG,(-163°C, 600 kg/m3, 0.25 bar) dat (-10ºC),EO, ICE C

Regulation: SOLAS 1974 and Protocol 1978, 1981 and 1983Amendments to SOLAS1974/Protocol 1978 as existing shipMARPOL 1973 and Protocol 1978 IMO code forexisting ships carrying liquefied gases in bulkUSCG (foreign ship) Suez Canal

Deadweight at 10.64m draught: 50,746tGross tonnage: 71,822tNet tonnage: 21,546t

Length overall: 249.555mLength between perpendiculars: 237.0mBreadth moulded: 40.0mDepth moulded: 23.0mService draught: 10.2mSummer draught: 10.641mCargo tank capacity: 87,603m3

Fuel oil tank capacity: 6,0677m3

Gas oil tank capacity: 194m3

Service speed: 17.5 knotsFuel oil consumption per day: 160 tonnes per day without boil-off

gas burning

Endurance/range at 17.5 knots: 13,200 nautical miles withoutboil-off gas burning

Manning design complement: 30 ship personnelOthers: 10 Total: 40

Main MachineryHeat cycle: Regenerative cycle

BoilersMaker: Foster WheelerType: ESD III top fired water tubeCapacity: 44 tonnes/hour

(maximum 57 tonnes/hour)513ºC 62.2 bar

Main TurbineMaker: General Electric Type: MST 141 cross compound

Impulse steam turbineMaximum continuous output: 22,370kW

Main Electrical Power GenerationMaker: Stal LavalType: VKI OF5HP turbine driven generatorCapacity: 1,690kWNo. of sets: 1

Maker: Nohab Type: Polar SF 112 VS-F diesel-generatorsCapacity: 1,500kWNo. of sets: 2

Cargo TanksMaker: Kvaerner Brug ASType: Spherical tank: equator suspension

by continuous skirtMaterial: 9% nickel steelDesign: Moss Rosenborg VerftTanks 1 and 5: 31.0 metres diameterTanks 2, 3 and 4: 33.1 metres diameterTanks 1 and 5 capacity: 15,490m3

Tanks 2, 3 and 4 capacity: 18,860m3

Safety valve setting: 0.25kg/cm2

Maximum specific gravity: 0.6 tonnes/m3

Maximum working pressure: 0.25 barMaximum test pressure: 2.15 barMinimum tank pressure: -0.05 barMaximum specific weight LNG: 500kg/m3

Cargo Tank Safety ValvesMaker: LuceatType: R2101-HPCapacity: 92,000Nm3/hNo. of sets: 15 (3 sets each tank)Setting: 0.25 bar

Cargo Shore Connections:2 x 16’ LiquidLiquid crossover ND 400ASA 150Raised face

1 x 12’ GasND 350ASA 150 Raised face

Section 1.1.1 - Page 1 of 1Issue: 1


1.1.2 Principal Particulars of Cargo Machinery

Main Cargo PumpsMaker: JC Carter Type: 60190-3450-32 Capacity: Rated at 750m3/h x 120 mthNo. of sets: 10 (2 per cargo tank)

Spray/Stripping PumpsMaker: JC CarterType: 6337-2113-3 Capacity: Rated at 20m3/h x 60 mthNo. of sets: 2 (No.3 and 4 tanks)

High Duty CompressorMaker: Airco CryogenicsType: Steam turbine drivenCapacity: 10,750m3/hNo. of sets: 2

Low Duty CompressorMaker: Airco CryogenicsType: Steam turbine drivenCapacity: 3,000m3/hNo. of sets: 1

LNG VaporiserMaker: Moss VerftCapacity: 597,000m3/hHeating: Steam at 10 barNo. of sets: 1

Gas HeaterMaker: Moss VerftType: Shell and tubeCapacity: 329,000kcal/h Heating: Steam at 10 barNo. of sets: 2

Void Space DryerMaker: Rosenberg VerftType: ContardoCapacity: 75,000kcal/h No. of sets: 2

Void Space Vent FanMaker: NyborgCapacity: 2,000m3/h No. of sets: 2Motor maker: NewmanType: E250 MDOutput: 60kW

Vent Fan for Gas Double PipeMaker: NyborgCapacity: 600m3/hNo. of sets: 2Motor maker: NewmanType: E100 LD/XOutput: 1kW

Nitrogen GeneratorMaker: Kvaerner MossType: ‘Prism’ nitrogen systemCapacity: 21m3/h at 97% N2

Nitrogen Recirculating FanMaker: NyborgCapacity: 2,000m3/hNo. of sets: 2Motor maker: NewmanType: E112 MD/XOutput: 2kW

Nitrogen Generator Air Feed CompressorMaker: KaeserType: FW cooled screw compressor Capacity: 50Nm3/h at 10 barNo. of sets: 1

Nitrogen Storage TanksMaker: LindeCapacity: 25m3 and 15m3

No. of sets: 2

Nitrogen DehumidifierMaker; Moss VerftCapacity: 66,400Kcal/h

Inert Gas Dehumidifier DryersMaker: Alfsen og Gunderson ASType: AG-SR-122E and AG-SR-122SCapacity: 2,500m3/h

Inert Gas GeneratorMaker: Moss VerftType: LPU 2500-0.2Capacity: Inert Gas Gas oil burner: 2,500m3/h

Dryer 1 x refrigeration/absorptionNo. of sets: 2

Ballast PumpsMaker: WorthingtonType: 10-LNCV-12Capacity: 1,200m3/hNo. of sets: 2

LPG Reliquification PlantMaker: Kvaerner BrugsType: Cascade




Section 1.1.3 - Page 1 of 2

Principal Dimensions

Length (Overall) 249.5m

Length (Between Perpendiculars) 237.0m

Breadth (Moulded) 40.0m

Depth (Moulded) 23.0m

Height from bottom/top of radio mast 48.4m

Illustration 1.1.3a General Arrangement

RopeStore

SteeringCompartment

No.5Cargo Tank

LNG CompressorRoom

Cargo ControlRoom

No.4Cargo Tank

No.3Cargo Tank

No.2Cargo Tank

No.1Cargo Tank

Cross SectionElevation

Plan

LiquidNitrogen

Accommodation

LiquidNitrogen

Manifold

LPG CompressorRoom

Electric MotorRoom

ChainLocker

FreshWater

DeepTank

Fuel Oil Fore PeakTank Dry

Lower CrossTank Involved in No.3

Double BottomTank Fuel Oil

No.2DoubleBottom

No.3DoubleBottom

No.4DoubleBottom

No.5DoubleBottom

No.1DoubleBottom

No.3Lower Cross

Water Ballast Tank

No.2Lower Cross

Water Ballast Tank

No.1Lower Cross

Water Ballast Tank

PipeDuct

PipeDuct

BottomWater Ballast

SideWater Ballast

Double BottomSpare Water Ballast

Issue: 1

Issue: 1


Illustration 1.1.3b Compressor Room Layout

Vapour HeaterEntrance Door

Void Space Dryer/Heat Exchangers

VaporiserControllers

Vaporiser

EscapeHatch

HDCompressor

CargoInstrument

Air Receiver

HDCompressor

LDCompressor

Vapour Heater


Issue: 1


1.1.4 Tanks and Capacity Plan

Compartment

CARGO TANKS ( 100% Full, +20ºC)

Cargo Tank No.1 15,556

18,953

18,980

18,950

15,555

87,994

543,355

669,320

670,272

669,214

549,320

3,107,482

97843.49

119,209.80

119,379.63

119,190.34

97,837.20

553,461.06

4,107,428

5,006,813

5,013,946

5,006,020

4,109,163

23,245,370

193.31

158.73

123.27

87.81

53.34

19.75

18.75

18.75

18.75

19.75

Cargo Tank No.2

Cargo Tank No.3

Cargo Tank No.4

Cargo Tank No.5

Total

Metres3 Feet3 US Barrels US GallonsForward of Ap

Centres of GravityAb Base

Compartment

NITROGEN BUFFER TANKS

Nitrogen (N2)

Nitrogen (N2)

59

59

Port

Starboard

25

15

40

883

530

1413

70.47

69.30

25.42

24.93

Frame Side Metres3 Feet3

20.3

12.2

32.5

TonnesCentres of Gravity

Forward of Ap Ab Base

Total

Compartment

GAS OIL TANKS

No.7 Side Tank

No.8 D.B. Tank

27 - 30

18 - 30

Starboard 2,684

5,438

8,122

76

154

230

64

130

19.42

16.63

20.08

1.66

194

Frame Side Metres3 Feet3 TonnesCentres of Gravity


Total

Compartment

HEAVY FUEL OIL TANKS

Deep Tank Forward

No.3 D.B. Tank

95 - 111

53 - 61

30 - 39 Port/Starboard

3382

2522

335

119,434

89,063

11,830

215.21

66.13

11.06

2.98

24.57 19.01


3215

2324

309



No.6 Side Tank

Compartment

WATER BALLAST TANKS

No.1 Side Tank

No.2 Side Tank

88 - 95

79 - 88

66 - 79

Port/Starboard

Port/Starboard

Port/Starboard

1,294

1,704

2,775

45,697

60,176

97,998

198.33

167.76

15.40

16.51


1,326

1,747

2,844



No.3 Side Tank

No.4 Side Tank

No.5 Side Tank

No.1 Lower Cross Tank

39 - 57

84 - 88

75 - 79

1,628

1141

1,499

57,492

40,294

52,937

42.39

176.28

17.39

4.92

57 - 66 1,762 62,225

1,669

1,170

1,537

1,806



No.1 Bottom Wing Tank


79 - 88

70 - 79

57 - 70

1,733

2,083

2,836

61,200

73,561

100,153

164.74

131.14

3.56

3.41

66 - 70 1,499 52,937

1,776

2,135

2,907

1,537


Aft Peak

No.2 D.B. Tank 61 - 88 3,187

39,218

112,548

1,384,972

134.32 1.07

-7 - 17 262 9,253

3,262

40,200

269

Port/Starboard

Port/Starboard

Port/Starboard

Port/Starboard

Port/Starboard

123.27

78.41

16.63

16.31

141.00

109.54

4.37

4.37

88.90

5.49

3.50

12.41

Total 6,574/6,534 232,157 6,057


Issue: 1


Illustration 1.1.4a Tank Capacity Plan

No.5 BallastSide Tank

No.6H.F.O.Tank





No.1 Ballast Side TankNo.5 BallastSide Tank


No.3 BottomWing Tank


PipeDuct



No.4 DoubleBottom Tank


Frame 53

Frame 60

Frame 77

Frame 94




No.2 LowerCross Tank

No.1 Ballast Side Tank

No.2 Ballast Side Tank (Port)

No.2 Ballast Side Tank (Stbd)






No.6 Side TankFuel Oil (Port)

No.6 Side TankFuel Oil (Stbd)

No.5 Ballast SideTank (Stbd)

No.1 D.B. TankNo.3 D.B. Tank




No.3 BottomWing Ballast Tank (Port)



No.3 BottomWing Ballast Tank (Stbd)




No.2 Double Bottom SpareWater Ballast Tank

Pipe Duct

Pipe Duct

No.3 Double BottomFuel Oil Tank

SeaChest

SeaChest

SeaChest






No.4 D.B.Tank

No.6 D.B.Tank

No.8 D.B.Tank

No.5 D.B.Tank

No.5 D.B.Fuel Oil

Tank

No.6 D.B.Storage

Tank

GasOil Tank

No.7 D.B.Tank

Aft PeakTank

Aft PeakWater Ballast

Tank

No.7 Lubricating

Oil Side TankI, II & III (Port)

No. 10 Feed Water

Tank

No.7 Gas OilSide Tank

(Starboard)





Water Ballast


Water Ballast


Water Ballast


Fuel Oil

No.4 D.B.Dry Tank

No.4 DoubleBottom

Dry Tank

Atm.Drain Tank

No.1 Double BottomDry Tank

No.1 Double BottomDry Tank

DeepTank

Fuel Oil

DeepTank

Fuel Oil

Fore PeakTank Dry

Fore PeakTank

Fore PeakDry Tank

(Port)

(Stbd)

No.2 D.B. Tank

0 5 10 15 20 25 30 35 40 45 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 100 105 110 115 120 125 130135 140145 150

No.8 Fresh Water Tank (Port)

No.9 Distilled Water Tank (Port)


1.2 Rules and Regulations

Since the introduction of liquefied gas carriers into the shipping field, it wasrecognised that there was a need for an international code for the carriage ofliquefied gases in bulk.

At the beginning of the 1970’s, the Marine Safety Committee (MSC) of theInternational Maritime Organisation (IMO), known then as the InternationalConsultative Maritime Organisation (IMCO), started work on a gas carriercode with the participation of the major country delegations representing gascarrier owners, the International Association of Classification Societies, theUnited States Coast Guard and several other international associations.

The result of this work was the ‘Code for the Construction and Equipment ofShips Carrying Liquefied Gases in Bulk’ introduced under assembly resolutionA328 (IX) in November 1975.

This was the first code developed by IMO having direct applicability to gascarriers.

The intention was to provide ‘a standard for the safe bulk carriage of liquefiedgases (and certain other substances) by sea by prescribing design andconstructional features of ships and their equipment, so as to minimise risks toships, their crew and the environment’.

The GC code has been adopted by most countries interested by the transport ofliquefied gases by sea, as well as all classification societies, and is now part ofSOLAS.

The USCG have added some extra requirements to the GC code for shipstrading in the USA’s waters.

The applicability of the code is as follows :

Gas carriers built after June 1986 (the IGC code)The code which applies to new gas carriers (built after June 1986) is the“International Code for the Construction and Equipment of Ships carryingLiquefied Gases in Bulk” known as the IGC code.

At a meeting of the MSC in 1983 approving the second set of amendments toSOLAS, the requirements of the IGC Code become mandatory with almostimmediate effect.

Gas Carriers built before 1977 (the Existing Ship Code)

The regulations covering gas carriers built before 1977 are contained in the‘Code for Existing Ships Carrying Liquefied Gases in Bulk’ first advertisedunder assembly resolution A 329 (IX). Its content is similar to the GC code,though less extensive.

The existing ship code was completed in 1976 and remains as an IMOrecommendation for all gas carriers in this fleet of ships.

The IGC code requires that a certificate (International Certificate of Fitness forthe Carriage of Liquefied Gases in Bulk) must be issued to all new gas carriers.The certificate should comply to a pro-forma, as set out in ‘Model Form’attached as an appendix to the code and should be available on board all newgas carriers.

The basic philosophy behind the code is summarised in the International Codefor the Construction and Equipment of ships Carrying Liquefied Gases in Bulkwhich is readily available on board in the ship’s library.

Preamble

Most of the provisions in the IMO code are covered by the ClassificationSociety’s rules and regulations, however, attention must be drawn to the factthat it contains requirements that are not within the scope of classification asdefined in the society’s rules, for example, chapter II Ship Survival Capability,chapter XIV Personnel Protection and chapter XVII Operating Requirements.

However, where the societies are authorised to issue the InternationalCertificate of fitness, these requirements, together with any amendments orinterpretations adopted by the appropriate national authority, will be appliedwhere applicable.

Since the IMO recommendations defer some matters to the discretion of eachadministration, and in other matters are not specific enough for Coast Guardregulatory purpose, several major changes have been introduced from the codein the proposed Coast Guard rules. These changes are discussed in thefollowing paragraphs.

‘Liquefied gas’ is changed from the codes definition of ‘a product having avapour pressure of 2.8 bar abs at 37.8°C’ to the proposed definition of ‘aproduct having a vapour pressure of 1.76 bar abs at 37.8°C’. This is a changein the definition from a Reid vapour pressure of 40 psi abs. to 25 psi abs.

The change in the Reid vapour pressure includes the ‘certain other substances’referred to in paragraph 1.2 of the Code, but does not include any product inIMO’s Chemical Code except ethylene, which is presently listed in the Codeand the Chemical Code. The change in the Reid vapour pressure was proposedby the U.S. delegation to the IMO but the change was not adopted, althoughthere was apparently no objection to it. The change, however, does not affectthe list of regulated cargoes.

The rate of air change between the air lock door is not specified in the Code(para 3.6.1) but is proposed at 12 changes per hour.

Chapter 4 of the Code includes a provision for the evaluation of the insulationand hull steel assuming, for the purpose of design calculations, that the cargotanks are at the design temperature and the ambient outside air and sea designtemperatures as follows:

General Worldwide

Still Air: +5°C (41°F)Sea Water: 0°C (32°F)

Chapter 4 also provides that each administration may set higher or lowerambient design temperatures. This document proposed the followingtemperatures:

Any Waters in the World, Except Alaskan Waters

Air (at 5 knots): -18°C (0°F)Still sea water: 0°C (32°F)

Alaskan Waters

Air (at 5 knots): -29°C (–20°F)Still sea water: - 2°C (28°F)

Issue: 2 Section 1.2 - Page 1 of 2


The proposed regulations specify enhanced grades of steel for crack arrestingpurposes in the deck stringer, sheer strake and bilge strake. The minimumacceptable grade for the deck stringer and the sheer strake is Grade E or anequivalent steel that is specially approved by the Commandant (G-MMT). Theminimum acceptable grades for the bilge strake are Grade D, or Grade E or anequivalent steel that is specially approved by the Commandant (G-MMT).

The Code allows pressure and temperature control of cargoes by venting cargovapours to the atmosphere when the vessel is at sea and in port if accepted byreceiving administration. It is proposed to prohibit normal venting of cargointo the atmosphere in many ports.

The Code requires the cargo system to be designed to withstand the full vapourpressure of the cargo under conditions of the upper ambient designtemperature, or have other means to maintain the cargo tank pressure below themaximum allowable relief valve setting (MARVS) of the tank. Theseregulations propose that when the cargo carried is a liquefied gas, the cargotank pressure must be maintained below the design vapour pressureindefinitely, the pressure on the LNG tank would be maintained below thedesign pressure for a period of not less than 21 days. Cargo tank pressure maybe maintained below the design pressure by several methods includingrefrigeration systems, burning boil-off in waste heat or catalytic furnaces,using boil-off as fuel, or a combination of these methods. Using the boil-off asa fuel for propulsion is limited to a vessel carrying LNG.

The proposed regulations also include the following:

1) Transfer requirements for vinyl chloride.

2) Loading requirements for methyl acetylene propadiene mixture.

3) Additional operating requirements.

4) Requirements for inspection or re-inspection of US flag vessels at intervalsthat are the same as for vessels inspected under Sub-chapter D. Inspection forcertification would be required every 2 years and re-inspection would berequired between the 10th and 14th month following the issue of a Certificateof Inspection.

5) Requirements for the initial and periodic inspections and tests of the cargocontainment system, cargo and process piping, and hull heating and cold spots.

The proposed Coast Guard regulations and the Classification Society’s ruleshave cross references showing the corresponding IMO code numbers to allowidentification of the required paragraph.

The latest version of the following regulations and recommendationsincorporating all subsequent additions and amendments currently in force, oragreed between the owner and the builder, but awaiting ratification, enactmentor implementation at the time of signing of the contract shall be applied.

a) Maritime Rules and Regulations of Korea, Indonesia, Malaysia, Oman andQatar for entry into those ports.

b) International Convention on Loadlines, 1966, amendments 1971,1975, 1979and 1983 and Protocol of 1988 as amended by Resolution A513(XIII) /A514(XIII).

c) International Convention for the Safety of Life at Sea, 1974 with Protocolof 1978 and Amendments of 1981, 1983, 1989, 1990, 1991, 1992 and 1994 and1988. GMDSS amendments including International Code for the Constructionand Equipment of Ships Carrying Liquefied Gases in Bulk (IGC-code) (hereincalled ‘SOLAS’).

d) International Convention for the Prevention of Pollution from Ships, 1973(Annex I, IV &V), as modified by the Protocol 1978 relating thereto (hereincalled MARPOL 73/78) and amendment 1987, 1989, 1991 and 1992.

e) Convention on the International Regulations for Preventing Collisions atSea, 1972 with Amendments of 1981, 1987 and 1989 as amended by resolutionA493(XII) and A494(XII).

f) International Convention on Tonnage Measurement of Ships, 1969, asamended by IMO Resolution A493(XII) and A494(XII).

g) International Telecommunication Union (ITU) Radio Regulation A343 withannex and revisions (1983 and 1987).

h) IMO Resolution A468(IX) Recommendation on method of measuring noiselevels at listening posts.

i) IMO Resolution A468(XII) Code on Noise Levels Onboard Ships.

j) USCG for foreign flag vessels operating in the navigable waters of theUnited States except Alaskan waters (CFR Title 33-Navigation and NavigableWaters, Part 155, 156, 159 and 164 and CFR Title 46-Shipping, Part 154) andPublic Law 95-474, 1978 ‘Port and Tanker Safety Act 1979’.

k) ISO draft proposal No.6954 ‘Guidelines for Overall Evaluation of Vibrationin Merchant Ships, 1984’.

l) ILO convention concerning crew accommodation on board ships, No.92 and133.

m) ILO Guide to Safety and Health in Dock Work, 1977 and 1979.

n) SOLAS 1994 Chapter V, Emergency Towing Arrangements for Tankers.

o) SOLAS Draft Resolution II-1/14-1, corrosion prevention of dedicatedballast tanks.

p) OCIMF Recommendations on Equipment for the Towing of DisabledTankers, September 1981.

q) OCIMF Standardisation of Manifold for Refrigerated Liquefied GasCarriers (LNG).

r) OCIMF Guidelines and Recommendations for the Safe Mooring of LargeShips’ at Piers and Sea Islands (except special conditions of the intendedterminal).

s) OCIMF Ship to Ship Transfer Guide (Liquefied Gases).

t) SIGTTO Recommendations for Emergency Shut Down Systems.

u) SIGTTO Recommendations for the Installation of Cargo Strainers.

v) IMO Resolution A708(17) Navigation Bridge Visibility and Function.

w) International Electro-technical Commission (IEC).

x) IMO Publication No.978 Performance Standards for NavigationalEquipment (1988 edition).

y) ISO 8309-1991 Refrigeration Light Hydrocarbon Fluids. Measurement ofliquid levels in tanks containing liquefied gases electric capacitance gauges.

z) IMO Resolution A601(15) Provision and display of manoeuvringinformation on board ships.



Issue: 1


Illustration 1.3.2a Construction of Containment System - Equatorial Ring and Wedge Space

Insulation

Wedge SpaceSkirt

VoidSpace

Tank Dome

Rubber Seal

Dome ShellUpper Hemisphere

Dome ShellLower Hemisphere Skirt

Weld

WedgeSpace

EquatorialForged Ring

Section 1.3 - Page 1 of 10

1.3 Cargo System Technology

1.3.1 Cargo Containment System Principle

The cargo containment system consists of five insulated independent sphericalcargo tanks encased within void spaces and situated in-line from forward to aftwithin the hull. The containment tank system is patented by the builders, MossRosenberg Verft.

The containment system serves two purposes:

To contain LNG cargo at cryogenic temperatures (-160°C).

To insulate the cargo from the hull structure.

The materials used for the hull structure are designed to withstand varyingdegrees of temperature. At temperatures below their specified limits, thesesteels will crystallise and become brittle. The materials used for thecontainment system are required to reduce the heat transfer from the hullstructure to minimise the boil-off gas from the cargo, as well as to protect thehull structure from the effects of cryogenic temperature.

1.3.2 Kvaerner-Moss Cargo Containment

The five tanks carry LNG at cryogenic temperatures and at a pressure close toatmospheric pressure. There is no secondary barrier as the tanks, primarily dueto their spherical construction, have a high degree of safety against fracture orfailure. The tanks are heavily insulated with approximately 215mm ofpolystyrene foam to reduce natural boil-off to a minimum.

The tanks are constructed of 9% nickel steel. Each tank is covered by aspherical steel tank cover which is mainly for tank and insulation protection.The cover also permits control of the hold space atmosphere.The lower edgeof each cover is welded to the deck, forming a watertight seal. A flexible rubberseal is used at the point where the tank dome protrudes out from the cover. Thetanks are each supported by a metal skirt from the equatorial ring, whichtransmits the weight of the tank and the cargo to the lower hull. The skirt isstiffened in the upper part by horizontal rings and the lower part by verticalcorrugated stiffeners.

A special casting joint is fitted between the skirt and the tank’s equatorial ringto provide the necessary strength at this point and to reduce heat conductioninto the tank and a corresponding conduction of low temperature to the skirtand hull.

The tanks contain a central pipe tower, fitted in the domes for the purpose ofaccess into the tank and for the support of pipes and cables running to and fromthe cargo pumps, spray pump (if fitted), discharge and filling lines, CTS(Custody Transfer System) capacitance level gauge, Whessoe float gaugesystem, spray lines and a gas sampling pipe.

The tower is fitted with guides at the lower end to restrict movement but allowfor expansion.

The insulation thickness of 215mm means that the boil-off rate isapproximately 0.22% of cargo weight per day. This corresponds to a heatleakage from the five tanks of 460kcal/h at 0.22%.

Leak Detection

The construction of gas carriers is currently governed by Volume III of theSOLAS International Code for the Construction and Equipment of ShipsCarrying Liquefied Gases in Bulk; usually referred to as ‘The Gas Code’.

The basis of the ‘Type B’ philosophy is the ‘leak before failure’ concept. Thispresumes that the primary barrier will fail progressively, not suddenly andcatastrophically. In order to meet these requirements certain conditions have tobe met. These include:

1) Stress levels, fatigue life and crack propagation characteristics ofthe tanks must be determined using finite element model tests andrefined analysis methods.

2) A partial ‘secondary barrier’ must be fitted which must be capableof containing any envisioned leakage from the ‘primary barrier’(the tank plating itself) for a period of 15 days and must preventthe temperature of the ship’s structure falling to an unsafe level.The failure of the primary barrier must not cause the failure of thesecondary barrier and vice versa.

3) A ‘spray shield’ must be provided to deflect any leakage downinto the secondary barrier and away from the hull structure.

In the exceptional case of a crack occurring in the tank nickel-steel material, asmall leakage of LNG within the insulation will be detected at an early stageby the gas detection system fitted at the equatorial ring area and at the drip pan.The drip pan, installed directly below each cargo tank, is fitted withtemperature sensors to detect the presence of LNG and an eductor system toallow for removal of the liquid.

The spray shield is formed by the aluminium foil surface of the tank insulation.The foil also protects the insulation as well as directing any leakage away. AnyLNG liquid leakage drains by gravity from between the tank plating and theinsulation to the drip pan via a drain tube at the bottom. The drain at the bottomof the insulation space is sealed in normal service by a bursting disc which isdesigned to fail at cryogenic temperatures.

Liquid flow from the northern hemisphere collects in the drain channel whichis formed by the upper skirt ring stiffener and is directed to the leakage pipeslocated forward, aft, port and starboard of the tank. These pipes direct theliquid on to the void space deck and then to the drip pan.

These areas are all protected with stainless steel sheet covers.

Cargo Operations

Before any cargo operation is started, the pipelines and equipment must becooled to avoid thermal shock and to reduce the rate of boil-off generated atthe start of the operation.

The cargo is loaded and discharged through the same manifold, locatedbetween No.3 and 4 cargo tanks. The pressures are equalised between all thecargo tanks by an interconnecting forward and aft vapour header. This headeris connected to the shore vapour lines via vapour crossover lines when loadingor unloading.

When the ship is on loaded and ballast voyages, the boil-off gas is normallyutilised as fuel for the boilers.

The cargo handling operations are controlled from the Cargo Control Room(CCR), located aft of the navigation bridge on Deck 6. This control centrecontains the DCS system control stations providing monitoring and control forthe cargo storage and handling system.

A local cargo control room is located centrally on the main deck between No.3and 4 cargo tanks. This control room contains a control station for the DCSsystem concerned primarily with cargo loading.

Cargo Equipment

The LNG compressor room, situated on the port side of the main deck betweenNo.4 and 5 cargo tanks contains the following major items of equipment:

The Low Duty (LD) gas compressor, used to:

Send boil-off gas to the ship’s boilers

The High Duty (HD) gas compressors, used to:

Return LNG vapour ashore during loading operations

Return gas/vapour ashore during gassing-up andinitial cooldown operations

Circulate heated cargo vapour through the cargo tanksystem during warm-up operations.

The two steam heated horizontal shell and tube type gas heaters, used to:

Supply warm gas to the boilers for burning and to supply gasto the cargo tanks during warm-up operations prior to inerting,aeration and entry.



Issue: 1


Skirt

Insulation

Rupture DiscRemoved forGas Sampling

Rupture Disc

RuptureDisc

Polystyrene Insulation withStainless Steel Cover

Blank Flange

Catch Basin

Leakage Pipes

NitrogenBleed

Illustration 1.3.2b Construction of Containment System - Rupture Discs

Rupture DiscCross Section

Pressure

Rupture Disc


Issue: 1


The two LNG steam heated horizontal shell and tube vaporisers, used to:

Produce gas to purge the inert gas from the cargo tanks priorto cooldown

Produce gas to maintain tank pressure when unloading, if theshore return gas is not available

In each cargo tank are two vertical, submerged, electric motor driven cargopumps. When all ten cargo pumps are in simultaneous operation, a full cargocan be unloaded in approximately 15 hours.

A vertical, submerged, electric motor driven spray pump is fitted in tanks 3 and4, discharging to a spray header. Branches are led from the header to spraynozzles inside each tank. Liquid is sprayed into the tanks on the ballast voyage,to maintain them at a temperature low enough to prevent excessive stress oneach tank structure, especially the equatorial ring, during loading.

An Inert Gas (IG) plant is provided for inerting cargo tanks before and afteraeration and entry, and for inerting the void spaces if required. Dry air is alsosupplied from the plant for drying cargo tanks and hold spaces following anyinspections and maintenance.

Two nitrogen generators are located in the aft storage room on the starboardside, to provide nitrogen for the following purposes:

Cargo compressor gland sealing

Cargo tank wedge and insulation space inerting/purging

Cargo line purging

Boiler gas line purging

A Custody Transfer System (CTS) is provided to enable accurate cargoquantity measurement. The system includes the equipment to measure liquidlevel, liquid and vapour temperatures and also the vapour pressure within eachcargo tank. This data, together with the tank calibration data tables, is used toperform cargo quantity calculations. A secondary float actuated mechanicalsystem (the Whessoe system) is also provided. The calibration of all the CTSand tank equipment, is carried out by an independent firm of sworn measurerswho act jointly for buyers, sellers and customs.

There is an Emergency Shutdown System (ESDS) which is provided to protectthe cargo systems on the ship and on the shore during loading and unloadingoperations. The system incorporates ship/shore links so that a shutdown maybe initiated either manually or automatically from the ship or from the shore.

Loaded Voyage

During normal operation, the boil-off gas from the tanks is compressed usingthe LD compressor and used as fuel for the boilers. The boil-off gas fuel supplysystem is controlled so that the tank pressure is maintained at its predeterminedvalue. Two methods are available to control the vapour pressure in the cargotank:

1) Disposal of excess vapour via the boil-off gas system andsubsequently the steam dump system (if required).

2) The venting of excessive vapour through the remotely operatedvent valve at vent mast No.4, via the heater.

Unloading

Normally, as the cargo pumps in each tank pump out the cargo, cargo vapouris returned from the shore and the pressure is monitored to ensure that thepressure in the cargo tanks remains within the acceptable range. In the event ofthe shore terminal being unable to return vapour, make-up vapour must begenerated by feeding LNG to the ship’s vaporiser.

A small amount of cargo is left in all the tanks (called the heel), with an extrareserve being left in tanks 3 and 4 (the tanks fitted with spray pumps) forcooling the cargo tanks and for fuel during the ballast voyage. During theballast voyage, the cargo tanks are spray-cooled utilising the spray pumps andthe extra cargo left on board for this purpose.

Operating Precautions

The LNG transfer system valves and pumps are normally operated from theCCR. The local valve controls are only used if the normal controls fail oremergency conditions arise.

All the cargo pumps will be started in sequence and operated simultaneouslyunder bulk discharge conditions.

(Note: The ship must never start cargo pumps until asked to do so by the shoreterminal control room.)

All liquid valves, except those on spray lines, should be kept closed when thetransfer system is not in use. Under normal operational conditions, valves inuse should be fully open. However, loading valves are partially closed whentopping-off and pump discharge valves are automatically controlled within thepermissible range to prevent overload or cavitation and to control the flow tothe shore. Any cavitation is indicated by fluctuations in pump current anddischarge pressure. The vapour line valves at the tank domes are locked openunder normal circumstances. The blank flanges fitted to the manifolds must bekept in place at all times except when connecting to either load or unload.

Pipework expansion bellows and welded joints should be inspected regularlywhere possible and manifold flange joints are to be checked under nitrogenpressure with a soap solution prior to loading or unloading. Special care mustbe taken to avoid LNG leaks, as the temperature of the liquid can cause steeldecks to fracture.

The presence of water or other contaminants in the cargo system can beeliminated by taking great care during refit and maintenance operations.Inerting and purging procedures are to be strictly followed. Cargo manifoldstrainers are fitted at the unloading port to prevent the possibility of shorecontamination. At the loading port, the ship is protected against contaminationby a strainer fitted in the shore liquid line in addition to the ship supplymanifold strainers fitted at each loading.


Issue: 2


12

13

24

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

27

19

20

21

22

23

24

25

26

25

28

19

21

20

26

23

22

14

4

17

1516

3

2

1

56

7

8 910

1129

Plan

Cargo Tank Dome Arrangement

Elevation

Discharge Pipe

Discharge Pipe

Loading Pipe

Spray Pipe

Spray Pipe

Spray Pipe

Spray Pipe(Tanks 3 & 4 only)

Ejector Pipe

Vapour Suction

Spray Pump Pipe(Tanks 3 & 4 only)

Hot Gas Pipe

Tank Safety Valve

Tank Safety Valve

Blank

Whessoe Level Indicator

Omicron Level Alarm

DCS Connection

Tank Pressure Gauge Pipe

29 Blank

28 Safety Valve Between Throttle and Loading/Discharge Valve

30 Snap-On Connections

Access

Cable For Spray Pump(Tanks 3 & 4 only)

Cable For Discharge Pump

Cable For Discharge Pump

Spare

Tank Safety Valve

Spray Line Safety Valve

Pressure Gauge Connections

Key

Illustration 1.3.2c Construction of Containment System - Dome and Tank Access

30

Cargo Tank Dome Arrangement

Whessoe Gauge

Level Alarm


Issue: 2


Illustration 1.3.2d Construction of Containment System - Insulation

Cold SideReinforcement

IncrementalContraction Slot

Stainless SteelSupport StrapsFrom Equator Skirt

Aluminium Foil(Spray Shield)

Tank Wall(Primary)

HOLD SPACETANK

CrackBarrier

Spinning Weld

Cargo Tank Lower Hemisphere Showing Support Straps

Stainless SteelSupport Straps

Void SpaceVentilationTrunking


Issue: 1


Illustration 1.3.2e Construction of Containment System - Piping Insulation

No Adhesives

Polyurethane Glue Elastified Polystyrene Galvanised SteelBand Polyurethane Foam

Fixed Clamp

Stainless Steel Stainless Steel

Weld

PolystyreneFibreglass Reinforcement (1 Layer)Bitumas (2 Layers)


Issue: 1



1.3.3 Failure of Containment

A failure of the cargo containment would most probably be due to a crack in atank weld. In order to discover any leakages, the ship is equipped withcomprehensive gas monitoring and leakage detection systems. The maincomponent in this system is the gas analyser which has four sample points ineach cargo tank hold. Gas and leakage detection is described in section 4.1.

In the case of a crack in the tank shell, the cargo is able to flow between thetank and the insulation. From the top of the tank upper hemisphere, a pressureequalising pipe leads to the insulated space between the tank and the skirt (thewedge space). Gas leakage due to a crack in the lower hemisphere is led to thewedge space. There is a suction point for the gas detection system located inthis wedge space. There are also suction points in one of the drain pipes fromthe upper insulation space, the top of the void space and the bilge well(sometimes called the drip pan or catch basin).

The leak protection system also includes a method of collecting andaccumulating small leaks of liquid cargo. This liquid is collected in the catchbasin on the double bottom. The catch basin is lined with polystyrene which iscoated with a protective cover of stainless steel, as shown in illustration 7.2.1a.The liquid cargo leakage collects in this basin, where the monitoringequipment is installed. The equipment consists of a sample point for the gasdetector, a liquid indicator and a temperature indicator to raise alarms in theCCR via the DCS system.

Any liquid flow from the upper hemisphere will be collected in the drainchannel formed by the upper ring stiffener of the skirt. There are four drainpipes, port, starboard, forward and aft of the tanks, which lead any cargoleakage to the catch basin. Any liquid flow in the lower hemisphere will be ledto the catch basin by a drain pipe at the south pole.

Any liquid collecting in the catch basin will raise a liquid alarm via the DCSsystem. Whether the liquid is LNG cargo due to a tank leakage, or water dueto leakage from the water ballast tanks, can be determined by observing the gasdetector and the temperature indicators. A low temperature (-163ºC for LNG)indicates cargo leakage, while temperatures above 0ºC indicate water leakage.

A bilge ejector is installed in the catch basin to empty the area when required.If the basin has to be emptied of water, water supplied from the ejector feedpump has to be used as the driving force. The exhausted water is deliveredoverboard. After use, the flexible hoses must be disconnected and the pipe endsblind-flanged. A needle valve, V1429, is located at each flange. Pressurised airfrom the working air system on deck is introduced to the ejector pipe throughthese valves by means of quick connecting couplings and the air will empty theejector pipe of water through the drainpipe.

When cargo has to be removed, cargo is also used as the eductor driving force.The procedure is fully explained in section 7.2.

Issue: 2


Key

Nitrogen

Dry Air

Moist Air

V2303 V2303

Illustration 1.3.4a Void Spaces and Ventilation

Cargo TankCross-Section

Moist Air Drawn Offto Recirculation Fans

NitrogenBleed

Dried/HeatedAir

Dried/HeatedAir Ducts

V2209V2303

V2306

V2306V2306

V2303V2303V2303

V2306V2306V2306

FromNitrogen

GeneratorSystem

StarboardNitrogenBuffer

Tank 15m3

PortNitrogenBuffer

Tank 25m3

IG Connection at Starboard Manifold

RecirculationFans 2000m3/h

Void SpaceDryers

LNGCompressors

LNGCompressor

Room

V2311 V2311

V2311

V2313 V2313

V2314 V2314

V2135

V2311

V2209V2213Boiler Purging/Compressor

SealingV2209V2209 V2209

V2216V2216V2216V2216 V2216

V2209

No.1Cargo Tank

No.2Cargo Tank

No.3Cargo Tank

No.4Cargo Tank

No.5Cargo Tank

PurgingOutlets

at Dome

View of Void Space ShowingLeakage Pipe and Cargo Tank


Issue: 1



1.3.4 Void Spaces

The areas between the water ballast tanks, the double bottom tanks, underneaththe cargo tank weather covers and the cargo tank are called void spaces. Thisspace around the tank and inside the tank skirt area is kept as dry as possible.The atmosphere in this space is controlled and monitored. It is especiallyimportant that the void spaces are monitored during cargo operations.

The pressure in the void spaces over that of the cargo tanks should not rise over0.05kg/cm2. This value has been determined by the builders to avoid anypossible chance of the tank buckling when empty. There are two void spacerelief valves for each void space which will open to atmosphere if this value isexceeded.

Before LNG is loaded into the tanks, the void spaces should be thoroughly dryto avoid any moisture penetration into the tank insulation.

The void spaces must also be free of carbon dioxide as CO2 gas will solidify ata temperature of -78.5ºC.

The operation to dry or inert the void spaces is dealt with in section 4.7. Thereis a void space heating and drying system to dry out these spaces, therebyremoving moisture and preventing any dew forming. This also has the addedbenefit of preventing corrosion. It can be seen from the graph in illustration1.3.4b that if the relative humidity is kept below 50/60%, the corrosion rate iskept extremely low.

The void spaces are fitted with gas detection and leakage detection. Thesesystems indicate/alarm in the CCR, via the DCS system.

The void spaces are accessed via air lock chambers to assist in maintaining theatmosphere.

The air in the void spaces is continuously recirculated via the recirculation fanswhich are fitted on the outside deck above the LNG compressor room. The fanssupply dried and heated air from the void space atmospheric steam heater andvoid space dryers to the vent outlets situated at the bottom of each void spacedirectly underneath the cargo tank lowest point. The air is exhausted from anoutlet situated adjacent to the cargo tank dome. In this way, the air is drawnfrom bottom to the top, across the entire void space.

The void spaces may be inerted, if required, using the IG connection located atthe starboard manifold. There is normally a spoon blank fitted at thisconnection.

Illustration 1.3.4b Relationship between Corrosion and Relative Humidity

RATE OFCORROSION

RELATIVE HUMIDITY

00 20 60 80 100%

20

40

60

80

100

120

40

Issue: 1


9m Radius 9m Radius 9m Radius 9m Radius 9m Radius

Illustration 1.4a Hazardous Areas and Gas Dangerous Zones

Elevation

Plan

Cross Section

No.5Cargo Tank

No.4Cargo Tank

No.3Cargo Tank

No.2Cargo Tank

No.1Cargo Tank

NORMAN LADY


1.4 Hazardous Areas and Zones(See illustration 1.4a)

Under the IMO code for the Construction and Equipment of Ships CarryingGases in Bulk, the following are regarded as hazardous areas:

Gas dangerous spaces or zones, are zones on the open deck within 3 metres ofany cargo tank outlet, gas or vapour outlet, cargo pipe flange, cargo valve andentrances and ventilation openings to the LNG compressor house. They alsoinclude the open deck over the cargo area and 3m forward and aft of the cargoarea on the open deck up to a height of 2.4m above the tank weather covers.

The entire cargo piping system and cargo tanks are also considered gas-dangerous.

In addition to the above zones, the code defines other gas-dangerous spaces.

The area around the air swept trunking, in which the gas fuel line to the engineroom is situated, is not considered a gas dangerous zone under the above code.

All electrical equipment used in these zones, whether a fixed installation orportable, is certified ‘safe type equipment’. This includes intrinsically safeelectrical equipment, flame-proof type equipment and pressurised enclosuretype equipment. Exceptions to this requirement apply when the zones havebeen certified gas free, e.g. during refit.



Part 2Properties of LNG

Issue: 1


Illustration 2.1a Vapour Pressure Diagram of Liquid Cargoes

-165 -160 -155 -150 -145 -140 -135 -130 -125 -120 -115 -110 -105 -100 -95 -90 -85 -80 -75 -70 -65 -60 -55 -50 -40 -30 -20 -10 0 25 50 75 100

-165 -160 -155 -150 -145 -140 -135 -130 -125 -120 -115 -110 -105 -100 -95 -90 -85 -80 -75 -70 -65 -60 -55 -50 -40 -30 -20 -10 0 25 50 75 100

60

50

40

30

20

109

8

7

6

5

4

3

2

10.9

0.8

0.7

0.6

Methane Ethylene Ethane Propylene Propane

Propane2mol % Ethane

Butadrene1.3

N. Butan

TEMPERATURE (OC)

TEMPERATURE (OC)

ata

P

bar


Part 2 Properties of LNG

2.1 Physical Properties and Composition of LNG

Natural gas is a mixture of hydrocarbons which, when liquefied, form a clearcolourless and odourless liquid; this LNG is usually transported and stored ata temperature very close to its boiling point at atmospheric pressure(approximately –160°C).

The actual composition of Qatar, Oman, Indonesia or Malaysia LNG will varydepending on its source and on the liquefaction process, but the mainconstituent will always be methane; other constituents will be smallpercentages of heavier hydrocarbons, e.g. ethane, propane, butane, pentane,and possibly a small percentage of nitrogen. A typical composition of LNG isgiven in Table 2.1b, and the physical properties of the major constituent gasesare given in Table 2.1a.

For most engineering calculations (e.g. piping pressure losses) it can beassumed that the physical properties of pure methane represent those of LNG.However, for custody transfer purposes when accurate calculation of theheating value and density is required, the specific properties based on actualcomponent analysis must be used.

During a normal sea voyage, heat is transferred to the LNG cargo through thecargo tank insulation, causing part of the cargo to vaporise, i.e. boil-off. Thecomposition of the LNG is changed by this boil-off because the lightercomponents, having lower boiling points at atmospheric pressure, vaporisefirst. Therefore, the discharged LNG has a lower percentage content ofnitrogen and methane than the LNG as loaded, and a slightly higher percentageof ethane, propane and butane, due to methane and nitrogen boiling off inpreference to the heavier gases.

The flammability range of methane in air (21% oxygen) is approximately 5.3to 14% (by volume). To reduce this range the oxygen content is reduced to 2%,using inert gas from the inert gas generators, prior to loading after dry dock. Intheory, an explosion cannot occur if the O2 content of the mixture is below 13%regardless of the percentage of methane, but for practical safety reasons,purging is continued until the O2 content is below 2%. This safety aspect isexplained in detail later in this section.

The boil-off vapour from LNG is lighter than air at vapour temperatures above-110°C or higher depending on LNG composition, therefore when vapour isvented to atmosphere, the vapour will tend to rise above the vent outlet andwill be rapidly dispersed. When cold vapour is mixed with ambient air thevapour-air mixture will appear as a readily visible white cloud due to thecondensation of the moisture in the air. It is normally safe to assume that theflammable range of vapour-air mixture does not extend significantly beyondthe perimeter of the white cloud. The auto-ignition temperature of methane, i.e.the lowest temperature to which the gas needs to be heated to cause self-sustained combustion without ignition by a spark or flame, is 595°C.


Table 2.1b Physical Properties of LNG

Issue: 1


Molecular Weight 16.042

-161.5

426

0.554

619

5.3 to 14

30.068

-88.6

544.1

1.046

413

3 to 12.5

44.094

-42.5

580.7

1.540

311

2.1 to 9.5

58.120

-5

601.8

2.07

311

2 to 9.5 3 to 12.4 Non-flammable

72.150

36.1

610.2

2.49

205

28.016

-196

808.6

0.97

649

595 510 510/583 510/583

55559 51916 50367 4953049404

4906948944

510.4 489.9 426.2 385.2 357.5 199.3

Boiling Point at 1 bar absolute (ºC)

Liquid Density at Boiling Point (kg/m3)

Vapour SG at 15ºC and 1 bar absolute

Gas Volume/liquid Ratio atBoiling Point and 1 bar absolute

Flammable Limits in AIr by Volume (%)

Gross Heating Normal:Value at 15ºC (kJ/kg) Iso:

Auto-ignition Temperature (ºC)

Vaporization Heat at Boiling Point (kJ/kg)

Methane CH4 Ethane C2H4 Propane C3H8 Butane C4H10 Pentane C5H12 Nitrogen N2

Arzew 87.4

91.23

90.4

84.83

91.09

89.33

8.6

4.3

5.2

13.39

5.51

7.14

2.4

2.95

2.8

1.34

2.48

2.22

0.05

1.4

1.5

0.28

0.88

1.17

0.35

0.12

0.07

0.17

0.03

99.8 0.1 0 0.1 0.1

89.4 6.3 2.8 1.3 0.05

0.02

0

0.02

0

0

0

0.05

466

457

453

465

N/A

0.08 0.01 N/A

421

463

Bintulu

Bonny

Das Is

Arun

Badak

Kenai

Methane CH4 Ethane C2H4 Propane C3H8 Butane C4H10 Nitrogen N2 C5+ Density (kg/m3)

Lamut

Marsa el Braga

Ras Lafan

Point Fortin

Skikda

Withnell

70

96.2

90.1

15

3.26

6.47

10

0.42

2.27

3.5

0.07

0.6

0.9

0.008

91.5 5.64 1.5 0.5 0.85

89.02 7.33 2.56 1.03 0.06

0.6

0.01

0.01

0

531

433

0.25 0.03 457

451

460

Table 2.1c Composition of LNG from Major Export Terminals (Mol%)

Variation of Boiling Point of Methane with Pressure

See illustration 2.1a, vapour pressure diagram of liquid cargoes.

The boiling point of methane increases with pressure and this variation isshown in the diagram for pure methane over the normal range of pressures onboard the vessel. The presence of the heavier components in LNG increases theboiling point of the cargo for a given pressure.

The relationship between boiling point and pressure of LNG willapproximately follow a line parallel to that shown for 100% methane.


+20

0

- 20

- 40

- 60

1.5 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5

- 80

-100

-120

-140

-160

Lighter than air

Ratio =Density of Methane Vapour

Density of Air

(Density of air assumed to be 1.27 kg/m3 at 15°C)

Methane VapourTemperature

°C

Illustration 2.1d Relative Density of Methane and Air

Heavier than air

Issue: 1


Issue: 1


M

%

O

x

y

g

e

n

Area ABEDH

Not capable of forming

flammable mixture with air

Mixtures of air and methane

cannot be produced above

line BEFC

0 10

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21B

E

F

20 30 40 50 60 70 80 90 100C

Methane %

A H

X

N

Area EDFE

flammable

D

G

Area HDFC

Capable of forming flammable

mixtures with air, but containing

too much methane to explode

This diagram assumes complete mixing

which, in practice, may not occur.

CAUTION

Illustration 2.2.1a Flammability of Methane, Oxygen and Nitrogen Mixtures

Y

Z


2.2 Characteristics of LNG

2.2.1 Flammability of Methane, Oxygen and Nitrogen Mixtures

The ship must be operated in such a way that a flammable mixture of methaneand air is avoided at all times. The relationship between gas/air compositionand flammability for all possible mixtures of methane, air and nitrogen isshown on the diagram above.

The vertical axis A-B represents oxygen-nitrogen mixtures with no methanepresent, ranging from 0% oxygen (100% nitrogen) at point A, to 21% oxygen(79% nitrogen) at point B. The latter point represents the composition ofatmospheric air.

The horizontal axis A-C represents methane-nitrogen mixtures with no oxygenpresent, ranging from 0% methane (100% nitrogen) at point A, to 100%methane (0% nitrogen) at point C.

Any single point on the diagram within the triangle ABC represents a mixtureof all three components, methane, oxygen and nitrogen, each present inspecific proportion of the total volume. The proportions of the threecomponents represented by a single point can be read from the diagram.For example, at point D:

Methane: 6.0% (read on axis A-C)Oxygen: 12.2% (read on axis A-B)Nitrogen: 81.8% (remainder)

The diagram consists of three major sectors:

1. The Flammable Zone Area EDF. Any mixture whose compositionis represented by a point which lies within this area is flammable.

2. Area HDFC. Any mixture whose composition is represented by apoint which lies within this area is capable of forming aflammable mixture when mixed with air, but contains too muchmethane to ignite.

3. Area ABEDH. Any mixture whose composition is represented bya point which lies within this area is not capable of forming aflammable mixture when mixed with air.

Using the DiagramAssume that point Y on the oxygen-nitrogen axis is joined by a straight line topoint Z on the methane-nitrogen axis. If an oxygen-nitrogen mixture ofcomposition Y is mixed with a methane-nitrogen mixture of composition Z, thecomposition of the resulting mixture will, at all times, be represented by pointX, which will move from Y to Z as increasing quantities of mixture Z areadded.

(Note: In this example point X, representing changing composition, passesthrough the flammable zone EDF, that is, when the methane content of themixture is between 5.5% at point M, and 9.0% at point N.)

Applying this to the process of inerting a cargo tank prior to cool down, assumethat the tank is initially full of air at point B. Nitrogen is added until the oxygencontent is reduced to 13% at point G. The addition of methane will cause themixture composition to change along the line GDC which, it will be noted,does not pass through the flammable zone, but is tangential to it at point D. Ifthe oxygen content is reduced further, before the addition of methane, to anypoint between 0% and 13%, that is, between points A and G, the change incomposition with the addition of methane will not pass through the flammablezone.

Theoretically, therefore, it is only necessary to add nitrogen to air wheninerting until the oxygen content is reduced to 13%. However, the oxygencontent is reduced to 2% during inerting because, in practice, complete mixingof air and nitrogen may not occur.

When a tank full of methane gas is to be inerted with nitrogen prior to aeration,a similar procedure is followed. Assume that nitrogen is added to the tankcontaining methane at point C until the methane content is reduced to about14% at point H. As air is added, the mixture composition will change along lineHDB, which, as before, is tangential at D to the flammable zone, but does notpass through it. For the same reasons as when inerting from a tank containingair, when inerting a tank full of methane it is necessary to go well below thetheoretical figure to a methane content of 5% because complete mixing ofmethane and nitrogen may not occur in practice.

The procedures for avoiding flammable mixtures in cargo tanks and piping aresummarised as follows:

1. Tanks and piping containing air are to be inerted with nitrogenbefore admitting methane until all sampling points indicate 5% orless oxygen content.

2. Tanks and piping containing methane are to be inerted withnitrogen before admitting air until all sampling points indicate 5%methane.

It should be noted that some portable instruments for measuring methanecontent are based on oxidising the sample over a heated platinum wire andmeasuring the increased temperature from this combustion. This type ofanalyser will not work with methane-nitrogen mixtures that do not containoxygen. For this reason, special portable instruments of the infrared type havebeen developed and are supplied to the ship for this purpose.



2.2.2 Supplementary Characteristics

When Spilled on Water:

1) Boiling of LNG is rapid, due to the large temperature differencebetween the product and water.

2) LNG continuously spreads over an indefinitely large area, itresults in a magnification of its rate of evaporation untilvaporisation is complete.

3) No coherent ice layer forms on the water.

4) Under particular circumstances, with a methane concentrationbelow 40%, flameless explosions are possible when the LNGstrikes the water. It results from an interfacial phenomenon inwhich LNG becomes locally superheated at a maximum limituntil a rapid boiling occurs. However, commercial LNG is farricher in methane than 40% and would require lengthy storagebefore ageing to that concentration.

5) The flammable cloud of LNG and air may extend for largedistances downward (only methane when warmer than -100°C islighter than air) because of the absence of topographic featureswhich normally promote turbulent mixing.

Vapour Clouds

1) If there is no immediate ignition of an LNG spill, a vapour cloudmay form. The vapour cloud is long, thin, cigar shaped and, undercertain meteorological conditions, may travel a considerabledistance before its concentration falls below the lower flammablelimit. This concentration is important, for the cloud could igniteand burn, with the flame travelling back towards the originatingpool. The cold vapour has a higher density than air and thus, atleast initially, hugs the surface. Weather conditions largelydetermine the cloud dilution rate, with a thermal inversion greatlylengthening the distance travelled before the cloud becomes non-flammable.

WARNINGThe major danger from an LNG vapour cloud occurs when it is ignited.The heat from such a fire is a major problem. A deflagrating (simpleburning) is probably fatal to those within the cloud and outside buildingsbut is not a major threat to those beyond the cloud, though there will beburns from thermal radiation.

2) When loaded in the cargo tanks, the pressure of the vapour phaseis maintained as substantially constant, slightly aboveatmospheric pressure.

3) The external heat passing through the tank insulation generatesconvection currents within the bulk cargo; heated LNG rises tothe surface and boils.

4) The heat necessary for the vaporisation comes from the LNG and,as long as the vapour is continuously removed by maintaining thepressure as substantially constant, the LNG remains at its boilingtemperature.

5) If the vapour pressure is reduced, by removing more vapour thangenerated, the LNG temperature will decrease. In order to makeup the equilibrium pressure corresponding to its temperature, thevaporisation of LNG is accelerated, resulting in an increased heattransfer from LNG to vapour.

Reactivity

Methane is an asphyxiant in high concentrations because it dilutes the amount ofoxygen in the air below that necessary to maintain life. Due to its inactivity,methane is not a significant air pollutant and, due to its insolubility, inactivity,and volatility, it is not considered a water pollutant.

Cryogenic Temperatures

WARNINGContact with LNG or with materials that are chilled to its temperature ofabout -160°C will damage living tissue.

CAUTION Most metals lose their ductility at these temperatures; LNG may cause thebrittle fracture of many materials. In case of LNG spillage on the ship’sdeck, the high thermal stresses generated from the restricted possibilitiesof contraction of the plating will result in the fracture of the steel.

Behaviour of LNG in the Cargo Tanks

When loaded in the cargo tanks, the pressure of the vapour phase is maintainedsubstantially constant, slightly above atmospheric pressure.

The external heat passing through the tank insulation generates convectioncurrents within the bulk cargo, causing heated LNG to rise to the surface andis then boiled-off.

The heat necessary for vaporisation comes from the LNG. As long as thevapour is continuously removed by maintaining the pressure as substantiallyconstant, the LNG remains at its boiling temperature.

If the vapour pressure is reduced by removing more vapour than is generated,the LNG temperature will decrease. In order to make up the equilibriumpressure corresponding to its temperature, the vaporisation of LNG isaccelerated, resulting in an increased heat transfer from LNG to vapour.

If the vapour pressure is increased by removing less vapour than is generated,the LNG temperature will increase. In order to reduce the pressure to a levelcorresponding to the equilibrium with its temperature, the vaporisation of LNGis slowed down and the heat transfer from LNG to vapour is reduced.

LNG is a mixture of several components with different physical properties,particularly the vaporisation rates; the more volatile fraction of the cargovaporises at a greater rate than the less volatile fraction. The vapour generatedby the boiling of the cargo contains a higher concentration of the more volatilefraction than the LNG.

The properties of the LNG, i.e. the boiling point, density and heating value,have a tendency to increase during the voyage.



Issue: 1


Properties of Nitrogen and Inert Gas

Nitrogen

Nitrogen is used on board for the pressurisation of the cargo tank wedge andinsulation spaces, the purging of cargo pipelines and heaters, boiler gas linesand Whessoe gauges and for the sealing of the LNG compressors. It isproduced by the nitrogen generators whose principle is based on hollow fibremembranes to separate air into nitrogen and oxygen (see section 4.7.2. -Nitrogen Generator).

Physical Properties of Nitrogen

Nitrogen is the most common gas in nature since it represents 79% in volumeof the atmospheric air.

At room temperature, nitrogen is a colourless and odourless gas. Its density isnear that of air, 1.25 kg/m3 under the standard conditions.

When liquefied, the temperature is -196°C under atmospheric pressure, densityof 810kg/m3 and a vapourization heat of 199kJ/kg.

Properties of Nitrogen

Molecular weight: 28.016

Boiling point at 1 bar absolute: –196°C

Liquid SG at boiling point: 1.81

Vapour SG at 15°C and 1 bar absolute: 0.97

Gas volume/liquid volume ratio at –196°C: 695

Flammable limits: Non

Dew point of 100% pure N2: Below –80°C

Chemical Properties

Nitrogen is considered as an inert gas; it is non-flammable and withoutchemical affinity. However, at high temperatures, it can be combined withother gases and metals.

HazardsWARNING

Due to the absence or to the very low content of oxygen, nitrogen is anasphyxiant.

At liquid state, its low temperature will damage living tissue and any spillageof liquid nitrogen on the ship’s deck will result in failure (as for LNG).

Inert Gas

Inert gas is used to reduce the oxygen content in the cargo system, tanks,piping, void spaces and compressors. This is in order to prevent an air/CH4

mixture prior to aeration post warm-up, before refit or repairs and prior to thegassing up operation post refit before cooling down.

Inert gas is produced on board using an inert gas generator supplied by MossVerft, which produces inert gas at 2,500m3/h with a -45°C dew point burninglow sulphur content gas oil. This plant can also produce dry-air at 2,500m3/hand -45°C dew point (see section 4.7.1 for more details).

The inert gas composition is as follows:

Oxygen: <2.5% in volume

Carbon dioxide: <15% in volume

Carbon monoxide: <65 ppm by volume

Sulphur oxides (SOx): <1 ppm by volume

Nitrogen oxides (NOx): <65 ppm by volume

Nitrogen: balance

Dew point: < -45°C

Soot: complete absence

The inert gas is slightly denser than air: 1.3-kg/m3 abs at 0°C.

WARNINGDue to its low oxygen content, inert gas is an asphyxiant.


Issue: 1


Avoidance of Cold Shock to Metal

Structural steels suffer brittle fracture at low temperatures. Such failures can becatastrophic because, in a brittle steel, little energy is required to propagate afracture once it has been initiated. Conversely, in a tough material, the energynecessary to propagate a crack will be insufficient to sustain it when it runs intosufficiently tough material.

Plain carbon structural steels have a brittle to ductile behaviour transitionwhich occurs generally in the range -50°C to +30°C. This, unfortunately,precludes their use as LNG materials (carriage temperature -162°C). The effectis usually monitored by measuring the energy absorbed in breaking a notchedbar and a transition curve, as shown in Illustration 2.2.2b, is typical for plaincarbon steels.

For this reason, materials which do not show such sharp transition from ductileto brittle fracture as the temperature is lowered, have found obviousapplication for use in cryogenic situations in general and particularly in liquidmethane carriers, for example, invar (36% nickel-iron alloy), austeniticstainless steel, 9% nickel steel and some aluminium alloys such as 5083 alloy.All of these materials behave in a ductile manner at -162°C, so that the chanceof an unstable brittle fracture propagating, even if the materials wereoverloaded, is negligible.

In order to avoid brittle fracture occurring, measures must be taken to ensurethat LNG and liquid nitrogen do not come into contact with the steel structureof the vessel. In addition, various equipment is provided to deal with anyleakages which may occur.

The manifold areas are equipped with a stainless steel drip tray, which collectsany spillage and drains it overboard. The ship, in way of the manifolds, isprovided with a water curtain from the deck driving water main which issupplied from the bilge ejector pump. The deck fire main must always beavailable and the manifold water curtain in operation when undertaking anycargo operation. Additionally, fire hoses must be laid out to each liquid dometo deal with any small leakages which may develop at valves and flanges.Permanent drip trays are fitted underneath the items most likely to causeproblems and portable drip trays are available for any other requirements.

During any type of cargo transfer, and particularly whilst loading anddischarging, constant patrolling must be conducted on deck to ensure that noleakages have developed.

In the event of a spillage or leakage, water spray should be directed at thespillage to disperse and evaporate the liquid and to protect the steelwork. Theleak must be stopped, suspending cargo operations if necessary.

In the event of a major leakage or spillage, the cargo operations must bestopped immediately, the general alarm sounded and the emergency deck waterspray system put into operation (refer to section 5.2.2).

Notchedbar testenergy absorbed

T1 T2

Brittlefracture

Ductilefracture

For a typical mild steel:T1 might be -30;T2 might be +15. Although this depends on composition, heat treatment etc. the curve can shift to left or right.

Fracture transitionrange (mixed fractureappearance)

Illustration 2.2.2a Structural Steel: Ductile to Brittle Transition Curve



THE MAIN HAZARDFLAMMABLE.

METHANE

FORMULA CH4

U.N. NUMBER 2043

FAMILY Hydrocarbon

APPEARANCE Colourless

ODOUR Odourless EMERGENCY PROCEDURES

FIRE Stop gas supply. Extinguish with dry powder, Halon or CO2. Cool surrounding area with water spray.

LIQUID DO NOT DELAY. Flood eye gently with clean fresh/sea water. Force eye open if necessary.

IN EYE Continue washing for 15 minutes. Obtain medical advice/assistance.

LIQUID DO NOT DELAY. Treat patient gently. Remove contaminated clothing. Immerse frostbitten area

ON SKIN in warm water until thawed (see Chapter 9). Obtain medical advice/assistance.

VAPOUR Remove victim to fresh air. If breathing has stopped, or is weak/irregular, give mouth-to-mouth/nose

INHALED resuscitation.

SPILLAGE Stop the flow. Avoid contact with liquid or vapour. Flood with large amounts of water to disperse spill and

prevent brittle fracture. Inform Port Authorities of any major spill.

EFFECT

OF

LIQUID

EFFECT

OF

VAPOUR

Frostbite to skin or eyes. Not absorbed through skin.

Asphyxiation - headache, dizziness, drowsiness. Possible low temperature damage to lungs, skin. No

chronic effect known.

PHYSICAL DATA

FIRE AND EXPLOSION DATA

BOILING POINT @ ATMOSPHERIC -161.5°CPRESSURE

VAPOUR PRESSURE See graphskg/cm2 (A)

SPECIFIC GRAVITY 0.42

COEFFICIENT OF CUBIC EXPANSION 0.0026 per °C @ -165°C

RELATIVE VAPOUR DENSITY 0.554

MOLECULAR 16.04

WEIGHT

ENTHALPYLiquid Vapour

(kcal/kg)7.0 @ -165°C 130.2 @ -165°C

68.2 @ -100°C 140.5 @ -100°C

LATENT HEAT OF VAPOURISATION See graphs(kcal/kg)

FLASH POINT -175°C (approx) FLAMMABLE LIMITS 5.3 -14% AUTO-IGNITION TEMPERATURE 595°C

HEALTH DATE

TVL 1000 ppm ODOUR THRESHOLD Odourless

2.3 Health Hazards REACTIVITY DATA METHANE

AIR

WATER(Fresh/Salt)

OTHER LIQUIDS/GASES

No reaction.

No reaction. Insoluble. May freeze to form ice or hydrates.

Dangerous reaction possible with chlorine.

CONDITIONS OF CARRIAGE

NORMALCARRIAGECONDITIONS

SHIP TYPE

Fully refrigerated.

2G.

GAUGING

VAPOUR DETECTION

Closed, indirect.

Flammable.

MATERIALS OF CONSTRUCTION

UNSUITABLE SUITABLE

Stainless steel, aluminium, 9 or 36% nickel steel, copper.

SPECIAL REQUIREMENTS

Mild steel.

Issue: 1



THE MAIN HAZARDFROSTBITE.

NITROGENFORMULA N2

U.N. NUMBER 2040

FAMILY Noble Gas

APPEARANCE Colourless

ODOUR Odourless

EMERGENCY PROCEDURES

FIRE Non-flammable. Cool area near cargo tanks with water spray in the event of fire near to them.

LIQUID DO NOT DELAY. Flood eye gently with clean sea/fresh water. Force eye open if necessary.

IN EYE Continue washing for 15 minutes. Seek medical advice/assistance.

LIQUID DO NOT DELAY. Handle patient gently. Remove contaminated clothing. Immerse frostbitten area

ON SKIN in warm water until thawed (see Chapter 9). Obtain medical advice/assistance.

VAPOUR Remove victim to fresh air. If breathing has stopped, or is weak/irregular, give mouth-to-mouth/nose

INHALED resuscitation.

SPILLAGE Stop the flow. Avoid contact with liquid or vapour. Flood with large amounts of water to disperse spill and

prevent brittle fracture. Inform Port Authorities of any major spillage.

EFFECT

OF

LIQUID

EFFECT

OF

VAPOUR

Frostbite to skin or eyes.

Asphyxiation. Cold vapour could cause damage.

PHYSICAL DATA

FIRE AND EXPLOSION DATA

BOILING POINT @ ATMOSPHERIC -195.8°CPRESSURE

VAPOUR 2 @ -190°C PRESSURE 10 @ -170°Ckg/cm2 (A)

SPECIFIC GRAVITY 0.9

COEFFICIENT OF CUBIC EXPANSION 0.005 @ -198°C

RELATIVE VAPOUR DENSITY 0.967

MOLECULAR 28.01WEIGHT

ENTHALPYLiquid Vapour

(kcal/kg)7.33 @ -196°C 54.7 @ -195°C

34.7 @ -150°C 52.0 @ -150°C

LATENT HEAT OF VAPOURISATION

47.5 @ -196°C

(kcal/kg) 17.3 @ -150°C

FLASH POINT Non-flammable FLAMMABLE LIMITS Non-flammable AUTO-IGNITION TEMPERATURE Non-flammable

HEALTH DATE

TVL 1,000 ppm ODOUR THRESHOLD Odourless

REACTIVITY DATA

NITROGEN

AIR

WATER

(Fresh/Salt)

OTHER

LIQUIDS/

GASES

No reaction.

No reaction. Insoluble.

No reactions.

CONDITIONS OF CARRIAGE

NORMALCARRIAGECONDITIONS

SHIP TYPE

Fully refrigerated.

3G.

GAUGING

VAPOUR DETECTION

Closed, indirect.

Oxygen analyser required.

MATERIALS OF CONSTRUCTION

UNSUITABLE SUITABLE

Stainless steel, copper, aluminium.

SPECIAL REQUIREMENTS

High oxygen concentrations can be caused by condensation and enrichment of the atmosphere in way of equipment at the lowtemperatures attained in parts of the liquid nitrogen system; materials of construction and ancillary equipment (e.g. insulation)should be resistant tot he effects of this. Due consideration should be given to ventilation in areas where condensation mightoccur to avoid the stratification of oxygen-enriched atmosphere.

Mild steel.

Issue: 1


Part 3Distributed Control System (DCS)

Issue: 1


Fridge

Work Bench

Wash Basin Air Lock

Fire ExtinguishersDeskLoad Master Workstation DCS Workstation

Ship/ShoreLink

Telephones

HotLine

Telephone

IntrinsicallySafe

Telephone

AutomaticExchangeTelephone

Illustration 3.1a Cargo Control Room Layout

VDU VDUPrinter

AirConditioning

Unit

EmergencyEscape

BreathingDevice

AirConditioningUnit Access

EmergencyEscape

ViaAccessWindow

DCS Workstation DCS Workstation


Issue: 1



Part 3: Distributed Control System (DCS)

3.1 Cargo Control Room (CCR ) Arrangement

The CCR is located midships between cargo tanks 3 and 4. This room containsthe DCS process and input/output (I/O) and loading computer stations, as wellas the operating panels for the ballast remote control valves, cargo pumps, highduty and low duty gas compressors, alarm and overfill alarms, cargo and voidspace gas detection system and the ESD equipment.

Normal control of all cargo loading and discharging operations is carried outfrom here.

The are telephones, including the shorelink ‘hotphone’ located on the aftbulkhead and on the gas sampling section of the control console.

A workshop bench is situated on the starboard side.

The CCR is accessed via two doors which act as an air lock to prevent anycargo gases entering the room.

The air lock contains four fire extinguishers, one CO2 type and two 12kg andone 25kg dry powder type.

In an emergency, escape from the control room is possible via the escapewindow on the port forward side. There is an emergency breathing devicepositioned near the window.

Issue: 1


Illustration 3.1b Cargo Control Room Console

NEBB

Key1 - DCS Workstation2 - Ballast System Remote Control Valves Operating Levers3 - Port of Montoir Hotline Telephone4 - Water Spray Pump Start/Stop Pushbuttons5 - Port and Starboard Ballast Pump Start/Stop Switch6 - Gas Sampling Monitor for Ballast and Void Spaces7 - Ship/Shore Hotline Telephone for Japan Ports8 - Fire Alarm9 - Port of Trinidad Mooring Release Pushbutton10 - Ballast System Illustration and Standing Orders11 - No.1 Cargo Tank Pressure Gauge12 - No.1 Cargo Tank Void Space Pressure Gauge13 - No.1 Cargo Tank Port Cargo Pump Discharge Pressure Gauge14 - No.1 Cargo Tank Port Cargo Pump Motor Current 15 - No.1 Cargo Tank Starboard Cargo Pump Discharge Pressure Gauge16 - No.1 Cargo Tank Starboard Cargo Pump Motor Current17 - No.1 Cargo Tank Spray Nozzles Pressure Gauge18 - No.1 Cargo Tank Port and Starboard Cargo Pump Start/Stop Pushbuttons19 - No.1 Cargo Tank Mimic Panel20 - No.2 Cargo Tank Pressure Gauge21 - No.2 Cargo Tank Void Space Pressure Gauge22 - No.2 Cargo Tank Port Cargo Pump Discharge Pressure Gauge23 - No.2 Cargo Tank Port Cargo Pump Motor Current 24 - No.2 Cargo Tank Starboard Cargo Pump Discharge Pressure Gauge25 - No.2 Cargo Tank Starboard Cargo Pump Motor Current25 - No.2 Cargo Tank Spray Nozzles Pressure Gauge

26 - No.2 Cargo Tank Port and Starboard Cargo Pump Start/Stop Pushbuttons27 - No.2 Cargo Tank Mimic Panel28 - Ballast System Illustration and Standing Orders29 - No.3 Cargo Tank Pressure Gauge30 - No.3 Cargo Tank Void Space Pressure Gauge31 - No.3 Cargo Tank Port Cargo Pump Discharge Pressure Gauge32 - No.3 Cargo Tank Port Cargo Pump Motor Current 33 - No.3 Cargo Tank Starboard Cargo Pump Discharge Pressure Gauge34 - No.3 Cargo Tank Starboard Cargo Pump Motor Current35 - No.3 Cargo Tank Spray Nozzles Pressure Gauge36 - No.3 Cargo Tank Port and Starboard Cargo Pump Start/Stop Pushbuttons37 - No.3 Cargo Tank Mimic Panel38 - No.3 Cargo Tank Spray Pump Discharge Pressure Gauge39 - No.3 Cargo Tank Spray Pump Motor Current40 - No.3 Cargo Tank Spray Pump Throttle Valve Control Dial41 - No.3 Cargo Tank Spray Pump Start/Stop Pushbuttons42 - ESD Pushbutton43 - Manifold Mimic44 - No.4 Cargo Tank Pressure Gauge45 - No.4 Cargo Void Space Pressure Gauge46 - No.4 Cargo Tank Port Cargo Pump Discharge Pressure Gauge47 - No.4 Cargo Tank Port Cargo Pump Motor Current48 - No.4 Cargo Tank Starboard Cargo Pump Discharge Pressure Gauge49 - No.4 Cargo Tank Starboard Cargo Pump Motor Current50 - No.4 Cargo Tank Spray Nozzles Pressure Gauge51 - No.4 Cargo Tank Port and Starboard Cargo Pump Start/Stop Pushbuttons

52 - No.4 Cargo Tank Mimic Panel53 - No.4 Cargo Tank Spray Pump Discharge Pressure Gauge54 - No.4 Cargo Tank Spray Pump Motor Current55 - No.4 Cargo Tank Spray Pump Throttle Valve Control Dial56 - No.4 Cargo Tank Spray Pump Start/Stop Pushbuttons57 - No.5 Cargo Tank Pressure Gauge58 - No.5 Cargo Tank Void Space Pressure Gauge59 - No.5 Cargo Tank Port Cargo Pump Discharge Pressure Gauge60 - No.5 Cargo Tank Port Cargo Pump Motor Current61 - No.5 Cargo Tank Starboard Cargo Pump Discharge Pressure Gauge62 - No.5 Cargo Tank Starboard Cargo Pump Motor Current63 - No.5 Cargo Tank Spray Nozzle Pressure gauge64 - No.5 Cargo Tank Port and Starboard Cargo Pump Start/Stop Pushbuttons65 - No.5 Cargo Tank Mimic Panel66 - Insulation Barrier Nitrogen Gas Pressure Gauge67 - Cargo Tanks High Level Alarm Indicator68 - LD Compressor Speed Dial69 - LD Compressor Running Light and Start/Stop Switch70 - Inboard HD Compressor Surge Pressure Controller71 - Inboard HD Compressor Running Light and Start/Stop Switch72 - Inboard HD Compressor Pressure Controller73 - Inboard HD Compressor Speed Controller74 - Outboard HD Compressor Surge Pressure Controller75 - Outboard HD Compressor Speed Controller76 - Outboard HD Compressor Running Light and Start/Stop Switch77 - LD Compressor Speed Control Dial

78 - LPG Compressor Motor Current79 - LPG Compressors Motor Current Selector Switch80 - LPG/LNG Compressors Changeover Switch and Key Lock81 - Cargo Tanks Ventilation Valve Control Dial Switch and Gauge82 - Inert Gas Flow to Consumers Indicating Light83 - Glycol Pump Running Indicator Light84 - Cargo Tanks Ventilation Valve Control Dial Changeover Switch (CCR/ECR)

1

1

1

1

2

3

4

5

10

69

18

19 28 37

43

52 65

27 3641

42

5651 64

8

11

12

13

14

15 17

16

20

21

22

23

24 26 29 31 33 35

30 32 34 38

39

40

44 46 48 50

45 47 49

57 59 61 63 68 70

7169

77

78

83 84 85

79

80

81

76

72 73 74 75

66

67

58 60 6253

54

55

257


Issue: 1


Illustration 3.2.1a Distributed Control System Overview

Report PrinterReport Printer

Report ServerAlarm Printer

Operator Stations Operator StationEngine Control Room Cargo Control Room Wheelhouse

Alarm Printer

LoadComputer

WhessoCargo Tank

Level

DGPSNavigationEquipment

Main

Reserve

Ethernet

System Bus

XOPSA201

ALPA2A1

ALPA1A1

XESA103

XOSA202

BUAB01

GTW:CISAC01

GTW:LISAL01

XOPSA102

XOPSA101

6MPIC R

7MPIC R

8MPIC R

8-SLOT1/0

6RPIC R

7RPIC R

8RPIC R

0 1/0

PCSAP03M

PCSAP03R

PCSAP02

1 1/0

2 1/0

3 1/0

0 1/0

1 1/0

2 1/0

3 1/0

4 1/0

5 1/0

8-SLOT1/0

8-SLOT1/0

8-SLOT1/0

8-SLOT1/0

8-SLOT1/0

DG2 andWheelhouse

DG1 andMSB STBD

TG andMSB Port

PCSAP01

2 1/0

3 1/0

0 1/0

1 1/0

4 1/0

5 1/0

Fieldbus R M Fieldbus R M

Fieldbus R M

SystemHard Disk

Emergency Panel

Ship AutomationVALMARINE

0%

25%

%

75%

StCo

se

Steam DumpC t l V l

25%

0%

25%

%

75%75%

StCo

le

Stb. SuperhTemp. Co

ed Steaml Valve

0%

25%

%

75%

Stb. Combustion AirI

Port Combustion Air


Issue: 1



3.2 Vessel Control System

3.2.1 Damatic XD Distributed Control System (DCS) Overview

The DCS system is an alarm, monitoring and control system which covers allthe important plant on board the vessel, such as propulsion, power generation,boilers, auxiliary machinery, cargo and ballast systems.

The DCS system on board is called a distributed control system, because theprocess control functions are defined locally in the process stations and not inthe operator stations. The operator stations function independently, so they canbe located at the ship control centres. This also means that each station iscapable of controlling any process, provided it has control of the appropriatecommand group and the user is logged on with the correct access.

There are two communication bus levels in the system:

System bus, connecting all types of stations

Field bus, connecting the input/output racks to the process stations

The basic functions include:

Process and system monitoring

Event logging and monitoring

Control functions (motor control, valve control, PID controllers etc)

The main applications to which these function are applied are:

Cargo and ballast control and monitoring

Cargo alarms

Machinery alarms

Power management system

Boiler control

Main turbine control

Watch call system

Main Components

The DCS system is made up of operator and history stations connected by adual bus to the Network Connection Units (NCUs) and the process stations.

Process Control Stations (PCS)The process control stations connect the XD system to the controlled processand provide the interface between the DCS system and the actual plant orequipment. They are able to handle group starts, sequences, trend histories andadvanced calculations for supervisory level controls.

Interface StationsGateway GWT:LIS connects the system to the DGPS navigation equipmentand the cargo tank level measuring system. The other gateway GTW:CISconnects the main and reserve bus systems with the ethernet and reportprinters.

Operator Stations (XOPS)The operator stations are the main interface between the operator and theprocesses under the operator’s control. The operator station has a colourmonitor, an operator panel with buttons and trackball and an operating display.These are installed in the cargo control room and the engine control room.

Operator Server (XOS)The operator server allows the operator to receive information on the processand enter commands to control the process.

External Systems (XES)It allows the operator to remotely open displays through servers running onother systems.

Alarm Processors ALPThe alarm processors, one for machinery alarms and one for cargo alarms,collect information on the process events and send the information to theoperator in the control room and to the long term alarm archive in theinformation server. The cargo alarms are acknowledged from the cargo controlroom and the wheelhouse and the machinery alarms can only be acknowledgedfrom the ECR.

Back-up Station (BU)The back-up station is connected to the system bus. The back-up station’s diskstorage contains the configuration of each station connected to the bus. In afailure situation, the automatic back-up function will load the configuration ofthe affected station.

Communication NetworkThe network used is two communication bus levels connecting the operatorand process stations. The System Bus, connecting all the stations and the FieldBus connecting the input/output racks to the process station.

The Operator InterfaceThe graphic displays are shown on the monitor of the operator stations. Thesedisplays show all or part of a system or process using standard symbols torepresent the actual plant/equipment (valves, motors etc). Events (alarms andmessages) are also shown on the displays.

The operator panel is used to interact with the monitor display and control theprocess. This is achieved by the use of the trackball and buttons to point andclick on symbols and menus on the monitor display.

Displays and ViewsThe system is made up of the following types of views:

Process

Flow

Event

Trends

Equipment

The number of views in a system depends upon the equipment under systemcontrol. The operator can select views with varying levels of detail.

When a view is selected showing an overall process, there may not be enoughroom to display all the detail on a single view. To account for this, the systemwill therefore have a number of views, accessed from the main view, that showthese details.

System Peripheral Equipment

Alarm PrintersThe alarm printers are connected to the alarm processor, which record all thealarms activated and the alarms which have returned to the normal conditionin the cargo control room and the ECR. A new alarm entering the list is giventhe following priority symbols:

Critical alarm **

Normal alarm !

Redundant alarm --

Report PrintersTwo report printers are connected to the ethernet and are used for processmonitoring and reporting in the cargo control room and the ECR.

Emergency PanelIn the event of a serious breakdown of the DCS, the boilers can be controlledusing the emergency panel.

Issue: 1


Illustration 3.2.2a Operator Station Keyboard

STORE

WND

ACT

DET PICK PICKOVW

DET

PICK

OVW

M

MR DET

WNDMOVE

CA

ACT

CA

ACK

ACK ACTDISP 0 . -

1 2 3

4 5 6

7 8 9

C CE EX

0 . -

1 2 3

4 5 6

7 8 9

C CE EX

DMON

ALMLIST

T

FLD

FLD

T

Scans the Event ListTowards Older Events

Selects a More General Display andMoves to a Higher Level in Hierarchy

Selects a More Detailed Display. InConfiguration the Function of this KeyMust be Defined Separately for Each Display

For Picking a Related Operating Display WindowAfter Pointing it by Cursor

Storing a Displayed Picture in Memory

Recalling a Stored Picture to the Monitor Activation Keys are Used to Start MonitorOperation (Such as Starting a Pump or Enteringa Set Point)

Key to Cancel Activated Monitor Operation

Selecting a Picture to Another Monitor

Selecting a Picture by Number toOwn Monitor

Scans the Event ListTowards Newer Events

Store Key

Scans Towards PicturesSelected Earlier

Scans Towards PicturesSelected Later

Scans TowardsNext Pictures

Scans TowardsPrevious Pictures

STORE

T

T

M

MR

Clears theEntire Entry

Executes theEntry

Clears the Last Character

DISP

DMON

Selecting a Related Monitor WindowAfter Pointing it by Cursor

Moving a Monitor WindowMOVE

WND

ACK

ACKALMLIST

FLD

FLD

Selecting the Display and LoopRelated to the Event and Scanningthe Events in the Alarm Area of theHeader Towards Older Events

Selecting the Display and LoopRelated to the Event and Scanningthe Events in the Alarm Area of theHeader Towards Newer Events

Direct Access Key to Alarm List

Alarm BuzzerAcknowledgement

Alarm FlashingAcknowledgement


Issue: 1



3.2.2 Operator Stations

Operator Panel

The system’s operator/user interface is the monitor screen, operating displaypanel, trackball and keyboard. The monitor screen displays the system viewsand the operating display panel is used to interact with those views. Thekeyboard is used for set-up and configuration purposes. The operating displaypanel is used to interact with the views on the monitor screen, display a newview or to act upon an element within a view.

Operator Panel Keyboard

The keyboard consists of the following keys:

1. PAGE SCANNING keys - viewing of previous and next screen displays andolder and newer events. Pressing the page scanning keys after the direct accesskey allows the operator to view the screens in the current hierarchy branch.

2. DIRECT ACCESS keys and STORE key - short cuts to screen displays mostused and ability to store a new direct access screen display.

3. T keys - allows scanning towards screen displays selected earlier or later.

4. OVW key for selecting a more general overview - moves to a higher levelin the hierarchy and selects an overview display, which includes the buttons forviewing the following systems:

Cargo

Main turbine

Boilers


Machinery

Integrated cargo and machinery system ICMS

5. DET key - selects a more detailed display. Is used after the the cursor ismoved to the area on the monitor display where more detail is required.

6. PICK key - for opening the related operating display window after pointingto it with the cursor.

7. M key - storing a displayed screen in memory.

8. MR key - recalling a stored screen to the monitor.

9. Numeric entry keys 0 to 9, decimal point and minus sign and also includes:

C key for clearing the entire entry

CE key for clearing the last character

EX key executes the entry

10. ACT key - used to open a dialogue box on the monitor screen, once thecursor has been positioned on the operating area.

11. CA key - to cancel the activated monitor operation.

12. DMON key - selecting a screen display to another monitor.

13. DISP key - selecting a screen display by number to own monitor.

14. FLD keys - used for selecting the display and loop related to the event,scanning the events in the alarm area of the header towards older and newerevents.

15. ALM LIST key - allows direct access to the alarm list.

16. ACK keys - acknowledges the buzzer sound and blinking light.

Trackball

The trackball is used to position the cursor on the screen display. The speed ofrotation will determine the distance the cursor will move on the screen display.

Monitor Screen Operations

To open a monitor display or window, move the cursor to the area required andpress the WND key. The monitor display or window can be closed by pressingthe CA key when the cursor is within the area.

A particular item on the screen can be operated by moving the cursor to withinthe operating area and pressing the ACT key. A field for user operations isdisplayed at the selected item on the monitor which shows the availableoptions for the current situation.

Inside the field the cursor is replaced by a pointer, which can only be movedto the permissible positions by using the trackball. The operating fields includekeys, menus and/or entry fields for numerical values. Using the keys andmenus is performed by pointing at the desired option with the pointer andpressing the ACT key.

Operations in an operating field can be stopped by moving the cursor off thefield and by pressing the CA key.

Operating Display Text Keys

These keys are automatically displayed on the operating panel when theoperator is prompted to enter text. The text is entered on the top line whichallows for 50 characters.

The display also includes the following keys:

CPS key - changes letters to upper case and cancels the effect of the ALT key

ALT key - selects characters on the top of some keys

BS key - deletes an entry

EX key - sends the command from the operating display to the DCS.

Printing an Alarm List

Touching the MORE key will reveal the COPY, STOP and CONT keys to bedisplayed. Pressing the COPY key will activate the hard copy unit to print anda copy of the alarms on the alarm printer. The printing can be stopped using theSTOP key and restarted using the CONT key.

Issue: 1


Illustration 3.2.3a Screen Display

NORMAN LADY CARGO

1

5.11 CARGO TANK 110.07.03 11:02.41

HH

LAHHLAH

0.10

barA

CPS

0.00

barA

CPP

-153.6 C

-110.4 C

-124.9 C-125.2 C

35.65 m15491 m3115.3 %

VAPOUR FLOAT

m30

LNG MODE

DRY AIR SUPPLY DEMANDFOR VOID SPACE

CARGO TK/ATMVOID SPACE/ATMCT/VOID SPACETANKDIFF PRESSSPRAY HEAD.PRESS

0.1610.000

-0.154PDAL0.151

barbarbar

bar

EQUATOR RING:FOREAFTERSTBDPORT

-110.7-111.5-111.7-104.9

CCCC

EQUATOR SKIRT PORTSTIFF. RING PORTEQUATOR SKIRT STBDSTIFF. RING STBDFOUNDATION DECK FWD

-62.7-52.0-65.8-58.125.0

CCCCC

VOID SPACE:SUMP LAHFWD BULKH.STBD BULKH.UPPSTBD BULKH.LOWPORT BULKH.UPPPORT BULKH.LOWPRESSURE PDAL PDAH

20.327.127.926.429.526.5

CCCCCC

Monitor Number

Page Number

Cargo TankLiquid

Temperatures

Cargo TankDischarge

Pumps

Cargo TankLevel Indicator

Reading

Cargo TankPressure IndicatorReading

Cargo TankTemperature IndicatorReading

Date and Time


Issue: 1



3.2.3 Screen Displays

Monitor Screen

HeaderThe header is displayed at the top of each monitor display and shows thegeneral information on the system and the display picture.

The header also includes the following information:

1. Page number

2. Display continuation marker

3. Display number

4. Monitor number

5. Selected monitor indicator

6. Display title

7. Date

8. Time

9. Event line in alarm area which displays the initial event.

The initial event is the first event requiring acknowledgement after all previousevents have been acknowledged.

10. Process zone fields in alarm area

A process zone field shows the zone identifier and event counter. The zoneidentifier specifies the process zone and colour of the background indicates themost urgent event in the process zone:

Red = critical alarm

Orange = normal alarm

Grey = message

Lilac = fault

11. Event counter, which shows the number of events that have occurred after the initial event in the process zone

12. Zone field continuation marker. The line has room for up to six zone fields and when there are more the continuation marker will be displayed

Graphic DisplayThis provides the user with an overview of the controlled process and displaysthe process in an illustrated format. The process status is displayed by meansof motor, valve and pump symbols, status data in text form such as ON/OFF,measured values in bar graph format and various numerical values.

In graphic display, any alarm will change the background colour of the affectedmotor or pump to the alarm colour.

Group DisplayThis gives detailed information on the controlled items of a specific section ofthe process. It consists of eight sections, each of which includes one or moreprocess tags, depending on the displayed item. In group display, any alarm willchange the background colour of the running status to the alarm colour.

Trend DisplayIt is possible to configure a process history trend in curve format, which iscontinually updated in accordance with the process, so as to display the actualstate of the process. The displayed colours indicate process status with regardto either normal, disturbance or failure conditions.

A trend may also be displayed in a split format containing up to four trends indifferent colours. The time scale can be in minutes, hours or days.

Event List DisplayAn event list shows a list of the received alarms and messages. They are usedto monitor the running of the process, to find out the causes of the disturbancesand to access the different process situations later.

An event refers to a change in a particular state and is divided into criticalalarms, normal alarms and messages. An alarm is an exceptional event andindicates an abnormal process status. A message is an event belonging to anormal operation of the process.

One line in the event list represents a single event and the events are displayedin chronological order in the list. One page of the event list can show 32 eventsand there can be up to ten pages, with the latest event always on the first page.

A new alarm is displayed in red text, with the symbol blinking. When the alarmis acknowledged, the blinking stops but the line will remain red until the alarmbecomes redundant (not active). Redundant alarms are coloured brown and areeventually deleted from the event list automatically.

Redundant alarms and messages can be deleted from the list by activating theCOMPR compress key at the top right corner of the screen. The active andunacknowledged alarms will remain in the list.

The alarm area shows the number of events for different process zones and thecolour of the zone field indicates the priority of the most urgent event. Theinformation related to the first alarm in an alarm sequence is shown on thealarm area’s event line. The event line allows the operator to scan through theevents and the related displays at the same time.

The event list is selected by pressing the ALM LIST key. Scanning through thepages is done by pressing the scanning keys and the ALM LIST key to returnto the first page.

If an event shows the letter D, a detailed display related to the event can beselected by moving the cursor to the event line and pressing the DET key. If anevent shows the letter I at the right hand end of the line, an information displayrelated to the event can be selected by moving the cursor to the letter I andpressing the DET key.

Operations on the Alarm AreaThe event line in the alarm area shows the systems first alarm. The operatingdisplay window related to the alarm can be accessed by pressing theappropriate FLD key.

Displays related to the event in the alarm area can be shown on the monitor andoperating display screen by continually pressing the appropriate FLD key tomove up or down the display list.

In this way the operator can more easily determine the causes and effects andaccess the displays to perform the required actions.

Using Two MonitorsIf there are two monitors connected to one operator terminal, they can beconfigured to be located adjacent to each other.

One of the monitors is defined as the first monitor and the other as the secondmonitor. The monitor shows that the cursor is currently active and the other ispassive and all operations are addressed to the active monitor.

To activate the passive monitor, the cursor is moved beyond the border of theactive monitor.

It is possible to select a display to another monitor by pressing the DMON key,followed by the number 2 key. The other monitor will show the same displayas the original monitor and it will be possible to scan displays on the newmonitor by pressing the right hand direction arrow scan key.

Issue: 1


Illustration 3.2.3b Operating Panel Display

MAININDEX

GRAPHDISP

BLROVW

MORE

CA

MENU

510.1M

300.0-600.0C

S BLR SUPERH. STEAM643.210 TIAHL T

T

Hierarchy Path

Keys for DisplayingOther OperatingDisplay Windows

Key for Clearingthe Present OperationDisplay

Key for Displayingthe Next Set ofStandard Keys

Reveals the RelatedDisplays Available

For BoilerSystem View

if Required

Title and Tag Number Press for Access toOther Controls

Present TemperatureTemperature Range


Issue: 1



Operating Display Screen

The operating display screen consists of a capacitive electro-luminescentpanel, displaying measured value bars, text, status data and soft keys inaccordance with the current situation.

(Note: Due to the nature of the matrix, only one finger should be used to touchthe display and touch only one key at a time.)

The operating display may have a screen saver in use which blanks theoperating display after a defined time if no operations have been made throughthe operating terminal. Touching any key or moving the cursor will return theoperating display to operating mode.

The operating display keys detail the following:

MAIN INDEX = hierarchical path

T = scanning operating display wndows

CA = clear activation

MORE = displaying the next set of standard keys

GRAPH DISP = reveal the related displays available

A hierarchical path shown at the left hand side of the operating screen displayindicates the current display and its selection path. The items at the centre ofthe display are related to the operating tag and the standard, non-configuration,keys are at the right hand side of the display. By touching the MORE key, thenext set of keys are displayed.

Operation in the operating display is started by picking the desired item to theoperating display. This is done by pointing at the item with the cursor andpressing the PICK key. The display may include bar graphs, texts andinformation on the items status. Actual operating keys are not yet displayed forthe item in this basic state, only the current information for the item is shown.

An item’s status is displayed inside rectangles in the operating display andoperations on a specific data are started by selecting the desired data. This isdone by touching the data with a finger, which will highlight the data.Operating keys for an operated item are displayed with rectangles or squareswhose corners are cut.

The screens are arranged in a hierarchy tree which consists of branches andlevels, with the route leading from one level to another called the hierarchypath. The hierarchy menu is accessed by touching the MAIN INDEX key,which will reveal the keys for the lower level screens and related displays. Therequired screen will be displayed on the monitor by touching the relevant key.

When required, a more detailed view of an item displayed on the monitor canbe requested to the operating display, which provides detailed information ona loop, for instance an interlock that has stopped a motor.

If text needs to be entered during operations, such as system login, creation ofa trend graph or a recorder connection, a text keyboard will be automaticallydisplayed. The keyboard is of the standard qwerty type with the followingadditional keys:

CPS key = to enter upper case

ALT key = to select the characters at the top of some keys

BS key = to remove the last entered character

EX key = the text entered disappears and the function is executed

If text is being entered on the monitor, the text will not be sent to the monitoruntil the EX key is pressed.

Issue: 1


Illustration 3.2.4a Operation

NORMAN LADY CARGO

1

5.31 SPRAY SYSTEM10.07.03 11:02.41

TANK1

TANK2

TANK3

TANK4

TANK5

SPRAY SPRAY

STOP STOP

0.15 bar 0.14 bar 0.01 bar0.14 bar0.15 bar

LIQUID LIQUID

VAPOUR

SHORE CONNECTION

22C 28C

30C

0A 0A0.00bar

0.00bar

SPRAY CROSSOVER

SPRAY HEADER

Cursor

CommandIcon

Monitor Number

Page Number

Date and Time


Issue: 1



3.2.4 Operation

Basic User OperationsUser operations are performed either with a cursor directly through themonitor, or through the operating display by pressing the relative key with afinger.

User AuthoritiesThe users of the operating station can be divided into three groups:

Display mode

Control mode

Maintenance mode

Display ModeIn this mode it is possible to view the screens and pick the displays, but allprocess operations are disabled.

Control ModeIn control mode most basic operations are enabled except for the following:

Controller parameter tuning

Changing of event limits

Masking of events

Maintenance ModeAll operations are enabled which allows for maintenance to be done on thesystem and parameters tuned.

Motor and Pump Control ModulesAll motors and pumps covered in the DCS system are supported by modulesproviding automatic, manual and local control, control status, operating status,interlocking, power demand, standby start, restart after blackout and shutdown.

The operating menu for a motor or pump contains the event masking, operationand trend commands available at that time.

All motor or pump control modules have control logic interlock functions toprevent the motor or pump from being damaged. The interlocks prevent themotor from being inadvertently started. Large motors (heavy consumers) havea power interlock function that prevents the motor from being started if thereis insufficient generator power available on the electrical network.

Some control modules will be configured with a blackout restart function. Thisfunction causes a motor to be automatically restarted, when power is re-established after a blackout, provided the motor was running before theblackout occurred. A configured start delay on each motor is provided toprevent too many motors starting at the same time.

The status symbols are displayed within squares and the operating keys aredisplayed within squares with cut corners.

From the MonitorWhen the cursor is moved to the motor/pump symbol status locating area, theACT key is pressed to reveal a graphic display with the following information:

1. Title and/or tag number

2. Running status(stop or running)

3. Control mode selection status

M = manual

A = automatic

L = local

4. Text pointing area

Running OperationsOnce the cursor is moved to the operating area, press the ACT key to reveal anoperating field showing the current status and a selection key.

I = start

O = stop

With the arrow pointing to the I or O symbol, press the ACT key to either startor stop the motor.

Control Mode ChangeThe control mode can be changed on the monitor screen by moving the cursorover the control mode status symbol locating area and pressing the ACT key.An operating display will be revealed, indicating the current status andselection keys available, such as M, A or L. The current status will be indicatedby an arrow, which can be moved up or down to another control mode by usingthe trackball.

Trend Graph DisplayThe trend graph display is revealed by moving the cursor to the system title onthe screen display and pressing the ACT key. On the resulting operating displayscreen press the GRAPH DISP key to reveal the related displays available andselect the TREND DISP key to show a trend graph for the system.

Valve Actuator Control ModulesAll valves in the DCS system are supported by modules that have either %position or open/closed position feedback. The basic module functions coverautomatic and manual, automatic or local control.

A valve is represented graphically by a status symbol containing a tag markcharacter that indicates the current operational mode of the valve.

The symbol may also contain a numerical value if the valve has a controllablemovement. This value indicates either the actual position of the valve or the setpoint of the valve in percentage terms.

Control of valves is similar to motors and pumps, ie, the operation menu willshow which commands are available for that specific valve.

Open or Close OperationRunning an actuator is possible when the actuator is in manual mode M andthe operations are enabled when the message NO OP is not on.

The valve is operated by moving the cursor to the status symbol locating areaand pressing the ACT key. An operating field is displayed, containing thesymbol for the current status and an open and/or close selection key, dependingon the application. The valve is opened or closed by moving the arrow to therequired selection key and pressing the ACT key. The moving actuator willdisplay a blinking status symbol.

Intermediate Position OperationThe method to start the operation is similar to an open/close type actuator. Theexception is that the ACT key is held down to run the valve to the requiredposition and released to stop the operation at the required position.

Changing the Position Set PointMove the cursor to the measured value locating area and press the ACT key.An operating field with the current measured value and set point is displayed.The field also includes an entry field for the new set point, as well as arrowkeys for driving the se tpoint.

Enter the new set point using the numerical keys or adjust the set point withthe arrow keys.

Issue: 1



From the Operating Display The control can also be carried out via the operating display window bypressing the PICK key when the cursor is moved to the motor/pump statussymbol locating area on the monitor. The operating display window will showthe following information:

1. Title and/or tag number.

2. Running status.

I = running (ON)

>I = starting

O = stopped (OFF)

>O = stopping

3. Control mode selection status.

M = manual

A = automatic

L = local

4. Operability.

NO OP = operations prevented (masked)

5. Measured current output.

6. Fixed status data.

RI = release ON

RO = release OFF

FI = forced control ON

FO = forced control OFF

WD = watchdog failure

CU = overcurrent

7. Status description.

NO REL I = no release ON

NO REL O = no release OFF

FORCED ON = forced control ON

FORCED OFF = forced control OFF

WATCHDOG = watchdog failure

CUR H = current over high limit

CUR HH = current over higher high limit

8. Explanation of watchdog failures.

FAIL ON = failed start

FAIL OFF = failed stop

DIST ON = disturbance start

DIST OFF = disturbance stop

ICONTFAULT = ON control fault

OCONTFAULT = OFF control fault

Starting or stopping is possible when:

The motor is in manual mode M

The NO OP symbol is not on to prevent operations

The preventive delay for restarting is not on when starting the pump

Running OperationsTo either start or stop a motor/pump, press the status symbol O or I. Thedisplay will change to show the operating symbol I or O in a square with cutcorners. Press the operating symbol to start or stop the motor and the displaywill then change to show a status symbol >I or >O, indicating that themotor/pump is starting or stopping. The symbol will change to I or O when themotor is at its final status.

Control Mode ChangeThe control mode can be changed on the operating display by pressing eitherof the currently displayed M, A or L symbols. This will reveal an operatingdisplay, confirming the current status and selection keys available, such as M,A or L in squares with cut corners. The control mode can be changed bypressing the necessary symbol and the display will change to indicate the newcontrol status within a square.

Valve Actuator Control The valve control is transferred to the operating display by pressing the PICKkey when the cursor is in the status symbol locating area. The display willshow two square symbols, showing the position of the valve and the operatingmode and a rectangular symbol displaying the amount open or closed.

Running an actuator is possible when the actuator is in manual mode M andthe operations are enabled when the message NO OP is not on.

Open or Close OperationTo operate a valve, press the valve position symbol which will then displaysquare symbols with cut corners. Pressing the necessary square symbol willstart the actuator and either open or close the valve.

Intermediate Position OperationThe method to start the operation is similar to an open/close type actuator. Thesecond display contains two operating symbols showing the valve 50% closedand fully closed and two operating symbols containing arrows. The valve caneither be 50% closed or adjusted to a desired position using the arrow keys andnoting the position on the indicator.

Changing the Position SetpointPress the rectangle symbol showing the valve position. The next display willshow the numerical keys and arrow keys. The set point can be reset by enteringthe new value using either the numerical or arrow keys, followed by pressingthe EX key.

Issue: 1



NORMAN LADY CARGO

1

5.18 PRESSURES10.07.03 15:39.30

CTR / ATMHIGH PRESS. ALARMLOW PRESS. ALARMLOW PRESS. STOP PMPS & COMPR

VOID SPACE / CTRHIGH PRESS. OPEN RELIEF VOID SPACEHIGH PRESS. STOP COMPR, PMPS, FANSHIGH PRESS. ALARM

VOID SPACE / ATMHIGH PRESS. OPEN RELIEF VLV VOIDSP.HIGH PRESS. ALARMLOW PRESS. ALARMLOW PRESS. N2 TO VOIDLOW PRESS. DRY AIR TO VOIDLOW PRESS. OPEN RELIEF VALVE VOIDSP

LIQUID CARGO FWD PRESSURELIQUID CARGO AFT PRESSUREVAPOUR CARGO PRESSURE

FUEL GAS TO ENG. ROOM PRESSURE

EMERGENCY RELEASE QUICK CLOSING LOOP

0.220.010.00

0.050.040.03

0.150.12

-0.02-0.05-0.07-0.08

0.00 bar0.00 bar0.03 bar

PAH

6.67 bar

LIMITVALUE

PAHPALPCL

PCHHPCHPAH

PCHPAHPALPCLPCLLPCLLL

CTK1

0.161 bar

-0.154 bar

0.000 bar

PAHPALPCL

PCHHPCHPAH


CTK2

0.160 bar

-0.128 bar

0.000 bar

PAHPALPCL

PCHHPCHPAH


CTK3

0.160 bar

-0.128 bar

0.001 bar

PAHPALPCL

PCHHPCHPAH


CTK4

0.156 bar

-0.127 bar

0.000 bar

PAHPALPCL

PCHHPCHPAH


CTK5

0.157 bar

-0.129 bar

0.002 bar

NORMAN LADY CARGO

1

5.19 TEMPERATURES12.08.03 16:19.03

EQUATOR RING FOREEQUATOR RING AFTEREQUATOR RING PORTEQUATOR RING STBD

-110.7 C-111.6 C-104.9 C-111.7 C

EQUATOR SKIRT PORTEQUATOR SKIRT STBDSTIFF. RING PORTSTIFF. RING STBD

LIQUID CARGO CROSSOVER FWDLIQUID CARGO CROSSOVER AFTVAPOUR CARGO CROSSOVERLIQUID CARGO HEADER FORELIQUID CARGO HEADER AFT

FWD BULKHEAD UPPFWD BULKHEAD LOWVOID SPACE AFT BULKHEADSTBD BULKHEAD UPPSTBD BULKHEAD LOWPORT BULKHEAD UPPPORT BULKHEAD LOW

FOUNDATION DECK FWD

VOID SPACE SUMP

-62.7 C-65.8 C-52.0 C-58.1 C

28.1 C22.4 C30.3 C31.8 C30.5 C

27.1 C

27.9 C26.4 C29.5 C26.5 C

25.0 C

20.2 C

CTK1-110.3 C-110.5 C-109.1 C-108.2 C

-58.9 C-68.9 C-27.7 C-45.9 C

24.9 C21.3 C

28.7 C27.0 C28.4 C26.7 C

22.7 C

15.2 C

CTK2-108.1 C-110.4 C-109.2 C-108.2 C

-71.5 C-56.8 C-62.9 C-70.7 C

24.9 C22.1 C

28.4 C26.9 C28.9 C26.6 C

22.2 C

10.9 C

CTK3-114.5 C-119.2 C-118.8 C-121.2 C

-42.7 C-71.0 C-55.6 C-68.0 C

25.8 C22.9 C

28.6 C27.1 C29.4 C27.6 C

22.8 C

6.5 C

CTK4-116.1 C-118.3 C-117.2 C-116.6 C

-83.8 C-82.6 C-87.2 C-88.6 C

25.0 C23.1 C25.5 C29.1 C25.3 C25.8 C29.1 C

26.4 C

21.2 C

CTK5

Cargo Tank Pressures Screen

3.2.5a Mimics

Cargo Tank Temperatures Screen

Issue: 1



3.2.5 Mimics

Mimics are available through the menus from the overview mimic or byrequesting a specific numeric identifier.

Equipment Views Available

The following equipment status views are available:

Cargo system

Cargo operation

Custody transfer

Cargo temperatures

Cargo pressures

Cargo tank levels

Cargo safety system

Cargo compressors

Nitrogen plant

Void spaces

Ballast system

Distributed control and monitoring system

Machinery alarm list

Cargo alarm list

Port and starboard boilers

Burner management

Master and steam dump control

Fuel oil control

Fuel gas control

Combustion air control

Water level control

Steam temperature control

LD compressor control

Cargo tank pressure control

Nitrogen purge

Main gas valve control

Boiler safety


Electric power monitoring

Generator control

Diesel generator inboard

Diesel generator outboard

Turbine generator

Main turbines

Operating condition

Gear and shafting

Lubricating oil

Operation

Trips and interlocks

Main sea water cooling ystem

Main steam system

Condensate and feed water system

Fuel oil tanks

Fuel oil transfer systems

Bilge alarm system

Compressed air system

Bridge alarms

Mode Indication

Symbol White Yellow Green

Motor Stopped Transient/undefined Running

Pump Stopped Transient/undefined Running

Valve Closed Transient/undefined Open

Generator Stopped Transient/undefined Running

Circuit breaker Open Transient/undefined Closed

Lines in views, representing pipes carrying fluids, are, where appropriate,coloured to indicate contents:

Pipe Colour Fluid

Blue Fresh water or condensate

Brown Heavy fuel oil or crude oil

Cyan or Light Blue Compressed air

Green Sea water, ballast water or bilge water

Red Steam

White Chemicals, inert gas or methanol

Yellow Lubricating oil, hydraulic oil or diesel oil

Issue: 1


Illustration 3.2.6a Ballast Operating Display Screen

NORMAN LADY MACHINERY

2

5.61 BALLAST SYSTEM12.08.03 13:25.10

mm3%

No.5 SIDETANK PORT

0.0000

mm3%

No.4 SIDETANK PORT

15.541592

95

mm3%

No.3 SIDETANK PORT

15.772624

97

mm3%

No.2 SIDETANK PORT

15.511567

96

mm3%

No.1 SIDETANK PORT

13.34998

82

mm3%

No.5 SIDETANK STBD

0.0000

mm3%

No.4 SIDETANK STBD

15.451610

95

mm3%

No.3 SIDETANK STBD

15.472517

95

mm3%

No.2 SIDETANK STBD

15.281521

94

mm3%

No.1 SIDETANK STBD

15.051173

92

mm3%

No.3 BOTTOMWING TK P

9.882836

100

mm3%

0.0000

mm3%

6.951725

100



mm3%

No.3 BOTTOMWING TK S

9.892836

100

mm3%

0.0000

mm3%

6.291733

100



TANK LEVELPARAMETERSDETAIL

WATER DECKPUMP

M

mm3%

AFTPEAK

6.21199

91

DRAFT FWD8.06 m

AUTO

DRAFT AFT8.74 m

AUTO

M

M

-0.24 bar0 A

STB

0.42 bar0 A

PORT

mm3%

No.3 LOWCROSS T

0.0000

mm3%

No.1 LOWCROSS TK

5.331141100

FOREPEAK

0.0000

mm3%

No.2 BOTTOM TANK

8.243187100

mm3%

No.2 LOWCROSS TK

0.0000

mm3%

Monitor Number

Page Number

Tanks andLevels

Draught Aft Draught Forward

Date and Time


Issue: 1



3.2.6 Cargo and Ballast Operations

This control application is a monitoring and control facility covering the onboard liquids such as ballast, cargo and the load and stability calculator.

Cargo control usually has two main process views, one for the tanks and theother for the pumps. From the cargo tank process view, the operator will beable to monitor the cargo fluid levels, temperatures and processes within eachtank, and control the valves for filling, emptying and stripping the tanks.

From the cargo pump process views, the operator will be able to monitor andcontrol the cargo and spray pumps together with the valves for routing fluidsto and from the cargo tanks. These views also allow the operator to monitorand control the auxiliary equipment associated with the cargo pumps.

Monitoring and Control FunctionsThe cargo tank levels are measured by the Whessoe float gauges and the DCSreceives the level data for each tank by a serial line communication.

The DCS calculates the correct cargo tank levels with reference to the specificgravity of the cargo and the trim and list of the ship.

The corrected level is then used by the DCS for the volume calculation fromthe cargo tank tables and the volume is finally corrected for the thermalcontraction factor of the tank shell.

User set parameters are available in mimic 5.2 Custody Transfer for LNG/LPGmode and specific gravity.

Cargo Tank Temperature MonitoringEach cargo tank is equipped with four PT100 probes for liquid and vapourtemperature measurement.

Ballast Tanks MonitoringEach tank, except the fore peak tank, is equipped with one pressure transmitterfor the level measurement. Alarms are related to the levels.

Alarm suppression is activated when both ballast pumps are stopped. Thesuppression can be switched off via mimic 25.1.

Engine Room Tanks MonitoringEach tank is equipped with one pressure transmitter for the level measurementand there is no alarm suppression.

Level monitoringEach cargo tank has a level transmitter used to indicate the level in the tank.

Draught MeasurementThe draught is measured by pressure transmitters from sensors positioned onthe ship’s keel. In the case of a sensor fault, manual draught readings can beviewed from mimic 5.61.

Load Computer InterfaceTank levels and draughts fore and aft are transferred to the load computerlocated in the cargo control romm.

Gas CompressorsThe LD compressor speed is controlled from either the ECR or CCR controlsystem. The LD compressor is started from the CCR and command is given tothe ECR. The DCS shutdown signal for the LD compressor is activated fromthe fuel gas pressure transmitter to the engine room and the main fuel gas valveclosed signal.

Alarm suppression is activated for the LD and HD compressors when thecompressors are stopped.

Ballast Control - to be Fitted in the Near Future

This function has a primary view, visualising the entire ballast system. Fromthis view the tank levels of all vessel fluids used as ballast can be monitoredand the ballast system pumps and valves can be controlled. The primary viewalso shows the vessel heel data.

Operator Interface

The cargo and ballast process views in the cargo control room show the fluidcontrol systems comprising tank, valve and pump symbols interconnected bypiping and manifolds. The operator monitors the status of each device bydisplaying the views and operating the equipment as required. The starting andstopping of pumps and the opening and closing of the valves is normally partof the automatic cargo and ballast tank filling and emptying sequences, whichare initiated from the operator stations.

The unit field shows the units in use for the level values. Depending upon theselection made, the text displayed in the unit field will be one of the following:

Vol%: % height of the sounding pipe

Level: Height of the fluid in the tank (in m)

Volume: Content of the fluid in the tank (in m3)

Part 4Cargo and Ballast Systems

Issue: 1

Skirt

Insulation

Rupture DiscRemoved

Rupture Disc

RuptureDisc

PolystyreneInsulation withStainless SteelCover

Blank Flange

Catch Basin

Leakage Pipes

NitrogenBleed

Illustration 4.1.1a Leakage Pipes

Rupture DiscCross Section

Pressure

Rupture Disc

Section 4.1/4.1.1 - Page 1 of 2


Part 4 Cargo and Ballast Systems

4.1 Cargo Containment and Monitoring Systems

General Description

The cargo containment system consists of five insulated cargo tanks encasedwithin the inner hull and situated in-line from forward to aft. The spacesbetween the inner hull and outer hull are used for ballast and will also protectthe cargo tanks in the event of an emergency situation such as a collision or agrounding.

The ballast spaces around the cargo tanks are divided into two double bottomwing tanks, port and starboard for each cargo tank. The double bottom tanksextend to the side of the cargo tanks as far up as the trunkways.

Cargo tanks No.1 and No.5 are slightly different in size due to their position inthe ship. The sizes and capacities are as follows:

Tanks 1 and 5: 31.0 metres diameter

Tanks 2, 3 and 4: 33.1 metres diameter

Tanks 1 and 5 capacity: 15,490m3

Tanks 2, 3 and 4 capacity: 18,860m3

There is no secondary barrier as the tanks, primarily due to their sphericalconstruction, have a high degree of safety against fracture or failure. The tanksare heavily insulated with approximately 215mm of polystyrene foam toreduce natural boil-off to a minimum.

The tanks are constructed of 9% nickel steel. Each tank is covered by aspherical steel tank cover which is mainly for tank and insulation weatherprotection. The cover also permits control of the hold space atmosphere. Thelower edge of each cover is welded to the deck, forming a watertight seal. Aflexible rubber seal is used at the point where the tank dome protrudes out fromthe cover.

The tanks are each supported by a metal skirt from the equatorial ring, whichtransmits the weight of the tank and the cargo to the lower hull. The skirt isstiffened in the upper part by horizontal rings and the lower part by verticalcorrugated stiffeners.

A special casting joint is fitted between the skirt and the tank’s equatorial ringto provide the necessary strength at this point and to reduce heat conductioninto the tank and a corresponding conduction of low temperature to the skirtand hull.

Insulation: The Spiral Generation Log System

The Norman Lady’s cargo tanks are insulated with expanded polystyrenefoam, fitted to the tanks by a spiral generating system. This system generatespolystyrene strakes (logs) as the machine moves spirally around the tank. Theequipment automatically fuses adjacent polystyrene logs as the machineadvances around the sphere.

The insulation consists of two polystyrene layers separated by a crack-arresting layer of glass fibre. The upper hemisphere insulation is coated withsquare aluminium foil plates. The aluminium foil splash barrier on the lowerhemisphere is automatically bonded to the outer surface of the insulationduring the log welding process. This process butt welds the logs to form acontinuous insulation layer. The insulation is not actually bonded to the tanksurface and this allows the passage of nitrogen gas between the insulation andthe tank.

Containment

The LNG in the ship’s cargo tanks is carried at a pressure that is marginallyhigher than atmospheric pressure. The cargo tanks are housed within holds andeach hold is separated by a watertight bulkhead. A positive pressure of inert gasor dry air (depending on operational requirements) is maintained in the voidspace surrounding each tank.

The boiling point of LNG at atmospheric pressure is extremely low (-163ºC)and so special equipment and procedures must be used to handle LNG. Thepiping system is designed to have the minimum number of bolted flanges.

Welding is used wherever practicable to reduce the possibility of joint leakage.Any liquid leakage must be dealt with by spraying the area affected with waterby means of the spray system provided, or by the use of a fire hose. Thisprevents any fractures of the affected local steelwork.

Monitoring

The DCS system provides monitoring of the cargo levels, pressures andtemperatures. Together with the cargo and void space gas detection system, theDCS system monitors the cargo containment systems, the tanks and the voidspaces etc for any signs which may indicate a failure of this containment andpossible gas or liquid leakage.

In the case of a cargo leak, the gas detection analyses the void space via foursampling points (see section 4.9, Fixed Gas Detection Systems) and raises analarm locally at the LCCR and via the DCS system.

If the leak is of a size where liquid is flowing, the leak would be directed via asystem of leakage pipes described in the next section, 4.1.1.

4.1.1 Liquid Leakage Detection

A leakage of LNG within the tank insulation will be detected at an early stageby the gas detection system fitted at the equatorial ring area and at the drip pan.The drip pan, installed directly below each cargo tank is fitted withtemperature, gas and liquid sensors to detect the presence of LNG. These willalarm via the gas detection and DCS systems. An eductor system allows theremoval of the liquid.

The aluminium foil surface of the tank insulation protects the insulation as wellas directing any leakage away. Any LNG liquid leakage drains by gravity frombetween the tank plating and the insulation to the drip pan via a drain tube atthe bottom. The drain at the bottom of the insulation space is sealed in normalservice by a rupture disc.

Liquid flow from the northern hemisphere collects in the drain channel whichis formed by the upper skirt ring stiffener and is directed to the leakage pipeslocated forward, aft, port and starboard of the tank. These pipes direct theliquid onto the void space deck and then to the drip pan. These areas are allprotected with stainless steel sheet covers.

All of the pipes except one are fitted with rupture discs. These discs are gastight but are designed to fail at cryogenic temperatures and will thereforerupture when LNG comes into contact with them. The leakage pipe without adisc has a gas detection sensor fitted to provide early warning of a possibleleakage.

From illustration 4.1.1a the layout of the leakage pipes can be seen.

Issue: 1 Section 4.1/4.1.1 - Page 2 of 2


Issue: 1

Skirt

Tank TopTemperature

Tank 95% LevelTemperature

Tank 50% LevelTemperature

Tank BottomTemperature

Skirt PortTemperature

Skirt StbdTemperature

Skirt StiffenerRing StbdUpperTemperature

Skirt StiffenerRing PortUpperTemperature

Void SpaceBulkheadTemperaturePort Lower

Equator RingForward

Temperature

DeckFoundation

ForwardTemperature

Void SpaceBulkhead

Forward UpperTemperature

Void SpaceBulkhead

Forward LowerTemperature

Equator RingAft

Temperature

Equator RingStarboard

Temperature

Equator RingPort

Temperature

Void SpaceBulkheadTemperaturePort Upper

Void SpaceBulkheadTemperatureStbd Upper

Void SpaceBulkheadTemperatureStbd Lower

Drip PanTemperature

Tank/VoidDifferentialPressure

Tank/VoidDifferentialPressure

Void SpacePressure

Illustration 4.1.2a Temperature and Pressure Monitoring System

View from Top View looking Forward



Issue: 1


4.1.2 Temperature and Pressure Monitoring System

General Description(See illustration 4.1.2a)

Monitoring equipment is provided in the CCR and the ECR via the DCSsystem for the void spaces and inner hull temperatures and pressures to givewarning in the case of a failure of insulation or leakage of the containmentinsulation barrier.

Each sensor is of the PT100 resistance type. The sensors are installed in thesecondary insulation barriers and alongside the inner hull associated with eachcargo tank. The temperature range of each sensor is : -200°C to +100°C.

During normal conditions, one thermocouple is in service whilst the other is onstandby. If the first sensor fails, the second sensor may be used.

For the inner hull temperature measurement, there are sensors in each tank.One is located along the bottom of the tank in the pipe duct, one doubleelement type sensor in the liquid dome.

The temperature measurements are indicated for each sensor in service in theCCR via the DCS system. Recording of these temperatures is also available viathe DCS system.

Temperature Measurement

The temperature measurement is obtained from the PT100 sensors whoseelectrical resistance decreases with temperature. The sensors are calibrated andcertificated and therefore have their own individual identification number. Thesensors are positioned equally throughout the height of the tank and includesensors at the top and bottom enabling the temperature of the liquid and thevapour to be measured separately. Average and individual temperaturereadings are available.

The sensors are wired with four conductors (four wire cable) and allterminations are sealed. There are spare sensors mounted in the tanks toprovide a degree of redundancy.

Pressure Measurement

The pressure measurement is obtained from a capacitive pressure transmitter.The transmitter consists of a movable ceramic diaphragm connected to a fixedceramic substrate. On each ceramic part is a gold plate which makes up acapacitor whose capacitance will vary according to the distance between them.The fixed part is mounted on the tank shell and the moveable part extends intothe tank space.The tank pressure imparts a force on the movable plate relativeto the tank pressure. This varying capacitance signal is converted to an outputsignal which varies according to the pressure in the tank.

Displays

The relevant displays/mimics where tank and void space monitoring aredisplayed are:

The individual cargo tank measurement mimic

The cargo tank spraying mimic

Cargo tanks overview mimic


Issue: 1

HIGH AND OVERALL ALARM SYSTEM99.2% 29.36M

99.2%TANK NO.1

TANK NO.3

TANK NO.2

TANK NO.4

TANK NO.5

95%

99.2%

95%

99.2%

95%

99.2%

95%

99.2%

95%

ACCEPT

TONSBERG NORWAY

FLASHNORMALARMHOLD

LAMPTEST

ON OFF

Level SensorTank No.5

Level SensorsTank No.s 2, 3 and 4

Float Switch Arrangement

99.2% OverfillAlarm

Audible Alarms on Deck

95% High LevelAlarm

Level SensorTank No.1

HAZARDOUS AREA

SAFE AREA

230V AC SupplyHigh Level System

Protective Cap

Test Lift Button

ConnectionBox

Float Guide

Low Density Float

Sensor Switch

High High

Cargo Tank Dome Shell

High

230V AC SupplyOverfill System

Illustration 4.1.3a High Level and Overfill Alarm System



Issue: 1


4.1.3 High Level and Overfill Alarm System

Maker: OmicronType: OAS - 5

The vessel’s cargo tank high level alarm system is fitted to comply with theIMO, DNV and USCG etc societies’ requirements. To comply with theserequirements the high level alarm and overfill alarms are completely separate.

The level switches are of the float type and can be tested independently fromthe top of the tank.

All the inputs from the level switches are connected directly to the input sidesof intrinsically safe alarm units. These alarm units are bus wired to onecommon output unit which interfaces with the SVC system. Separate outputsfor alarms and indication are available at the alarm/control panel mounted inthe Cargo Control Room.

In addition to tank alarms, the system also indicates and raises separate alarmsif a loop fails for the level switches and their associated wiring or if a processoror a power failure occurs.

The level switch has two floats with built-in permanent magnets in each float.As the float moves upwards, a reed switch inside the housing is deactivatedand an alarm is raised. When the float moves downward, the reed switch isclosed again. This is the non-alarm position so the alarm loop fails safe (ie,alarms) in the event of any open circuits/wire-breaks.

Two resistors are connected to the reed switch inside the sensor. One is inseries and one is in parallel with the switch contacts. This enables the detectionof broken or shorted alarm circuits.

Testing

Each level switch is equipped with a mechanical testing device. The testingdevice is located under a protective screw cap on top of the level switch’sjunction box. By lifting the testing device slowly, the HIGH LEVEL alarm(95%) for that particular tank will be raised. Lifting the device further up willcause the OVERFILL alarm (99.2%) to be raised.

When testing is complete, the test device should be pressed back down and theprotective screw cap replaced.

(Note: The high level and overfill alarm are to be tested prior to each loading.)

Alarm Panel

The alarm panel has ACCEPT ALARM, RESET ALARM, ALARM HOLD,LAMP TEST and unit ON/OFF pushbuttons. There are LED indicators for alltank alarms and also loop and power/system failure.

Operation

When a cargo tank float moves upwards, the relevant red LED on theintrinsically safe alarm module and the alarm panel will start to flash and theACCEPT ALARM pushbutton will illuminate.

The alarm lamp and horn on deck as well as the buzzer on the alarm panel willstart. The corresponding alarm will also be raised via the DCS system.

Pressing the ACCEPT ALARM pushbutton will cause the common alarms(horn and lamp) to stop. The LEDs on the intrinsically safe alarm unit and thealarm panel will continue to flash. The operator should then press the RESETALARM pushbutton and the flashing LED(s) will illuminate steadily.

The common alarm unit is configured to raise different alarms for either the95% HIGH LEVEL or 99.2% OVERFILL alarm. This unit pulses the exteriorhorn and illuminates the yellow lamp for high level or sounds continuously andilluminates the red lamp for the overfill alarm. The horn and lamps are situatedon a floodlight mast adjacent to No. 3 cargo tank dome.

The 99.2% OVERFILL alarm is also configured to automatically close thefilling valve for that tank.

The overfill alarm has a remote reset OVERFILL pushbutton on the port outeroperating station in the CCR.

Alarm Hold Facility

In addition to the above normal alarm functions, there is also an ALARMHOLD function. This function handles all tanks separately and independentlyand is selected by pressing the ALARM HOLD button on the alarm panel. Thefunction remains in operation as long as the button is activated. The alarm holdfunction operates as follows:

If, prior to loading, the ALARM HOLD pushbutton is alreadyactivated, it must be released and reactivated. This clears anyprevious alarms.

If the ALARM HOLD button is on, the first alarm from each tankactivates the alarm horn and light on deck, the buzzer on thecontrol panel and the DCS alarm. The appropriate LEDs on thecontrol panel and the intrinsically safe alarm module will alsoflash.

If one of the level switches, that is already in an alarm condition, should be deactivated and then reactivated because of movementon the cargo liquid surface, the alarm will not be repeated due tothe ALARM HOLD function.

(Note : Any loop/wiring or system faults must be rectified as soon as possibleas a sensor with a loop failure will not alarm.)


Issue: 1

Illustration 4.2a Cargo Piping System

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

ToEmergencyDischarge

Astern

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

FromSafetyValves

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

To LPG

Plant

To LPG

Plant

FromLPGPlant

V2201

V2015A

Liquid

Vapour

Nitrogen

Liquid

Liquid

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2016A

V2200A

V2015

V2120

V2120

From

Recirculating Fans

For Void Space Heating

To Void Spaces

PI

V2016V2200

To No. 4Vent Mast

OverflowDrain Tank

LAH



4.2 Cargo Piping System

Description

The cargo piping system is shown in illustration 4.2a in a simplifiedperspective showing only the principal features of the system.

Liquid cargo is loaded and discharged via the two crossover lines midshipsbetween cargo tanks 3 and 4 and is delivered to and from each cargo tank liquiddome via the liquid header which runs forward and aft. Each crossover line atmidships separates into two loading/discharging connections, port andstarboard, making a total of four loading/discharge connections.

The cargo tank vapour domes can be connected by the vapour header runningforward and aft along the trunk deck. The vapour main also has a cross-connection at the midship manifold for use in regulating tank pressures whenloading and discharging.

When loading, the vapour header and crossover, together with the HDcompressors, are used to return the displaced gas from the tanks back to theshore installation. When discharging, the vapour header is used in conjunctionwith either the vapour crossover, or a vaporiser, to supply gas to the tanks toreplace the outgoing liquid cargo.

The spray line can be connected to the liquid crossover lines and can be usedto drain or to cool down each cargo tank, and also to spray during dischargingif the return vapour is insufficient.

The vapour header and stripping/spray headers are both connected to thevapour dome of each tank. The vapour domes also house the tank safetyvalves, pressure pick-up and sample points. The spray line on each tankconsists of four spray lines inside the tank to distribute the incoming liquid intothe spray nozzles in order to assist in evaporation and thus achieve a bettercooldown rate.

The spray and vapour headers have branches to and from the LNG compressorroom with connections to the compressors, heaters and vaporiser for variousauxiliary functions. Removable bends are supplied for fitting where necessaryto allow cross-connection between the various pipework for infrequent usessuch as preparing for dry dock and recommissioning after dry dock.

The vapour header connects the vapour domes to each other for the venting ofboil-off gas, which discharges to atmosphere through vent mast riser No.4. Thevapour main also directs the boil-off gas to the engine room for gas burning,via the LD compressor and gas heaters.

The inert gas and dry-air system, located in the engine room, is used to supplyinert gas or dry air to the cargo tanks via piping which connects with the maincargo system through a double, non-return valve to avoid gas returning to theengine room.

All of the cargo piping is welded to reduce the possibility of joint leakage.Flanged connections are electrically bonded by means of straps providedbetween flanges to ensure that differences in potential, due to static electricitybetween cargo and other deck piping, tanks, valves and other equipment, areavoided.

Both liquid and vapour systems have been designed in such a way thatexpansion and contraction are absorbed in the piping configuration. This isdone by means of expansion loops and bellows on liquid and vapour pipingrespectively.

Fixed and sliding pipe supports and guides are provided to ensure that pipestresses are kept within acceptable limits.

All sections of liquid piping that can be isolated, and thus possibly trappingliquid between closed valves, are provided with safety valves set at 5 bar,which relieve excess pressure to the collecting tank and on to No.4 vent mast.This tank is situated on the deck above the cargo control room and has a levelalarm fitted to alert the operator to the situation. This is a safety measure,although normal working practice is to allow any remaining liquid to warm upand boil-off before closing any such valves.

All major valves such as the midships manifold (port and starboard) valves,individual tank loading and discharge valves, are remotely power operatedfrom the DCS system, so that all normal cargo operations can be carried outfrom the Cargo Control Room. The pipeline layout at the manifolds is shownin illustration 4.2b.

When an emergency shutdown is activated, the manifold valves are closed,discontinuing loading or unloading operations.

A non-return valve is fitted at the discharge flange of each cargo pump. A holeis drilled in the valve disc to allow the tank discharge lines to drain down andbe gas freed. Non-return valves are also fitted at the discharge flange of thecompressors. A small diameter spray nozzle is also fitted at the top of eachcargo pump discharge line to cool down the pipework.

(Note: Electrical bonding by means of straps is provided between boltedflanges. Whenever a section of pipe or piece of equipment is unbolted, thebonding straps MUST be replaced when the flanged joint is remade.)

The LPG system is de-commissioned and all lines are blanked and the electricmotors disconnected.

When operational the system will take suction from the vapour header anddischarge liquid to the spray header.

There is also a pipeline from the the liquid line which can be used as a hotvapour suction.



Collecting Tank: Situated Above Cargo Control Room

Issue: 1

Illustration 4.2b Manifold Arrangement

Side Viewof Manifold A

V2015A

V2061

V2410 V2410 V2410V2410

V2015 V2016

V2061

V2061

V2034

V2061V2061

V2120 V2120

V2046A

V2015A

V2015V2016

V2016A

Gauge ValveGauge Valve

Relief andGauge Valve

Drain Valve Drain Valve

Side Viewof Manifold B

Side Viewof Manifold C

Side Viewof Manifold D

Side Viewof Manifold E

Side Viewof Manifold F

Side Viewof Manifold G

Liquid

LiquidCross-over

ToCollecting

Tank

Vapour Line Liquid Liquid Vapour Line Liquid

Port Side Starboard Side

A B E F G

ToCollectingTank

ToCollectingTank

LiquidCross-over

ToVaporisers

SprayCross-over

SprayCross-over

Gauge Valve

Drain Valve

Relief andGauge Valve

C D

ToCollecting

Tank

ToCollecting

Tank

Gauge Valve

Drain Valve

Gauge Valve

Drain Valve

Gauge Valve

Drain Valve

Gauge Valve

Drain Valve

V2211



Issue: 1


4.2.1 Liquid Line

The system comprises a 550/500/450/350mm butt welded, cryogenic stainlesssteel pipeline connecting each of the five cargo tanks to the loading/dischargemanifolds at the ship’s side by means of a common line.

At each tank liquid dome there is a manifold which connects to the loading anddischarge lines from the tank to allow for the loading and discharge of cargo.

This manifold on the liquid dome connects to the tank discharge lines from theport and starboard cargo pumps, the loading line and the spray line.

At certain points along the liquid line, blank flanges and sample points arefitted to facilitate inerting and aeration of the system during dry dock/refit.

All sections of the liquid line outside the cargo tanks are insulated and coveredwith a moulded cover to act as a tough water and vapour tight barrier.

4.2.2 Vapour Line

The system comprises a 300/550/450/400/300mm cryogenic stainless steelpipeline connecting each of the five cargo tanks by means of a common line tothe ship side vapour manifold, the LNG compressor room and No.4 vent mast.

The line to the LNG compressor room allows for the vapour to be used in thefollowing manner:

Sent ashore during cargo loading by means of the HDcompressors, in order to control pressure in the cargo tanks.

During ballast/loaded voyages, the boil-off gas is sent to theengine room via the LD compressor and heater for use as fuel inthe boilers.

During repair periods the gas is vaporised and used to purge-drythe cargo tanks if required.

At certain points along the vapour line, blank flanges and sample points arefitted to facilitate inerting and aeration of the system during dry dock/refit.

All sections of the vapour line outside the cargo tanks are insulated andcovered with a moulded cover to act as a tough water and vapour tight barrier.

Section 4.2.1/2 - Page 1 of 1

Issue: 1

Illustration 4.2.3a Spray Pipes In the Cargo Tanks

Spray Nozzle Characteristics/Capacity

Fwd

V2028

Spray Pipes

Column InCargo Tank

Spray PipesNozzles

1

100

200

300

400

500

600

700

2 3 4

100

150

200

P

Q

Q = Capacity Of Each Nozzle (kg/h)

Key

P = Pressure Drop Through The Nozzle (kp/cm2) = Mass Median Diameter Of Droplets (10-3mm)

Q

m

m

m

Section 4.2.3/4/5/6 - Page 1 of 2


4.2.3 Spray Line

The spray system piping consists of a main header, running along the ship fromtank No.1 to tank No.5. This header is connected to the liquid crossovers forLNG cargo supply from the shore and to the two spray pumps. One pump isfitted in tank No.3 and the other in tank No.4, for the supply of LNG when theship is at sea.

The spray pipe header is connected to each tank dome by four spray pipessupplying the spray nozzles with liquid. The LNG can be sprayed through upto 20 nozzles in each tank to obtain a uniform distribution within the tank. Theoperator decides how many pipes and nozzles to use by opening or closing thenozzle inlet valves V2051, V2054, V2057, V2063 or V2065 to suit the speedof cooling down required.

The nozzles connected to pipe No.1, 2 and 4, each have a spray rate capacityof 500kg of LNG at 1.53kg/cm2 pressure drop across the nozzle. The nozzlesconnected to pipe 3 each have a capacity of 1,000kg of LNG. The nozzlecharacteristics/capacity diagram is shown in illustration 4.2.3a.

The system comprises a 80/50mm butt welded, cryogenic stainless steelpipeline connecting the spray pump in tanks three and four to thestripping/spray header and serves the following functions by supplying LNGto:

The spray rails in each tank, used for tank cooldown and gasgeneration.

The main liquid line, used for cooling down lines prior to cargooperations.

Priming of discharge lines in the cargo tanks to prevent line surgewhen starting main cargo pumps.

Supply of LNG or LN2 to the vaporisers for gas generation to thecompressors and heaters.

All sections of the spray line outside the cargo tanks are insulated and coveredwith a moulded cover to act as a tough water and vapour tight barrier.

(Note: The pressure drop shown in illustration 4.2.3a, the spray nozzlecharacteristic/capacity graph, will differ from the pressure drop indicated onthe spray pressure indicator PI-22, as the latter includes pressure drop in thepipe from the control valve to the nozzles and also the static pressure from theliquid in the pipe.)

4.2.4 Fuel Gas Line

During transportation of LNG at sea, gas vapour is produced due to the transferof heat from the outside sea and air, through the tank insulation; also energy isabsorbed from the cargo motion due to the vessel’s movement.

Under normal power conditions, the boil-off gas is used as a means of fuel inthe ship’s boilers.

The gas vapour is taken from the vapour header and passed on into the LDcompressor. It then passes through the boil-off /warm up heater before goingto the ship’s boilers where it is burnt as fuel.

The pipe runs along the port side of the main deck. The main gas isolatingvalve V2140 is located immediately forward of the accommodation. Thenitrogen purging connection is also located at this point. The pipe then entersthe machinery spaces and from that point the pipe runs inside a ventilated ductpipe. This duct pipe has two exhaust fans situated on the open deck to draw thesurrounding air to the atmosphere. This vent duct is fitted with gas detection.

Gas Valve V2140 and Gas Duct Pipe Exhaust Fans

4.2.5 Vent Masts

During normal operations, the pressure in the tanks is controlled by the use ofthe boil-off gas in the boilers as fuel, or controlled via the vent mast (No.4tank) and the common vapour line.

Each cargo tank is also fitted with two independent safety valves, comprisingtwo 350mm lines exiting the tank top into their own pilot operated reliefvalves.

Sections of the vent line outside the cargo tanks are insulated and covered witha moulded cover to act as a tough water and vapour tight barrier.

4.2.6 Inerting/Aeration Line

The system comprises of a 300mm flanged line which supplies inert gas or dryair to the cargo tanks and pipelines for inerting and drying during refit periods.

The inert gas/dry-air is supplied from the inert gas plant situated in the engineroom. The dry-air is supplied by the inert gas generator running in the dry-airmode (see section 4.7.1, Inert Gas Generator).

The line is connected to the gas header and the liquid header by means of aspool piece. By selective use of the spool pieces and flexible hoses it ispossible to inert or aerate all or a single cargo tank.

There is also a spoon blank fitted at the void space air recirculation line to theIG main cross-connection, located at the starboard manifold. The removal ofthis blank enables the supply of inert gas or dry-air to the void spaces, ifrequired.

Issue: 2 Section 4.2.3/4/5/6 - Page 2 of 2


Issue: 1

UpperBearing

Rotor andShaft

Pump Discharge

ElectricalTerminal Box

Stator

LowerBearing

Impeller

Inducer

Key

Liquid Flow

Lubrication Flow

Illustration 4.3.1a Main Cargo Pump

StatorWindings

0 100 200 300 400 500 600 700 800 900 1000 1100 1200

CAPACITY (m3/h)

HORSEPOWERKILOWATTS

EFFC

IEN

CY

PER

CEN

T

0

100

200

300

140

130

120

110

100

90

80

70

20

30

40

50

60

70

80

3

2

1

0

Head Capacity

Minimum Pump Down

Pump Efficiency

Horsepower to Pump Motor Rating

(275 BHP)SP. GR. = 0.50

KW Input to Motor

SP. GR. = 0.50

SP. GR. = 0.60

Min NPSHMETRESHEAD

MET

RES

OF

LIQ

UID

AB

OVE

INLE

T B

ELL



4.3 Cargo Pumps

4.3.1 Main Cargo Pumps

Maker: JC Carter Type: 60190-3450-32 Capacity: Rated at 750m3/h x 120 mLcNo. of sets: 10 (2 per cargo tank)Operating temperature: -163°CHead capacity: 155mPower: 275hp Speed: 1,780 rpm

The cargo tanks are fitted with two main cargo discharge pumps. These pumpsare single stage centrifugal pumps with one inducer stage. The single stagehelps to obtain a very low NPSH (Net Positive Suction Head).

The pumps are of the submerged motor type, with the motor windings cooledby the pumped LNG. The LNG also lubricates and cools the pump and motorbearings. As the LNG serves as the lubricant and the coolant it is criticallyimportant for the pump that the following operational procedure is strictlyadhered to.

There is an automatic starting sequence available via the DCS system. Thisautomatic start will check all the interlocks and open the throttle valveaccordingly before starting the pump.

Before Starting a Cargo Pump

a) Check the level of the liquid in the tank. The pumps must not bestarted when the tank is dry. The cargo pump must be completelysubmerged in LNG.

b) Before starting the pump, open the throttle valve to about 25%.Starting the pump with the valve fully open when pumping liquidwhich has a high specific gravity will overload the motor.

c) Start the cargo pump. The operator should keep a close watch onthe discharge pressure and the motor current. The currentconsumption should steady after the motor has been running for 3seconds. During starting, while the discharge pipe is being filled,the current may be above the ammeter red line. The current shouldnot exceed the maximum rated current by more than 50% for morethan 2 or 3 seconds when the tank is full. If the running currentafter this time is more than 150% of the maximum rated current,stop the pump immediately and determine the cause of the highcurrent, (possible suction blockage).

d) When the pump discharge pipe is filled to the discharge valve, asubstantial increase in the discharge pressure and a correspondingdecrease in current should be observed.

e) Once the pump is operating normally, adjust the discharge valveto obtain the required flow or pressure. The operator shouldmonitor the pump motor running current, taking care not to exceedthe maximum current level.

(Note: When the pump is operating correctly, closing the pump discharge valveduring operation will raise the head pressure and consequently reduce therunning current.)

The cargo pumps may be restarted concurrently a maximum of 3 times, afterthe third time a 30 minute waiting period must be applied, after this timeanother 3 starts may be made. This procedure must be adhered to as heat build-up from the high starting current may not be carried away during strippingoperations. This may be due to the lack of liquid flow when (and if) the pumpdoes not prime, due to the extremely low level of LNG during strippingoperations. The pumps are started and stopped from the CCR via the DCSsystem. In an emergency all pumps will be stopped by activation of theEmergency Shut Down System trip.

Discharge of Cargo

Operating a pump at, or close to, its design flow level is in the best interests ofthe pump lifespan and operating performance. However, operating the pump atflow rates which are less than this cannot be avoided. This is especially the casewhen the shore receiving facility cannot accept the rated flow. However, itshould be remembered that it is better to operate one pump at the design flowrather than two pumps running at 50% flow. The pump’s rated flow should onlybe exceeded during the starting period while the discharge valve is adjusted.

Stripping or Low Liquid Level Operation

As the end of a discharge approaches, the pump suction head will approach theNPSH for a given flow. From the above illustration (4.3.1a) the blue curvedisplaying NPSH required as a function of flow rate can be seen. Atapproximately 0.80 to 1 metre liquid level above the pump inlet bell, the NPSHfor the rated capacity will be reached. When the amount of liquid falls to thislevel, the motor ammeter and the pump discharge pressure should be monitoredcontinuously by the operator.

The low level alarm is triggered when the liquid level is about 1 metre aboveNPSH, the flow should be reduced by use of the throttling valve on the pumpdischarge side. If any fluctuations are observed on the motor ammeter or on thepump discharge pressure gauge during final pumping, the discharge flow rateshould be further reduced until the readings stabilise. When the flow isthrottled, it can be seen from the above graph that restricting the flow down toabout 230m3/h the required NPSH will be about 10cms. This level representsthe minimum level attainable by pumping.

CAUTION It is of the utmost importance that the pumps are never allowed to run dry,even for short periods, as this will result in motor failure. A momentaryloss of priming during cargo stripping should not be considered as runninga pump dry. Up to 30 seconds of operation with dry suction but with fluidin the discharge pipe will not damage the pump or the motor.

When the liquid level reaches less than one metre above the pump inlet, avoidstopping the pump if at all possible until the cargo has been fully discharged. Ifthe shore facility is unable to accept the liquid for intermittent periods, it ispreferable to keep the pump going and recirculate the liquid back into the tanksuntil the cargo discharge can be resumed and completed.

Issue: 1 Section 4.3.1 - Page 2 of 4


Issue: 1

Illustration 4.3.1b Pump Arrangement In Cargo Tank

Discharging Pipes

Temp Sensors, Alcohol/N2 Tubes& Fixed Tubes

Fixed ClampFor Level Indicator Pipe

Temperature Sensor Hot Vapour Pipe

Cables ForCargo & Spray Pumps

Cargo Pump Cargo Pump

Loading Pipe



Issue: 1


Points to Remember

The operator should check the cargo liquid level before starting a pump andmaintain at least 2kg/cm2 discharge pressure. This is to ensure the lubricationof the bearings on all pumps in cargo service.

The operator should always open the throttle valve to 25% open, before staringa pump.

The operator should always monitor the motor ammeter and the dischargepressure gauge.

The operator should always try to run the pump at the design flow ratewhenever possible.

The operator should never run pumps dry.

The operator should never blow hot air through a discharge line. This may turnthe impeller and rotor at high speed in the wrong direction, damaging thebearings.

The operator should never operate the pump above the motor ammeter red line.

The operator should never assume that all electrical interlocks and safetyrelays will continuously function correctly. The operator should be ready at alltimes for any eventuality.

The operator should not allow sea water, water, steam or any cleaning agentcontaining water to come into contact with a pump or its cables andconnections.

(Note: An insulation test of all pumps is to be carried out after leaving theloading port in order to establish that all pumps are operational and to allowtime for the implementation of emergency procedures, should it be necessary.)

Pump Trips and Shutdowns

As well as the shutdown via the ESD system, the following will trip the pumps:

Low current: <126A for 5 seconds

High current: 100% current (motor starter setting)

Single phasing: 1 phase lost (motor starter setting)

Low low cargo pressure: 0.0 bar

High void/tank differential pressure: 0.04 bar

ESD low loop pressure: >3.0 bar


Issue: 1

Key

Liquid Flow

Lubrication Flow

Illustration 4.3.2a Spray Pump

UpperBearing

Rotor andShaft

ElectricalTerminal Box

Stator

StatorWindings

LowerBearing

Impeller

Inducer

PRESSURE(kg/cm2)

40

0

2

4

6

8

10

12

14

16

20

30

20

10

0

0 4 8 12 16 20

CURRENT(Amperes)

CAPACITY (m3/h)

VOLTAGE 440

SP. GR. = 0.601

SP. GR. = 0.57

SP. GR. = 0.50

SP. GR. = 0.601

SP. GR. = 0.57

SP. GR. = 0.50

OCR = 30 AMPS

PRESSURE v's FLOW



4.3.2 Stripping/Spray Pumps

Specification

Maker: JC Carter Type: 6337-2113-3 Capacity: Rated at 40m3/h x 60mLcNo. of sets: 2 Operating temperature: -163°C

One spray pump is installed in each of the tanks No.3 and 4.

The pumps are in principle similar to the main cargo pumps and a similaroperating procedure should be used. Each spray pump has a capacity of 8m3/hat a discharge head of 146mLc.

The performance curve is shown in illustration 4.3.2a.

The spray pumps are intended for the cooldown of cargo tanks before loadingafter a ballast voyage.

The pumps are started and stopped from the CCR via the DCS system. In anemergency all pumps will be stopped by activation of the Emergency ShutDown System trip.

The instances when these pumps can be used are:

To cool down the liquid header prior to discharging.

To cool the cargo tank during ballast voyage prior to arrival at theloading terminal by discharging LNG to the spray nozzles in thetanks.

To pump LNG from the tanks to the vaporisers (emergency case)when forced vaporisation of LNG to the boilers is required.

To enable the tanks to be stripped as dry as possible for reasonssuch as a cargo tank entry.

Whenever possible, the stripping/spray pumps should be started early enoughto avoid any possible starting problems due to very low tank levels (about 0.5mminimum).

Pump Trips and Shutdowns

The stripping/spray pumps will be stopped automatically should any of thefollowing occur:

Vapour header pressure below or equal to atmospheric pressureplus 0.3kPa (ESDS: Stage 1)

Extreme high level in cargo tank (99.2% volume)

Activation of ship/shore pneumatic, fibre optic or electricalshutdown (ESDS: Stage 1)

Motor single-phasing

Low motor current

High motor current (electrical overload)

Low discharge pressure with time delay at starting

Activation of ESDS stage 2

Cargo tank level low low

The end of a DCS cargo automatic sequence

Spray Pump Safety System

In addition to the above shutdowns, the spray pump safety system will stop thepumps and close the discharge valves if any of the following conditions occur:

Low current: <10A for 5 seconds

Low low cargo tank pressure: 0.0 bar

High void/tank differential pressure: 0.04 bar

ESD low loop pressure: 3.0 bar

(Note: An insulation test of all pumps is to be carried out after leaving theloading port in order to establish that all pumps are operational and to allowtime for the implementation of emergency procedures, should it be necessary.)



Issue: 1

LCCR

Lubricating Oil Tank

PI

68

PI

68

PI

71

PI

79

TI

85

SI

74

PI

70

PI

90

PI

88

PI

84

Cooling

Water

Seal Gas

From Nitrogen

System

Draw Off Line

To / FromSteam System

Compressor

Suction

Pressure

SVC Compressor

Suction Gas

Temp. Indic.

Compressor Low

Suction Pressure

Cut-out

Compressor Discharge

Gas Temp.

SVC

Discharge

Gas Press.

Indic.

SVC

Discharge

Gas Temp.

Indic.

Byp

ass

Su

cti

on

Dis

ch

arg

e

Compressor

Stop

Other Compressors

Tanks/Ashore

PDCLA

2

PDIAL

3

PCLA

121

TI

TI PIPI

PI

67

69

PDT

PT

TE

PDT

PT

PACL

TITTE

75

79

78

76

71

72

8573

66 67

TI

TI

TI

PS88 87

TS

TI

Pneumatic Indicators

Local

Compressor Panel

Steam L.O.Pump Shaft Driven

L.O Pump

SafetyShutdown

ValveControlPress.Valve

Governor

Steam Shut-off Valve

For Steam Driven Pump

L.O. Pressure

Valve L.O. Temp.

/PressureL.O. Cooler

InletVane

Control

System Shut Offand Regulating Valve

Low LOShut

-downSwitch

Key

LNG Vapour

Steam

Lubricating Oil

Instrumentation

Turbine Compressor

Steam Connectionfor Oil Heating

Cooling WaterConnections

ExhaustSteam

Drainage

Oil Drainage

ImpulseConnection

SpeedActuator

Discharge

SpeedGovernor

External View of High Duty Compressor

Electrical Signal

Nitrogen

Compressor

Stop

SVCSpeed

Surge ValveActivated

CompressorFailure

CompressorSpeed

Diff. Press.

Tank/Atmos

Diff. Press.

Tank/Void

ESD

System

Compressor Shutdown

Relays LCCR

Cargo Tanks

TS

85

PC

LSS

77

HC

SIC

LSS HC

ZA

XA

PS

84

SS

86

Illustration 4.4.1a High Duty Compressor





4.4 Gas Compressors

The Norman Lady is equipped with three steam turbine driven gascompressors (and heat exchangers) which are used for:

The compression and heating of boil-off gas used as fuel for theboilers

The recirculation and heating of cargo vapour for heating thecargo tanks

The compression of vapour to be returned to the shore stationwhen loading

The generation of cargo vapour

There is one low duty compressor, used for the gas supply to the boilers andtwo high duty compressors, used for vapour return to the shore and for cargotank heating. The compressors utilise a single stage centrifugal compressorwhich is directly driven by a single stage axial impulse steam turbine.

4.4.1 High Duty Compressors

Maker: Airco CryogenicsType: Steam drivenCapacity: 10,000m3/hNo. of sets: 2Suction temperature: -120ºCDischarge temperature: -75ºCSpecific weight: 1.3kg/m3

Suction pressure: 1.05 barPressure increase: 11,000mm WG (suction to discharge)Discharge pressure: 2.15 barSpeed: 14,700 rpmSteam turbine output: 480kW

The following conditions trip the HD compressors:

The ESDS system

High differential pressure: void/tanks 1 - 5

Low low pressure: tanks 1 - 5

Compressor high outlet temperature

Electrical power failure

Compressor suction pressure low

ESD close loop low pressure

Low or high temperature after heaters (aft or forward)

Overspeed (mechanical or electronic via DCS)

Compressor lubrication is provided by a gear driven oil pump which is housedin the steam turbine bearing housing. The turbine and radial compressor havea common lubricating oil supply system. This oil is drawn from the oilreservoir tank by a pump and then fed to the bearing points via a filter and oil-cooler unit. Excess oil is conveyed into the lubricating oil line by an overflowvalve which keeps pressure in the pipes at a constant level. Oil pressure willnot exceed 1.8 to 2.5 bar at an oil supply temperature of 20º to 50ºC.

Prelubrication and lubrication at the starting period is achieved by a smallturbine driven oil pump consisting of a vertical steam turbine and geared oilpump directly coupled to the steam turbine. This geared oil pump provides theoil supply for the turbine and compressor until the mechanically driven maingear oil pump is feeding oil. The pressure of the lubricating oil is monitoredand there is also an oil pressure shutdown trip which will stop the machine andstart the turbine driven oil pump if the oil pressure drops below 1.2 bar.

The LD and two of the HD compressor turbines are supplied with saturatedsteam from the secondary LP steam system.

Nitrogen is used as the seal gas for the compressors. Special shaft seals areinstalled on the impeller side of the compressors. Labyrinth tips are cut into thecompressor shaft. Opposite the tips is a stuffing box, the tips cut into theartificial carbon stuffing. The stuffing box can be accurately adjusted to givean extremely tight clearance resulting in very low losses. Two annular groovesare cut into the carbon sleeve and leakage gas is sucked off from the impellerside annular groove and returned through a pipe connected to the suction side.The sealing nitrogen is supplied into the second annular groove to provide aseal against leakage gas from the impeller side. On the turbine, a combinedradial and axial labyrinth seal shuts off the shaft passage (at the turbine casing)to the outside. Vapour and leakage steam is led away by correspondingconnections.

Each compressor has a local control panel with gauges fitted to show thevarious pressures and temperatures relating to the machine operation. Morelimited monitoring is available from the DCS system compressor mimics.

Control of the compressor is achieved by regulating the turbine steam flow rateto maintain the cargo tank pressure at a preset value. The suction pressure ofthe compressor is detected by a pressure transmitter and this signal, togetherwith a speed signal, is sent to the compressor controller. The required suctionpressure is set and the system then regulates the governor and guide vanes toaccurately control the compressor speed and output.

An anti-surge control system operates independently of the compressorsuction pressure control. This system monitors the pressure differential acrossan orifice plate and the compressor pressure differential. According to themeasured value, the controller modulates a surge control valve returning gasfrom the discharge side to the suction side of the compressor. This maintainsthe compressor in the safe operating region.

Local Compressor Start Up Procedure

The compressors are started locally and once the compressor is running, speedcontrol and monitoring is carried out from the CCR/ECR via the DCS system.

a) At the control panel, check the supply air pressure for thegoverning and control air circuits. The air supplies should be 1.4bar for the governor and 3.2 bar for the control. Ensure the LNGcooling water system is in operation (see section 5.3.1).

b) Check the level of lubricating oil in the reservoir tank. The levelshould be in the middle of the sight glass. Check the oiltemperature. If it is below 10ºC, the oil heaters should be switchedon. The oil temperature should have risen above 10ºC beforestarting.

c) Close the steam control and emergency stop valve by turning thehandwheel to the right, all the way to the end stop.

d) Open the shut-off valve in the exhaust steam line and drain offany water which may have accumulated.

e) Open the shut-off valve which is ahead of the steam control andemergency stop valve in the main steam line and drain off anywater which may have accumulated.

f) The automatic trip actuator should now be engaged by pulling onthe trip handle.

g) Read the cargo tank pressure and adjust the compressor suctionpressure set point locally at the control panel.

h) Adjust the suction pressure transmitter (for suction pressurecontrol) to the minimum value. This means the nominal value forthe turbine speed controller is set to a minimum level.

i) Open the sealing gas supply valves. Ensure the sealing gas purgevalves are closed.

j) Open the main and exhaust steam shut-off valves and theauxiliary oil pump will start. Drain off any water which may haveaccumulated. Turn the handwheel of the steam control valveslowly to the left until the end stop is reached.

k) The operator should keep the oil pump in operation until thebearing temperatures have reached a minimum of 20ºC. Theimpeller side compressor bearing temperature may fall below20ºC at standstill and therefore require particular attention.Monitor the oil pressure, it should be a minimum of 0.8 bar.

Issue: 1

Illustration 4.4.1b High Duty Compressor Performance Curves

01,0

1,1

1,2

1,3

1,4

1,5

1,6

1,7

1,8

1,9

2,0

2,1

2,2

P2 CH4 -120OCP1

6963

6389

6214

5628

5130

4623

4083

3461

2883

2211

15281,13

1,19

1,25

1,31

1,375

1,44

1,48

1,55

1,627

1,691

804

1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 13000 14000 20000

INLET VOLUME FLOW m3/h

P2 CH4 -40OCP1

Had(m)

Surge Line

1,05n

0,9n

0,8n

0,7n

0,6n

0,5n

1,0n = 14 7000u/min



l) Regulate the sealing gas valve to achieve a seal gas pressure of 0.2bar. Close the vent valve.

m) Check the inlet vane position and the corresponding signalpressure.

n) Open the bypass at the control panel, set the signal pressure to3psi.

o) Set the minimum speed at the control panel, set the signal pressureto 3psi. Press the RESET button.

p) Open the stop valves on the suction and discharge side of thecompressor.

q) After prelubrication has been achieved and the oil pressure hasreached 1.8 - 2.5 bar, the compressor may be started.

r) Press the START pushbutton, the control air pressure closes acontrol valve and full control oil pressure builds up for the turbinecontrol system, opening the steam valve. The compressor startsrunning. Open the steam control and emergency stop valve byturning the handwheel to the left, all the way to the end stop. Themachine now runs at its lowest speed.

s) Slowly close the bypass by manually regulating the signalpressure to equal that of the anti-surge controller output pressure.Set the signal pressure to 15 psi.

CAUTION It is essential that enough gas is consumed on the discharge side for thebypass valve to completely close.

t) Increase the pressure to the turbine speed controller with thesignal pressure actuator. When the signal pressure shown on theindicator reaches the same level, the turbine speed controller isactuated for constant suction pressure. The signal pressureactuator is further opened to 15psig.

u) Switch off the oil heater, if originally on, by shutting off the steamto the heater. Open the cooling water valves to supply the oilcooler. The oil temperature at the cooler outlet should be 40 -50ºC.

v) Close the drain valves when no further water is seen to be drainingoff.

During operation, the oil and bearing temperatures should be monitored andshould be as follows:

Oil at cooler outlet: 45 - 50ºC

Compressor bearing: 55 - 70ºC

Turbine bearing: 50 - 95ºC

The oil pressures should be monitored and should be as follows:

Lubricating oil: 1 - 2 bar (minimum 0.8 bar)

Governor oil: 9 - 11 bar

The oil filter flag should be monitored and the filter changed when the redindicator appears.

Local Compressor Stopping Procedure

a) Turn the handwheel of the steam control and emergency stopvalve to the right, all the way to the end position.

b) On the compressor, close the valves in the suction and dischargelines.

c) Close the seal gas line and open the vent valve.

d) Stop the oil pump after a suitable delay of about 10 minutes byturning the handwheel to the end position. Check the bearingtemperatures before stopping the oil pump to ensure therecommended temperatures are not exceeded.

e) On the turbine, close the valves in the main steam and exhauststeam lines and open the drain valves.

f) Turn off the cooling water supply.

Allow the steam valves to be open for approximately 30 minutes beforeshutting down.

Compressor Lubrication System

Compressor lubrication is provided by a gear oil pump installed in the steamturbine bearing housing. The steam turbine and radial compressor have acommon lubricating oil supply system. Oil is drawn from the reservoir tank bya pump and fed to the bearing points via a filter and cooler. Excess oil isconveyed into the lubricating oil line by an overflow valve, which keeps thepressure in the piping at a constant level. The pressure of the lubricating oil ismonitored by an oil pressure switch which stops the machine and starts theturbine driven oil pump (auxiliary LO pump) when the oil pressure dropsbelow l.2 bar. There is a dual oil filter to clean the oil and an oil cooler.

Inlet Guide Vanes

There is a set of adjustable inlet guide vanes installed between the suctionbranch and the suction pipe. The vanes’ positions alter the volumetric flow rateof the compressor. They are housed in a split casing and project radially intothe flow space. The vanes are mounted in teflon coated bushings which requireno lubrication and little maintenance.

The guide vanes are adjusted by a gear rim with longitudinal slots with ballpivots. The pivots engage with a lever to vary the position of the vanes. Thevanes may be moved by a handwheel or by the automatic positioner. The ‘0’position on the controller corresponds to the capacity of the machine withoutany effective control. The capacity is reduced by setting the vanes in variouspositions from -20º, -40º, -60º and -80º. The capacity can be slightly increasedby positioning the vanes at +20º.

Compressor Maintenance

The oil filter must be cleaned once a month. The filter is reversed by turningthe filter cock and when the filter head is deaerated, the filter can be removed.After every 10,000 operating hours, the compressor should be stripped and theimpeller and bearings inspected.

Compressor Shutdowns

Surge valve activated: I/O

Overspeed: 17,000 rpm

Lubricating oil pressure low: 3.6 bar

Lubricating oil temperature high: 50ºC

Low seal gas pressure: 0.1 bar

In addition, the DCS system will shutdown the compressor if any of thefollowing values are exceeded:

High outlet temperature: 100ºC

Suction pressure low: 0.0 bar

Low low cargo tank pressure tanks 1 - 5: 0.0 bar

High differential pressure void space/tank: 0.04 bar

ESD loop pressure low: 3.0 bar

Low gas temperature after LNG heater: -20ºC

High gas temperature after LNG heater: 70ºC (alarm at 60ºC)



Issue: 1

LCCR

Lubricating Oil Tank

PI

68

PI

68

PI

71

PI

79

TI

85

SI

74

PI

70

PI

90

PI

88

PI

84

Cooling

Water

Seal Gas

From Nitrogen

System

Draw Off Line

To / FromSteam System

Compressor

Suction

Pressure

SVC Compressor

Suction Gas

Temp. Indic.

Compressor Low

Suction Pressure

Cut-out

Compressor Discharge

Gas Temp.

SVC

Discharge

Gas Press.

Indic.

SVC

Discharge

Gas Temp.

Indic.

By

pa

ss

Su

cti

on

Dis

ch

arg

e

Compressor

Stop

From Engine Room

Boilers

Valve Closed: LD

Comp. Shutdown

Other Compressors

TIALHC

TIALHC

PCLA

99

PDCLA

2

PDIAL

3

PCLA

121

99

92

HeaterLNG

LNGHeater

TI

TI PIPI

PI

67

69

PDT

PT

TE

PDT

PT

PACL

TITTE

75

79

78

76

71

72

8573

66 67

TI

TI

TI

PS88 87

TS

TI

Pneumatic Indicators

Local

Compressor Panel

Steam L.O.Pump Shaft Driven

L.O Pump

SafetyShut Down

ValveControlPress.Valve

Governor

Steam Shut-off Valve

For Steam Driven Pump

L.O. Pressure

Valve L.O. Temp.

/PressureL.O. Cooler

InletVane

Control

System Shut Offand Regulating Valve

Low LOShut

-downSwitch

Key

LNG Vapour

Steam

Lubricating Oil

Instrumentation

Turbine Compressor

Electrical Signal

Nitrogen

Compressor

Stop

SVCSpeed

Surge ValveActivated

CompressorFailure

CompressorSpeed

Diff. Press.

Tank/Atmos

Diff. Press.

Tank/Void

ESD

System

Compressor Shutdown

Relays LCCR

Main Gas

Shut-Off

Valve

Cargo Tanks

TS

85

PC

LSS

77

HC

SIC

LSS HC

ZA

XA

PS

84

SS

86

Illustration 4.4.2a Low Duty Compressor



LD Compressor Running

4.4.2 Low Duty Compressor

Maker: Airco CryogenicsType: Steam drivenCapacity: 3,000m3/hNo. of sets: 1Suction temperature: -120ºCDischarge temperature: -75ºCSpecific weight: 1.3kg/m3

Suction pressure: 1.05 barDischarge pressure: 1.95 barSpeed: 18,200 rpm

This compressor is essentially for the compression and heating of the boil-offgas when used as fuel for the ship’s boilers. The compressor is started locallyand can be monitored via the DCS system. The LD compressor is similar to theHD compressors, being basically a lower capacity model.

The following conditions trip the LD compressors:

The ESDS system

High differential pressure: void/tanks 1 - 5

Low low pressure: tanks 1 - 5

Compressor high outlet temperature

Electrical power failure

Compressor suction pressure low

ESD closed loop low pressure

Low or high temperature after heaters (aft or forward)

Gas firing shutdown on port and starboard boilers

Fire alarm

Local Start-Up Procedure

The compressor is started locally. Operation after starting is carried out fromthe cargo or engine control rooms, depending on which location has control.The start-up procedure described is for the operations where the low dutycompressor is required discharges vapour to the boilers, due to the pressure inthe cargo tanks reaching 18mbar.

a) Request the ECR to prepare for boil off gas burning/

b) At the DCS mimic screen 5.21 Cargo Compressors, move thecursor over the Details area near the LD compressor and press theACT pushbutton on the DCS panel, to reveal which control roomhas control.

c) Move the cursor to the CCR icon and press the ACT pushbuttonon the DCS panel to take control of the compressor.

d) On the compressor panel on the CCR console, turn thecompressor speed controller back to 20%.

e) Crack open the steam to the vapour heater and set the steamcontrol valve to 33ºC gas outlet temperature.

(Note: It is important that the vapour heater is properly heated before gas isallowed to pass through.)

f) Check the level of lubricating oil in the reservoir tank and for anywater present. The level should be in the middle of the sight glass.Ensure that the oil temperature is above 10ºC before starting.

g) Open the steam chest drains on the turbine and drain off any waterwhich may have accumulated.

Meanwhile the engine will be preparing for burning boil-off gas on free flow.

h) Open the turbine exhaust steam valve and the compressordischarge valve.

i) Open the shut-off valve which is ahead of the steam control andemergency stop valve in the main steam line and drain off anywater which may have accumulated.

j) Open the exhaust and steam inlet valves to the auxiliary oil pump,which will cause it to start. Once prelubrication has been achievedand the oil pressure has reached 4.0 bar, the compressor may bestarted.

k) Open the SW cooling inlet and outlet valves to the LO cooler.

l) Adjust the control air pressure to the surge control valve to 4.5bar, then crack open the steam valve to the turbine and allow theturbine to warm through.

m) After 10 minutes close the turbine drains.

n) Open the surge control valve to the fully OPEN position.

o) Fully open the steam inlet valve to the turbine and observe theturbine speed increase and the green running light come on.

p) The automatic trip actuator should now be engaged by pulling onthe trip handle.

q) Once the LD compressor is running under steady conditionsconfirm that the engine room is ready to receive cargo vapour andtransfer control to the ECR on the DCS screen.

r) Switch off the oil heaters if originally switched on. Open thecooling water valves to supply the oil cooler. The oil temperatureat the cooler outlet should be 40 - 50ºC.

During operation, the oil and bearing temperatures should be monitored, thevalues should be as follows:

Oil at cooler outlet: 60ºC

Compressor bearing: 60ºC

Turbine bearing: 60ºC

The turbine will trip at 65ºC.

The oil pressures should be monitored and should be as follows:

Lubricating oil: 4.0 bar

The turbine will trip at 65ºC.

The oil filter flag should be monitored and the filter changed when thedifferential pressure is 1.5 bar.

Local Compressor Stopping Procedure

The operator must ensure that when the unit is stopped, the auxiliary LO pumpmust start as soon as the oil pressure drops below 1.2 bar and keep runninguntil the compressor has come to a complete standstill.

a) Inform the engine room that the LD compressor is to be stopped.The ECR will make arrangements for the boiler supply fuel to bechanged over.

When confirmation has been received from the engine room that the boilers arenow running on fuel oil transfer control to the CCR on the DCS mimic screen5.21 Cargo Compressors.

b) Turn the handwheel of the steam control and emergency stopvalve to the right, all the way to the end position.

c) On the compressor, close the valves in the suction and dischargelines.

d) On the turbine, close the valves in the main steam and exhauststeam lines.

e) Close the seal gas line and open the vent valve.



Issue: 1

Illustration 4.4.2b Low Duty Compressor Performance Curves

0 1000 2000 3000 40001,0

1,1

1,2

1,3

1,4

1,5

1,6

1,7

1,8

1,9

2,0

2,1

2,2

P2 CH4 -120OCP1

5940

5400

4375

3455

2645

1945

13501,114

1,116

1,23

1,313

1,403

1,582

1,52

INLET VOLUME FLOW m3/h

P2 CH4 -40OCP1

Had(m)

Surge Line

1,05n

0,9n

0,8n

0,7n

0,6n

0,5n

1,0n = 18 200Rpm



f) Open the drain valves.

g) Turn off the cooling water supply.

h) Stop the oil pump after a suitable delay of about 10 minutes byturning the handwheel to the end position. Check the bearingtemperatures before stopping the oil pump to ensure therecommended temperatures are not exceeded.

i) Close the main steam and exhaust steam valves, open the drainvalve.

Compressor Lubrication System

Compressor lubrication is provided by a gear oil pump installed in the steamturbine bearing housing. The steam turbine and radial compressor have acommon lubricating oil supply system. Oil is drawn from the reservoir tank bya pump and fed to the bearing points via a filter and cooler. Excess oil isconveyed into the lubricating oil line by an overflow valve, this keeps thepressure in the piping at a constant level.

The pressure of the lubricating oil is monitored by an oil pressure switch whichstops the machine and starts the auxiliary oil pump when the oil pressure dropsbelow l.2 bar. There is a dual oil filter to clean the oil and an oil cooler.

Compressor Shutdowns

Surge valve activated: I/O

Overspeed: 15,000 rpm

Lubricating oil pressure low: 3.6 bar

Lubricating oil temperature high: 65ºC

Low seal gas pressure: 0.2 bar

In addition, the DCS system will shutdown the compressor if any of thefollowing values are exceeded:

High outlet temperature: 100ºC

Suction pressure low: 0.0 bar

Low low cargo tank pressure tanks 1 - 5: 0.0 bar

High differential pressure void space/tank: 0.04 bar

ESD loop pressure low: 3.0 bar

Low gas temperature after LNG heater: -20ºC

High gas temperature after LNG heater: 70ºC (alarm at 60ºC)



Issue: 1

To Vent Mast/Boilers/Tanks

Remote TemperatureIndication DCS

PI98

Control Air8.8 bar

Illustration 4.5a Cargo Heater

Steam Inlet

Air ToOpen

Air ToOpen

TIALHC99

TIT96

TI99

MethaneInlet

CondensateOutlet

InstrumentationPanel

V3025

TIT96HA96

Hand/Auto

Station

TemperatureTransmitter

Air PressureReducing

Valve: 20 psi

PCV 96Air Set withFilter: 30 psi

TemperatureController

/ComputingRelay

TC96

Gas Inlet Control ValveV2131

Gas Outlet ValveV2132

Steam Control ValveV911A

LC 97

VP 96

V1033A

LevelController

ManometerPositioner

Compressed Air

Steam

Key

C1S

C2

Condensate

Instrumentation/Control Air



Forward Cargo Heater

4.5 Cargo Heaters

Gas HeaterMaker: Moss Verft Type: Shell and tubeCapacity: 329,000 kcal/h Heating: Steam at 12 barNo. of sets: 2Vapour inlet temperature: -100°CVapour outlet temperature: +45°CSteam operating pressure: 9 barMethane operating pressure: 0.9 bar

General Description

There are two steam heated boil-off/warm up heaters located in the LNGcompressor room.

The heaters are used for the following functions:

Heating the LNG vapour which is delivered by the HDcompressors at the specified temperature for warming up thecargo tanks before gas freeing.

Heating boil-off gas supplied to the main boilers via the LDcompressor.

CAUTION When returning heated vapour to the cargo tanks, the temperature at theheater outlet should not exceed +85°C, to avoid possible damage to thecargo piping insulation and safety valves.

The vapour heaters are heat exchangers of the horizontal shell and tube type.The heating surface consists of ‘U’ shaped tubes whose configuration is suchthat cargo vapour flows through the tubes and steam condenses outside thetubes. The tube bundle and end cover are bolted to the shell to permitinspection or the plugging of damaged tubes, should this be required.

CAUTION The vapour heaters should be thoroughly preheated by steam before theadmission of methane vapour. This prevents ice formation.

When shutting down the heaters, the methane vapour supply to the heatersshould be shut off before the steam supply, preventing any ice formation at theend of the operation.

The heaters are pneumatically controlled. Methane supply to the vapour heateris controlled by the cargo vapour temperature leaving the heater. Thistemperature set point is adjustable.

When cargo is being used as fuel, the set point should be set to +45ºC.

CAUTION When using cargo as fuel for the boilers, the vapour heater to be usedmust be properly heated before the compressor is started. If necessary, theoperator should use the bypass valve in the steam inlet pipe.

Heater Control

The control system uses compressed air from the receivers at 8.8 bar. The airis then reduced via reducing valves. Gas control valve regulates an internalbypass valve in the heat exchanger. The measured temperature set point iscompared to the hand/auto required value signal and a deviation signal isapplied to to keep the gas outlet temperature at the required value.

There is a pneumatic level switch mounted in the condensate receiver. If thecondensate level rises too high, steam valve is closed, shutting off steam to theheater. This action halts any increases in water level which could lead to theformation of ice.

If the gas outlet temperature reaches a high of +60ºC or a low of +5ºC, analarm is raised via the DCS system.

If the gas outlet temperature reaches a high of +70ºC or a low of -20ºC, thesteam supply to the heater is shut off.

Operating Procedures To Warm Up the Cargo Heater

a) Open the shell side vent valve.

b) Open the shell side condensate valves and check the drains.

c) Crack open the manual steam supply valve. Ensure that the steamto deck is available, ie the isolating valve is open.

d) When all the air has been expelled from the shell, shut the ventvalve.

e) When water has been drained from the shell, shut the drain valve.

After venting and warming up the heater, pressures and temperatures shouldstabilise in approximately 30 minutes. Operation of the heater can now beinitiated.

To Start Up the Heater

a) Slowly open up the steam inlet valve.

b) Set the LNG vapour lines as detailed for the operation and theheater to be put in use.

c) Set the controls for the heater to the ON position.

d) Open the control air supply to the controls for the heater.

e) Check the condensate level in the sight glass.

f) Set the temperature and level controller to the correct settings forthe operation being undertaken (first stage: 0°C, second stage:+80°C).

g) Open the hydraulically operated gas inlet and manually operatedgas outlet valves.

h) Change over from MANUAL to AUTO at the hand/auto station.

i) Set the required temperature at the hand/auto station.

j) Monitor the gas vapour outlet and condensate temperatures.

To Shut Down the Heater

a) Switch the automatic control from AUTO to MANUAL. Set themanual signal to 50% at the hand/auto station.

b) Close the gas supply and outlet valves on the heater.

c) Close the steam supply valve to the heater when the temperatureat the heater outlet is above 0°C.

d) Open the steam side vent, then open the drain when all the steamhas vented.

Issue: 1 4.5 Boil-Off/Warm Up Heater Page 2 of 2


Issue: 1

Illustration 4.6a LNG Main Vaporiser

PI

SteamInlet

MethaneInlet To Vaporiser No.2

Gas SupplyControl Valve

with Air Cylinder

FromCompressed AirSystem (8.8 bar)

PIPI 103Steam

Manometer

PI 104Gas

Manometer

V3025

V2040A

Air toOpen

Air toOpen

Air to Open

V937A

V1035ALC 102Level

Controller

Steam

Compressed Air

Control Air/Instrumentation

Key

TI

Working AirReceiver

LNG Compressor Room

Condensate

LNG Liquid

LNG Vapour

V2037

V2037A

Void Spaces/Atmospheric

Heater

FromVaporiser

B

CargoSystem

V2122

V2135

To Deaerating TankIn Engine Room

D

R

TC100

TT101 HA100

Control Air8.8 bar

InstrumentationPanel

V3025

TT100

Hand/Auto

Station

TemperatureTransmitter


Valve: 30 psi


Valve: 50 psiComputing

Relay

PCV100Air Set withFilter: 20 psi

Direct/ReverseRelays

ShuttleValve

Manual ResetHand Valve


Valve: 3 bar



Vaporiser

Vaporiser Instrumentation Panel

4.6 LNG Vaporisers

Maker: Moss VerftCapacity: 597,000 kcal/hHeating: Steam at 12 barNo. of sets: 1Steam inlet temperature: 179°CMaximum gas flow: 25,000kg/hInlet LNG temperature: -163°COutlet gas temperature: -140°C to +20°CSteam operating pressure: 9 barLNG operating pressure: 0.5 bar

The vaporiser’s main role is to vaporise liquid nitrogen and natural gas fromthe shore station before purging the cargo tanks, piping and void spaces.

Each vaporiser is a shell and tube type heat exchanger. The heating surfaceconsists of straight tubes arranged so that cargo vapour flows through the tubesand steam condenses outside the tubes. The shell has a bellows arrangement tocompensate for thermal contraction of the tubes in relation to the shell. The endcovers are welded to the tube sheets, but are flanged so that the tubes can beinspected or plugged on board the ship if required.

The vaporiser is pneumatically controlled. The LNG supply to the vaporiser iscontrolled by the cargo vapour temperature leaving the heater.

The set point is adjustable. When used for nitrogen purging, the set pointshould be some degrees above the dew point of the tank atmosphere, thesuggested temperature is +20ºC.

CAUTIONThe vaporisers should be thoroughly preheated with steam before theintroduction of liquid. This protects the vaporiser. The bypass valve in thesteam inlet pipe should be used, if required.

Personnel should always be present when the vaporiser is put into operation,in order to locally monitor the temperature in the steam exhaust line and thecargo vapour outlet. There are no monitoring facilities on the DCS mimic pagefor the vaporisers, the page is purely a vaporiser system piping diagram.

Vaporiser Control

The control system uses compressed air from the working air receiver at 8.8bar. The air pressure is then reduced via reducing valves. Steam is supplied viathe pneumatic control valve. The measured temperature value from sensorTT100 is compared to the hand/auto station required value set point and adeviation signal is applied to the gas nozzle control valve, regulating the liquidvolume to the spray coils.

The vaporiser liquid gas supply valve is controlled by an output of TT101temperature controller via TC101 pneumatic valves. If the gas outlettemperature reaches +60ºC or drops below +30ºC the supply valve closes.

There is a pneumatic level switch, LC102, mounted in the condensate receiver.If the condensate level rises too high the steam valve is closed, shutting offsteam to the vaporiser. This action halts any increases in condensate waterlevel which could lead to the formation of ice.

Operating Procedures

Set the LNG pipelines as detailed for the operation about to be undertaken.

To prepare the LNG vaporiser for use:

a) Open the shell side vent valve.

b) Crack open the shell side drain valve. Check that the condensatedrain valves are open.

c) Crack open the manual steam supply valve.

d) When all air is expelled from the shell, shut the vent valve.

After approximately 30 minutes, when pressures and temperatures havestabilised on the vaporiser:

e) Slowly open the steam inlet manual valve to the fully openposition.

f) Open the instrument air supply to the vaporiser controls.

g) Set the controls for the LNG vaporiser.

h) Fill up the vaporiser with liquid using manual control. Check allflanges and joints for any signs of leakage.

i) When vapour is produced, switch the control for the liquid valveto REMOTE and AUTOMATIC.

CAUTION Thorough checks around the LNG vaporiser and associated flangeconnections must be conducted during the operation.

On completion of the operation.

a) Shut the liquid valve.

b) Shut the steam supply valve when no LNG remains.

c) Open the steam side vent and then open the drain when all steamhas been vented.

d) Keep the vapour side valve open to the system until the vaporiserreaches ambient temperature.

Vaporiser Alarms and Trips

Low condensate temperature alarm set point: +120°C

Low low condensate temperature trip set point: +80°C

Gas outlet high temperature (supply valve shuts): +30ºC

Gas outlet low temperature (supply valve shuts): -60ºC

High condensate level alarm contact switch

High high condensate level trip

Local hand trip alarm

Common alarm trip alarm



Issue: 1

Illustration 4.7.1a Inert Gas System

To LPG Plant,Cargo CompressorLO Coolers andWater Spray System

To Bilge SystemFrom Bilge System

SteamSupply

TestPoint

Poop Front Stbd

TI TI

PI

PI

PI

PI

FI

PI

FI

PI

PI

Gaseous Nitrogen

Air

Gas Oil

Sea Water

Steam

Fresh Water

Instrument Air

Key

Inert Gas

Air Cooler Combustion Air

Inert GasCooler

Drain

Drain

Drain

O2Analyser

Instrument AirSupply

FuelPump

To IGGeneratorNo.2 FuelSystem

Fresh WaterCirculating Pump

From/ToFresh Water

CoolingSystem

FromBilge Eductor

System

Air Inlet

AirCompressor(Roots Type)

WaterSeal

From No.2IG Generator

To No.2IG Generator

InertGas

Generator

Scrubber

WaterSeparator

ToFunnel

Inert Gas PipeAt MidshipCrossover

Wet AirTo Funnel

N2

S

SSS

Gas OilSupply

RefrigerantInlet

R22 RefrigerationCompressor

RefrigerantOutlet

V633

V336A

V336

V340 V340

V344

V344

V2350A

V2355A

V2352 V2352A

V2354A

V2354B

V2354B

V2354

V2353

V2352

V2355

V2350

FromNo.2 IG

Generator

V452

V451

TITHA

THCOPLA

PLCO

LHALHCO

THATHCO

O21

O2HAO2LA

FCOAPHA

PHCO

PLAPLCO

Note: One of Two Inert Gas Plants

PI63

DPI62

TI64

Steam HeatedDryer

ElectricallyHeated Dryer

RegeneratedAir From

Engine RoomSpace

Inert Gas Plant Cooling Water Pump(340m3/h at 5kg/cm2)

LPG Plant Cooling Water Pump(170m3/h at 5kg/cm2)

V330

V407A

V331

V341

V329

PI

PISeaChest

To Aft Peak Tank Condenser/Receiver

To CentralFW Cooler

V335

V407



4.7 Void Space Systems

4.7.1 Inert Gas Generators

Maker: Moss VerftType: LPU 2500 - 0.2No. of sets: 2Inert gas delivery rate: 2,500Nm3/hDry air delivery rate: 2,500Nm3/hDelivery pressure: 0.2kg/cm2

Inert Gas CompositionOxygen (O2): 0.5% (by vol)Carbon dioxide (CO2): 15% (by vol)Hydrogen (H2): 0.1% (by vol)Nitrogen (N2): Remainder

Sea water consumption: 170m3/hFresh water consumption: 15m3/hFuel oil consumption: 210kg/h

Inert Gas Sea Water Cooling Pump

Maker: Thune EurekaNo. of sets: 1Type: CGD 200 centrifugal verticalCapacity: 340m3/h at 5kg/cm2

Speed: 1,750 rpm

LPG Sea Water Cooling PumpMaker: Thune EurekaNo. of sets: 1Type: CGB 100Capacity: 170m3/h at 5kg/cm2

General

Inert gas is used for the inerting and gas freeing of cargo tanks, cargo pipes andvoid spaces when required. The inert gas blowers may be used separately forthe supply of dried air to the cargo tanks and void spaces. The inert gas isproduced by removing oxygen from the air by a combustion process. Thisprocess takes place in a combustion chamber where gas oil is used as the fuel.

The inert gas contains approximately 85% nitrogen (N2), 15% carbon dioxide(CO2) and about 0.5% of oxygen (O2) and is at a temperature approximately5ºC above the sea water temperature.

After combustion, the inert gas has a high water content due to the waterformation from the combustion process. Most of this water has to be removed.The inert gas enters a sea water cooling tower and water separator where itsdew point is lowered to about 5ºC above sea water temperature.

The inert gas is then dehumidified to a dew point of about +5ºC in the inert gascooler where an R-22 refrigerant is used as the cooling medium. The gas isfurther dried in one of two desiccant dehumidifiers, using steam or electricallyheated air in the regeneration process, before passing into the discharge line.

Each inert gas generator is manually started from the control panel mountedlocally but their operation can be monitored from the DCC system.

Each inert gas generator contains an O2 analyser for the indication of oxygencontent in the inert gas. The analyser is fitted with maximum and minimumsetting alarms.

The connection to the cargo piping system is made through two non-returnvalves and is normally blanked off. The connection to the cargo system is madethrough a spool piece which is not normally connected.

Working Principle

Inert gas is produced by the combustion of gas oil supplied by the fuel oilpump with air, provided by the blower, in the combustion chamber of the inertgas generator. Good combustion is essential for the production of a goodquality, soot free, low oxygen inert gas.

The products of the combustion are mainly carbon dioxide, water and smallquantities of oxygen, carbon monoxide, sulphur oxides and hydrogen. Thenitrogen content is generally unchanged during the combustion process and theinert gas produced consists mainly of 85% nitrogen and 15% carbon dioxide.

Initially, the hot combustion gases produced are cooled indirectly in thecombustion chamber by a sea water jacket. Thereafter, cooling of the gasesmainly occurs at the scrubber section in the cooling tower where the sulphur oxides are washed out. The sea water for the inert gas generator is supplied byone of two inert gas sea water cooling pumps.

A pressure control valve located at the dryer outlet maintains a constantpressure throughout the system, thus ensuring a stable flame at the combustionchamber.

Dry-Air Production

The generator can produce dry-air at the same rate. For the production of dry-air there is no combustion, no oxygen content measurement and the oxygensignal is overridden when the mode selector is set to dry-air (compressor only)production.

As long as the dew point is correct after the processes of cooling and drying,the dry-air is supplied to the cargo system.

Generator Description

The generator consists of the following main items:

Fuel system

Cooling tower

Combustion chamber

Turning chamber

Combustion air system

Gas system

Cooling water system

Control, monitoring and instrumentation systems

Fuel System

The fuel oil system comprises the oil pump, duplex filter and flow meter. Theoil gun and nozzle are of the bypass type whilst the oil burner is of the pressureatomising type. A capacity regulating valve and a solenoid shut off valve aremounted in the bypass line. There are are two solenoid shut off valves in theoil supply line.

The burner has an ignition pilot burner. During the start-up period, the solenoidvalves open supplying fuel oil and air to the pilot burner. A glow plug at thepilot burner ignites the fuel/air mixture and this flame then ignites the mainburner. With the bypass closed, the burner oil pressure is regulated by theregulating valve on the fuel oil pump. This is the normal running condition forthe burner.

The fuel oil nozzle is fitted with tangential shaped outlet slots which impart arotating motion to the fuel. The combustion air is fed from a roots type aircompressor with silencer, air filter and valves for high and low air quantity.The air is also supplied tangentially through ducts to the burner but in the otherdirection to the atomised fuel oil. This ensures a thorough mix of fuel and airto ensure good combustion.

Combustion Chamber

The combustion chamber is divided into a cylindrical upper part and a coneshaped lower part. These two parts have an outer water jacket for cooling anda stainless steel internal lining. These two parts are also of specific sizes so thata recirculating ram-air effect takes place, forcing any colder air, not completelyburnt, back into the combustion area.



Issue: 1




SteamSupply

TestPoint

Poop Front Stbd

TI TI

PI

PI

PI

PI

FI

PI

FI

PI

PI

Gaseous Nitrogen

Air

Gas Oil

Sea Water

Steam

Fresh Water

Instrument Air

Key

Inert Gas


Inert GasCooler

Drain

Drain

Drain

O2Analyser


FuelPump



From/ToFresh Water

CoolingSystem

FromBilge Eductor

System

Air Inlet


WaterSeal


To No.2IG Generator

InertGas

Generator

Scrubber

WaterSeparator

ToFunnel


Wet AirTo Funnel

N2

S

SSS

Gas OilSupply

RefrigerantInlet


RefrigerantOutlet

V633

V336A

V336

V340 V340

V344

V344

V2350A

V2355A

V2352 V2352A

V2354A

V2354B

V2354B

V2354

V2353

V2352

V2355

V2350

FromNo.2 IG

Generator

V452

V451

TITHA

THCOPLA

PLCO

LHALHCO

THATHCO

O21

O2HAO2LA

FCOAPHA

PHCO

PLAPLCO


PI63

DPI62

TI64

Steam HeatedDryer


RegeneratedAir From

Engine RoomSpace



V330

V407A

V331

V341

V329

PI

PISeaChest


To CentralFW Cooler

V335

V407



Issue: 1



The water for the combustion chamber jacket and the cooling tower passesthrough a fresh water cooler.

Turning Chamber

The turning chamber acts as a base for the burner and cooling tower, and alsoconnects these two parts.

Cooling Tower

The cooling tower (scrubber) is where the gas is cleaned and cooled down. Thegas flows against the water sprayed from the nozzles at the top of the tower.The inlet and outlets of the cooling tower are fitted with thermometers andthermostats for temperature monitoring and alarms.

The drain and its water seal allow dirty water from the cooling tower to bedrained without inert gas escaping.

Gas System

The gas system consists of the water separator, safety valve, constant pressurevalve, two electro-pneumatically operated shut-off valves, an oxygen analyser,a refrigerated gas cooler and two desiccant dehumidifiers.

The water separator is of the centrifugal type, where the water droplets areseparated and collected in the bottom of the separator. The water is fed outthrough the cooling tower water seal. There is a pressure gauge and a safetylifting valve on the gas outlet manifold. The constant pressure valve is fitted toavoid pressure fluctuations in the combustion chamber. From here the gas isled by means of the shut-off valves to the atmosphere outlet or to the cargosystem, depending on the operator’s selection.

The shut-off valve in the pipe to the cargo system is fitted with an interlockingsystem. This interlock prevents the generator starting if the valve position isincorrect ie, gas to consumer.

Cooling Water System

The cooling water system comprises both fresh water and sea water systems.The fresh water used in the burner chamber cooling jacket is recirculatedthrough the fresh water cooler by the fresh water pump. Sea water is used tocool the turning chamber walls and for cooling and cleaning the inert gas in thecooling tower. The water flow regulation is carried out via hand operatedvalves.

Monitoring

A flow meter is installed in the fuel oil system for the measurement of oilconsumption.

An oxygen analyser is installed and monitors the gas after the water separator.

Local thermometers are installed to enable the following items to be measured:

Sea water inlet temperature

Cooling tower sea water inlet temperature

Burner chamber cooling jacket water temperature

Fresh water cooler outlet temperature

Inert gas after cooling tower temperature

Remote pressure gauges are installed at the control panel to enable thefollowing items to be measured:

Burner inlet air pressure

Gas pressure before constant pressure valve

Gas pressure after constant pressure valve

Oil pressure after oil pump

Sea water pressure before the cooling tower

Fresh water pressure in the burner chamber cooling jacket.

Plant Shutdowns

The following circumstances will cause an alarm and subsequent shutdown ofthe inert gas generator:

Burner chamber cooling jacket high water temperature

High gas temperature after cooling tower

Sea water pressure low

Fresh water pressure low

Air pressure high

Burner failure

Alarms

The system has alarm outputs to the SVC system but the alarm must also beaccepted locally by pressing the STOP HORN pushbutton to silence theaudible alarm and the STOP FLASH pushbutton to cancel the flashing lamp onthe alarm panel at the centre of the control panel. As well as the alarmsmentioned previously in plant shutdowns, there are the following alarms:

Lamp Indicates

FLAME FAILURE: Burner flame is out or weak

HIGH AIR PRESSURE High air pressure after compressor

HIGH SEA WATER LEVEL High turning chamber water level

HIGH TEMP/LOW PRESSURE High water temperature or low waterFRESH WATER pressure in the burner chamber

cooling jacket

HIGH INERT GAS TEMP/ High gas temperature after cooling LOW SEA WATER PRESSURE tower or low sea water pressure

before the water nozzle in thecooling tower

HIGH/LOW OXYGEN CONTENT High or low inert gas O2 content

A further alarm panel is mounted at the right of the main control panel. Thealarms must also be accepted locally by pressing the HORN STOP pushbuttonto silence and accept the alarm. This panel houses the following alarms:

Lamp Indicates

FUEL OIL PRESSURE LOW: Fuel oil pressure is too low

POWER FAILURE: Electrical supply has failed

CONTROL AIR PRESSURE LOW: The control air pressure is too low

Pilot and Main Burner Control

The pilot burner is ignited from a glow plug which operates from a low voltagetransformer. The main flame is monitored by a photo-cell connected to anelectronic flame relay. This relay will shut down the main burner, via the mainprogramming unit, if the flame is too weak or has gone out. In the case of aflame failure, the RESET FLAME FAIL RELAY switch on the control panelmust be activated to reset the flame relay and enable a new burner startsequence.

The main programming unit controls the start and shutdown sequences of theburner and monitors all alarm and shutdown functions. The unit raises alarmsor stops the plant if any levels exceed the set parameters. Incorrect O2 contentof the combustion gas will cause an alarm to be raised and the gas will vent toatmosphere, when operating in the consumer mode. The TEST PROGRAMpushbutton starts a self-test sequence of the programming unit.

Control Panel Description

The control panel contains the following equipment:

Switch Function

MANUAL/NORMAL Selection of manual or automatic OPERATION burner start

WATER CIRCULATION Water pumps start/stop

AIR COMPRESSOR Air blower start/stop

Issue: 1




SteamSupply

TestPoint

Poop Front Stbd

TI TI

PI

PI

PI

PI

FI

PI

FI

PI

PI

Gaseous Nitrogen

Air

Gas Oil

Sea Water

Steam

Fresh Water

Instrument Air

Key

Inert Gas


Inert GasCooler

Drain

Drain

Drain

O2Analyser


FuelPump



From/ToFresh Water

CoolingSystem

FromBilge Eductor

System

Air Inlet


WaterSeal


To No.2IG Generator

InertGas

Generator

Scrubber

WaterSeparator

ToFunnel


Wet AirTo Funnel

N2

S

SSS

Gas OilSupply

RefrigerantInlet


RefrigerantOutlet

V633

V336A

V336

V340 V340

V344

V344

V2350A

V2355A

V2352 V2352A

V2354A

V2354B

V2354B

V2354

V2353

V2352

V2355

V2350

FromNo.2 IG

Generator

V452

V451

TITHA

THCOPLA

PLCO

LHALHCO

THATHCO

O21

O2HAO2LA

FCOAPHA

PHCO

PLAPLCO


PI63

DPI62

TI64

Steam HeatedDryer


RegeneratedAir From

Engine RoomSpace



V330

V407A

V331

V341

V329

PI

PISeaChest


To CentralFW Cooler

V335

V407



Issue: 1


OIL PUMP Oil pump start/stop

BURNER Automatic burner sequence start/stop

ATMOSPHERE/CONSUMER Inert gas to atmosphere or cargo

TEST PROGRAM Self-test of program unit

RESET FLAME FAILURE RELAY Reset after flame failure

AIR PURGING The tanks can be purged with this switch in position I and the air compressor and water pumps runningwith the cargo (consumer) valve open

IGNITION Ignition on/off (glow plug on/off)

AIR/OIL TO PILOT BURNER Opens valves to supply air and fuel oil to the pilot burner.

HIGH OIL/LOW OIL Full (100%) fuel oil capacity (normalrunning)/50% fuel oil capacity(for start-up)

HIGH AIR/LOW AIR Full (100%) air capacity (normal running)/50% air capacity (start-up)

OIL TO BURNER Opens valve to supply fuel oil to the main oil nozzle.

MAIN SWITCH Main electrical isolator

NORMAL/COMPRESSOR ONLY: Selects dry-air or inert gas modes

Running Lamps Indication Function

MAIN SWITCH ON Main electrical isolator/power on

IGNITION Glow plug on

AIR/OIL TO PILOT BURNER Pilot burner air/fuel oil valves open

LOW OIL Low fuel oil pressure

LOW AIR Low air pressure

OIL TO BURNER Burner fuel oil valve open

FLAME ESTABLISHED Flame is alight

Switches (local running lamps) Function

WATER CIRCULATION Start/stop water circulation pumps

AIR COMPRESSOR Start/stop air compressor

OIL PUMP Start/stop oil pump

Operation: Normal Starting of the Plant

a) Check that all the switches on the control panel are switched off.Ensure that the control air supply is on and that the IG coolingwater system is in operation (see section 5.3.1 for information).

b) Turn the MAIN SWITCH to position I, and the MAIN SWITCHON lamp illuminates.

c) Turn the MANUAL/NORMAL OPERATION switch to theNORM position.

d) Turn the TO ATMOSPHERE/TO CONSUMER switch to the TOATMOSPH. position. Valve V2350A will open to vent the gas toatmosphere.

e) At the alarm panel, the LOW SEA WATER PRESSURE, HIGHTEMPS/LOW PRESSURE FRESH WATER and HIGH/LOWOXYGEN CONTENT alarms will be on and can be accepted.

f) Start the water pumps by turning the WATER CIRCULATIONswitch ON. The sea water supply, fresh water and drain pumpswill start. The fresh and sea water pressure alarms are cancelled.

g) Start the air blower by turning the AIR COMPRESSOR switch tothe I position.

h) Check the air pressure. Normal pressure should be approximately0.5-0.7kg/cm2.

i) Check the water pressure to the cooling tower by observation ofthe SEA WATER PRES. pressure gauge; the pressure should beapproximately 1-1.5kg/cm2. The inlet flow can be adjusted ifnecessary by means of the inlet valve V336.

j) Check the gas pressure, the normal pressure should beapproximately 0.2kg/cm2.

k) Ensure that the water level in the cooling tower is normal.

l) Check the fresh water pressure by observation of the FRESHWATER PRES. pressure gauge; the pressure should beapproximately 1.5-2kg/cm2.

m) Start the oil pump by turning the OIL PUMP switch to the Iposition.

n) Check the oil pressure by observation of the OIL PRES. pressuregauge; the pressure should be approximately 20-25kg/cm2.

o) At the engine room first platform, starboard side, start thedehumidifier dryers and the refrigeration compressor and put theinert gas cooler in line.

p) Turn the BURNER switch to position I, this will start the programsequence. After an air purging period of approximately 45seconds, the burner will start. The burner will initially fire at thelow air/oil level and after 10-20 seconds (adjustable) the changeto high air/oil level will take place. The flame can be monitoredthrough a sight glass.

q) Check the oil consumption via the flow meter, the normalconsumption is approximately 210kg/h.

r) Check that the O2 analyser is functioning and that the O2 contentof the gas is within limits for use in the cargo system. The O2content can be adjusted using the valve adjacent to the pressuregauges.

s) Turn the TO ATMOSPHERE/TO CONSUMER switch to the TOCONSUMER position. As long as the O2 content of the gas iswithin limits, valve V2350A will open and valve V2355A willclose.

t) Check the gas temperature and adjust if required.

Operation: Normal Stopping of the Plant

a) Turn the TO ATMOSPHERE/TO CONSUMER switch to the TOATMOSPHERE position. The valves will change over.

b) Turn the BURNER switch to position 0. The oil solenoid valve tothe burner will close and the program unit will reset, ready for anew start if required.

c) Turn the OIL PUMP switch to position 0 and the oil pump willstop. The operator should now wait approximately 1 minute forthe plant to cool down.

d) Turn the AIR COMPRESSOR switch to position 0 and the aircompressor will stop.

e) Turn the WATER CIRCULATION switch to position 0 and thewater pumps will stop.

f) Stop the inert gas cooler refrigeration compressor and isolate thecooler.

g) Stop and isolate the dehumidifier dryers.


Issue: 1




SteamSupply

TestPoint

Poop Front Stbd

TI TI

PI

PI

PI

PI

FI

PI

FI

PI

PI

Gaseous Nitrogen

Air

Gas Oil

Sea Water

Steam

Fresh Water

Instrument Air

Key

Inert Gas


Inert GasCooler

Drain

Drain

Drain

O2Analyser


FuelPump



From/ToFresh Water

CoolingSystem

FromBilge Eductor

System

Air Inlet


WaterSeal


To No.2IG Generator

InertGas

Generator

Scrubber

WaterSeparator

ToFunnel


Wet AirTo Funnel

N2

S

SSS

Gas OilSupply

RefrigerantInlet


RefrigerantOutlet

V633

V336A

V336

V340 V340

V344

V344

V2350A

V2355A

V2352 V2352A

V2354A

V2354B

V2354B

V2354

V2353

V2352

V2355

V2350

FromNo.2 IG

Generator

V452

V451

TITHA

THCOPLA

PLCO

LHALHCO

THATHCO

O21

O2HAO2LA

FCOAPHA

PHCO

PLAPLCO


PI63

DPI62

TI64

Steam HeatedDryer


RegeneratedAir From

Engine RoomSpace



V330

V407A

V331

V341

V329

PI

PISeaChest


To CentralFW Cooler

V335

V407



Issue: 1


h) Turn the MAIN SWITCH (power) OFF.

Manual (Not Programmed) Start of the Plant

a) Check that all the switches on the control panel are switched off.Ensure that the control air supply is on and that the IG coolingwater system is in operation (see section 5.3.1 for information).

b) Turn the MAIN SWITCH to position I, the MAIN SWITCH ONlamp illuminates.

c) Turn the MANUAL/NORMAL OPERATION switch to theMANUAL position.

d) Turn the TO ATMOSPHERE/TO CONSUMER switch to the TOATMOSPHERE position.

e) Check the alarm panel. The alarms LOW SEA WATERPRESSURE, HIGH TEMPS/LOW PRESSURE FRESH WATERand HIGH/LOW OXYGEN CONTENT will be on and can beaccepted.

f) Start the water pumps by turning the WATER CIRCULATIONswitch ON. The sea water supply, fresh water and drain pumpswill start. The fresh and sea water pressure alarms are cancelled.

g) Start the air blower by turning the AIR COMPRESSOR switch tothe I position.

h) Check the air pressure at the gauge. Normal pressure should beapproximately 0.5-0.7kg/cm2.

i) Check the water pressure to the cooling tower by observation ofthe SEA WATER PRES. pressure gauge, the pressure should beapproximately 1-1.5kg/cm2. The inlet flow can be adjusted ifnecessary by means of the inlet valve V336.

j) Check the gas pressure; the normal pressure should beapproximately 0.2kg/cm2.

k) Ensure that the water level in the cooling tower is normal.

l) Check the fresh water pressure by observation of the FRESHWATER PRES. pressure gauge; the pressure should beapproximately 1.5-2kg/cm2.

m) Start the oil pump by turning the OIL PUMP switch to the Iposition.

n) Check the oil pressure by observation of the OIL PRES. pressuregauge; the pressure should be approximately 20-25kg/cm2.

o) Start the dehumidifier dryers and the refrigeration compressor andput the inert gas cooler in line.

p) The air compressor should run for approximately 45 seconds topurge the plant before the next step is carried out.

q) Turn the IGNITION switch to position I. The operator should waitapproximately 45 seconds to allow the glow plug to heat up.

r) Turn the AIR/OIL TO PILOT BURNER switch to position I. Thepilot burner is now on.

s) Turn the HIGH OIL/LOW OIL switch to the LOW OIL position.

t) Turn the HIGH AIR/LOW AIR switch to the LOW AIR position.

u) Turn the OIL TO BURNER switch to position I. The burnershould start, check the flame through the sight glass on top of thecombustion chamber.

(Note: The previous steps, r), s), t) and u) should preferably be carried outswiftly, ie, with only 1 or 2 seconds between each step.)

v) If burner ignition has not taken place within 4 seconds of the OILTO BURNER switch being turned on, the switch must be turnedback to position 0, in order to stop the oil supply. The operatorshould investigate the cause of the burner not firing or try againafter waiting for approximately 1 minute for the chamber topurge.

w) If normal ignition has taken place, the operator should wait for aperiod of 10 seconds and then turn the HIGH AIR/LOW AIRswitch to the HIGH AIR position and the HIGH OIL/LOW OILswitch to the HIGH OIL position.

x) Turn the AIR/OIL TO PILOT BURNER switch to position 0. Thepilot burner will be extinguished.

y) Check the oil consumption via the flow meter, the normalconsumption is approximately 210kg/h.

z) Check that the O2 analyser is functioning and that the O2 contentof the gas is within limits for use in the cargo system. The O2

content can be adjusted using the valve adjacent to the pressuregauges.

aa)Turn the TO ATMOSPHERE/TO CONSUMER switch to the TOCONSUMER position. As long as the O2 content of the gas iswithin limits, valve V2350A will open and valve V2355A willclose.

bb) Check the gas temperature and adjust if required.

CAUTION During MANUAL operation, a watchman must be on hand to monitor theburner flame once the system has been switched over to CONSUMERmode, as the flame sensor is out of service in the MANUAL mode.

Manual Stopping of the Plant

a) Turn the TO ATMOSPHERE/TO CONSUMER switch to the TOATMOSPHERE position. The valves will change over.

b) Turn the OIL TO BURNER switch to position 0. The operatorshould now wait approximately 1 minute for the plant to cooldown.

c) Stop the oil pump by turning the OIL PUMP switch to the 0position.

d) Turn the AIR COMPRESSOR switch to position 0 and the aircompressor will stop.

e) Stop the inert gas cooler refrigeration compressor and isolate thecooler.

f) Stop and isolate the dehumidifier dryers.

g) Turn the WATER CIRCULATION switch to position 0 and thewater pumps will stop.

h) Turn the MAIN SWITCH (power) OFF.

Changeover Between Atmosphere and Consumer

The inert gas can be led either to atmosphere or to the consumer (cargo system)by this switch. The plant must be started with the switch in the TOATMOSPHERE position, due to an interlock on the consumer valve.

When the O2 content is within limits, the switch is turned to the TOCONSUMER position and inert gas is led to the cargo tanks. The gas willautomatically be led to atmosphere if the O2 content is above or below thelimits. The changing over is delayed by a time delay relay in connection withthe O2 alarm.


Issue: 1




SteamSupply

TestPoint

Poop Front Stbd

TI TI

PI

PI

PI

PI

FI

PI

FI

PI

PI

Gaseous Nitrogen

Air

Gas Oil

Sea Water

Steam

Fresh Water

Instrument Air

Key

Inert Gas


Inert GasCooler

Drain

Drain

Drain

O2Analyser


FuelPump



From/ToFresh Water

CoolingSystem

FromBilge Eductor

System

Air Inlet


WaterSeal


To No.2IG Generator

InertGas

Generator

Scrubber

WaterSeparator

ToFunnel


Wet AirTo Funnel

N2

S

SSS

Gas OilSupply

RefrigerantInlet


RefrigerantOutlet

V633

V336A

V336

V340 V340

V344

V344

V2350A

V2355A

V2352 V2352A

V2354A

V2354B

V2354B

V2354

V2353

V2352

V2355

V2350

FromNo.2 IG

Generator

V452

V451

TITHA

THCOPLA

PLCO

LHALHCO

THATHCO

O21

O2HAO2LA

FCOAPHA

PHCO

PLAPLCO


PI63

DPI62

TI64

Steam HeatedDryer


RegeneratedAir From

Engine RoomSpace



V330

V407A

V331

V341

V329

PI

PISeaChest


To CentralFW Cooler

V335

V407



Issue: 1


Therefore if the O2 content during operation exceeds the normal set points, thechangeover is delayed for approximately 1 minute. During this time the plantwill not stop.

The changeover valves for gas to consumer and atmosphere are only operatedautomatically when the switch is in the TO CONSUMER position.

The changeover valves can also be operated manually by pressing a redpushbutton (located at the changeover valves) and leaving the button in thatposition. The gas goes then to the consumer independent of the O2 analyser andthe selector switch. This pushbutton is for emergency use only.

O2 Analyser

Maker: Servomex Type: 264A xendos 1800Range: 0 - 25% oxygen

The analyser is a microprocessor-based electronics unit for the continuousmonitoring of the oxygen levels in the inert gas generator outlet.

The gas sample continuously flows through the analyser sensor because of thehigher pressure in the inert gas system. This ensures that the oxygen content iscontinuously measured. The analyser has a 4-20mA output signal which isproportional to the oxygen content and this signal is the input signal to the O2

indicator on the control panel. Adjustment of the alarm set points can be madevia the membrane keys on the unit front.

When the instrument is first switched on, the upper and lower displays areilluminated for approximately three seconds and the sensor cell then warms upand stabilises. The unit then gives the O2 reading.

Refrigeration Plant

Maker: Sabroe Type: 6 cylinder reciprocating Speed: 1,400 rpm

The inert gas is cooled by being passed through a finned gas cooler which isdivided into two parallel sections. The cooler is cooled by R-22 refrigerantfrom a 6 cylinder reciprocating compressor. This is driven by an electric motorwhich is directly driven by the compressor.

The cooler tubes contain cooling R-22 and to prevent any water condensingand turning into frost or ice, the evaporating temperature is kept at slightlybelow zero so that the water drains away.

The compressor is fitted with high and low pressure cut-outs and a lubricatingoil pressure cut-out. There is also a lubricating oil pressure differential cut-outto stop the compressor in the event of the lubricating oil pressure droppingbelow that of the crankcase.

The compressor is fitted with automatic capacity control. The compressor iscontrolled by a ‘Unisab’ PLC. A regulator will unload cylinders one at a timein accordance with the load demand. The minimum operating level is twocylinders. There is also an automatic crankcase oil heater which is switched onwhen the compressor stops and vice versa. A dryer/filter is also fitted. Thedryer part must be changed regularly while the filter part may be cleaned.

This compressor can supply refrigerant to the air conditioning system as wellas the inert gas cooler.

Dehumidifier Dryers

Maker: Alfsen og Gunderson AS Flow rate: 2,500m3/hType: AG-SR-122E (electrically heated)Type: AG-SR-122S (steam heated)No. of sets: 2

There are two dehumidifier dryers fitted to the inert gas outlet. One is heatedwith steam and the other with electrically powered heaters. The air dryers startautomatically when the inert gas generator is started.

The dehumidifiers consist of an inlet air filter, preheater, silica gel rotor, wetair fan and steam or electrical heater.

Operation

The dehumidifiers operate continuously with wet air entering the dehumidifier.This air stream is divided into two separate streams, process air andregeneration air.

The process air is dried as it passes through the silica rotor and then passes outas dry-air. The rotor retains the removed moisture until it rotates into theregeneration section. The regeneration air is used to heat the moisture-ladensilica rotor in the separate regeneration section of the dryer. The regenerationair then leaves the dryer separately from the process air as wet air. Heat fromthe regeneration section is transferred by the rotor and is used by the incomingairflow to preheat the regeneration air.

Inert Gas Dehumidifier Principle


Wet Air

2500m3/h

Dry Air

2500m3/h

Regenerated Air 5oC

2500m3/h

Bypass Inert Gas

Cooler

From

Inert Gas

Generator

Adjusting

Damper

Wet Air

Fan

Rotor UnitFunnel

Rotor Drive Motor

Regeneration

Heater

(Steam/Elec.)

Filter Pre-heater

V2352

Issue: 1

PdS106

PdAH106

Illustration 4.7.2a Nitrogen Generator

S

Oil Cooler

After Cooler

To Consumers(See Illustration 4.7.2b)

FEED AIR COMPRESSOR

XA

CommonFault SVC

440V 60HzElectrical Supply

NitrogenBuffer Tank

NitrogenBuffer Tank

OilSeparator

V9B

AD4B

LA

Compressed Air

Electrical Signal

Oxygen Enriched Air

Gaseous Nitrogen

Key

Control PanelPdS104

PdAH104

N2Membranes

148-1147-1

148-2147-2Cooler

110S 111S 112S

TT120

TI120

PI109

TS120

Tah120

Tah120

PIC120

DCS

PI113

142-1

Rich O2 Outlet

FI140

AT140

HC131

AE140

AI140

AI140

AAh/hh140

AS140

M

M

PIC130

HC130

141

FCV130

157

DCS

PS150

PAI150

PI150

PT150

PAI

PS119

DCS

From GSAir System

XA140

N2 To Atmosphere

142-2

142-3

161160165

3 5 8 1 1 0 4 h

LAMPTEST

ALARMACCEPT

SELECTREMOTESTART

START

ALARMRESET CO2 CONTROL

AUTO/MANUAL

1 2

POS 2:MANUAL

CO2-CONTENT

POS 1:CO2-CONTENT

SET POINT

- +

LAMP/LEDPUSH BUTTON, SWITCHOXYGEN CONTENT HIGH,VERY HIGHSENSOR FAILURETEMPERATURE ALARM HIGHTEMPERATURE ALARM LOWPRESSURE ALARM LOWPRESSURE DIFF. ALARM HIGHCOMMON ALARMHAND OPERATED CONTROLLER

h%AAh/hhXATAhTAIPAIPd/AhYAHC

----------

KVAERNER - MEDALNITROGEN GENERATOR

PS

Start/StopSystem

BUFFE

Operating Panel



Issue: 1


4.7.2 Nitrogen Generator

Maker: Kvaerner - MedalType: Membrane Capacity: 21Nm3/h at 5bar and 5% O2

Oxygen MeterMaker: TeledyneRange: 0-10% O2

Feed CompressorMaker: KaeserType: SM 11 Oil lubricated screw fresh water cooledCapacity: 50Nm3/h at 8 barMotor: 7.5Kw

Nitrogen is used on the vessel for the following purposes:

As a sealing gas for the cargo compressor glands

Purging the gas fuel line and boiler gas burner manifold

Inerting and gas freeing of the level indicators

Bleeding to the cargo tank wedge spaces

Nitrogen vapour is bled into the wedge space and into the upper insulationspace at the top of the tank via valve V2209, from the nitrogen generator. Thenitrogen vapour then flows down along the surface of the tank shell to adrainpipe. The nitrogen vapour and any LNG leakage gas is exhausted into thevoid space where it mixes with the dry air atmosphere in this space.

The generator is fitted in the starboard side of the aft store on the first platformlevel of the engine room and the feed air compressor is fitted next to the GScompressors, also on the first platform level.

Principle of Operation

The generator uses a membrane system to produce nitrogen. The principle ofthe membrane’s operation is selective permeation. Each gas has a characteristicpermeation rate which is a function of its ability to dissolve and diffuse througha membrane. This characteristic allows a gas like oxygen, which dissolves anddiffuses at a fast rate, to be separated from a gas like nitrogen which dissolvesand diffuses at a much slower rate.

The key components of the generator are the membrane modules. Each modulecontains many hollow fibre membranes to achieve the maximum membranesurface per unit of volume. Compressed air is fed to the bore side of the hollowfibre bundles enclosed in the pressure vessel.

This vessel is arranged geometrically, in the same way as a shell and tube heatexchanger. As the air flows along the bore of the fibres, O2, CO2 and H2O(vapour) contained in the air permeate faster than N2 (Nitrogen) to the lowpressure side of the fibres. The air in the bore is gradually depleted of the fastpermeating gases and becomes nitrogen enriched.

The air flow rate through the membrane module can be adjusted to obtaindifferent levels of nitrogen purity.

Description of System Operation

The compressed air from the air feed compressor is fed to the nitrogengenerator inlet and firstly passes through a series of three automatic filters.These protect the membranes from any harmful solid particles and also fromany oil and water present in the air. These filters have automatic drains.

The air then passes through a 1kW electric heater which will heat the air toapproximately 50ºC, which is the optimal temperature for the design capacity.

The heated air is now fed via a manifold to each individual membraneseparator. The permeated gases such as the O2, CO2 and H2O (vapour) arevented off to atmosphere and the nitrogen leaves the membrane. The nitrogenis then collected in a manifold and passes through a flow control valve. Byadjusting the flow with this valve the nitrogen purity will be adjusted, as thelonger the air is in the membrane system, the higher the purity (Refer to themanufacturer’s manual for further in-depth information). If the nitrogen purityis out of the set specification it will dump the product to atmosphere. Thevariable area flow meter is installed at this point to allow the operator tomonitor the nitrogen flow.

The generator is equipped with an oxygen analyser to continuously monitor theoxygen content in the product nitrogen. Should the oxygen content rise, analarm will be initiated. If the oxygen content continues to rise, a second alarm(oxygen content high high) will be initiated and the delivery valve will closeand the dump valve will open. When the oxygen content has fallen to the limitswithin the set parameters, the dump valve will close and the delivery valve willopen.

The nitrogen is then fed to the N2 buffer tanks on deck. The feed pipe to thetanks is fitted with pressure switches which control the start and stop of thegenerator.

Normal Operation

The generator is completely automatic in its operation and once set up willrequire little operator intervention.

The system is started from the main control panel, after setting the compressorsto standby mode.


Issue: 1

VentMast at Tank No.5

VentMast at Tank No.4

PoopFront

DoublePipe

Boiler Gas Piping Purge LineLNG Compressor Room

PurgingVent Lines

Illustration 4.7.2b Nitrogen System

Boil-Off Gas SupplyFrom LD Compressor/Cargo Heaters

Gas BurnersPort Boiler

Gas BurnersStarboard Boiler

V2132V2233V2232

V2226

V2140 S2140V2140A

V2228

V2227

V2141

V2141A

V2141

V2141A

V2227

Key

No.5Cargo Tank

Cargo TankInsulation Space

and Wedge SpaceNitrogen Bleed

Dome NitrogenOutlet for Whessoe

Purging etc

No.4Cargo Tank

No.3Cargo Tank

No.2Cargo Tank

Wedge SpaceWedge SpaceWedge SpaceWedge SpaceWedge Space

InsulationSpace

No.1Cargo Tank

Nitrogen Generator(Starboard Rope Store)

Air Supply Compressor(1st Platform Level)

V2228V2228

Cargo Heaters

HD Compressor BHD Compressor ALD Compressor

To Port SideNitrogen Buffer

Tank

V2209 V2209 V2209

V2209

V2216V2216V2216V2216V2216



Issue: 1


Procedure to Start and Stop the Nitrogen Generator

a) The power supply switch to the heater is on the starboard side ofthe cabinet and the power supply for the instrumentation is insidethe cabinet.

b) If there are any alarms active, press the the followingpushbuttons:

Accept AlarmReset AlarmSelect Remote Start

If the GS compressor is required to supply the feed air, press the SELECTSERVICE AIR pushbutton and the Service Air Inlet Valve indicator lamp willlight. Otherwise the nitrogen generator’s feed air compressor will supply thenecessary air.

c) Once the START pushbutton is pressed, the compressor indicatorlamp will light together with the Select Remote Start indicatorlamp.

Production will be vented to the atmosphere for 10 minutes before switchingto the buffer tanks.

When the buffer tanks reach 1.95 bar, production is vented to atmosphere for10 minutes and then the generator will stop. The Select Consumer light willstart flashing. If during the 10 minutes the pressure in the buffer tank drops by0.15 bar, the consumer valve will open and the vent valve will close.

The generator will start automatically when the buffer tank pressure falls to1.49 bar.

During normal operation, the system and compressor will cut in and out underthe control of the line pressure switches. The compressor will run off load fora certain time before it stops.

To stop the generator system, press the SYSTEM STOP pushbutton.

Alarms

Any alarm activates the alarm horn and a flashing red lamp on the panel. Aremote alarm is raised via the DCS system.

High O2: 6.5%Air temperature low: 40ºCAir temperature high: 55ºCBuffer tank pressure low: 1.3 bar - one minute delayAir filter differential pressure high: 0.9 bar


Nitrogen Generator Operating Panel

Nitrogen Generator Air Feeder Compressor



Void SpaceRecirculation Fans

2,000m3/h

Illustration 4.7.3a Void Space Dryers

Void Space Dryer

Void Space Dryer

Gas toBoilers

Gas toBoilers

VapourHeader/

Crossover

LNG Vapourto LD/HD

Compressors

From Tanks2 - 5 VoidSpaces

V2310

V2306

V2310

Recirculation Fans: Top of LNG Compressor Room

V2311

V2313

V2313

V2314

V2314

V2316

V2303

V2135V2311

To Tanks2 - 5

Void Space

To Tank 1Void Space

Suction

From Tank 1Void Space

Moist Air

Dry Air

LNG Vapour

Condensate

Key

Steam

Compressed Air

Instrumentation

V2114 V2113

V2113

V2124

V2124V2114

Issue: 1


4.7.3 Void Space Dryers

Void Space Dryers

Maker: Moss VerftType: Shell and tubeNo. of sets: 2

System Description

The available cold temperature in the boil-off vapour is used for drying thevoid space atmosphere. Drying is carried out in two heat exchangers of theshell and tube type in which cargo vapour flows through the tubes.

Moisture in the void space atmosphere will condense outside the tubes andthen freeze to ice. The ice formation will reduce the heat exchange within thedryer. When the temperature of the void space atmosphere coming out from thedryer is higher than -50ºC, regeneration is necessary.

The supply of void space atmosphere and cold cargo vapour is shut off andheated cargo vapour is introduced through the tubes. The ice will now melt andthe water is drained off through a drain pipe.

The dryers are used one at a time. When one is in service, the other isregenerated. After the flow has passed the dryer, it will be heated toapproximately 30ºC in the steam heater.

The outlet temperature of the atmospheric heater is controlled by the controlvalve in the steam inlet. The variable position valve is controlled via a signalfrom TC107, the temperature controller. The controller regulates the valve inaccordance with the temperature received from transmitter TT107, located inthe void space outlet.


Issue: 1

Product

Tank Vol. 100% in m3

Level Reading 1 in meter



Level Reading Average in meter

Specific Gravity Correction in meter

Tape Correction in meter

Trim Correction in meter

List Correction in meter

Corrected Liquid Level in meter

Liquid Volume m3

Thermal Factor Liquid

Correction Volume m3

15556.275

27.928

27.928

27.928

27.928

0.009

-0.004

0.001

0.000

27.934

15148.087

0.99500

15072.347

18953.232

30.215

30.215

30.215

30.215

0.009

-0.004

0.001

0.000

30.221

18554.471

0.99500

18461.698

18950.408

30.618

30.618

30.618

30.618

0.009

-0.004

0.001

0.000

30.625

18653.215

0.99500

18559.949

15555.498

28.145

28.145

28.145

28.145

0.009

-0.004

0.001

0.000

28.151

15188.909

0.99500

15112.964

Tank 1 Tank 2

CARGO CALCULATION REPORT

LNG/C ''NORMAN LADY'' HOEGH FLEET SERVICES A.S.

CARGO MEASUREMENT BEFORE DISCHARGING DATE: July 16, 2003

TIME: 18:02 UTCPLACE: Lake Charles

VOYAGE NUMBER: RY-0903 Tank 3 Tank 4 Tank 5

Surveyor Chief Officer

LNG

18979.546

30.237

30.237

30.237

30.237

0.009

-0.004

0.001

0.000

30.243

18578.762

0.99500

18485.868

-138.9 -137.0 -147.0 -137.4-140.9

-140.2

Illustration 4.8.1a CTS Printout

Temperatures Vapor

Average Temp. Vapor All Tanks

0.150

0.150

0.150

146.7

0.148

mmHG:

0.149

909.5

0.151Tank Pressure

Tank Pressure x 980,662

-159.2

-159.2

-159.2

-159.2

-159.1

-159.2

-159.1

-159.1

-159.1

-159.1

-159.1

-159.1

-159.3

-159.2

-159.3

-159.3

-159.2

-159.2

-159.2

-159.2

-159.2

Temperature Liquid mid 1


Temperature Liquid bottom

Temperature Liquid Av. Each Tank

Temperature Liquid Av. All Tanks

Corr. Volume

85692.827

85692.827

0.000

Quantity on Board: ON ARRIVAL Ships Figure

Quantity on Board:

Survey Figure

Diff. Survey Fig. - Ships Fig.

Ambient Temp

Density

Atm. Pressure

mmHG.

(mb x 0.75006 = mmHG)

29.0 C

430.103 t/m3

1017

762.811

Trim / in mtr

0.25

List/degree

0

Sag cm

Hog cm

Density water

0

0

1.025 kg/m3

Draft fwd in meter 10.15

Draft aft in meter 10.40

Draft average in meter 10.28 FWD TRIM/PORT LIST = NEGATIVE

Product

Tank Vol. 100% in m3




Level Reading Average in meter

Specific Gravity Correction in meter

Tape Correction in meter

Trim Correction in meter

List Correction in meter

Corrected Liquid Level in meter

Liquid Volume m3

Thermal Factor Liquid

Correction Volume m3

15556.275

0.303

0.303

0.303

0.303

0.009

-0.034

0.002

0.000

0.280

3.803

0.99499

3.784

18953.232

0.387

0.387

0.387

0.387

0.009

-0.038

0.002

0.000

0.360

6.688

0.99499

6.654

18950.408

5.054

5.054

5.054

5.054

0.009

-0.034

0.002

0.000

5.031

1181.784

0.99499

1175.863

15555.498

0.335

0.335

0.335

0.335

0.009

-0.034

0.002

0.000

0.312

4.701

0.99499

4.677

Tank 1 Tank 2

CARGO CALCULATION REPORT

LNG/C ''NORMAN LADY'' HOEGH FLEET SERVICES A.S.

CARGO MEASUREMENT AFTER DISCHARGING DATE: July 16, 2003

TIME: 18:02 UTCPLACE: Lake Charles

VOYAGE NUMBER: RY-0903 Tank 3 Tank 4 Tank 5

Surveyor Chief Officer

LNG

18979.546

0.441

0.441

0.441

0.441

0.009

-0.038

0.002

0.000

8.832

18578.762

0.99499

8.788

-159.5 -159.4 -159.7 -159.5-159.3

-159.5

Temperatures Vapor

Average Temp. Vapor All Tanks

0.139

0.139

0.139

135.9

0.138

mmHG:

0.138

900.2

0.139Tank Pressure

Tank Pressure x 980,662

-88.3

-144.5

-144.5

-125.8

-97.0

-147.8

-147.8

-130.9

-112.3

-151.2

-151.3

-138.3

-90.6

-145.7

-145.8

-127.4

-103.6

-148.8

-148.8

-133.7

-131.2



Temperature Liquid bottom

Temperature Liquid Av. Each Tank

Temperature Liquid Av. All Tanks

Corr. Volume

85692.827

1199.767

84493.060

84493.060

0.000

Quantity on Board: ON ARRIVAL Ships Figure

Quantity on Board: ON DEPARTURE

Quantity: DISCHARGED

Survey Figure

Diff. Survey and Ships Figure

Ambient Temp

Density

Atm. Pressure

mmHG.

(mb x 0.75006 = mmHG)

33.0 C

430.103 t/m3

1019

764.311

Trim / in mtr

1.00

List/degree

0

Sag cm

Hog cm

Density water

0

0

1.025 kg/m3

Draft fwd in meter 8.15

Draft aft in meter 9.15

Draft average in meter 8.65 FWD TRIM/PORT LIST = NEGATIVE



Issue: 1


4.8 Custody Transfer System

4.8.1 Custody Transfer System (CTS)

Level Measurement

The level measurement system consists of a microwave horn antenna and atransmitter/receiver mounted inside a 50mm pipe mounted in the tank centralcolumn which extends over the full depth in which the level is to be measured.

The liquid level is determined by measuring the time taken for a transmittedsignal to travel to and from the liquid level surface. The time taken is measuredand converted into a distance measurement (the ullage). The values for the sizeand shape of the tank are stored in the signal processing unit and so the systemcan calculate the exact contents of the tank. The system also employs time-averaging techniques to balance out the effects of liquid movement.

Cargo tank gauging is via the transmitter on the Whessoe gauge. The speed ofthe radar signal travelling (propagating) within the tank is influenced by thevarying vapour densities and temperatures. To compensate for this the systemautomatically compares results to previously measured pipe joint signaturesand calibrates the system accordingly. This ensures the accurate measurementof contents independent of tank conditions. This automatic calibration meansthat no separate mechanical operations are required to verify the accuracy ofthe system.

Temperature Measurement

The temperature measurement is obtained from the PT100 sensors whoseelectrical resistance decreases with temperature. The sensors are calibrated andcertificated and therefore have their own individual identification number. Thesensors are positioned equally throughout the height of the tank and includesensors at the top and bottom enabling the temperature of the liquid and thevapour to be measured separately. Average and individual temperaturereadings are available.

The sensors are wired with four conductors (four wire cable) and allterminations are sealed. There are spare sensors mounted in the tanks toprovide a degree of redundancy.

Pressure Measurement

The pressure measurement is obtained from a capacitive pressure transmitter.The transmitter consists of a movable ceramic diaphragm connected to a fixedceramic substrate. On each ceramic part is a gold plate which makes up acapacitor whose capacitance will vary according to the distance between them.The fixed part is mounted on the tank shell and the movable part extends intothe tank space. The tank pressure imparts a force on the movable plate relativeto the tank pressure. This varying capacitance signal is converted to an output

signal which varies according to the pressure in the tank.

Independent Very High Level Alarm System

Two high level alarms per tank are provided by independent point sensingelements. Float sensors inside the cargo tanks detect the cargo at predeterminedlevels (see section 4.1.3, High Level and Overfill Alarm System).


Issue: 1

Illustration 4.8.2a Whessoe Float Level GaugeCounter Window

Cushion Spring

Inspection Hatch

Nitrogen PurgeConnection

Handle To RaiseThe Float

10" Closure Valve

Spherical Float



4.8.2 Float Level Gauges

Maker: WhessoeType: Whessmatic 50

The Whessoe float level measurement system is of the conventional tankertype, but uses a stainless steel tape to compensate for temperature variations.

The system comprises a level gauge assembly for each cargo tank. The levelgauge is mounted on an assembly comprising a float well, isolating valve andinspection chamber.

The gauge head contains a mechanical indicator, a stainless steel tapetensioned by a tensator spring and a 12'' diameter PV float attached to the lowerend of the tape. One level gauge is fitted at each cargo tank dome.

The shrinkage of the float in LNG is 15mm and the minimum level which canbe read from the gauge is 145mm.

CAUTION To reduce the risk of tape failure and wear on the gauging mechanism, thefloats should be fully stowed at all times, except when taking a sounding.Care should be taken when stowing the float as excessive tension maycause tape breakage. It is possible for a failed tape to foul the capacitancecolumn, resulting in the loss of gauging facilities for that tank.

To obtain the liquid level, the float is released from its stowage position usingthe release lever and allowed to descend freely to the liquid surface. The tanksounding may then be taken by observation of the local mechanical read-outsto provide level indication. The Whessoe gauges should be checked against theCustody Transfer System (CTS) during each alternate loading.

Each cargo tank is provided with a Whessoe gauge as an approved secondarylevel measurement system. This secondary system provides an alternativemeans of cargo level measurement in the event of the failure of the primaryradar gauges system.

Float Well

The float well comprises a 300mm diameter tube installed vertically within thecargo pump tower. The upper end of the float well penetrates the top of the tankdome where it terminates in a flange. The lower end extends to within 75mmof the bottom of the tank where it is closed by a perforated plate. The lowerend of the float well is provided with a bolted inspection cover. Expansion isallowed for by a sliding connection just below the dome penetration. To avoidlevel errors caused by the ‘till well’ effect, there is a 25mm diameter holespaced every 300mm below the sliding connection.

Isolating Valve and Float Inspection Chamber

A 300mm gate valve, bolted to the top of the float well, allows the gauge headto be isolated for maintenance. A stainless steel inspection chamber is mountedabove the isolating valve to provide access to the float and for the connectionof special float recovery tools in the event of tape breakage. The inspectionchamber flange can be used for gas freeing of the tank, if required, duringmaintenance periods, etc.

Level Gauge Assembly

The level gauge assembly comprises the gauge head and float assembly. Thefloat is clamped to an accurately perforated tape manufactured from stainlesssteel, a viscous damper to control the rate of descent of the float to the cargolevel, a crank for raising the float to the storage position and a mechanical readout which is observed through the counter window. A float lock-uparrangement provides isolation of the level gauge from the tank when in thestored position. It also provides a gauge datum reference and a means oflocking the float in the storage position.

Operation: Gauging

a) Open the gauge isolating valve fully, (normally left open).

b) Put the crank handle in the STORED position, ie, with the handletowards the gauge cover.

c) Put the spring-loaded automatic float lock-up and the datumplunger up to release the float and allow it to descend at acontrolled rate to the liquid level.

To Return the Gauge to the Stored Position

a) Put the crank to the CRANKING position, ie, with the handleoutwards.

b) Carefully raise the float by turning the crank slowly in a counterclockwise direction, as indicated by the arrow on the main coverinspection plate.

c) Watch the read out counter, which will indicate when the floatnears the top. When resistance is felt by the float touching thecushion spring, continue cranking until the plunger is seated,sealing the gauge from the tank, and the automatic float lock-upand datum plunger spring fully inward, securing the float.

d) Check that the counter reads exactly the same before and afteruse.

e) Move the crank handle to its STORAGE position.

CAUTIONDo not attempt to turn the crank clockwise or to interfere with the free fallof the float. To do so will severely damage the tape or the tensator spring.

Maintenance

The Whessoe system must be operated at regular intervals to ensure that thesystem is available in the event of any failure of the primary tank contentsmeasuring system. The stored reading and error between the Whessoe systemand the custody transfer system should be recorded at each operation.

The float must not be left at liquid level after gauging because constantmovement of the tensator spring, which ensures tension on the tape, will leadto premature failure.

An inspection hatch is provided in the float inspection chamber for access tothe float assembly and for retrieving the float in the event of tape breakage.

The gauge head is sealed with locking wire and lead seals by Class. It isimportant to avoid damaging these seals. In the event of these seals beingbroken, head office should be informed without delay in order thatarrangements can be made for the attendance of Class to check and re-seal thegauges.

When the gauges are not in use, the float must be raised and secured.

An inspection housing is provided between the gauge head and the closurevalve on each unit. The closure valve is used to cut off vapour flow to theinspection housing. The inspection housing is provided with a pipe connectionfor inerting the space with nitrogen before inspection or renewal of the tape orfloat. The nitrogen is supplied from the nitrogen line available at the tank domearea and is introduced by means of a flexible pipe from outlet valve V2216 tothe Whessoe unit.

Tape Breakage

In the event of tape breakage, head office is to be informed, as anymaintenance requiring opening of the gauge will necessitate the attendance ofClass to recalibrate and seal the gauge to satisfy buyers, sellers and customs.Instructions for the recovery and replacement of the float assembly or tape areincluded in the manufacturer’s instruction book.



Issue: 1

Illustration 4.8.3a Loading Computer Screen

Loadmaster LMC-6039 NORMAN LADY : RY 0903 TP1 - TP2 Jul/16/03 12:15File View Tools Settings Window Help

X

XCargo Compartment Trim and List correction ON X

NO 1 CARGO TANK Default Cargo 0.00 0.00 0.000.000 0.0 0.0 0.0 00.9989 15556.315.00NO 2 CARGO TANK Default Cargo 0.00 0.00 0.000.000 0.0 0.0 0.0 00.9989 18953.215.00NO 3 CARGO TANK Default Cargo 0.00 0.00 0.000.000 0.0 0.0 0.0 00.9989 18979.615.00NO 4 CARGO TANK Default Cargo 0.00 0.00 0.000.000 0.0 0.0 0.0 00.9989 18950.415.00NO 5 CARGO TANK

C1

Code Compartment name Cargo Type Flow(m3/h)

Innage con.(m)

Volume(%)

Volume(m3)

FSM(tm)

LCG(m)

TCG(m)

Max Volume(m3)

Weight(t air)

Obs. dens.(t/m3 air)

Temp.( C)

C2C3C4C5 Default Cargo 0.00 0.00 0.000.000 0.0 0.0 0.0 00.9989 15555.515.00

Cargo 0.0% Ballast 0.0% Fuel Oil 0.0% Diesel Oil 0.0% Lub. Oil 0.0% Fresh Water 0.0% Misc. 0.0% Dry 0 ton

XIntact Stability X

Visual Intact Displ. GZ

Open Save Print Stab Stress Comp D Surv Crg Sat L Sum D Sum Onl Exit

0 5261614.59 m

m

mmm

m aftS.S

18.78

1.97

3.685.40

3.420.0

tonDwKGGM

dl wddeqdaft

TrimHeel

WARNING: Max GZ deq: IS OUT OF LIMIT

XLongitudinal Strength - SEAGOING CONDITION X

Stress Curve Stress Table Stress curve %

Max BM: 159703 tm at 99.54 m from AP Max SF: 2989 t at 36.60 m from AP

Frame 50 59 63.5 68 72.5 77 81.5 86 95

0

4

8

-8

-4

0

100

200

300

-200

-100

-300

SF [Kton]

Limits

BM [Kton]

Limits

14.59 SEAGOING CONDITIONtonDispl

14.59 tonDW 71Max SF % 80Max BM %

14.59 ton/W3Swd

1.97 mD fwd

3.63 mD mid

3.42 m aftTrim

0.0 S.SHeel

14.59 mKG

18.78 mGM

5.43 mD aft



Issue: 1


4.8.3 Loading Computer

Maker: Kockumation ABProgram: Loadmaster

General

The Loadmaster program is computerised system for planning and evaluatingship loading and discharge. It quickly calculates ship stability and stresscharacteristics based on any loading condition specified by the user.

The program is developed from the technical information supplied by thebuilders that reflects the physical characteristics of the ship. The informationincludes the following data:

Principal particulars

Operating lightship

Load line data

Draught mark locations

Visibility restriction data

Hydrostatic tables

Cross curves of stability

Bonjean tables

Required GM curve

Capacity tables

Variable centre/free surface tables

Lightship weight distribution

Allowable bending moments and shear forces

The program allows for the loading condition information to be stored to disk.These stored conditions can be recalled at any time for modification or re-evaluation. In addition stored loading conditions can be sent ashore for reviewon a shore based computer.

The Loadmaster system is an on-line stand alone computer with a directinterface to the various tank and draught gauge systems and is linked to thevessel’s DCS system. The Loadmaster system automatically reads the gaugesystem data at specified intervals and calculates all the tank and vesselcharacteristics. It is possible to vary the time of each update from 1 minuteintervals to 30 minutes.

Determination of load/discharge rates and projections of time to finish arepossible.

During cargo operations the Loadmaster program constantly upgrades theinformation. Prior to or during cargo operations the operator can check, usingmanual inputs, that the sequence of loading or discharge will always remainwithin the acceptable limits.

The Loadmaster program is run from Windows and as such is accessed via theWindows menu bar at the top of the screen. In addition to the menu bar thereare two fixed display areas, the results bar and status bar (which cannot bechanged or hidden).

The results bar provides information on the current loading condition. This baris always visible on the far right hand side of the main window and iscontinuously updated to reflect any changes in the loading condition.

The status bar is a single text line located at the bottom of the main window.The program uses this space to display messages about the current status andwarnings about data entry.

In addition to the above there is the workspace, the area of the screen wherethe different views of the load condition are displayed.

General Program Operation

Main Menu BarThe layout of the main menu bar follows Windows conventions. The File,Windows and Help items all provide selections consistent with other Windowsprograms.

Procedure to Operate the Loadmaster

To Work with Load Types

In this part all the load types that should be used in the system are prepared.Every tank, cargo compartment/position, store position etc. must have a loadtype assigned to it. This assignment is done in the screens where its possible toenter the weight, for example cargo tanks and Misc Tanks screens. For tanks,density values are defined per load type.

Procedure to Access the Load Type Screen

a) Place the cursor on the load type key area and click the left mousebutton.

b) Press the F1 function key.

It is possible to work with following items in the load types screen.

Defining densities for the various loads

Displaying accumulated weights for the subtotal categories

Use the horizontal scroll bar to see remaining field in the load types screen.

Definition of Load Types

Load type is a description of the current load based on information from thetrim and stability book. Several common load types are predefined. Theoperator can define additional ones by using the load types codes A-D.

The following values are associated with each load type:

Upper Part of the Screen

Code: The code is used in the cargo load that should be used in the system to link a certain load type to each tank space

Name: For the operator’s easy identification of the load type

Load category:

Predefined short name for load category

LIQ for density input

OIL1 - OIL5 for density vac 15C/API 60ºF inputs

For load category LIQ

Density: Current density value for the cargo

For load category OIL1 - OIL5

API 60F: API value for liquid at 60ºF

Dens vac 15C: Density value for liquid in a vacuum at 15ºC

Lower Part of the Screen

Sub total: Define to which subtotal category the weight shall be summarised

Density: Relevant only when the load load category has been set to liquid

Weight: Summary of the weight for the tanks and other cargo positionswith this load type

Volume: Summary of the loaded volume for tanks with this load type

Max Volume: Maximum available volume in tanks with this load type


Issue: 1

Illustration 4.8.3a Loading Computer Screen

Loadmaster LMC-6039 NORMAN LADY : RY 0903 TP1 - TP2 Jul/16/03 12:15File View Tools Settings Window Help

X

XCargo Compartment Trim and List correction ON X

NO 1 CARGO TANK Default Cargo 0.00 0.00 0.000.000 0.0 0.0 0.0 00.9989 15556.315.00NO 2 CARGO TANK Default Cargo 0.00 0.00 0.000.000 0.0 0.0 0.0 00.9989 18953.215.00NO 3 CARGO TANK Default Cargo 0.00 0.00 0.000.000 0.0 0.0 0.0 00.9989 18979.615.00NO 4 CARGO TANK Default Cargo 0.00 0.00 0.000.000 0.0 0.0 0.0 00.9989 18950.415.00NO 5 CARGO TANK

C1

Code Compartment name Cargo Type Flow(m3/h)

Innage con.(m)

Volume(%)

Volume(m3)

FSM(tm)

LCG(m)

TCG(m)

Max Volume(m3)

Weight(t air)

Obs. dens.(t/m3 air)

Temp.( C)

C2C3C4C5 Default Cargo 0.00 0.00 0.000.000 0.0 0.0 0.0 00.9989 15555.515.00

Cargo 0.0% Ballast 0.0% Fuel Oil 0.0% Diesel Oil 0.0% Lub. Oil 0.0% Fresh Water 0.0% Misc. 0.0% Dry 0 ton

XIntact Stability X

Visual Intact Displ. GZ

Open Save Print Stab Stress Comp D Surv Crg Sat L Sum D Sum Onl Exit

0 5261614.59 m

m

mmm

m aftS.S

18.78

1.97

3.685.40

3.420.0

tonDwKGGM

dl wddeqdaft

TrimHeel

WARNING: Max GZ deq: IS OUT OF LIMIT

XLongitudinal Strength - SEAGOING CONDITION X

Stress Curve Stress Table Stress curve %

Max BM: 159703 tm at 99.54 m from AP Max SF: 2989 t at 36.60 m from AP

Frame 50 59 63.5 68 72.5 77 81.5 86 95

0

4

8

-8

-4

0

100

200

300

-200

-100

-300

SF [Kton]

Limits

BM [Kton]

Limits

14.59 SEAGOING CONDITIONtonDispl

14.59 tonDW 71Max SF % 80Max BM %

14.59 ton/W3Swd

1.97 mD fwd

3.63 mD mid

3.42 m aftTrim

0.0 S.SHeel

14.59 mKG

18.78 mGM

5.43 mD aft



Issue: 1


Lmom: Sum of the longitudinal moment for all compartments with this load type

Vmom: Sum of the vertical moment for all compartments with this load type

Tmom: Sum of the transversal moment for all compartments with thisload type

FS: Sum of the free surface moment for all compartments with thisload type

Operating Procedure

Enter the basic information such as the load category, density, temperature, etcfor all load types that are used in the system.

To Define the Density of a Load Type

a) Position the cursor in the high lighted density field for the desiredload type.

b) Enter the value for the density.

To Alter the Load Category

a) Position the cursor in the highlighted load category field for thedesired load type.

b) Enter the value for the load category (Liq, OIL1-5).

Operator Defined Load Types

a) Position the cursor in highlighted name field for the load typecode A - D.

b) Enter the load type name.

c) Move the cursor to the next field.

d) Enter the relevant load category (Liq, OIL1-5).

(Note: In case of Liq, move the cursor to the right and define the density).

e) Select the tank that is to be used in the system and define for whattank the new load type is relevant.

To Define the Subtotal Groups

A number of sub total groups are predefined, such as ballast, bunkers andcargo.

Each subtotal group consists of one or many load types.

a) Enter the name of a desired subtotal group in the subtotal field bythe load type.

Command Keys

Report: To create a condition report

Print: To print out different reports

Error Messages

Error messages are displayed in the bottom part of the screen. Press the ESCkey to confirm that the message has been read.

Relationship Between Density Parameters

Load Types Screen

The load category OIL1 - OIL5 determines which API formula is used andcalculates the current density at 0ºC (32ºF). This density will appear in thecargo tanks screen at start up.

The density will, however, not appear in the load types screen because differenttanks labelled with the same load category may have different temperaturesand consequently, different densities.

If the load catagory LIQ is used, the fields for API, Tot vol 60ºF etc areremoved.

Cargo Tanks Screen

For the load category OIL1 - OIL5 the API value from the load types screen,together with the temperature value for the tanks, is used to calculate thecurrent density.

For the load category LIQ the current density is not affected by the temperaturevalue.

In both cases the current density value may be changed directly for acompartment by moving the cursor to the density column and pressing manualkey. This will lead to an asterisk (*) appearing at all values affected by thedensity.

(Note: If the density value for a tank is online, the density input field is markedwith a * to indicate that the load type density is overruled by the online values.)

API and Oil Categories

In order to obtain the unanimous results in the trade of petroleum products, itis customary to refer to cargo density in vacuum at a fixed base temperature.

The tables prepared by the American Petroleum Institute (API) use for thispurpose 15ºC as the base temperature for density in a vacuum or 60ºF for itsequivalent the API gravity and cover the following oil categories:

Load Fluid Group Density at API at CorrespondingCategory 15ºC 60ºF to Table

OIL1 Crude Oils 0.770 - 0.990 0 100 A

OIL2 Gasoline and naphthenes 0.657 - 0.770 50 - 85 B

OIL3 Jet fuels and kerosines 0.785 - 0.825 37 - 50 B

OIL4 Diesel oil and fuel oils 0.812 - 1.075 0 - 37 B

OIL5 Lubricating oils 0.861 - 0.940 12 - 22 D

Method

The full range of petroleum measurement tables and the associated formulashave been programmed into the Loadmaster program. The vacuum andatmospheric pressure results can thus been reviewed instantly if the currentcargo temperature and any of the following are known:

Density in a vacuum at 15ºC

API at 60ºF

Density in air.

For each load type, a load category can be defined for different input/outputfacilities for the compartment using that load type.

When defining load categories OIL1 to OIL5 enter API or density in a vacuumvalues that, together with an entered compartment temperature, will producethe actual density for the load.

To Work with On-Line Cargo Tanks

This section contains the current information for all on-line cargo tanks.Concerning on-line and API, refer to ONLINE OPERATION (tab 3). Thecomplete condition is calculated after each entry.


Issue: 1


The values displayed for each tank are:

Name: Name of tank

Load Type Code: Refer to the Load Type picture for finding the code onthe Load Type with the properties of the content in tank.

Density: The value for density associated to selected Load Type Code will be displayed. This value may be overwritten by the operator.

Weight, Volume, The operator can choose to enter any of these values Ullage, Sounding, and the others will be calculated with reference to Percent fill: entered value.

KG, TCG, LCG, FS: These values are displayed from predefined curves (KG and FS) or as fix values(TCG and LCG), but canmanually be changed by the operator.

Operating Procedure

Define the content in each tanks as follows.

a) Position the cursor in the highlighted field Weight, Volume,Percent Fill or level (sounding or ullage).

b) Enter the current value.The condition is calculated after eachentry.

To modify the predefined values for KG, FS, TCG or LCG.

a) Position the cursor in the field which needs to be modified.

b) Enter desired value and press ENTER. The background colourwill change when the cursor is moved to a new position.

To change to the predefined value for KG, FS, TCG or LCG after a manualmodification.

a) Position the cursor in the field which needs to be predefined. Thisfield will have a coloured background.

b) Place the cursor on the Defaul key area and click on the mouseleft button or use SHIFT + F6.

Command Keys Available

Online: To choose online work area as current mode and update fromthe tank radar system every 30 seconds

Offline: To choose off-line work area as current mode

Onlupd: To update on request all online values

On-tk: To connect a specified compartment to online environment

Man-tk: To disconnect a specified compartment from online environment

Defaul: Reset to predefined value for KG, FS or TCG after a manual modification

Repor: To create a Condition Report

Print: To print different Reports

Error Messages

Error messages are displayed in the bottom line of the screen. To confirm thata message has been read, press the ESC key.

Loadmaster Online to the Tank Radar

The Loadmaster has two working modes, online and offline. They should beseen as two separate working areas that are totally independent of one another.

In the ONLINE mode, all the online tanks are updated automatically or at theoperator’s request, but in the OFFLINE mode each input must be mademanually.

Data exchange between the two working modes is performed via the StoredCondition screen. In the current mode the present condition is stored and it canbe accessed in the other mode.

(Note: When operating in OFFLINE, the program is still collecting data e.g.levels in the background. If any warning limits are exceeded an alert messagewill be issued to the operator even though the program is working in OFFLINEmode.)

Working with inputs are described on the previous pages.

Online Supervision

Screens and commands are similar to those in the offline mode.

The tank levels and temperatures, as measured by the tank radar system, areupdated every 30 seconds in the online mode or at the operator’s request whenOnlupd is chosen in the command keys.

The current tank levels are used in the online load calculations.

A red letter is displayed in case of a sensor failure and the tank values will notbe updated by the tank radar system.

Online values may be entered manually in the event of a sensor failure.

Tanks changed to manual input will be indicated with M and not be updated bytank radar system.

The online load condition may be copied to the offline mode via the storecondition in online and the fetch condition in offline. The copy procedure canalso be performed in the other direction from offline to online.

Online Gauging

The loadmaster online loading calculation program allows level, temperatures,level rate and density values supplied by tank radar system to be collected.

Online values may be entered manually in the event of a sensor failure.

Sensor errors are indicated with a red letter :

L = Online level not available

D = Online density not available

T = Online temperature not available

A = More then one of the above mentioned error indications

No online updating is then performed.

From the measured levels and keyboard input, the Loadmaster program iscontinuously calculating stresses and stability.

(Note: The levels collected from the tank radar system are corrected for trimand list. Therefore it is of great importance that all items which are not gaugedare entered manually in a corrected way.)

(Note: The online temperatures displayed are used in the calculations. Forcorrect weight calculations it is important to make a correct keyboard inputinto the LOADTYPE screen, to define a correct API/density for the tanks thatdo not have density or/and temperature online.)


Issue: 1


It is also important to define the correct sea water density in the observationsscreen.

Online Tank Screen

Some of the online screens include the following special commands.

1. To manual request to update the tank radar value:

Toggle between the manual or online input for each compartment.

2. Optional:

Online temperature information.

Procedure for a Manual Request to Update the Tank Radar Values

a) Place the cursor on the ONLUPD key area.

b) Press the mouse left button or press CTRL + F3 to update allonline values.

Procedure to Toggle Between the Manual or Online Input for eachCompartment.

a) Change to a MANUAL input.

b) Place the cursor into the level, weight, volume, density ortemperature field to prepare for a status change. The level, weightand volume fields are the same tank radar input.

c) Place the cursor on the MAN-TK key area (manual input for theabove chosen tank value) and press the left mouse button or pressCTRL + F5.

This will disconnect the online input for the current item. A yellow letter willappear in the second column to indicate that the current values are based onmanual input. L = level, weight or volume, D = density, T = temperature, M =more than one of L, D or T are closed for a manual input.

d) Enter a suitable value.

e) Change to online input.

f) Place the cursor in the level, weight, volume, density ortemperature field to prepare for a status change. The level, weightand volume fields are the same tank radar input.

g) Place the cursor on the ON-TK key area to resume the automaticonline updating and press the mouse left button or press CTRL +F4.

This will disconnect the online input for the current item. The correspondingyellow letter will disappear in the second column to indicate that the currentvalues are based on the online input.

To make a manual update ONLUPD, follow the instructions above or wait for30 seconds to receive the latest online values.

Ballast and Miscellaneous Tanks

This screen displays the contents in all the tanks and the complete condition iscalculated after each entry.

Some of the values displayed for each tank are:

Name: Name of tank

Load Type Code: Refer to the Load Type picture for finding the code onthe Load Type with the properties of the content in tank.

Density: The value for density associated to the selected load type code will be displayed. This value may be overwritten by the operator.

Weight, Volume, The operator can choose to enter any of these values Ullage, Sounding, and the others will be calculated with reference to Percent fill: entered value.

KG, TCG, LCG, FS: These values are stored as curves (KG and FS) or as fixed values(TCG and LCG), but may be overwrittenby the operator.


To define the contents in the tanks

For each tank

a) Position the cursor in the highlighted field, Weight or Volume orPercent Fill or level (sounding or ullage).

b) Enter the value. The condition is calculated after each entry.

To modify the predefined values for KG, FS, TCG or LCG.

a) Position the cursor in the field whose values are to be modified.

b) Enter the desired value and press the ENTER key.

The background colour will change when the cursor is moved to a newposition.

To change to a predefined value for KG, FS, TCG or LCG back after a manualmodification.

a) Position the cursor in the field whose value is to be set topredefined. This field has a coloured background.

b) Place the cursor on the Defaul key area and click on the leftmouse button or use SHIFT + F6.

The following command keys are available.

Defaul: To obtain a predefined (=default) value back for the selected KG, FS or TCG, whichever is selected.

Repor: To create a condition report.

Print: To print different reports.

Error Messages

Error messages are displayed in the bottom line of the screen. To confirm thata message has been read, press the ESC key.

Stability

This picture shows the GZ-curve, analysis of the curve and GZ-table.

No entries are possible in this picture.

Stress Bars

The calculated shear forces and bending moments are displayed in tabularform. The shear forces and bending moments as a percentage of allowed limitsare also displayed as bars. The shear forces and bending moments as apercentage are also displayed as curves in the stress curve screen.

(Note: There are different colours for shear forces and bending moments in thebar graph, blue = bending moments, red = shear forces.)

The locations at which the stress is calculated are prescribed by theclassification society and the frame numbers are displayed both in the table andon the x-axis of the bar graph.


Issue: 1



a) Select the seagoing condition or the harbour condition.

b) Click the relevant button to select the set of limits not currently inuse.

(Note: If the size of the bars and the values in the table change, the % valuesfor the limits for the shear forces and the bending moments will also change.)

Stress Curve

The calculated shear forces and bending moments compared with the limitsdefined by the classification society are displayed both in tabular form and ascurves. More information on absolute values and also on the limits are foundin the Stress Bars screen.

(Note: There are different colours for shear forces and bending moments in thebar graph, blue = bending moments, red = shear forces.)

The locations at which the stress is calculated are prescribed by theclassification society and the frame numbers are displayed both in the table andon the x-axis of the curves.


a) Select the seagoing condition or the harbour condition.

b) Click the relevant button to select the set of limits not currently inuse.

(Note: If the size of the bars and the values in the table change, the % valuesfor the limits for the shear forces and the bending moments will also change.)

Observations

This screen is used to define sea water density, warning limits for draughtsdeadweight and to observe the condition of the ship.

Warnings will be issued when any of the calculated results exceed thecorresponding limit value.

Observation of Current Condition

The discrepancy between current condition (left side of the screen) and manualgauged draughts (right side of the screen) is displayed in the lower part of thescreen.


To change the sea water density

a) Position the cursor in the field for the sea water density.

b) Enter the actual value for the sea water density and press theENTER key.

When the sea density is changed the program will make a new calculation ofthe current condition.

Procedure to Compare the Calculated Draughts against the GaugedDraughts

The draughts of the current condition are displayed on the left side of thescreen and are based on whatever entries have been made by the operator ortransferred from the tank gauging/automation system.

a) Enter the actual sea water density in the list in the upper leftcorner of the screen.

b) Enter the gauged draughts and the corresponding locations in thearea of the screen called the manually gauged draughts.

Result

The discrepancy (if any) between the current condition and the manuallygauged draughts will be displayed in the bottom of the screen.

If they are different it may be that an unknown weight or inaccurate sea waterdensity has been entered.

The following command keys are available.

Defaul: To obtain a predefined (default) value back for the selected KG, FS or TCG, whichever is selected.

Repor: To create a condition report.


Error Messages

Error messages are displayed in the bottom line of the screen. Press the ESCkey to confirm that a message has been read.

Conditions

To store the present load condition, to transfer an already stored condition orto clear a stored condition.

The conditions stored in the end of the list are used for the classificationsociety’s reference. They may be transferred but they cannot be cleared by theoperator.

By using the functions in this screen the operator is able to obtain a startcondition very quickly.

Operating Procedure

To store current the condition.

a) Position the cursor in the highlighted field Condition Name.

b) Enter an appropriate name for the later easy identification of thecondition.

c) Position the cursor in the desired Condition Number.

d) Place the cursor on the store key area and click the mouse leftbutton.

e) Press the function SHIFT key and the F2 key.

To transfer an already stored condition

a) Position the cursor in the desired Condition Number.

b) Place the cursor on the store key area and click the mouse leftbutton.

c) Press the function SHIFT key and the F1 key.

(Note: The current condition in the Loadmaster will be replaced by transferredcondition.)

To clear a stored condition.

a) Position cursor in the desired Condition Number.


Issue: 1


b) Place the cursor on the store key area and click the mouse leftbutton.

c) Press the function SHIFT key and the F3 key.

Quick Start

Define all weights considered as being permanent (small tanks in engine room,stores, workshops etc.) and store the condition as described above. Give thecondition an appropriate name, eg Start Condition Summer Voyages. A numberof such conditions can be defined. Proceed using the start instructions.

Only cargo needs to be defined.

Command Keys

Fetch: Condition marked by the cursor will be transferred and replaces a previous condition in Loadmaster.

Store: Present condition in the Loadmaster will be stored in Condition Number marked by the cursor. Number 0-3 cannotbe used, since they are only used for the classification society’s reference.

Repor: To create a Condition Report.


Error Messages

Error messages are displayed in the bottom part of the screen. Press the ESCkey to confirm that the message has been read.

Reports

There are two types of reports, an ullage report and a report on the vessel’scondition.

Procedure to Generate a Condition Report

From a large number of screens, the condition report can be created, using theREPOR function key.

The report will be stored in a predefined directory under the name rcndrep.txt.

Procedure to View the File

a) Select FILE from the menu bar.

b) Select OPEN.

c) Enter the file name:C:\u\sml\XXXX\rep\rcndrep.txt

XXXX is the identification number of the Loadmaster software.

a) Press the PRINT key if a printed copy is required.

To Generate an Ullage Report

This report can only be created from the UllAPI screen. The correspondingfunction key is called REPOR.

The ships quantity reports will be stored in a predefined directory under thename Ullrep.txt.

Procedure to View the File

a) Select FILE from the menu bar.

b) Select OPEN.

c) Enter the file name:C:\u\sml\XXXX\rep\rcndrep.txt

XXXX is the identification number of the Loadmaster software.

Procedure to Print a Report

a) Select the desired file.

b) Press the PRINT key.

The PRINT key can be used in several screens.


Issue: 1

Illustration 4.9.1a Ballast and Void Spaces Gas Sampling System

OMICRONTONSBERG - NORWAY

1. STEAM LNG HEATERS

3. DOUBLE GAS PIPE

5. 1ST PLATFORM PORT

11. BOILER CASING PS

13. CARGO CONTROL ROOM

LOW GAS ALARM HIGH GAS ALARM ACCEPTED

ACCEPTED

ACTIVE

FLOW FAIL

DISCONNECTED

7. LABORATORY

9. ENGINE CONTROL ROOM

15. SPARE

2. UPPER FUNNEL

4. TOP OF LIFTSHAFT

6. 1ST PLATFORM STBD

12. BOILER CASING SS

14. SPARE

8. WORKSHOP

10. INNER BOTTOM

16. SPARE

HC. GAS SAMPLING SYSTEM OGS 3.0/16FOR BALLAST AND VOID SPACES

AUTOMATIC

CALIBRATION

PURGE

DIS/RE-CONNECT

(DIM)

UP

SAMPLE SELECTOR

SAMPLEPOINT

DOWN(DIM)

MANUAL

ACCEPTALARM

RESETALARM BUZZER

GAS IN CAB.PWR. RESET

LAMPTEST ON/OFF

1

2

3

45

76 8

9 10 12 13 14

Key

1. Type and Number of Sampling Points2. Sample Points in Full Text3. LED Colour and Function Legend4. LCD Display 2 x 20 Characters5. Dis/Reconnect Switch6. Mode Selector7. Manual Selector8. Sample Point Selector9. Accept Alarm Button10. Reset Alarm Button11. Buzzer12. Power Reset13. Lamp Test Button14. On/Off Switch

11



Issue: 1


4.9 Gas Detection Systems

4.9.1 Fixed Gas Detection Systems

Accommodation and Machinery Spaces Detection System

Maker: OmicronType: OGS 3.0/16

Introduction

The OGS 3 gas detector is based on the measurement of infrared radiationpassing through a volume of gas. The OGS 3 employs a dual beam, dualwavelength measuring principle with separate optical detectors.

Different types of gas have unique absorption spectra and can be easilyidentified by proper selection of the infrared wavelength at which absorptionis measured. Radiation at another wavelength measures the overalltransmission through the optical system and in the air volume.

By comparing the transmission of the two wavelengths, the gas concentrationin the air is determined. Selecting a wavelength with the unique characteristicof a particular gas prevents other types of gas present in the sample activatingthe detector and giving false alarms.

Radiation from two infrared sources passes through two narrow banded filtersselecting a measuring wavelength and a reference wavelength. Radiation isdivided by a beamsplitter into an external and internal path. The external pathis viewed by the measuring (main) detector which detects if the selected gas ispresent. The internal path is viewed by the compensation detector, thismonitors and compensates for any drift in the infrared source or detectors.

The four signals, two from each of the detectors, are amplified, digitised andfed into a microprocessor. The microprocessor calculates the gas concentrationand the results are presented as either a voltage, a current or a digital outputsignal. Internal signals are compared with test limits to monitor the electronicsand optical parts and if values outside the test limits are detected specific errormessages are displayed.

The system is situated on the bridge and the sampling sequence isautomatically controlled by solenoid selection valves, with the sampled gasbeing drawn into the panel by pumps, before passing over the infrared gasanalyser. The unit has a cycle time of 15 minutes.

If the methane concentration of any sample point reaches 30% lower explosivelimit LEL, an audible alarm is sounded and the corresponding indicator lampis lit on the panel.

Sample Point Location

1 Steam exhaust from steam/LNG heater

2 Upper funnel

3 Ventilating duct: gas pipe to boilers

4 Top of lift shaft

5 First platform: port side

6 First platform: starboard side

7 Laboratory on 3rd platform

8 Workshop on 2nd platform

9 Engine Control Room on 3rd platform

10 Inner bottom

11 Boiler casing: port

12 Boiler casing: starboard

13 Cargo control room

Boil-Off Gas to the Boiler Pipe Vent Duct System

Maker: OmicronType: OGS 21/1 IR

This system panel is situated on the bridge and continiously monitors a samplefrom the vent duct surrounding the boil-off gas pipe to the boilers.

If the methane concentration of any sample point reaches 30% LEL, an audiblealarm is sounded and the corresponding indicator lamp is lit on the panel.

If the methane concentration of any sample point reaches 50% LEL, an audiblealarm is sounded, the corresponding indicator lamp is lit on the panel and themain gas valve V2140 is tripped.


Illustration 4.9.1b Boil-Off Gas Pipe Vent Duct Gas Sampling System


ALARM ACCEPTED

ACCEPTALARM

RESETALARM BUZZER

LAMPTEST ON/OFF

HIGH GAS ALARM

LOW GAS ALARM

SYSTEM FAILURE

% HC.L.E.L.

HYDROCARBONSENSOR

GAS DETECTOR IN DOUBLE PIPE

3

2

2

1

54 7 8 9

Key

1. Sample Point in Full Text2. LED Colour and Function Legend3. LCD Display - % Hydrocarbon4. Accept Alarm Button5. Reset Alarm Button6. Buzzer7. Blank8. Lamp Test Button9. On/Off Switch

6

LOW GAS ALARM = 30 %

HIGH GAS ALARM AND GAS TO ENGINE TRIP = 50 %

Issue: 1

Skirt

Insulation

Rupture Disc

Removed

Rupture Disc

Rupture

Disc

Polystyrene

Insulation with

Stainless Steel

Cover

Catch Basin

Leakage Pipes

Upper Void

Lower

Insulation

Void

Upper

Insulation

Void

Bilge Well

Location of Cargo Area Gas Detection Points: Cargo Tank No.1

Nitrogen

Bleed


17. TOP VOID 5

19. UPPER INS. VOID 5

21. FWD PUMP VOID T/B

27. LPG EL. ROOM

29. CCR AIRLOCK

LOW GAS ALARM HIGH GAS ALARM ACCEPTED

ACCEPTED

ACTIVE

FLOW FAIL

DISCONNECTED

23. DRYER VOID ATM

25. CARGO CONTROL ROOM

31. SPARE

18. BILGEWELL VOID 5

20. LOWER INS. VOID 5

22. STORE ROOM FCSL

28. LPG EL. RM AIRLOCK

30. SPARE

24. LNG COMPR. ROOM

26. LPG COMPR. ROOM

32. SPARE

HC. GAS SAMPLING SYSTEM OGS 3.0/32

FOR BALLAST AND VOID SPACES

AUTOMATIC

CALIBRATION

PURGE

DIS/RE-CONNECT

(DIM)

UP

SAMPLE SELECTOR

SAMPLEPOINT

DOWN(DIM)

MANUAL

1

1. TOP VOID 1


5. TOP VOID 2


13. TOP VOID 4


9. TOP VOID 3


2. BILGEWELL VOID 1


6. BILGEWELL VOID 2






2

3

4

5

76 8

Key

1. Type and Number of Sampling Points

2. Sample Points in Full Text

3. LED Colour and Function Legend

4. LCD Display 2 x 20 Characters

5. Dis/Reconnect Switch

6. Mode Selector

7. Manual Selector

8. Sample Point Selector

9. Accept Alarm Button

10. Reset Alarm Button

11. Buzzer

12. Power Reset

13. Lamp Test Button

14. On/Off Switch

ACCEPTALARM

RESETALARM

GAS IN CAB.PWR. RESETBUZZER

LAMPTEST

ON/OFF

9 10 13 1411 12

Illustration 4.9.1c Cargo Areas Gas Sampling System

Gas Detection Point

Key



Issue: 1


Cargo Areas Gas Detection System

Maker: OmicronType: OGS 3.0/32

A separate gas detection system is set to givean alarm at a 30% LEL in thecargo hold and miscellaneous areas listed below. The control unit is similar inoperation to the accommodation and machinery spaces gas detection system.The control unit is situated in the cargo control room. The unit has a cycle timeof 36 minutes.

Sample Point Location

1 Top of void space above cargo tank No.1

2 Bilge well at bottom of cargo tank No.1 void space

3 Drain pipe from cargo tank No.1 insulation space

4 Nitrogen outlet from cargo tank No.1 wedge space

















21 Top and bottom of forward fire pump room

22 Bosun’s store upper level

23 By atmospheric heater - LNG compressor room

24 LNG compressor room

26 Local cargo control room - air lock

(Note: Sample position No.21, the emergency fire pump room has a three wayvalve on the forward deckhouse. The valve must be in the top position whenthe cargo is LNG and in the bottom position when the cargo is LPG.)


Issue: 1

Illustration 4.9.2a Portable Gas Detectors

OX-226/227For O2 in Air and InertUse: All Areas. O2 in Tanks

GX-7For O2 and % LEL in AirUse: All Areas Prior to Entry

NP-237MFor HC % VCL and % LELUse: Gas Freeing. HC in Inert

GX-2001BFor HC % LEL, O2, H2SPersonal Protection

O2 O2 %LEL O2 %VOL %LEL HC % LEL + O2 + H2S

00

2020 4040 60608080

1001001100

0022 44 66 888888

1010BATT.BATT.BATTBATT

4444 88 12121616

2020

VOL% ZERO %LELZEROZERO %LEL%LEL

OUTOUT

MODEL NP-237HMODEL NP-237H

% LEL% LEL% LEL% LEL

100 100

10 10

RIKEN KEIKIRIKEN KEIKIRIKEN KEIKIRIKEN KEIKI

RIKEN KEIKIRIKEN KEIKI

ININ

BATT.BATT.BB(PUSH)(PUSH)

ALARMALARM

ZEROZERO

2020OFFCHG.OFFCHG.

100100BATT.BATT.

OXYGEN MONITOROXYGEN MONITOR

RIKEN KEIKIRIKEN KEIKI

00

2020 4040 60608080

100100

BATT.BATT.% O2% O2

- ++++ - ++++

00

2020 4040 60608080

100100

%LEL00

2020 4040 60608080

100100

%LEL

ALARM RESET

METER LIGHT

OXYGEN ALARMCOMB ALARM FLOW INDICATOR

COMBZERO ADJ.

OXYGENCAL ADJ.

SPAN GAS INLET TOXIC GASDETECT.

BATTCHECK.

OFFCO2MEAS

CO2 PREP

COMB O2SPAN

GX-7RIKEN KEIKI



Issue: 1


4.9.2 Portable Gas Detection Instruments

The portable gas detection equipment on board is both comprehensive and wellproven. Each instrument is certificated and comes with manufacturer’soperating instructions and recommended spares and test kits. The certificatesare to be suitably filed and the monthly tests recorded.

The instruments are stored in the ship’s computer room on the main deckaccommodation.

Hydrocarbon and LEL Detector

Maker: RikenModel: NP-237HNo. of sets: 2

The ship carries two Riken portable combustible detectors designed for themeasurement of hydrocarbon gas/vapour % concentration and % LEL duringpurging and gas freeing. Normal operating instructions are carried inside thecover of each unit with additional instructions detailed in the manufacturer’shandbook.

On a monthly basis, each unit should be tested for gas sensitivity with the spangas test sampling bags which are stored in the ship’s computer room.

The use of the equipment and any maintenance carried out should be logged inthe appropriate file in the ship’s computer system.

Personal Multi-gas Analyser

Maker: RikenModel: GX-2001Type: H2S, O2 and HC LEL% No. of sets: 2

The ship carries two Riken GX-2001 personal H2S ppm and O2 % detectorswhich are designed to be clipped to the clothing of the operator. Operation andcalibration instructions are printed on the inside of the stowage container.

The use of the equipment and any maintenance carried out should be logged inthe appropriate file in the ship’s computer room.

Oxygen Meter/Analyser

Maker: RikenModel: OX-226No. of sets: 1

The ship carries two personal oxygen meters for the testing of the atmospherein tanks that have been gas freed before tank entry. An O2 detector head withextension cable line can be fitted into the bayonet fitting on top of the unit fortesting of the cargo and ballast tank atmosphere prior to entry.

Operation and calibration instructions are printed on the rear of the unit.

The use of the equipment and any maintenance carried out should be logged inthe appropriate file in the ship’s computer room.

Oxygen Meter/Analyser

Maker: RikenModel: GX-7No. of sets: 1

The ship carries two oxygen meters for the testing of the atmosphere in tanksthat have been gas freed before tank entry. An O2 detector head with extensioncable line can be fitted into the bayonet fitting on top of the unit for testing ofthe cargo and ballast tank atmosphere prior to entry.

Automatic Dew Point Meter/Analyser

Maker: ShawNo. of sets: 2

The ship carries two dew point meters to measure the moisture in air or gassamples with positive pressure. The battery powered hygrometer indicates bothdew point temperatures and water vapour to less than one part per million, onthe large meter dial. As the reading is specific to water vapour, calibration isaccurate for different gases.

The dew point meters are sent ashore every twelve months for reconditioningand recalibration.


Dew Point Meter/Analyser

Issue: 1

Illustration 4.10.1a Cargo Valve Remote Control SystemRemote Control Of Cargo Valves

Remote Control Of Throttling Valves

PI

PI

0 - 100%

SVC ClosedSignal/Indication

SVC OpenSignal/IndicationActuator

ESD Emergency Air Circuit

7psi

Power Air 8.8 bar

Power Air8.8 bar

Power Air 8.8 bar

Power Air 8.8 bar

SVC PositionFeedback/Indicator SVC Order

Signal

Close

OpenControl Pneumatics, Solenoids,

Pressure Transducers and Converters are located in Panels adjacent to the

Cargo Tank Domes

ESD Emergency Air Circuit

PI

PIAL

FCV126

XE111

ESD ShutdownSignal

Power AirFor Cargo Valves

Key

Air

Electrical Signal

Instrumentation

V3001

V3000 V3000

ESD System

V3000V3000

LNG Compressors/Cargo Heaters/

Vaporizers Control Air

V3002

PCAL168

Cargo Instrument Air ReceiverLNG Compressor Room

(1.5m3)

Drain

PI

PI2

PC5A

HC5

SA5

XC5

SI5A

SI5B PC

5B

PC3

PC3

Drain

V1424

V1424

Air Receiver(4m3)

V1432

V1431

V1433

HC3

SA3

XC3 SI

3BSI3A

PI PI PI PIAlumine Active

Air Dryers

ToWorking AirSystem

ToCO2

Alarm

ToQuick Closing

ValvesPanel

V1438

ToWorking Air

Receiver

ToEngine Room

Working AirSystem

To Engine RoomInstrument Air

System

To DeckWorking Air

System

PCV5PCV

3

Automatic Drain

Quincy Instrument Air Compressors

Drain

Type235

Type245



Issue: 1


4.10 Valve Remote Control and Emergency Shutdown System

The Emergency Shutdown System (ESD) is designed to ensure a controlledshutdown of cargo equipment both ashore and on the ship to avoid any unsafeconditions arising. It is essential that the machinery is stopped and valvesclosed in the correct order to avoid any pressure surges ashore or on board.

In the event that the ship accidentally moves away from the jetty, it is of theutmost importance that all plant is stopped to allow emergency disconnectionwithout the risk of LNG spillage.

The valve remote control system and the ESD system are both operated bypneumatic air fed from the cargo instrument air system. This system is itselffed from the main instrument air system.

Compressed air is supplied to this system from whichever of the threeinstrument compressors is/are selected for duty. The compressor(s) will cut inand out automatically according to the air pressure in the instrument airreceiver. The instrument air receiver has an outlet valve, which feeds the cargoinstrument air system via a system of filters and dryers to ensure the quality ofthe compressed air.

The instrument air receiver, filters and dryers are located in the engine room.The cargo instrument air receiver is located in the LNG compressor room.

Cargo Tank High Level Shut-off System

The cargo tanks each have an independent high level alarm and shut-offfunction which works independently. The shut-off function is connected to theOmicron high level alarm system (see section 4.1.3 for further details). Whenthe liquid level in the tank reaches a position equal to 99.2% full by volume, asignal is sent to the tank loading valve remote control system to close the valveautomatically. When this valve is activated, red warning lights will flash andan alarm horn will sound on deck.

A prewarning alarm is sounded when the tank volume reaches 95%. Thisactivates an alarm in the CCR and an alarm horn with a different tone fromabove will sound on deck, accompanied by an orange flashing warning light.The reset for this system is at the DCS system control console in the cargocontrol room. For further details, see section 4.1.3, high level alarm andoverfill system.

4.10.1 Cargo Valve Remote Control System

Type: Pneumatic/electronic

The actuator air system supplies air to all cargo valve actuators. Air is suppliedfrom the instrument air compressors at 8.8 bar. The air is filtered, dried andstored in a 1.5m3 receiver, located in the LNG compressor room. After thisreceiver there is one pipe for the supply of power air for the actuators and onepipe for the rest of the pneumatic control system. The last pipe is branched intothe emergency air, control air and instrument air circuits.

Actuator Air

This air system supplies air to all the actuators. The air supply is controlled bya 3-way valve, FCV 126. This valve will open for the power air supply whenthe emergency air circuit is pressurised. If the emergency loop pressure isreleased, this valve will open to atmosphere and the actuator air will vent off.

The remotely operated shut-off valves at the crossovers and the domeconnections are fitted with air return actuators. The actuators on the throttlingvalves in the loading lines control the variable valve position, enabling remoteflow control of the loading rate.

The control air circuit for each actuator is pressurised with air by hand operated3-way valves to the shut off cargo valves and spring loaded valves to the fillingpipe throttling valves.

Cargo Valve Operation

The cargo valves are normally closed. To open a valve, the valve’s controlcircuit is pressurised by the opening of the solenoid operated control valve inthe pneumatic valve panel. This action is initiated by the operator selecting theopen command via the DCS system. These valves are situated at the cargo tankdome or at a convenient location close to the actual valve. The control airpressure opens a pilot valve for the supply of working air to the actuator andthe cargo valve opens.

The valves take approximately 10 seconds to open and 15 seconds to close.The cargo valves are closed by releasing the control air circuit by the controlvalve.

The valves in the cargo discharge and spray pump lines close automaticallywhen the pump motors stop. This arrangement contains a pneumatic time relay,which after a delay time will enable these cargo valves to be operated again.

A detailed description of the valve operation follows after the cargo gate valveillustration (4.10.1b) overleaf.


Issue: 1

Key

Compressed Air

Exhaust

Pneumatic Gate Valve Closed: Actuator Opening

Illustration 4.10.1b Cargo Gate Valve

Pneumatic Gate Valve Open: Actuator Closing

Spring

From Control Valve

Non-Return Valves

3 Way

Differential Valve

Opening Speed

Adjustment

Needle Valve

Open Stroke Limit Valve

Open Stroke Limit Valve Seat

O Ring

Accumulator

Chamber

Access for

Emergency

Jacking

Of Piston

Piston Seals

Closing Speed

Adjustment Needle Valve

Spring

Exhaust

3 Way

Differential Valve

Limit Valve

O Ring

Open Stroke Limit Valve

Spindle

Exhaust Port

to Atmosphere



Issue: 1


Cargo Gate Valve Pneumatic Actuator Operation

(See illustration 4.10.1b)

Opening

The operator selects the OPEN command from the DCS system valveoperation menu. The system opens the solenoid operated control valve for thatvalve and compressed air fills the accumulator chamber via non-return valveB. This valve prevents the air from being exhausted.

The air also enters the piston chamber via non-return valve A, through the portimmediately above the valve. This lifts the piston when the air pressure reachesa level high enough to overcome the friction of the piston seals.

The piston lifts the valve gate spindle at a speed which is regulated by thesetting of the opening needle valve.

As air is entering the piston chamber, air also flows to the three-waydifferential slide valve, located at the bottom left of the unit. This is forced tothe left which opens the exhaust port and vents the air from the top part of thepiston chamber to atmosphere. The slide valve is held against a spring by thecontrol air pressure.

When the piston moves to within 25mm of the top of the chamber it will openthe stroke limit valve. This valve will bleed air from the signal line which willin turn cause a pressure switch to register this pressure loss and send a closesignal to the control valve, shutting off the supply of control air.

The control line remains pressurised therefore the piston will remain in thisposition until a close cycle is initiated.

There is an emergency closing/opening facility for this type of valve. The topcap is removed and a special threaded tool is inserted into the piston chamberwhich is then screwed in to the piston crown. The valve piston can then bejacked open or closed as required.

Closing

The operator selects the CLOSE command from the DCS system valveoperation menu. The system opens another solenoid operated control valve forthat valve and the compressed air in the control line is exhausted.

The three-way differential slide valve, located at the bottom left of the unit,moves to the right via the action of the spring and the drop in air pressure. Thisopens the port to supply air from the accumulator chamber to the top of thepiston chamber which forces the piston down, closing the gate valve.

The closing speed is regulated by the setting of the closing speed needle valveand can be set from approximately 15 seconds to one minute.

When the piston moves to within 25mm of the bottom of the chamber it willopen the close stroke limit valve. This valve is similar in operation to the openstroke limit valve, bleeding air from the signal line to cause a pressure switchto register this loss and send a close signal to the control valve. This stops theexhausting of control air.

The piston will then remain in the closed position.


Issue: 1

Illustration 4.10.2a Fibre Optic Ship/Shore Link System and Pneumatic ESD Circuit

ManifoldStbd

ManifoldPort

DomeTank 5

DomeTank 4

Cargo Control Room

JunctionBox

JunctionBox

DomeTank 3

DomeTank 2

DomeTank 1

PS

PS

JunctionBox

Internal TelephoneHotline Automatic

ExchangeTelephone

ESD RelayPanel

220V 60Hz

From / ToNEBB System

At C.CConsole

SV1

SV2

PS3

LNG CompressorRoom

ConferenceRoom

ConverterRoom

876

1524VDC

220V60HZ

CutOff

RelayBox

Accommodation

Emergency QuarterHead

Optical FibreTransmission

Panel

ESD RelayPanel

To ManifoldValves

From AirReceiver

SV2

PS3

220V / 60Hz SupplyFrom CCC

PCLA4b

DUAL4

PI4

SV1

7.0 BarAir Supply

Key

Compressed Air

Electric Cable

Fibre Optic

OPTICAL FIBRE



Fibre Optic and Pneumatic Telephone Cabinet Under Port Manifold

Issue: 1


4.10.2 Emergency Shutdown System

The emergency shutdown (ESD) system is a safeguard provided in addition tothe individual safety devices for plant and equipment. The system may beactivated manually or automatically from on board or from ashore and has twolevels of priority, namely ESD1 and ESD2.

The ESD panel is fitted in the local cargo control room. It is interfaced to theDCS system and has links to the Pyle and Miyaki systems.

ESD1 may be initiated from on board or from ashore and will result in ashutdown of the cargo system both on board and ashore.

ESD2 can only be initiated manually from the terminal or automatically if theship drifts outside the working area of the loading/unloading arms. Activationof an ESD2 will automatically initiate an ESD1 and, after stopping cargooperations, cause the disconnection of the loading/unloading arms (in certainterminals).

Initiation of ESD1 causes the following on board:

a) The low duty (LD) and high duty (HD) compressors stop.

b) All cargo and spray pumps stop.

c) ESD quick-closing manifold valves shut within 30 seconds. Theemergency air circuit ensures ESD valve operation in the event ofa loss of main air.

d) The inert gas generator blower stops.

e) An ESD shutdown signal is transmitted to the shore terminal viathe ship-to-shore link.

Initiation of ESD1 causes the following actions in the loading terminal:

Stops the terminal loading pumps

Shuts the terminal ESD valves within 15 seconds

Immediately opens the terminal loading pumps’ kickback valves

ESD1 is initiated on board by the following actions:

1) Manual initiation: Switches are positioned at the followinglocations:

Cargo control room

LNG compressor room

Emergency headquarters

Each cargo tank dome

Port and starboard manifold platforms

2) High temperature (fire). Fusible plugs, designed to melt atbetween 98ºC and 104ºC, are fitted at the following locations:

Catwalk aft of each cargo tank dome

Two at each port and starboard manifold platforms

3) Electrical power failure: In the event of a failure of the electricalpower supplies.

4) Low pneumatic control air pressure. A low-low control airpressure of 3 bar will initiate an ESD1 trip. To prevent spurioustripping, a time delay is incorporated which may be adjustedbetween 0 and 30 seconds and is normally set at 10 seconds.

5) An ESD1 signal from the shore. A shutdown signal from the shorelink.

6) Low pressure in the pneumatic shore to ship link. After thepneumatic link has been pressurised from the shore, the overridekey switch at the ESD cabinet in the local cargo control roomconsole can be switched to normal. Loss of air pressure willinitiate an ESD1. The pneumatic hose link is not connected undernormal conditions, but it is tested by ship/shore on a routine basis(following NWS requirements).

Automatic initiation is carried out in the event of:

Low pressure in the loading arm hydraulics

Low pressure in the hydraulic circuit of the emergencyrelease coupling of the individual loading/unloading arms

Power loss in the control system

Excess angle of the loading/unloading arm slewing or apex angle

High level in the surge drum

Fire alarm on the jetty

Loss of signal between the ship and shore ESD link

Activation of ESD2

The ESD2 system can only be activated from the shore terminal andautomatically activates ESD1. After the cargo operations have been stoppedthere is a time delay and a warning before the terminal loading/unloading armsemergency release couplers operate. A section of the emergency releasecoupler incorporating a valve remains attached to the ship’s manifold flanges.

The arms will lift clear allowing the mooring arrangements to be released. Thesections of shore arms remaining bolted to the ship’s manifold flanges have tobe removed and returned when convenient.

ESD System Testing

The ship’s ESD1 system is to be tested prior to arrival at the loading orunloading ports.

A different activation point, including manual pushbuttons or the removal of afusible plug, should be utilised at each test, to allow a complete check of thesystem just prior to arrival in port. After arrival alongside and with armsconnected, operation of ESD1 will be checked by the ship and the shore whilethe ship’s manifold is warm and then checked again after the cooldown iscompleted.

The closure time of the shore valves will be checked by the terminal, but theclosing times of the ship’s manifold valves should be checked at every test bythe cargo engineer or chief officer. The closing time for the ship’s manifoldvalves must be within 30 seconds. The shore valves for loading and unloadingterminals close within 15 seconds.


Issue: 1

Illustration 4.10.2b Emergency Shutdown Logic

PUSH BUTTONS IN CARGO CONTROLROOM. EACH CARGO TANK DOME,PORT AND STARBOARD MANIFOLDAND EMERGENCY HEAD QUARTER.

THERMAL MELTING FUSES AT EACHCARGO TANK DOME.

FLEXIBLE HOSE VENTED.

SIGNAL FROM FIBRE OPTIC TRANSMISSION PANEL.

CONTROL AIR PRESSURE LOW.

ELECTRIC POWER FAILURE.

CLOSE MANIFOLD VALVES.

CLOSE CARGO TANK FILLINGVALVES.

CLOSE MAIN GAS VALVE TOENGINE ROOM.

STOP CARGO PUMPS ANDSPRAY PUMPS.

CLOSE PUMP VALVES.

SIGNAL TO FIBRE OPTICTRANSMISSION PANEL.

STOP COMPRESSORS.

ALARM.

DELAY90 SEC

OR

OR



Issue: 1


Emergency Loop System

There is an emergency air loop system to quickly close all valves in the cargohandling system in the case of a fire or pipe fracture.

The emergency loop system consists of a special air circuit, pressurised fromthe control panel. The circuit is fitted with fusible plugs, melting at 102.5ºC,and manual releases (described in the ESD section), located at strategic pointsaround the cargo system.

The emergency circuit is supplied with air from the main control air circuitheader via spring loaded valve HCV-122 in the control panel. The pressure onthis valve keeps valve FCV-124 open. In the case of any small leakages, thepressure will be maintained through restriction valve FO 125. The capacity ofthis valve is so small that the emergency circuit pressure will blow off if afusible plug melts or a manual release is opened.

The emergency circuit controls the three-way valve FCV 126 in the power airheader. The pressure in the emergency circuit will open this three-way valveto pressure from the air receiver. If the emergency circuit is released, the valvewill open to atmosphere and the pressure drop in the power circuit will closethe actuator controlled cargo valves.

The emergency air circuit can also be released from the control panel byopening the hand control valve HCV 123.

4.10.3 Ship Shore Link

Linked ship-shore emergency shutdown systems have been required bySIGGTO since the early days of LNG loading and discharge installations. Theyminimise the consequences of an accident or, if abnormal conditions arise, theyallow the process to be shut down with minimum spillage of liquid. Thusconsequent risk to jetty and ship’s structures and escape of flammable vapouris avoided. Since both the ship and the shore terminal exchange liquid andvapour, the shipside and shoreside emergency shutdown systems must belinked. This is to avoid:

Excessive surge pressure on the loading arm connection causing damage. The upstream valve is closed first.

Overfilling the ship or shore tanks.

Risk of damage or spillage due to excessive movement of theship with respect to the berth.

In addition to the safety requirement for ESD, the ship to shore link has beenextended to handle communications by telephone. Each loading/unloadingterminal has the ship/shore communication and ESD system integrated and allterminals have a common ship/shore interface connection.

The key switch which selects which ship/shore link method to be used(dependent on the terminal) has an inhibit position to prevent spurious ESDsignals being transmitted to the shore before the ship’s systems are ready.

The ship-shore links are implemented on this ship as follows:

36-way Miyaki connectors designed for Zone 1, Div II, temp rise T4 are fittedport and starboard. These are for use at P’yeong Taek, Inchon and Bintulu.

A 37-way Pyle national connector system for Oman is fitted port and starboard.

WARNINGFour way earth bonding connectors are provided but not used due toISGOTT regulations prohibiting their use.

A 13-way ITT Cannon MIL - Std connector is fitted port and starboard. Theseare for use at Arun and Bontang.

Pneumatic Systems

Two quick-connect male umbilical pneumatic connectors are provided at themanifolds for use with the similar systems used at Ras Laffan and otherterminals. These directly trip the loading valves on pressure loss and are sensedby the ESD system.

ESD System - Shore Connection Box at Port Manifold


Pyle National Electrica Connection Box at Port Manifold

Issue: 1

Tank Relief Valves: Whessoe

Flanged Pipe

to Vent Mast

Low Pressure

Pilot Valve

High Pressure

Pilot Valve

Illustration 4.11.1a Cargo Tank Relief Valves

Section 4.11.1/2 - Page 1 of 2


View of Relief Valves on Cargo Tank Dome

Tank Relief Valve on Cargo Tank Dome

Issue: 1 Section 4.11.1/2 - Page 2 of 2


4.11 Relief Systems

4.11.1 Cargo Tank Relief Valves

Maker: LuceatType: R2101-HPNo. of sets: 15No. per tank: 3

Settings:Overpressure: 0.25 barFlow rate per valve: 2,2811Nm3/h

Vacuum Relieving: -1kPa gaugeFlow rate per valve: 4,302Nm3/h

Each cargo tank is fitted with two pressure/vacuum relief valves as required bythe IMO code.

The cargo tank relief valves are fitted at the vapour domes of each tank andvent to their associated vent mast riser. The relief valves are of the PORV (pilotoperated relief valve) type. A cargo tank pressure sensing line relays thepressure directly to the pilot operating valve. In this way, the accurateoperation required at the relatively low pressure inside the tank is assured.

The valves consist of the following basic components:

Main pilot valve

Auxiliary pilot valveUpper housing, containing diaphragm and pallet assembly

Exhaust manifold, which discharges the gas from the tank

The cargo relief valves are set up initially by the manufacturers for therequirements on the ship. If an overhaul of the valves by ship’s staff is carriedout, the valves must be checked and reset to the original settings. (Seemanufacturer’s instructions for details.)

It is extremely important that the vent mast is checked on a regular basis anddrained of any accumulation of water. This is to ensure that the relief valvesoperate at their correct settings, which would otherwise be altered if waterwere to accumulate in the vent mast and flow onto the valve assembly.

Valve Operation

Operation Under Pressure Using the Main Pilot ValveWhen the pressure in the tank is less than the opening pressure, the main pilotvalve allows the tank pressure to act on the larger upper area of the diaphragmand pallet assembly, keeping the valve closed.

When the pressure in the tank is more than the opening pressure, the main pilotvalve is forced to vent the pressure on the upper area to the atmosphere,causing the valve to fully open.

Operation Under Vacuum Using the Auxiliary Pilot ValveWhen the vacuum in the tank is lower than the opening vacuum, the auxiliarypilot valve allows atmospheric pressure to act on the larger upper area of thediaphragm and pallet assembly, keeping the valve closed.

When the vacuum in the tank is more than the opening vacuum, the auxiliarypilot valve shuts off the port to the atmospheric and allows the tank vacuum toact on the larger upper area of the diaphragm and pallet assembly, causing thevalve to open.

4.11.2 Line Relief Valves

Each section of the cargo pipework, except the vapour line, that can be isolatedby two valves has an overpressure relief valve fitted.

The cargo manifold relief valves and the relief valves on the liquid header areset to lift at 10 bar and relieve pressure back to a collecting tank above thecargo control room. This tank vents to vent mast No.4.

The collecting tank is fitted with a level alarm which raises an alarm via theDCS system.

Relief valves between the tank dome and the throttle valve release pressureback to the nearest cargo tank dome.

Issue: 1

PDCLA

2

PDIAH

3

FCV

33

PDICA

5

PDAL

4

PDAH

4

PDIALH

1

Electrical Signal

Instrumentation

Vouid Space and Void/Tank Relief Valves

Void Space

Void Space

V-2245

V-2245

Atmosphere

Atmosphere

Cargo Power AirOpen Void Space

Relief Valves

SVC Signal From:

PDICA 5: -0,08 bar

PDICA 5: 0,015 bar

PDIAH 3: 0,05 bar d.p.

Key

FCV

34

FCV

34

Aft

Port Starboard

Location of Instrument Box

for Void Space and Tank

Relief Valve Pneumatics

Illustration 4.11.3a Void Space Relief Valves



View Inside Instrument Cabinet at Cargo Tank Dome Showing Pressure Transmitters

Issue: 1


4.11.3 Void Space Relief Valves

The void spaces are protected against an overpressure of 0.15 bar or anunderpressure of -0.08 bar. If void space pressure switch 5PDICA is activatedby either of these pressures, a signal is sent to the DCS system which will opensolenoid valve FCV33 and supply air to the pressure control valves FCV34.These control valves will supply power air to the actuators of the butterflyvalves. These valves will open to vent the void space to atmosphere.

The cargo tanks and void spaces are also protected against differential pressurebetween each other. Pressure switch 3PDIAH will initiate the above sequenceif the differential between the tank and void space exceeds 0.05 bar.


Illustration 4.11.3b Monitoring of Pressure Relatives (Tank - Void Space - Atmosphere)

-0.1

0.0

0.1

0.2

-0.1

0.0

0.1

0.2

Open Relief Valve Position 5(Each Void)

Atmosphere AtmosphereVoid Void Tank Tank

Open Mechanical ReliefValve on Tank (Each Tank)

High Pressure Alarm Position 1 (Each Tank)

Compressor:Main Header PressureAdjustable.Normal Setting 1060 mbar

High Pressure Alarm Position 4(Each Void)

High Pressure Alarm Position 3(Each Tank)

Low Pressure AlarmPosition 4 (Each Void)

Dry Air to VoidRequested Position

Low Pressure Alarm Position 1(Each Tank)

Open Relief Valve Void Position 3(Each Tank)Open Relief Valve Position 5

(Each Void)

Stop LNG Compressor Tank Vent FansPumps and Spray Valves Position 3

(Each Tank)(Common Cutout)

Safety Stop LNG Compressor Position 72(One Pressure Switch in Suction Line)

Stop LNG Compressorand Pumps Position 2 (Each Tank)

VOID PRESSURE TANK PRESSURE

Position 1 ; One Sensor per TankPosition 2 ; One Sensor per TankPosition 3 ; One Sensor per TankPosition 4 ; One Sensor per TankPosition 5 ; One Sensor per TankPosition 72 ; One Sensor per Tank (Common)

ATMbar

ATMbar

Issue: 1

PI1

HC1A

80120a

HC1

SI1

PI2

HC2A

80120b

HC2

SI2

Illustration 4.12.1a Ballast Piping System

Key

Sea Water

Bilge

Electrical Signal

V66

V55A V55

V54A V54 V52 V52

V58 V59A

V57

V57

V63

V33

From

Bilge System

Ballast

Pump

1,200 m3/h

Ballast

Pump

1,200 m3/h

From

Fire and Deck

Wash System V33

V53

V64 V59

V64 V59

V13

V96

No.5 Side Tank

(Port)

No.4 Side Tank

(Port)

No.3 Side Tank

(Port)

No.2 Side Tank

(Port)

No.1 Side Tank

(Port)

No.5 Side Tank

(Starboard)

No.4 Side Tank

(Starboard)

No.3 Bottom Wing

Tank (Starboard)

No.2 Bottom Wing

Tank (Starboard)

No.1 Bottom Wing

Tank (Starboard)

No.3 Bottom Wing

Tank (Port) No.2 Bottom Wing

Tank (Port)

No.1 Bottom Wing

Tank (Port)

No.1

Lower Cross

Tank

No.2

Lower Cross

Tank

No.3

Lower Cross

Tank

No.2

Double Bottom

Spare Water

Ballast Tank

No.3 Side Tank

(Starboard)

No.2 Side Tank

(Starboard)

No.1 Side Tank

(Starboard)

V94 V92 V90 V88 V86 V84 V82 V80 V78 V74

V72

V95 V93 V91 V89 V87 V85 V83 V81 V79 V77 V73

V23 V99 V69

V97V98

V53

V61

V56 V60

Sea SuctionOverboard

Emergency

Connection For

Backflushing

Main Condenser

Sea Suction

Emergency

Bilge Suction

Overboard

V70

V71

V71

V72




4.12 Ballast System

4.12.1 Ballast Piping

Ballast Pumps

Maker: WorthingtonType: 10-LNCV-12 vertical centrifugalCapacity: 1,200m3/hSpeed: 1,750 rpmNo. of sets: 2

Stripping Ejector

Maker: GolarType: 4” - 5” - 5”Capacity: 120 m3/h at 3m suction lift

Driving water at 106m3/hNo. of sets: 1

In the ballast system there are two ballast pumps with suction from all ballasttanks. Each pump is of the electric vertical centrifugal type with a dischargecapacity of 1200m3/h. The pumps are primed from the stripping ejector. Thepumps are located at the forward end of the engine room, at tank top level. Thehydraulic unit which drives the remote operated ballast valves is located at thislevel, centrally between the two ballast pumps.

In normal service, the port pump is connected to all port tanks and thestarboard pump to all the starboard tanks. However, it is possible to draw fromboth sides with one pump. The ballast pumps can have suction simultaneouslyfrom a number of tanks, this reduces the water velocity in the pipe branchesand valves.

From the cargo control room, all the ballast valves can be hydraulicallycontrolled. The same pipes and valves are used both for the filling andemptying of all the ballast tanks.

Special drop valves (hydraulically operated) are installed for direct emptyingto the open sea. The bottom wing tanks can be filled directly through the dropvalves.

The ballast eductor works as a stripping pump for the ballast tanks and as apriming unit for the ballast pumps. This is a water driven unit with a dischargecapacity of 100m3/h. The stripping ejector driving force comes from the ejectorpump (106m3/h).

Ballast operations from the DCS will be fitted in the near future.

Ballast Valves

The hydraulic valves are all located in the duct keel, adjacent to the actualballast tank. The hydraulic pump unit is situated between the two ballastpumps in the engine room. Commands from the DCS system are transmittedto electrically operated solenoid valves located in a section of the local cargocontrol room automation cabinet. The valves may be operated locally in theevent of a failure of the remote operation electrical/hydraulic systems. Thevalves are designated as follows:

Ballast Tank Valve No. Hydraulic BlockSide tank 5 port V96 216Bottom wing 3 port aft V94 234Bottom wing 3 port forward V88 231Side tank 4 port V92 213Side tank 3 port aft V90 210Side tank 3 port forward V84 207Bottom wing 2 port aft V86 228Bottom wing 2 port forward V82 225Side tank 2 port V78 204Bottom wing 1 port aft V80 222Bottom wing 1 port forward V74 219Side tank 1 port V71 201Double bottom 2 aft V65 413Double bottom 2 forward V69 410Lower cross 3 V99 407Lower cross 2 V98 404Lower cross 1 V97 401Side tank 5 starboard V95 316Bottom wing 3 starboard aft V93 334Bottom wing 3 starboard forward V87 331Side tank 4 starboard V91 313Side tank 3 starboard aft V89 310Side tank 3 starboard forward V83 307Bottom wing 2 starboard aft V85 328Bottom wing 2 starboard forward V81 325Side tank 2 starboard V77 304Bottom wing 1 starboard aft V79 319Bottom wing 1 starboard forward V73 322Side tank 1 starboard V70 301

4.12.2 Ballast Control and Indicating System

The ballast system is primarily controlled via the DCS system. Operation iscarried out from the ballast primary window which this visualises the entireballast system. From this view the tank levels of all vessel fluids used as ballastcan be monitored and the ballast system pumps and valves can be controlled.The primary view also shows the vessel heel and trim data.

Ballast system and alarm status can be viewed in more detail by selecting thesecond (lower) level ballast or status views. The cargo control functioncomprises the following:

Manual control Route guidance

Automatic routing Heeling control

Operator Interface

The cargo and ballast process views show the fluid control systems comprisingtank, valve and pump symbols interconnected by piping and manifolds. Theoperator monitors the status of each device by displaying the views andoperating the equipment as required. The starting and stopping of pumps andthe opening and closing of the valves is normally part of the automatic cargoand ballast tank filling and emptying sequences, which are initiated from theoperator stations.

In the manual operating mode, the pumps and certain valves are controlledfrom the module operating menu for each individual item of equipment. Inaddition to tank, valve and pump symbols, some views contain a global controlmodule which makes it possible to control the operation of several tanks,pumps and valves simultaneously. The cargo and ballast second (lower) levelprocess views are displayed via a hot spot on the process view, the navigatorfunction or the navigator button on the operator panel.

The global control module symbol comprises a box with text components thatshow the current operational state of the module. The text varies depending onthe selections made via the commands on the global control module operationmenu. The text box at the left of the symbol shows the selected control modefor the module, ie, ballast or stripping mode. The mode field shows the selectedoperating mode, ie, manual or auto.

The ballast levels can be seen on the DCS system ballast primary window.Each tank has a graphic representation of the level and a read out of thecontents in cubic metres. The tank level sensors are of the Autronica pressuretransmitter type.

At the bottom of the screen is a graphic representation of the ship’s trim andheel, measured in metres forward and aft and degrees respectively.

Issue: 1


Part 5Cargo Auxiliary and Deck Systems

Issue: 1

Illustration 5.1a Fire Detection System

RESET

AUTRONICA

MORE ALARMS

SOUNDER SILENCE

DYFIDynamic Filter Process

DEVICE(S) STILLIN ALARM COND.

PREWARNING

BS100FAULT

MAINS

FUNCTIONS DISABLED

AUTRONICA

PREWARNING

MORE ALARMS

FIRE

FAULT

POWER

SILENCE BUZZER

Common Fire Alarm Output 2 Minutes Delayed

Common Fire Alarm Output For Door Release System

Failure Output

Common Fire Alarm Output

24V DC For Flame Detectors

Repeater Panel Engine Control Room

To Engine Room Monitoring System(No Time Delay)

Mains(230 VAC)

Loop00 etc to

Loop03Disconnection and Test Mode Switches

Inside Cabinet

Buzzer and Battery Inside Cabinet

Detectors

Detectors

The five element keypad consists of four arrow keysand one 'carry-out' (enter key). The keypad is used to accessand handle information on the system. The four arrow keyscontrol the cursor on the control panel text display.

These keys scroll the menu and move the cursorup and down in the menu text on the text display.These keys also scroll figures and letter values.

These arrow keys scroll the menu and move the cursorleft or right in the menu on the text display.

'Carry-out' (entry) key. Selects the menu part on which thecursor is currently pointed.

Operating Buttons:

More AlarmsRed lamp illuminates when morealarms are present.

Text display(Information Window)

FireRed Lamp Sign illuminates foran alarm condition.*

PrewarningAmber (yellow) lamp illuminateswith a pulsating light when aprewarning situation occurs.*

FaultAmber (yellow) lamp illuminates forany fault. Pulsating light.*

Function DisabledAmber (yellow) lamp illuminateswhen any part of the systemis disabled (isolated).

MainsGreen lamp illuminates when thepower is on.

Device(s) Still in Alarm Condition.Amber (yellow) lamp illuminateswhen an address (detector)is automatically disabled.

These lamps can be customassigned.

Indication Devices: More AlarmsThis button allows the second lineof the text display to be scrolled.Reveals additional alarms on thesystem.

Sounder SilenceWhen this red button is pressed,all alarm devices and the internalbuzzer are muted.

PrinterResetWhen the green button is pressed,all events in the system are reset.

BU70



Issue: 1


Part 5 Cargo Auxiliary and Deck Systems

5.1 Fire Detection System

Maker: AutronicaType: BS-100/4

The BS-100/4 fire detection system is a computerised, fully addressableanalogue fire alarm system with analogue detectors. The central control unitwith back-up battery, operating panel and power supply is contained in acentral cabinet on the bridge. There is a repeater panel in the fire headquarters.

The system is interfaced to the Valmarine DCS system via a converter andRS232 serial interface. The DCS system indicates loop status and can alsocontrol the fire pumps. The operator can also access deck plans indicating theexact location of individual detectors.

The system uses a wide range of detectors and sensors to suit different needsand conditions. It includes detectors with different alarm parameters, forexample, ion and optical smoke detectors, heat and flame detectors, manualcall points, short circuit isolators and timers where required. The detectors arewired in a loop configuration with 4 loops in total. A fault in the system or afalse alarm is detected immediately since the function of the detectors andother installed loop units are automatically and continuously tested.

Operation

The operating panel consists of a text display information window, indicationlamps, operating buttons and a five button/arrow keypad. These control itemsenable the entire fire detection and alarm system to be controlled.

The five arrow keypad consists of four arrow keys and one ‘carry-out’ (enter)key. The keypad is used for accessing system information. The four arrow keyscontrol the cursor on the control panel text display.

The up and down arrow keys are used for scrolling in the menu and for movingthe cursor up or down in the menu text on the text display. The keys also scrollfigures and letter values when they are to be entered in the menu functions.

The left and right arrow keys are used for scrolling in the menu and formoving the cursor to the left or right in the menu, on the text display.

The ‘carry-out’ (enter) key selects the menu part to which the cursor currentlypoints.

Prewarning

In certain conditions, such as a rise in the detector ionisation level, a detectormay trigger a prewarning alarm. This may be a prelude to an actual fire alarm,so the alarm should be thoroughly investigated.

The following indications appear on the control panel in the event of aprewarning:

The text display indicates the address(es) of the detector(s)which are in the in prewarning mode

The yellow prewarning lamp flashes and the internalbuzzer sounds

The display and printer will show text such as:

‘PV05 ADDRESS NO. 0605INVESTIGATE PREWARNING LOCATION’

If more than one prewarning event is registered, the display will change to:

‘PV07 ADDRESS NO. 06072 PREWARNINGS REGISTERED’

All active prewarnings may be seen via the menu function; ‘SHOW STATUS’‘PREWARNING’. Access to the menu is obtained by pressing the enter key onthe front panel.

Action to be Taken in the Event of a Prewarning

a) Follow all the precautions as described in the local fireinstructions.

b) Open the control panel door.

c) Press the SOUNDER SILENCE button. The buzzer will give ashort signal approximately every fourth minute as long as thedoor remains open.

d) The PREWARNING indication lamp will now change to a steadylight.

e) Press the RESET button. The following text will shortly appear inthe display; ‘RESET PROCEDURE IN PROGRESS WAIT .....’.This text will remain on the display for up to 60 seconds. Thereset procedure is executed within this 60 second period.

f) If the detectors have now returned to a normal condition, thefollowing text will appear in the display; ‘RESET OK’‘NORMAL CONDITION’.

g) Close the panel door.

In the normal condition, the MAINS indication lamp will be the only indicatorilluminated when the door is closed.

Fire Alarm

The following indications appear on the control panel in the event of a firealarm:

The red FIRE indication lamp flashes and the buzzer sounds

The text display indicates the address(es) of the detector(s)which initiated the first fire alarm. The display will also showany items which may be disabled, eg, bells, sounders etc

If the alarm was preceded by a prewarning alarm, the prewarninglamp will illuminate steadily

The display and printer will show text such as:‘AL 01 ADDRESS NO. 0605’

All sounders/fire doors/alarms/fan stops are activated(as connected/programmed)

Action to be Taken in the Event of a FIRE Alarm

Follow all precautions described in the local fire instructions. When the sceneof the fire has been investigated and the necessary action carried out, thesounders may be switched off.

a) Open the control panel door.

b) Press the SOUNDER SILENCE button.

c) All alarm devices (including the internal buzzer) will be muted.The red FIRE indication lamp will switch to a steady light.

All alarm outputs from the control panel will be turned off when theSOUNDER SILENCE button is pressed.

(Note: There are various silent alarm functions such as; day/night/master clocktime controlled functions and sounder activation time delays available, see themanufacturer’s manual for further information on these functions.)

If the MORE ALARMS indication lamp illuminates, see the next section.

d) Press the RESET button. The following text will appear in the textdisplay; ‘RESET PROCEDURE IN PROGRESS WAIT.....’ Thistext will remain on the display for up to 60 seconds. The resetprocedure is executed within this 60 second period.


Issue: 1

Illustration 5.1a Fire Detection System

RESET

AUTRONICA

MORE ALARMS

SOUNDER SILENCE

DYFIDynamic Filter Process

DEVICE(S) STILLIN ALARM COND.

PREWARNING

BS100FAULT

MAINS

FUNCTIONS DISABLED

AUTRONICA

PREWARNING

MORE ALARMS

FIRE

FAULT

POWER

SILENCE BUZZER

Common Fire Alarm Output 2 Minutes Delayed

Common Fire Alarm Output For Door Release System

Failure Output

Common Fire Alarm Output

24V DC For Flame Detectors

Repeater Panel Engine Control Room

To Engine Room Monitoring System(No Time Delay)

Mains(230 VAC)

Loop00 etc to

Loop03Disconnection and Test Mode Switches

Inside Cabinet

Buzzer and Battery Inside Cabinet

Detectors

Detectors

The five element keypad consists of four arrow keysand one 'carry-out' (enter key). The keypad is used to accessand handle information on the system. The four arrow keyscontrol the cursor on the control panel text display.

These keys scroll the menu and move the cursorup and down in the menu text on the text display.These keys also scroll figures and letter values.

These arrow keys scroll the menu and move the cursorleft or right in the menu on the text display.

'Carry-out' (entry) key. Selects the menu part on which thecursor is currently pointed.

Operating Buttons:

More AlarmsRed lamp illuminates when morealarms are present.

Text display(Information Window)

FireRed Lamp Sign illuminates foran alarm condition.*

PrewarningAmber (yellow) lamp illuminateswith a pulsating light when aprewarning situation occurs.*

FaultAmber (yellow) lamp illuminates forany fault. Pulsating light.*

Function DisabledAmber (yellow) lamp illuminateswhen any part of the systemis disabled (isolated).

MainsGreen lamp illuminates when thepower is on.

Device(s) Still in Alarm Condition.Amber (yellow) lamp illuminateswhen an address (detector)is automatically disabled.

These lamps can be customassigned.

Indication Devices: More AlarmsThis button allows the second lineof the text display to be scrolled.Reveals additional alarms on thesystem.

Sounder SilenceWhen this red button is pressed,all alarm devices and the internalbuzzer are muted.

PrinterResetWhen the green button is pressed,all events in the system are reset.

BU70



Issue: 1


e) If the detectors have now returned to a normal condition, thefollowing text will appear in the display; ‘RESET OK’‘NORMAL CONDITION’.

f) Close the panel door.

After resetting, an address may still be in an alarm condition. This can be dueto mechanical damage, water damage, the presence of smoke still within thechamber or an electrical fault. The address still in alarm will automatically bedisabled (isolated from the rest of the system). The yellow DEVICE(S) STILLIN ALARM COND. indication lamp will illuminate and the following text willappear in the display:

‘01 ALARM ADDRESS DISABLED’‘CONTROL PANEL IN ABNORMAL CONDITION’.

In this case contact Autronica technical personnel.

While an address is automatically disabled, the yellow DEVICES STILL INALARM COND. indication lamp will be illuminated. If the alarm conditiondisappears, the indication lamp will turn off and the address will beautomatically restored to the system.

More Alarms

The following indications appear on the control panel in the event of morealarms:

The red FIRE indication lamp flashes and the internalbuzzer sounds

The red MORE ALARMS indication lamp illuminates

The text display upper line indicates the first address in alarm.The lower text line will indicate the last address in alarm

The prewarning lamp flashes. If the alarm was preceded by apre-alarm, the prewarning lamp will illuminate steadily

The display and printer will show text such as:‘AL 01 ADDRESS NO. 0605‘AL 03 ADDRESS NO. 0608

All sounders/fire doors/alarms/fan stops are activated(as connected/programmed)

Action to be Taken in the Event of a ‘More Alarms’ Situation

Follow all precautions described in the local fire instructions. When the sceneof the fire has been investigated and the necessary action carried out, thesounders may be switched off.

a) Open the control panel door.

b) Press the MORE ALARMS button. The first press will indicatethe second alarm address on the text display lower line. Thesecond press will indicate the third alarm address etc.

c) Press the SOUNDER SILENCE button. All alarm devicesincluding the internal buzzer will be turned off. The red FIREindication lamp will switch to a steady light.

d) Press the RESET button. The following text will appear in the textdisplay; ‘RESET PROCEDURE IN PROGRESS WAIT.....’ Thistext will remain on the display for up to 60 seconds. The resetprocedure is executed within this 60 second period.

e) If the detectors have now returned to a normal condition, thefollowing text will appear in the display; ‘RESET OK’‘NORMAL CONDITION’.

f) Close the panel door.

Faults

The following indications appear on the control panel in the event of a fault.

The yellow FAULT indication lamp flashes and the internalbuzzer sounds

The text display upper line indicates the nature of the fault;FA indicates a loop or detector fault, SF indicates a system fault

If more (multiple) faults are present on the system, the display will indicate thelatest extra fault and label it ‘FAULT 2’ etc.

Action to be Taken in the Event of a Fault

a) Press the SOUNDER SILENCE button.

b) The internal buzzer is muted and the yellow FAULT indicationlamp will switch to a steady light.

c) Note the fault text indicated in the display and file the printoutfrom the printer.

d) Contact Autronica technical or service personnel.

Menu Structure

The main menu is accessed by pressing the MAIN MENU button. It consistsof the following sub-menus:

Out/In control: Disable and restore addresses, zones etc

Show status: Alarms, warnings etc

Test: Test the panel facilities, sounders etc

System: Sensitivity, configuration, data etc

Feed Paper: Printer

Service: Reports, disabling/restoring, address and data control

Within the sub-menus are sections that can only be accessed by technical orservice personnel who have the required passwords. The password protectedlevels are divided into two levels:

Password Level 1: Operator Level

Disable - Controls

System - Data

Disable - Sounders

Change display and printer text

Password Level 2: Service Level

System - Configuration

Service

Change control, alarm and disable group outputs

Further, more detailed information on facilities available within the sub-menuscan be found in the manufacturer’s manual.


Issue: 1

Illustration 5.2.1a Fire and Deck Wash System

Sea

ChestSea

Chest

Sea

Chest

Emergency

Connection for

Driving Water

to Bilge Ejectors

Driving Water

to Ballast

Ejector

From

LPG

Pump

Fire

PumpFire and

Deck Wash

Pump

Emergency

Connection

to Fresh Water

Cooling System

Near

Boilers

Near

Boilers

Near

Tube

FW Cooler

Starboard

Accommodation

Port

Accommodation

Engine Room

V522

V521

V520

V505

V513

V513

V501A

V506

V520 V520

V512

V512

V509

V509 V509

V509

V509

V509

V511 V511

V509

V500

V501 V501V534

V33 V534

V530

V531

V514V514

V517

V514

Connection to Deck

Driving Water System

V514

V503

V514V514 V514

V515V515V515

V514V514V514

V503

V503

V503

V502

V502 V502 V502

V502

V502

V503

V500

V520 V520 V520 V520

V520 V520 V520 V520 V520

V522

Aft

StbdPort

Hydraulic

Oil Pump

and Tank

Diesel

Engine

Stores Deck

Emergency

Fire Pump

Emergency Fire Pump

and FO Transfer

Pump Space

Water SprayCovering

FO TransferPump

Hatch

V525

V514

V515V515

Ejector ForeDeep Tank

V526

EjectorFwd Pump Room

and Duct Keel

V527

EjectorChain Locker

V518

V518 Anchor

Chain Washing

Sea Water

Hydraulic Oil

Instrumentation

Electrical Signal

Key

Fire Water

Hydraulic Oil

Motor

No.5 Cargo

Tank

Isolating

Valve

Isolating

Valve

Isolating

Valve

No.4 Cargo

Tank

No.3 Cargo

Tank

No.2 Cargo

Tank

No.1 Cargo

Tank

V523

PC1

HC1

SI1A

SI1B

V528

V509




Norman Lady Cargo Operating Manual 5.2 Fire Fighting Systems

5.2.1 Fire and Deck Wash System

The following pumps can supply the fire and deck wash system:

Main Fire Pumps

Maker: EurekaType: CGB 80 vertical, ventrifugalCapacity: 100m3/h at 120 mwgSpeed: 3,500 rpmNo. of sets: 2

Emergency Fire Pump

EngineMaker: ListerType: HR4 MASerial No: 582HR4AM22Capacity: 45kWHydraulic starter: Bryce Berger

Hydraulic PumpMaker: KrachtType: KP 42/71 CIZJZOOCapacity: 140 litres/min at 160 bar

PumpMaker: RitzType: 4408/3st Capacity: 50m3/h at 113 mwg

Hydraulic MotorMaker: KrachtType: KM 22/50F 3 XALOOPressure: 120 bar

The fire main system is supplied from the two engine room fire pumps. Theyare single speed centrifugal pumps, with a delivery capacity of 100m3/h. Thepumps can be started from their main switchboard starters in the ECR, theemergency fire headquarters or locally.

The system can also be supplied from the emergency fire pump. This is locatedin its own compartment aft of the fore peak. This pump is a self-primingcentrifugal pump with its own direct sea suction. The pump is rated at 50m3/hand is powered by a hydraulic motor. The remote hydraulic pump to supply thismotor is driven by a diesel engine, located in the bosun’s store. This engine canonly be started locally.

The deck fire ring main has a main isolator valve V501A, fitted before the portand starboard feeder.

The ring main is fitted with further section isolator valves to allow any part ofthe system to be supplied from either side of the ship.

This set up also allows a section of fire main to be isolated for maintenancepurposes whilst the rest of the fire main remains available.

The fire main also supplies the driving water for the bilge eductors in the chainlocker, the fore deep tank and duct keel and the forward pump room. Thesystem can also supply washing water for the anchor chains within the hawsepipe.

There are fire hydrants strategically positioned throughout the decks, each withits fire hose mounted adjacent.

Under normal operating conditions, the fire main will be under pressure duringcargo discharge or loading with hoses run out as a fire precaution.

Preparation for the Operation of the Fire Main

Assume all system valves are initially closed.

a) All deck, engine room, boiler room and accommodation hydrantsare closed. Set up the valves as shown in the table below.

Position Description Valve

Open Isolating valve to deck main V501

Open Section isolating valve (port) V502

Open Section isolating valve (starboard) V503

Open Isolating valve to accommodation (port) and aft V505

Open Isolating valve to accommodation (starboard) and aft V506

Closed Discharge valve to hawse pipes V518

Closed Discharge valve to chain locker eductor V527

Closed Discharge valve to forward pump room andduct keel eductor V526

Closed Discharge valve to forward deep tank eductor V525

Closed Discharge valve to forward pump room spray V528

Closed Discharge valve to bilge/ballast ejectors V534

b) Set up the main fire pumps:


Open Sea chest suction valve V500

Open Main fire pump discharge valve V501

c) Start/stop the required main fire pump.

d) Open fire main sections, hydrants or outlets as required.

Preparation for the Operation or Testing of the Emergency Fire Pumpand Engine

a) Start the duct keel fan to vent the forward pump room.

b) Open a hawse pipe valve one turn and the pump suction valveV530 and discharge valve V531 fully.

c) Check the gas oil and hydraulic oil levels in the tanks.

d) Close the two engine exhaust pipe drains, pull out the engine coldstart lever and press the engine electric START pushbutton.Alternatively, pressurise the start cylinder by pumping at least 60strokes with the red lever before operating the hydraulic starter.

e) Allow 3 minutes for the engine to settle before moving thehydraulic coupling lever to engage the fire pump hydraulic motor.

f) Enter the pump room to check the pump and note that thedischarge pressure should 10 bar.

To Stop the Engine/Pump

a) After approximately 10 minutes disengage the hydraulic pumpand stop the engine by moving the stop lever towards the airintake, the engine will run down. When the engine has completelystopped, reset the lever.

b) Close the suction and discharge valves and open the exhuast pipedrains.

c) Check the tension on the engine water pump drive belt and mopup any oil that may have dripped during the test run period.

Issue: 1

Illustration 5.2.1a Fire and Deck Wash System

Sea

ChestSea

Chest

Sea

Chest

Emergency

Connection for

Driving Water

to Bilge Ejectors

Driving Water

to Ballast

Ejector

From

LPG

Pump

Fire

PumpFire and

Deck Wash

Pump

Emergency

Connection

to Fresh Water

Cooling System

Near

Boilers

Near

Boilers

Near

Tube

FW Cooler

Starboard

Accommodation

Port

Accommodation

Engine Room

V522

V521

V520

V505

V513

V513

V501A

V506

V520 V520

V512

V512

V509

V509 V509

V509

V509

V509

V511 V511

V509

V500

V501 V501V534

V33 V534

V530

V531

V514V514

V517

V514

Connection to Deck

Driving Water System

V514

V503

V514V514 V514

V515V515V515

V514V514V514

V503

V503

V503

V502

V502 V502 V502

V502

V502

V503

V500

V520 V520 V520 V520

V520 V520 V520 V520 V520

V522

Aft

StbdPort

Hydraulic

Oil Pump

and Tank

Diesel

Engine

Stores Deck

Emergency

Fire Pump

Emergency Fire Pump

and FO Transfer

Pump Space

Water SprayCovering

FO TransferPump

Hatch

V525

V514

V515V515

Ejector ForeDeep Tank

V526

EjectorFwd Pump Room

and Duct Keel

V527

EjectorChain Locker

V518

V518 Anchor

Chain Washing

Sea Water

Hydraulic Oil

Instrumentation

Electrical Signal

Key

Fire Water

Hydraulic Oil

Motor

No.5 Cargo

Tank

Isolating

Valve

Isolating

Valve

Isolating

Valve

No.4 Cargo

Tank

No.3 Cargo

Tank

No.2 Cargo

Tank

No.1 Cargo

Tank

V523

PC1

HC1

SI1A

SI1B

V528

V509



Issue: 1


Control and Alarm Settings

Setting Description

5kg/cm2 Fire main pressure low

5kg/cm2 Fire main pressure low - start standby aft pump

4kg/cm2 Fire main pressure low - start standby forward pump

In the event of a fire on board, the locations listed below have the followingcontrols:

Bridge

Emergency stops for engine room and accommodation supply and exhaust fans

Fuel gas valve

Deck fans and pipe duct fans

Start/stop switches for the engine room fire pumps

Air Conditioning Rooms Port and Starboard on Accommodation ThirdDeck

Stop buttons for engine room and accommodation supply and exhaust fans

Emergency Headquarters on the Upper Deck, Starboard Side

Operation of the CO2 system release to:

LPG room

Cargo control room

Electric motor room

LNG room

Engine room

Vent masts

Operation of the quick-closing and remote operating fuel valves to:

Diesel oil tank

Port and starboard HFO settling tanks

Fuel gas vent flap valve

Emergency stops for:

Engine room vent fans

Accommodation vent fans

Deck fan

Pipe duct fan

Port and starboard boiler steam stop valves

HFO transfer pump

Main gas valve

Engine Control Room

Emergency stops for engine room and accommodation supply and exhaust fans

Start/stops for the engine room fire pumps - forward and aft

Start/stops for the fuel oil pumps

Control (shutting) of the boiler superheated steam outlet valves


Issue: 1

Illustration 5.2.2a Water Spray System

Engine Room

No.5 Cargo

Tank

LPG Compressor Room

Manifold Area

(Port)

From BilgeEjector Pump

Manifold Area

(Starboard)

No.4 Cargo

Tank

No.3 Cargo

Tank

Cargo

Control

Room

No.2 Cargo

Tank

No.1 Cargo

Tank

LNG Compressor

Room

Key

Spray Water

Sea Water

Inert Gas

Plant

Cooling

Water

Pump

V331

PI

LPG

Plant

Cooling

Water

Pump

From

Bilge

MainV330

V331

PI

Sea Chest

Bilge

Ejector

Pump

To

Main

Condenser

Flushing

To

Ballast

and Bilge

Eductors

Bilge Ejector

Pump System

To Cargo Hold Eductors/

Manifold Water Curtains

PC52

SeaChest

To

SW

Cooling

System

To

IG

Plant

To

IG Refrigeration

Plant Coolers

To LPG Plant

V330

Regulating Valve

Water Curtain

Water Curtain



5.2.2 Water Spray System

System Capacities and Rating

LPG Sea Water PumpMaker: Thune EurekaNo. of sets: 1Type: CGB 100Capacity: 170m3/h at 5kg/cm2

Inert Gas Plant Sea Water PumpMaker: Thune EurekaNo. of sets: 1Type: CGD 200Capacity: 340m3/h at 5kg/cm2

Bilge Ejector PumpMaker: Thune EurekaType: CGB 100Capacity: 132m3/h at 7mth

Spray NozzlesType: 11/4 H 16 W capCapacity: 100 litres/min at 1.5kg/cm2

The accommodation block front, LNG and LPG compressor rooms, cargo tankliquid and vapour domes, main cargo valves and manifolds are protected bywater spray from the effects of fire, gas leakage, or liquid spill by a water spraysystem.

Normally the the LPG SW pump is used to supply the water spray system andthe system. The inert gas plant cooling water pump can be used via a cross-connection valve. These pumps deliver water to a common distribution rail,along which are fitted individual branches with isolating valves.

The branches are as follows:

Accommodation block

No.5 cargo tank

No.4 cargo tank

Cargo control room

No.3 cargo tank

LPG compressor room

Starboard manifold area

LNG compressor room

Port manifold area

No.2 cargo tank

No.1 cargo tank

Each main spray branch, except No.1 cargo tank, has a manually operatedisolating valve located at the distribution rail. The spray pumps can be startedlocally, or from the ECR or CCR (via the DCS system) and the emergencyheadquarters.

Each branch sub-divides into smaller branches. The accommodation front iscovered by 3 sub-branches. The spray nozzles are fitted approximately 1.2metres apart and 450 or 650mm from the surface they are protecting. There arevarious drains provided throughout the system.

Procedure to Supply the Deck Spray System Using the LPG Sea WaterPump

Assuming all valves in the system are closed.

a) Open the spray section supply valve(s) as required at thedistribution rail.

b) Open the pump suction valve V330 and ensure the dischargevalve V331 is slightly open.

c) Ensure the deck water spray line supply valve is open.

d) Vent off the pump casing and ensure that it is flooded and ensurethat the pump turns freely by hand.

e) Start the pump and slowly open the discharge valve V331.

f) Check the delivery pressure is approximately 5 bar.

Manifold Curtain

The water curtains that protect the vessel’s hull during cargo operations are fedfrom the deck driving water system. This system is supplied with sea waterfrom the bilge ejector pump.

Procedure to Supply the Manifold Water Curtains

Assuming all valves in the system are closed.

a) Open the port or starboard manifold curtain supply valve(s) asrequired at the manifold area.

b) Open the bilge ejector pump sea chest suction valve and ensurethe discharge valve is slightly open.

c) Ensure the deck driving water line supply valve is open.

d) With the power off, ensure that the bilge ejector pump turns freelyby hand.

e) Vent off the pump casing and ensure that it is flooded.

f) Start the pump and slowly open the discharge valve to the system.The manifold water curtain(s) will now be supplied.



Issue: 1

Illustration 5.2.3a Forward Fire Pump System

Sea

Chest

V530

V531

V517

V514

V503

V514

V503

V502

Hydraulic

Oil TankDiesel

Engine

Emergency

Fire Pump

Emergency

Fire Pump

and FO Transfer

Pump Space

Water SprayCovering

FO TransferPump

Hatch

Fire Main

V525

V526

V527

V518

V518

Sea Water

Hydraulic Oil

Key

Fire Water

Compressed Air

Diesel Oil

Hydraulic

Motor

No.1 Cargo

Tank

V528

Diesel Oil Tank



View of Emergency Fire Pump Engine and Hydraulic Tank

View of Engine Cold Start Lever and Local Electric Start Pushbutton

View of Emergency Fire Pump Engine Inertia Start

View of Battery Charger on Aft Bulkead

5.2.3 Forward Emergency Fire Pump System

Emergency Fire Pump

EngineMaker: ListerType: HR4 MASerial No: 582HR4AM22Capacity: 45kWHydraulic starter: Bryce Berger

Hydraulic PumpMaker: KrachtType: KP 42/71 CIZJZOOCapacity: 140 litres/min at 160 bar

PumpMaker: RitzType: 4408/3st Capacity: 50m3/h at 113 mwg

Hydraulic MotorMaker: KrachtType: KM 22/50F 3 XALOOPressure: 120 bar

The forward emergency fire pump system can supply the fire and deck washsystem.

The pump is located in its own compartment aft of the fore peak and is a self-priming centrifugal pump with its own direct sea suction. It is rated at 50m3/hand is powered by the hydraulic motor. The hydraulic motor is driven from theremote hydraulic pump which is driven by the diesel engine. The diesel engine,pump and hydraulic tank are fitted in the diesel motor room area on thestarboard side of the bosun’s store.

The pump is mounted in a compartment shared with the fuel oil transfer pumpwhich is also hydraulically driven. This design enables a high degree ofwaterproof integrity etc.

The hydraulic tank is also used to supply the adjacent FO transfer pump whichis electrically driven. The hydraulic tank capacity is 240 litres.

The diesel engine has an air start motor which is solenoid valve operated. Theengine starting air receiver is also fitted in the same area of the focsle store.There is also a manually operated Bryce Berger hydraulic starter.

Preparation for the Operation or Testing of the Emergency Fire Pumpand Engine

a) Start the duct keel fan to vent the forward pump room.

b) Open a hawse pipe valve one turn and the pump suction valveV530 and discharge valve V531 fully.

c) Check the gas oil and hydraulic oil levels in the tanks.

d) Close the two engine exhaust pipe drains, pull out the engine coldstart lever and press the engine electric START pushbutton.Alternatively, pressurise the start cylinder by pumping at least 60strokes with the red lever before operating the hydraulic starter.

e) Allow 3 minutes for the engine to settle before moving thehydraulic coupling lever to engage the fire pump hydraulic motor.

f) Enter the pump room to check the pump and note that thedischarge pressure should 10 bar.

To Stop the Engine/Pump

a) After approximately 10 minutes disengage the hydraulic pumpand stop the engine by moving the stop lever towards the airintake, the engine will run down. When the engine has completelystopped, reset the lever.

b) Close the suction and discharge valves and open the exhuast pipedrains.

c) Check the tension on the engine water pump drive belt and mopup any oil that may have dripped during the test run period.



Issue: 1

Illustration 5.2.4a Dry Powder Systems

14 Pneumatic Piping Control

15 Stop Cock

16 Relief Cock

17 Flushing Pipe

18 Stop Cock

19 Safety Valve

20 Filling Opening

21 HP Pressure Gauge

22 LP Pressure Gauge

23 Pressure Regulator

24 Stop Cock

25

8

Pressurising Valve

Dry Powder Room: Main System

Hose BoxHose Box

750 kg

Container

26 Drain Connection

27 Powder Container

29 Pneumatic Release Piston

30 Main Powder Cock

31 Testing/Flushing Connection

32 Stop Cock

33 Relief Cock

34 Pneumatic Release Piston

35 Direction Cock

36 Flushing Connection

46 Powder Piping

40 LP Pressure Gauge

47 Pneumatic Control Piping

48 Powder Piping

49 Pistol Trigger Nozzle

50 Powder Hose

51 Hose Box

52 Stop Cock

53 Pressure Reducer

54 Release Cylinder (Nitrogen)

HA High Pressure Stop Cock

HL High Pressure Piping

28 Limit Valve

1

1

Blanked Flanges

Key

2 Non-Return Valve

3 Filter

4 Relief Vent

5 Release Rods

6 Relief Cock

7 Pneumatic Piston

8 Release Lever

9 Release Mechanism

10 Electric Switch

11 Pressure Cylinder (Nitrogen)

12 Nitrogen Control Cylinder

13 Non-Return Valve

3 2

6

5

7

1514

1920

21 22

16 17

33

18

29

30

31

32 32

8

9

10

11 11 11 11 11

5

24

25 25

27

26

36

47

47

48 50 51

40

49 52 53 54

4

23

28

HA

HL

HA

HL

34

35

1,500 kg

Container

Fill Level

PLO 750 Unit

PLO 1500 Unit



5.2.4 Dry Powder Systems

Main Systems

Aft System

Maker: TotalitType: PLO 1,500/750

The system consists of a dual 1,500/750kg system situated in the powder room,located in the starboard forward accommodation block on the upper deck.

The remote hose stations for the system is located along the cargo tank domecatwalk. These stations are equipped with nitrogen release bottles enabling thedry powder systems to be activated remotely.

The system has dry powder containers filled with 1,500 and 750kg of ‘Totalit’dry powder. The main pressure nitrogen bottles are fitted adjacent to the maincontainers. There is a main dry powder valve with automatic opening. Thisfeeds a distribution manifold with a number of outlets and each outlet has adistribution valve. The distribution valve has a pneumatic piston for openingas well as a manual control. Each of the outlets is connected via a pipe to a hosestation.

Each hose station has a 30 metre hose fitted with a pistol type trigger nozzlewith a stopcock. To initiate the release of the dry powder from the hosestations, there is a 3 litre 150 bar nitrogen bottle fitted with a handwheel,pressure reducing valve and pressure gauge.

Theory of Operation

When the hose box nitrogen release cylinder (54) and local stop cock (52) isopened, nitrogen flows through the pneumatic piping (47) to the correspondingoutlet release piston (34) for the direction cock (35) on the manifold. Nitrogenalso flows to the main nitrogen bottles’ release lever pneumatic piston (7),releasing nitrogen into the main container via the pressure regulator (23) andthen through the pressurising valves (25). The regulator ensures the nitrogenpressure does not exceed 14 bar in the main container.

The powder is then fluidised and pressurised to 14 bar by the nitrogen. Whenthis service pressure is reached, limit valve (28) opens and pressurised nitrogenflows through the piping (14) to the pneumatic release piston (29) which thenopens the main cock (30) for the powder. The pressurised powder in thecontainer flows through the syphon tubes in the container and out into thepowder pipe line to the hose box powder pipe and pistol unit.

(Note: If the main powder container pressure reaches 16 bar, the safety valvewill open.)

In normal circumstances, stop cocks (15), (24), (32) and HA must be open.Relief cocks (6), (16), (33), relief cock (18) and test connection (31) must beclosed. All pipes must be connected.

Procedure to Operate a Hose Box Outlet

If a fire occurs, requiring the use of the system, the procedure is as follows:

a) Remove the hose and trigger pistol from the hose box.

b) Fully open the release cylinder valve.

c) Check the pressure reducing valve (53) and open stop cock (52).

d) Open the hose connection cock and operate the hand trigger valveas required.

(Note: If the fire is extinguished, the operator should stand by in case of anyre-ignition. During this time the pistol trigger should be operated at shortintervals to flush the lines to ensure they remain clear.)

Remote Release Failure

In the event of a remote release failure, the powder can be released locally atthe main container using the following procedure:

a) Manually open the powder direction cock (34) for the pipelinerequired.

b) Manually pull down the release lever (8).

If the PLO 1500 unit is not sufficient or has run down, the PLO 750 unit shouldbe used as follows:

a) Manually close the stop cock (32) for the PLO 1500 unit.

b) Open the PLO 750 unit’s supply stop cock (32) and manually pulldown the release lever (8).

Post Operation Procedure for the Main Systems

At the hose box:

a) Close the cylinder valve.

b) Close the hose connection cock.

c) Stow the hose in a figure of eight configuration and secure.

At the main container, carry out the following:

a) Close the stop cock (15) in the pneumatic control piping.

b) The relief cock (16) is to be opened.

c) The main powder cock (30) is to be closed manually.

d) The stop cock (18) in the flushing pipe (17) is to be opened.

e) The stop cock (18) is to be closed as soon as the powder containerhas been relieved of pressure by operating the powder pistols.Observe the low pressure gauge (22).

f) Close the stop cock ‘HA’ in the high pressure pipeline.

g) The powder pipeline and powder hose should be thoroughlycleaned through, preferably using a compressed air line andreducer (lower than 12 bar) via the flushing connection (31). Thepipeline and hose should be blown through with the cocks open.Afterwards, stow the hoses in the figure eight configuration.

h) The pressure in the release cylinder and the secondary pressure inthe reduction valve should be checked using the followingprocedure:

1. Close the stop valve (52) on the secondary pressure side of thereduction valve (53).

2. Open the release cylinder (54) by turning the valve counter-clockwise. The pressure in the bottle must not be more than 150bar and not less than 50 bar. The secondary pressure in thereduction valve must not be more than 8 bar and not less than 5bar.

3. Close the release cylinder (54) by turning the valve clockwise.

4. Open the stop valve (52) again.

(Note: If the pressure in the release cylinder is lower than 50 bar, it must bereplaced. The nitrogen for the cylinders must be ‘high percentage nitrogen’ ie,a nitrogen content of at least 99%.)

i) Close any direction cocks (35) which are open.

j) Open the main container filling orifice (20) and refill with ‘TotalitSuper Powder’ using the correct filling funnel.



Issue: 1

Illustration 5.2.4b Dry Powder Systems: Hose Boxes and Units

No.1

No.1

Port No.1

No.2No.3No.4

NORMAN LADY

Dry Powder

Room

Location of Main System Hose Boxes

Location of PLA 250 Dry Powder Units

No.5

Starboard No.3 Starboard No.2 Starboard No.1

Port No.3Port No.4 Port No.2 Port No.1

No.6

Key

PLA 250 Dry Powder Unit

Hose Boxes



View of Deck Dry Powder Station Port No.3

View of Deck Dry Powder Hose Box No.1

Issue: 1


k) Fill the container with 750/1,500kgs of powder. Ensure thecontainer is not completely full. The filling limit line is the upperwelding seam of the container. Fasten the top cover closed,ensuring that the base is clean to assure tightness.

l) Replace the empty nitrogen cylinders (11) with cylinders whichare at least 220 bar in pressure. Ensure that stop cock ‘HA’ isclosed (see cylinder manufacturer’s instructions).

m) Check the pressure of the nitrogen cylinders (see cylindermanufacturer’s instructions).

n) All connections should be thoroughly checked.

o) All cocks should be brought into the operational position.

For the correct operation of the container, the relevant valves and cocks shouldbe set up and sealed for correct operation as follows:

Position Valve/Cock Description

Open Monitor three-way cock

Open High pressure stop valve ‘HA’

Open Stop cock (15)

Open Stop cock (32)

Open Stop cock (24)

Open Stop cock (52)

Open Stop cock (1)

Closed Main powder cock (30)

Closed Direction cock (35)

Closed Stop cocks (18), (31) and (45)

Closed Relief cocks (6), (16) and (33)

The system is now ready for operation.

Deck Systems

Maker: TotalitType: PLA 250

There are seven 250kg dry powder systems strategically located around theupper deck. These independent systems are equipped with a nitrogen releasebottle enabling the dry powder systems to be activated locally.

Each system has a dry powder container filled with 250kg of ‘Totalit’ drypowder. The main pressure nitrogen bottle is fitted in front of the maincontainer. There is a main dry powder valve with automatic opening. Thisfeeds a distribution manifold with a number of outlets and each outlet has adistribution valve. The distribution valve has a pneumatic piston for openingas well as a manual control. Each of the outlets is connected via a pipe to a hosestation.

The hose station has a 30 metre hose fitted with a pistol type trigger nozzlewith a stopcock. To initiate the release of the dry powder from the hosestations, there is a 3 litre 150 bar nitrogen bottle fitted with a handwheel,pressure reducing valve and pressure gauge.

To Operate the System

If a fire occurs, requiring the use of the system, the procedure is as follows:

a) Remove the hose and trigger pistol from the hose box.

b) Fully open the release cylinder valve.

c) Ensure that the manometer indicates a satisfactory operatingpressure, ie, the needle is within the green segment.

d) Open the red-handled hose connection cocks, the green-handledpressure relief cocks should be closed.

e) After a short delay the hose will become charged and the triggerpistol can be used as required to fight the fire.

CAUTIONThe operator should be ready for considerable jet reaction from the pistolwhen operated.

On Completion of Fire Fighting

a) Close the release cylinder valve.

b) Close the red-handled hose connection cocks.

c) Open the green-handled pressure relief cocks. Operate the pistoltrigger to relieve pressure in the lines and container.

d) Close the pressure relief cocks.

e) Stow the hose in a figure of eight configuration and secure.

f) The system must now be recharged with ‘Totalit’ dry powderstrictly according to the manufacturer’s instructions.

g) The nitrogen bottles must be refilled according to themanufacturer’s instructions or replaced. The replacement bottlesmust be 20 litre capacity and charged to a maximum pressure of150 bar.


Issue: 1

Illustration 5.2.5a CO2 System

No.5Cargo Tank

No.4Cargo Tank

No.3Cargo Tank

BoilerCasing

Main CentralStore

EngineRoom

CO2 Release Lockers(Paint Store andIncineratorRoom)

CO2 Release Lockers(LNG Compressor Room,LPG Compressor Room,Electric Motor Room,Cargo Control Room,Vent Masts)

Paint Store andIncinerator Room

CO2 ReleaseLocker

Cargo TankVentilation

Mast

CO2Room

EmergencyHeadquarters


CO2 Startt Ct C(2 x 45Kg)))

2

CO2Room

Cargo Control Room

KeyCO2 Smothering

A - CO2 Master Valves

B - CO2 Starting Valve

C - CO2 Release Wire Handle to CO2 Start Cylinders

D - Compressed Air Valve for Alarm Siren

Automatically Opened by Release Locker Door

1 - 5" CO2 from CO2 Cylinders

2 - 1/2" CO2 from CO2 Start Cylinders in Deck Workshop

3 - 3/8" Air from Instrument Air Receiver in Engine Room

4 - Wire Release from CO2 Start Cylinders in 3/8" Pipe

5 - 1/2" CO2 to Gang Release Working Piston No.1 and No.2

6 - 3/8" Air to Alarm Sirens in Engine Room

7 - 1/2" CO2 to Gang Release Working Piston No.3

8 - 3/8" Air to Alarm Sirens in Electric Motor Room

Cargo Control Room and LNG Compressor Room

9 - 2" CO2 to LNG Control, Motor and LPG Room

10 - CO2 Pressure Switches for Cutting off Deck Fans

11 - CO2 Pressure Switches for Cutting off Ventilation in

Engine Room and Boiler Room

12 - 5" CO2 to Engine Room

13 - CO2 Release Locker for Ventilation Masts

14 - Wire Release for 6 x 45kg CO2 Cylinders to Vent

Masts

15 - 1/2" CO2 to Ventilation Masts

Key

C

D

1

4

9

12

13

4

15

Engine Room and LNG RoomCO2 Operating Panel

PaintRoom

Local CargoControl Room

LNG CompressorRoom

LPGRoom Electrical Motor

Room

s

s

s

CO2 Release Lockers(LNG Compressor Room,LPG Compressor Room,

Electric Motor Room,Cargo Control Room,

Vent Masts)



5.2.5 CO2 System

Maker: Heien-LarssenType: Centralised storage, remote releaseCylinder size: 45 kgsNo. of cylinders: 189Total CO2: 8,820 kgs

The central CO2 flooding system covers the engine room, LNG compressorroom, electric motor room, LPG compressor room, cargo control room, cargotank ventilation masts, incinerator room and paint store. The central systemcylinders are situated in the CO2 room, located extreme aft on the main deckand the two starter cylinders are situated in the deck workshop on the starboardside of the main deck.

The paint store is covered by two cylinders situated in a locker on the maindeck on the port side below the paint store.

The allocation of cylinders is as follows:

Engine room 189 cylinders

LNG compressor room 6 cylinders

Electric motor room 2 cylinders

LPG compressor room 4 cylinders

Cargo control room 2 cylinders

Cargo tank ventilation masts 6 cylinders

Incinerator room 3 cylinders

Paint store 2 cylinders

WARNINGRelease of CO2 into any space must only be considered when all otheroptions have failed and then only on the direct instructions of the Master.

Flooding of the protected areas is achieved by the operation of the valves fromthe control cabinet in the emergency headquarters on the starboard side of themain deck.

Upon opening the control cabinet door, the CO2 alarm is activated and theventilation fans for that area are stopped. The pilot gas is directed by theoperation of the respective valve onto the gang release line for the selectedarea.

Procedure in the Event of a Fire in the Engine Room

a) Stop any machinery within the engine room, check that all doors,hatches and fire flaps are shut and that all ventilation is stopped.However, this should not delay the release of CO2.

b) Ensure all personnel have evacuated the engine room and havebeen accounted for.

c) Go to the emergency headquarters on the starboard side of themain deck. Unlock the control cabinet for the engine room areaand open the door.

d) The alarm sirens will activate due to the door releasing the springoperated valve which directs compressed air from the engineroom to the piston operated trip switch, situated on the inboardbulkead of the fire headquarters.

e) Pull all the valve levers outwards.

f) Pull the CO2 wire release handle to activate the starter cylinders.

The starter cylinders release CO2 gas to operate the gang release pistons on theport side of the CO2 room.

g) CO2 will now fill the affected area.

h) Proceed directly to the CO2 room to ensure that the correctnumber of cylinders have discharged for the particular area.

i) If the starter system fails to operate the cylinders, the CO2 can bereleased by operating the cylinder levers by hand.

j) Do not re-enter the engine room for at least 24 hours and ensurethat all reasonable precautions have been taken, such asmaintaining boundary inspections, noting cooling down ratesand/or any hot spots which may have been found. After thisperiod, an assessment party using radio communication andwearing breathing apparatus and lifelines can enter the spacequickly through a door, which is then shut behind them. Checkthat the fire is extinguished and that all surfaces have cooled priorto ventilating the engine room. Premature opening could cause re-ignition if oxygen contacts hot combustible material.

For added safety, the master valve is interlocked with the release locker doorin the closed position.

Should any cylinder discharge accidentally, it will pressurise the main line upto the stop valve. This line is monitored by a pressure switch and will activatea ‘CO2 leakage’ alarm.

Overpressure of the main line is prevented by a safety valve, which will ventthe gas to atmosphere.

WARNINGCO2 gas will suffocate personnel in its vicinity. All personnel should beinstructed to evacuate rooms and spaces immediately when the alarmsounds.

Procedure in the Event of a Fire in the Cargo Tank Ventilation Masts

a) Go to the emergency headquarters on the starboard side of themain deck. Unlock the control cabinet for the ventilation mastsand open the door.

b) Pull the valve lever outwards to activate the six cylinders in thecentral CO2 flooding system.

c) Proceed directly to the CO2 room to ensure that the correctnumber of cylinders have discharged for the particular area.

d) If the starter system fails to operate the cylinders, the CO2 can bereleased by operating the cylinder levers by hand.

e) CO2 will now fill the pipe to the ventilation masts.

Procedure in the Event of a Fire in the LNG Compressor Room

a) Go to the emergency headquarters on the starboard side of themain deck. Unlock the control cabinet for the LNG compressorroom and open the door.

b) The alarm sirens will activated due to the door releasing thespring operated valve which directs compressed air from theengine room to the LNG compressor room alarm sirens.

c) Proceed directly to the CO2 room and manually release the sixcylinders marked LNG - COMPRESSOR ROOM.



Issue: 1

Illustration 5.2.5a CO2 System

No.5Cargo Tank

No.4Cargo Tank

No.3Cargo Tank

BoilerCasing

Main CentralStore

EngineRoom

CO2 Release Lockers(Paint Store andIncineratorRoom)

CO2 Release Lockers(LNG Compressor Room,LPG Compressor Room,Electric Motor Room,Cargo Control Room,Vent Masts)

Paint Store andIncinerator Room

CO2 ReleaseLocker

Cargo TankVentilation

Mast

CO2Room



CO2 Startt Ct C(2 x 45Kg)))

2

CO2Room

Cargo Control Room

KeyCO2 Smothering

A - CO2 Master Valves

B - CO2 Starting Valve

C - CO2 Release Wire Handle to CO2 Start Cylinders

D - Compressed Air Valve for Alarm Siren

Automatically Opened by Release Locker Door

1 - 5" CO2 from CO2 Cylinders

2 - 1/2" CO2 from CO2 Start Cylinders in Deck Workshop

3 - 3/8" Air from Instrument Air Receiver in Engine Room

4 - Wire Release from CO2 Start Cylinders in 3/8" Pipe

5 - 1/2" CO2 to Gang Release Working Piston No.1 and No.2

6 - 3/8" Air to Alarm Sirens in Engine Room

7 - 1/2" CO2 to Gang Release Working Piston No.3

8 - 3/8" Air to Alarm Sirens in Electric Motor Room

Cargo Control Room and LNG Compressor Room

9 - 2" CO2 to LNG Control, Motor and LPG Room

10 - CO2 Pressure Switches for Cutting off Deck Fans

11 - CO2 Pressure Switches for Cutting off Ventilation in

Engine Room and Boiler Room

12 - 5" CO2 to Engine Room

13 - CO2 Release Locker for Ventilation Masts

14 - Wire Release for 6 x 45kg CO2 Cylinders to Vent

Masts

15 - 1/2" CO2 to Ventilation Masts

Key

C

D

1

4

9

12

13

4

15

Engine Room and LNG RoomCO2 Operating Panel

PaintRoom

Local CargoControl Room

LNG CompressorRoom

LPGRoom Electrical Motor

Room

s

s

s

CO2 Release Lockers(LNG Compressor Room,LPG Compressor Room,

Electric Motor Room,Cargo Control Room,

Vent Masts)



Issue: 1


d) Do not re-enter the LNG compressor room for at least 24 hoursand ensure that all reasonable precautions have been taken, suchas maintaining boundary inspections, noting cooling down ratesand/or any hot spots which may have been found. After thisperiod, an assessment party using radio communication andwearing breathing apparatus and lifelines can enter the spacequickly through a door, which is then shut behind them. Checkthat the fire is extinguished and that all surfaces have cooled priorto ventilating the LNG compressor room. Premature openingcould cause re-ignition if oxygen contacts hot combustiblematerial.

Procedure in the Event of a Fire in the Electric Motor Room

a) Go to the emergency headquarters on the starboard side of themain deck. Unlock the control cabinet for the electric motor roomand open the door.

b) The alarm sirens will activated due to the door releasing thespring operated valve which directs compressed air from theengine room to the electric motor room alarm sirens.

c) Proceed directly to the CO2 room and manually release the twocylinders marked EL MOTOR ROOM.

d) Do not re-enter the electric motor room for at least 24 hours andensure that all reasonable precautions have been taken, such asmaintaining boundary inspections, noting cooling down ratesand/or any hot spots which may have been found. After thisperiod, an assessment party using radio communication andwearing breathing apparatus and lifelines can enter the spacequickly through a door, which is then shut behind them. Checkthat the fire is extinguished and that all surfaces have cooled priorto ventilating the electric motor room. Premature opening couldcause re-ignition if oxygen contacts hot combustible material.

Procedure in the Event of a Fire in the LPG Compressor Room

a) Go to the emergency headquarters on the starboard side of themain deck. Unlock the control cabinet for the LPG compressorroom and open the door.

b) The alarm sirens will activated due to the door releasing thespring operated valve which directs compressed air from theengine room to the LPG compressor room alarm sirens.

c) Proceed directly to the CO2 room and manually release the fourcylinders marked LPG - COMPRESSOR ROOM.

d) Do not re-enter the LPG compressor room for at least 24 hoursand ensure that all reasonable precautions have been taken, suchas maintaining boundary inspections, noting cooling down ratesand/or any hot spots which may have been found. After thisperiod, an assessment party using radio communication andwearing breathing apparatus and lifelines can enter the spacequickly through a door, which is then shut behind them. Checkthat the fire is extinguished and that all surfaces have cooled priorto ventilating the LPG compressor room. Premature openingcould cause re-ignition if oxygen contacts hot combustiblematerial.

Procedure in the Event of a Fire in the Cargo Control Room

a) Go to the emergency headquarters on the starboard side of themain deck. Unlock the control cabinet for the control room andopen the door.

b) The alarm sirens will activated due to the door releasing thespring operated valve which directs compressed air from theengine room to the control room alarm sirens.

c) Proceed directly to the CO2 room and manually release the twocylinders marked CONTROL ROOM.

d) Do not re-enter the control room for at least 24 hours and ensurethat all reasonable precautions have been taken, such asmaintaining boundary inspections, noting cooling down ratesand/or any hot spots which may have been found. After thisperiod, an assessment party using radio communication andwearing breathing apparatus and lifelines can enter the spacequickly through a door, which is then shut behind them. Checkthat the fire is extinguished and that all surfaces have cooled priorto ventilating the control room. Premature opening could causere-ignition if oxygen contacts hot combustible material.

Procedure in the Event of a Fire in the Paint Store

a) Close the paint store door and the ventilation flap, in order toisolate the fire.

b) Go to the control cabinet on the starboard side of the central CO2flooding system room on the main deck aft. Unlock the controlcabinet for the paint store and open the door.

c) Pull the handle to activate the two cylinders in the locker on themain deck on the port side below the paint store.

d) Ensure that all reasonable precautions are taken, such as thecooling of the boundary and/or any hot spots which may be found.

Procedure in the Event of a Fire in the Incinerator Room

a) Close the incinerator room door and the ventilation flap, in orderto isolate the fire.

b) Isolate the incinerator by pressing the emergency stop pushbuttonon the bulkhead, aft of the incinerator door and closing the gas oiltank outlet valve.

c) Go to the control cabinet on the starboard side of the central CO2flooding system room on the main deck aft. Unlock the controlcabinet for the incinerator and open the door.

d) Pull the handle to activate the three cylinders in the central CO2flooding system.

e) Proceed directly to the CO2 room to ensure that the correctnumber of cylinders have discharged for the particular area.

f) Ensure that all reasonable precautions are taken, such as thecooling of the boundary and/or any hot spots which may be found.


Issue: 1


5.2.6 Emergency Headquarters

The emergency headquarters is situated on the starboard side of theaccommodation block on the main deck. The room contains the followingsafety equipment:

Start and stop pushbuttons for the engine room forward and aft fire anddeck wash pumps

Cargo ESD activation lever

Three sets of fireman outfits

Recharging compressor for the self contained breathing apparatus bottles

Automatic exchange telephone

Release valve to close engine room skylight hatch

Drager emergency escape breathing device

Spare fire hoses and fire axes

CO2 system release cabinets for the following areas:

Engine room

LNG room

Electric motor room

Cargo control room

LPG room

Cargo tank ventilation masts

Quick-closing system for the following valves:

Diesel oil storage tank outlet valve

Port HFO storage tank outlet valve

Starboard HFO storage tank outlet valve

Gas ventilation flap valve

Emergency stop pushbuttons for the following:

Engine room ventilation fans

Accommodation ventilation fans

Deck ventilation fans

Boil-off gas pipe duct ventilation fans

Port boiler steam stop valve

Starboard boiler steam stop valve

Boiler heavy fuel oil supply pumps

Boil-off gas valve V2140

Breathing Apparatus Compressor

Maker: BauerModel: U1HOperating pressure: 200 barMotor: 2.2kW

Starting Procedure

a) Check the oil level in the compressor sump and replenish it ifnecessary.

b) Open the filling valve and the vent valve first, then the bottlevalve.

c) Turn the switch on the starter panel to the ON position and pressthe START pushbutton.

d) Close the vent valve after the compressor has started producingair.

e) When the pressure gauge indicates 200 bar, close the bottle valve,followed by the filling valve.

f) Open the vent valve and stop the compressor by pressing theSTOP pushbutton on the starter panel.


Veiw of Breathing Apparatus Compressor

Issue: 1

HC3a

PI3a

HC3c

PI3cHC

3b

Illustration 5.3.1a Cargo Plant Water Cooling System

SeaChestSea

Chest

Key

Sea Water

Electrical Signal

Instrumentation

Bilge

Fresh Water

IG PlantCW Pump

(340m3/h at 5kg/cm2)

LPG PlantCW Pump

(170m3/h at 5kg/cm2)

ToAft Peak

Tank

EmergencyBilgeSuction

StarboardForwardBilgeWell

FromBilge Main

Sea WaterCoolingPump

(650m3/h at 25mth)

From/ToAuxiliary

CirculatingPump

FromAuxiliaryCirculatingPump

V329

V330 V407A

V407

V331

FromBilge

Eductor

PC52

PCV52

PI

IG Refrigeration PlantCondenser

ToLPG Plant

ToWater Spray

System

Tube and Shell TypeFresh Water Cooler

InboardInert GasGenerator

Plate TypeFresh Water Cooler

Connection FromFire and Deck WashSystem

To/FromEngine RoomFresh WaterCoolingSystem

To/From Engine RoomFresh Water Cooling System

V322

V323

V409 V409 V409

OverboardHD/LDCompressorsLO Coolers

V408 V408 V408

HDHDLD

V407A

V479

V335

V335

V341

V407A

V412

PIInboard

Inert Gas GeneratorFresh Water

Circulating Pump

From OutboardInert Gas

Generator

To OutboardInert Gas

Generator

From/ToFresh Water

CoolingSystem

V452

V451

V340 V340



5.3 Cargo Compressor Room Systems

5.3.1 Cooling Water System

Inert Gas Sea WaterCooling PumpMaker: Thune EurekaNo. of sets: 1Type: CGD 200 centrifugal verticalCapacity: 340m3/h at 5kg/cm2

Speed: 1,750 rpm

LPG Sea WaterPumpMaker: Thune EurekaNo. of sets: 1Type: CGB 100 centrifugal verticalCapacity: 170m3/h at 5kg/cm2

Sea water pump is used to cool the LNG high duty (HD) and low duty (LD)compressors’ lubricating oil coolers, the inert gas refrigeration plant cooler andthe inert gas generator scrubber towers.

The compressor coolers are supplied with sea water circulated by the LPGcooling water pump and may be cross-connected from the IG sea water systemor the engine room SW cooling system.

The IG refrigeration plant cooler and the IG generators are supplied with seawater from the IG cooling water pump. This system may be cross-connectedfrom the LPG sea water cooling pump.

The auxiliary SW circulating pump can also be used to supply the coolingwater in an emergency.

Both the IG and LPG pumps are normally used together, with the cross-connection valve used when required if one pump is not available.

The IG cooling water pumps also supply the water spray system.


Inert Gas Cooling Water Pump System

a) Ensure that the engine room SW cooling system and LPG coolingsystem cross-connection valves are closed.

b) Ensure that the IG cooling system stop valves V335 are closed.

c) Ensure that the sea chest suction valve V329 is open.

d) Open the pump suction valve V330 and ensure the dischargevalve V331 is slightly open.

e) With the power off, ensure that the pump turns freely by hand.

f) Vent off the pump casing and ensure that it is flooded.

g) Ensure that the inlet and outlet valves on all the IG plant andcoolers to be used are open and that the drain valves are shut.

h) Open the overboard valve V341 from the cooler and IG plantdischarge line.

i) Start the IG pump and slowly open the discharge valve V331.

j) Check that the delivery pressure ia approximately 3.5 bar.

k) Check that all the in-use coolers are venting off at the outlet waterboxes to ensure that no air is entrained in the units. Ensure thevent valves are tightly closed.

The IG plant can now be started as required. See section 4.7.1 for furtherinformation.

LPG Circulation Pump System

a) Ensure that the deck water spray line supply valve V479, the LPGplant supply valve, the overboard and aft peak tank filling valvesare closed.

b) Ensure that the sea chest pump suction valve V329 is open.

c) Ensure the discharge valve V407 is slightly open and suctionvalve V407A is open.

d) With the pump isolated, ensure that the pump turns freely byhand.

e) Vent off the pump casing and ensure that it is flooded.

f) Ensure that the inlet valves V408 and outlet valves V409 on allthe compressor coolers to be used are open and that the drainvalves are shut.

g) Open the overboard valve V412 from the cooler discharge line.

h) Start the LNG circulation pump and slowly open the dischargevalve V407.

i) Check that the pump delivery pressure is at least 2 bar.

j) Check that all the in-use coolers are venting off at the outlet waterboxes to ensure that no air is entrained in the units. Ensure thevent valves are tightly closed.

The compressors can now be used as required. See section 4.4 for furtherinformation.



Issue: 1

Illustration 5.3.2a Steam To Deck Consumers

Condensate

Exhaust

Key

Steam

Steam Supply From

LP Steam GeneratorForward Winches

To

Atmospheric

Condenser

Main Deck Steam Exhaust Line

From Forward Winches

To Contaminated

Steam Condenser

To Deaerating Tank In Engine Room

V1035A V1035 V1035

V1035

V1033A V1033 V1033

V1033

V1033A V1033 V1033

V1033V911

V1035V1042

V1002

V911 V911V911A

V911

V911 V911V911A

V937

V937

V1038

Turbine

Compressor

V921AV921

V942V1040

V1038

V941 V941

V1032

V1032

V1032

V1032

V1032V908

V902

V1032

V1032

V1032

V1032

V937V937A

Cargo Heater

Cargo Heater

LNGVaporiser

LD

Compressor

V1038

Turbine

Compressor

V909AV909

V942V1040

V1007

V941 V941

HD

Compressor

Turbine

Compressor

V1038

Drain to Deck

SteamSeparator

V886AV886

V888V1040

V1279

V889 V889

V890 V1039 V1039

HD

Compressor

TurbinePre-Lub.

Pump

TurbinePre-Lub.

Pump

TurbinePre-Lub.

Pump

Drain to Deck Drain to Deck

Drain on Deck



Issue: 1


5.3.2 Steam to Cargo Consumers

Cargo Equipment Steam Supplies

All the steam requirements for the vessel are generated in the two main boilers.In each boiler, steam from the steam drum is led to the primary superheatersection. Steam from the superheater outlet is led to the internal desuperheater,situated in the steam drum, from where it is distributed to the various steamservices (for further information about the desuperheated steam system, see thevessel’s Machinery Operating Manual, section 2.1.1).

Superheated steam from the outlet of each boiler is also led to two externalcooling/pressure control valve desuperheaters. The internal desuperheatersupplies the steam required during normal steaming conditions, with No.1desuperheater ‘making up’ if the demand exceeds the output of the internaldesuperheater. These desuperheaters supply the ship’s services.

High duty compressors A and B, the low duty compressor, the cargo heatersand the vaporisers are all fed with 10kg/cm2 steam from the low pressure steamsystem.

The low pressure steam service system is supplied from the low pressure steamgenerator at a pressure of 10 kg/cm2. In an emergency, the LP steam servicescan be supplied from the desuperheated steam system. The low pressure steamservice system also feeds the winches and windlasses. For further informationabout the low pressure steam system, see the vessel’s Machinery OperatingManual, section 2.1.5.

Cargo Machinery

The steam is used as follows:

To drive the HD and LD compressors and their associatedlubricating oil pumps

To heat the compressor’s lubricating oil heaters

To heat the LNG cargo heaters

To heat the LNG vaporiser

The low pressure steam is supplied from the engine room to a steam headerlocated in the LNG compressor room. The desuperheated steam for HDcompressor C is supplied directly from the engine room to the compressor.

The steam supply to each compressor is regulated by their control valveaccording to the compressor suction pressure. As well as driving the maincompressor turbine, steam is used to drive a small turbine which drives aprelubricating oil pump.

This is fitted to provide the oil supply for the turbine and compressor beforeand during starting until the mechanically driven main gear oil pump is up tospeed and feeding oil.

The steam supply to the vaporisers is controlled by valve 937A. This valve isregulated by the level controller according to the condensate level. If the levelrises too high, the steam valve is closed, shutting off steam to the vaporiser.

The steam supply to the cargo heaters is controlled by valve 911A. This valveis regulated by the level controller according to the condensate level. If thelevel rises too high, the steam valve is closed, shutting off steam to the heater.This action halts any increases in water level which could lead to the formationof ice.

The steam supply to the atmospheric heater is controlled by valve 946A. Thisvalve is regulated by the signal from the heater’s temperature controller. Thecontroller regulates the valve in accordance with the temperature receivedfrom a temperature sensor located in the void space outlet.

There are various steam traps and drains fitted to the system to removecondensate and therefore improve the efficiency of the heat exchangers.


Issue: 1

Illustration 5.4.1a Mooring Winches and Deck Steam System

Cont. Condenser

Instrumentation

Condensate

Electrical Signal

Mooring Winch

Steam

KeySteam Exhaust

LNGCompressor

Room

From Vaporiserin LNG Room

VentDeaerating

Tank

CoolingWater

HotWaterHeater

To FO Tanks

IG DehumidifierDryer

To FO Tanksand Boilers

ToFilter Tank

ToFilter Tank

1st Poop Dk Port

Makeup fromDesuperheatedSteam System

CargoControlRoom

To Fire PumpSea ChestDe-icing

H.F.O Tank

Port andStarboardOverboardDe-icing

AirCond.

PI53

PIC53

PCV013A

TCV914A

PT53

TI PI

ContaminatedCondenser

V905

V905

V905

V1005

V1028

V1028

V1028V915

V915A

V1005

V1005

V905 V1005V902

V905 V1005

V905

V905

V905

V1005

V1005V1005

V918C

V934V934

V1000V1009

V1000V1010

V1011

V1030

V914V914 V914A

V914

V901

V900

V912

V900A

V814BV814AV814

V815

V913B

V901AV912A

V913

V913A

V1030

V1002

V1005

V1005

V905

V905

V1005

V904V904AV904

V917

V904

LP SteamGenerator

10 bar at 20 tonnes/hTo LP SteamGeneratorHeating Coils

PCV915A

V1001



Issue: 1


5.4 Deck Machinery and Systems

5.4.1 Mooring Winches, Windlasses and Deck Steam System

Windlass

Maker: AS Pusnes Mekaniske VerkstedChain stopper type: WRW 14Cable lifter type: M60 CU 14a0.14a

Mooring Winches

Windlass WinchesMaker: AS Pusnes Mekaniske VerkstedType: 30/60 SMNo. of sets: 2

Focsle Centre WinchMaker: AS Pusnes Mekaniske VerkstedType : 30 SMNo. of sets: 1

Focsle Port and Starboard Outer (Spring) WinchesMaker: AS Pusnes Mekaniske VerkstedType: 30 SMNo. of sets: 2

Aft Port and Starboard Outer (Spring) WinchesMaker: AS Pusnes Mekaniske VerkstedType: 30 SMNo. of sets: 2

Aft Mooring Deck Port Starboard Outer WinchesMaker: AS Pusnes Mekaniske VerkstedType: 30 SMNo. of sets: 1

Aft Mooring Deck Midship WinchesMaker: AS Pusnes Mekaniske VerkstedType: 30 SMNo. of sets: 2

The deck winches and windlass are fed from the deck steam system. Thissystem is fed from the engine room low pressure steam generator. For furtherinformation about the deck steam system, see the vessel’s MachineryOperating Manual section 2.1.2 Desuperheated Steam System.

Each winch uses a double acting 2 cylinder steam engine driving a singlereduction gear in an oil bath. The main gear case bearings and the crossheadare force lubricated from a plunger type pump.

Operating Procedure for Winches Unused for a Long Period

If the winches have been left unused for a long period of time, the followingprocedure should be applied:

a) Check the oil level in the gear case by observation of the dipstick.

b) Check that the supply steam valves are closed (on all winches)and check that all control levers are at the NEUTRAL position.

c) Open the deck steam system supply valve.

d) Check that all the drums and heads have their drives disengagedand that the brakes are on. Set the control lever to the LOWERposition.

e) Open the exhaust valve.

f) Open the bypass valve (between the supply and exhaust lines).

g) Open the drain cock.

h) Open the supply steam valve until the winch runs very slowly andleave in this condition for approximately 2 minutes.

i) Close the drain cock and the bypass valves. This will cause thewinch to accelerate. If any water shocks are observed, repeat thedraining sequence.

j) Slowly close the supply steam valve until the winch is idlingslowly. Lubricate all the bearings (for further in-depth lubricatinginstructions refer to the manufacturer’s manual).

k) Increase the speed to full slack-rope speed for approximately 3 or4 seconds.

l) Move the control lever to the NEUTRAL position. The winch isnow ready for service. If the winch is not to be used immediately,the steam supply valve should be closed.

Operating Procedure - Normal

The winches are ready for service, the steam system supply valves are openand there is no condensate (eg, arriving in harbour):

a) Open the winch steam supply valve.

b) Engage the drum or head coupling by moving the coupling lever,if necessary, moving the control lever gently around theNEUTRAL position. When engaged, lock the coupling lever withthe locking pin.

c) Control the winch by slowly moving the control lever in therequired direction.

d) To hoist/heave in, push the control lever slowly in the HEAVEdirection. The speed increases proportionally with the levertravel.

e) To lower/pay out, pull the control lever slowly in the LOWERdirection.

Sensitive Winch Handling Procedure

When very slow or delicate winch handling is required, the procedure is asfollows:

a) Before engaging or connecting up to the load, close the steamsupply valve.

b) Set the control lever to the HEAVE position.

c) Connect up the load. The winch is now controlled by means ofadjusting the steam supply valve: Open the valve slowly to hoistand close it slowly to lower the load. When lowering, the load willrun away in a controlled manner, opening the valve(anticlockwise) will apply a braking effect.


Issue: 1

Cylinder Guide

Case

Crank

Case

Live Steam

Valve

Exhaust Steam

Valve

Gear Wheel Cover

Views of WInch/Windlass Drive Cylinders and Main Gear Wheel Showing Pistons etc

Illustration 5.4.1b Winch/Windlass



Veiw of Winch/Windlass Steam and Exhaust Valves

Issue: 1


Anchor/Windlass Operation - Dropping an Anchor

a) At the windlass drive winches, engage and disengage thecouplings to suit the anchor requirements, ie, one or two driveengines.

b) Ensure the control levers are in the NEUTRAL position and openthe steam supply valve and the exhaust valve of the winches.

c) Engage the cable lifter.

d) Set the control lever to HEAVE.

e) Release the cable lifter brake so that the chain is tightened enoughto disengage the chain stopper. Tighten the brake again.

f) With the control lever in the HEAVE position, remove thelashings.

g) With the control lever still in the HEAVE position, regulate thethe anchor lowering speed down to the water surface by gentlymoving the control lever. The speed should not exceed15metres/min.

h) Stop the windlass when the anchor is just above the water. Tightenthe cable lifter brake.

i) Disengage the cable lifter. Gently moving the control lever willmaker the disengaging easier.

j) The anchor is ready to be dropped. This should be carried out insteps in a controlled manner, using the brake as required.

k) When sufficient cable is payed out, the brake should be tightenedon and the stopper bar fitted, if required.

Anchor/Windlass Operation - Heaving/Stowing an Anchor

a) Heave in the anchor reducing speed accordingly as the anchorreaches home.

b) When the anchor is fully home, the winch heave can then beincreased to ensure the anchor is seated correctly for lashing.

c) Secure the anchor correctly with lashings and make fast.

d) Close the steam supply valve and disengage the cable lifter.

Hydraulic Cable Lifter Brake

The hydraulically operated brake consists of the power pack, operating leverand actuator cylinder. The power pack is situated at the forward bulkhead inthe focsle store. The hydraulic power pack consists of a 100 litre oil tank,4.5kW electric motor and two tandem driven pumps. The brake cylinder isenergised by moving the respective port or starboard operating lever, situatedon a console on deck between the two windlass. The cable lifter brake may beoperated manually or hydraulically. To operate the brake manually, turn thehandle clockwise, the brake will engage gradually according to the turnsapplied. To operate the brake hydraulically:

a) Tighten the brake manually until the two indicators cover eachother.

b) Start the power pack in the focsle store.

c) Move the operating lever to the BRAKE RELEASE position andhold until the brake is released.

d) The released anchor speed can be controlled by moving theoperating lever toward the STOP position.

The brake is failsafe in operation as a loss of hydraulic pressure will cause thebrake to be applied due to the fitting of spring discs in the piston.

Completion of Mooring Operations

When the vessel is safely tied up, the winch ballcocks can be set toAUTOMATIC and the winches will automatically hold the lines under tensionindependent of loading, discharging and tidal range. However, some harbourshave restrictions concerning the use of automatic winches when alongside andthe vessel’s winches are usually left in the HAND configuration.

After Use - Vessel Left Harbour

a) Lock the control levers in the NEUTRAL position.

b) Close the steam supply valves and the exhaust valves.

c) Close the main deck system steam valve for the winches, if theweather conditions permit.

d) Open the drain cocks on the winches.

e) Open draining cocks on the pipe lines. When the winches are coldand all condensate has drained away, the drain cocks may beclosed.

f) The winches should be left with all the brakes tightened down andthe couplings disengaged.


View of the Windlass Hydraulic Brake

Issue: 1


Loading PlatformBD-4 BD-3 BD-2 BD-1

MD-1

MD-2MD-3MD-4MD-5

MD-6

BD-3

4 Stern Lines

2 Breast Lines 2 Breast Lines

3 Head Lines2 Springs

No.4

No.3No.2

2 Springs

Illustration 5.4.2a Mooring Arrangement

No.12 No.13

No.5No.6

No.7

No.1

No.8No.9

No.11No.10


Issue: 1


5.4.3 Pilot and Accommodation Ladders

Pilot Ladders

Two SOLAS compliant pilot ladders are available, for use in pilot embarkationand disembarkation in cases where the accommodation ladder cannot be useddue to sea conditions for example.

The pilot ladders are moved from their stowage position to a position in whichthe pilot ladder can be used in conjunction with the accommodation ladder tofacilitate easier access for the pilot.


At night pilot ladder and ship's deck lit by forward shining overside light

PILOT

The steps mustbe equally spaced

Spreaders must not belashed between steps

The loops are a trippinghazard for the pilot and can become fouled on the pilot launch

The side ropes mustbe equally spaced

The steps mustbe horizontal

There must notbe any shackles,knots or splices

PILOT

Very DangerousLadder too long

PILOT

Rigging for Freeboards of 9 metre or Less

SpreaderMin. 180cm long

5th step mustbe a spreader

Maximum 8 stepsbetween spreaders

Height requiredby pilot

Man-ropes withoutknots. Min. diameter28mm (If requiredby pilot)

Steps must be againstship's side

Side ropes Min. diameter 18mm

30-38cm

40cmMin

Illustration 5.4.3a Required Boarding Arrangement for Pilot

PILOT PILOT

Accommodation ladder should rest firmly againstship's side and should lead aft.Maximum 55° slope.Lower platform horizontal.Rigid handrail preferred.

3 to 7 metres depending on size of pilot launch and swell

Ladders to restfirmly against ship's side

Pilot ladder mustextend at least 2 metres above lower platform

A Pilot Ladder Combined With An Accommodation Ladder Is Usually The Safer MethodOf Embarking Or Disembarking A Pilot On Ships With A Freeboard Of More Than 9 Metres

Officer In Contact With The Bridge

Issue: 1

Illustration 5.4.3b Pilot and Accommodation Ladders

Plan

Upper Deck

HoistingWinch

HoistingWinch

HoistingWinch

Turn Table

Rail For UpperPlatform

Rest's

MaximumAngle 55°

Pilot Ladder

Hoisting Wire

Hoisting Wires



Issue: 1

Norman Lady Cargo Operating Manual Accommodation Ladders

Maker: ActaType: 16kNS-12ASerial No. 99.32510.01No. of sets: 2Capacity: 2 x 6kNSpeed: 10m/minute

One aluminium alloy accommodation ladder is provided on each side of themain deck. The ladders are traversed, lowered and hoisted by means ofcompressed air motors operated from a control stand situated at the ship’s side.

(Note: The ladders are designed to reach the ballast water line with an angleof inclination of not more than 55°. Always leave at least 2 layers of wire onthe lowering drum. Always check it is safe to lower or raise the ladder.)

Procedure for Lowering the Accommodation Ladder

The accommodation ladder on the port or starboard side is controlled from itsown control stand. Compressed air motors are used to hoist/lower and to swingthe ladder in and out.

WARNINGThis procedure requires work to take place outside of the ship’s rails.Appropriate personal protective equipment should be donned includinglifelines attached to a suitable strong point. At night there must beadequate illumination to safely complete the task.

Rigging

a) From the stowed position, un-ship all of the wire lashings.

b) Ensure the air supply valve is open, blow the air supply line freeof water and drain the water filter.

c) Adjust the lower platform angle to a suitable position for theintended use. Lower the ladder to clear it from its stowed positionand continue lowering until there is sufficient space underneaththe davit to erect the handrails.

d) Two men are required to don safety harnesses and inflatablelifejackets and then rig the stanchions on the upper platform.

e) One man is to go down the ladder until he is just below the davit,and raise each handrail in turn. The man at the ladder top securesthe handrails with the pins. In order to move up and down theladder safely, the safety harness can be attached to the wirelashings.

f) The two lower lightweight platform stanchions are then fitted.Roping of the lower platform is then carried out and whencomplete, the ropes are led up each side of the ladder forming themiddle rail.

g) Fit the upper platform ropes. The ladder is now rigged and can belowered when required, keeping an eye on the tightness of theropes.

h) Check there is a lifebuoy available, that the deck is clear ofobstructions and a heaving line is ready. If using the ladder inport, a safety net is to be rigged.

Securing

a) Hoist the ladder until the handrails are just below the davit.

b) One man wearing harness and an inflatable life jacket unlashesthe platform and ladder ropes.

c) Swivel and remove the stanchions from the upper and lowerplatforms of the ladder.

d) The second man wearing harness and an inflatable life jacketremoves the pins securing the ladder handrails, one at a time. Hethen lowers each handrail in turn, so that the handrails rest flat onthe ladder.

e) When the men are clear, hoist the ladder until it is vertical.

f) Secure the ladder with all the lashings.

g) Close the main air supply valve. Apply the covers to the winchand air motor. Remove the hose from the air motor and stow it toensure that the deck is kept clear.


Issue: 1

SWL 2.67 T - 12MHose Handling Cranes

Provisions Crane SWL 4 T - 12M

Illustration 5.4.4a Deck Cranes

QUARTER

WINCH

WEAVE

LOWER

CYLINDER

LIFT

LEFT

SLEWING

RIGHT



Issue: 1


5.4.4 Deck Cranes

Hose Handling Crane

Maker: ActaNo. of sets: 2Type: HHC-30-26.7-12SWL: 2.67 tonnes at 12 metres radius

Provisions Crane

Maker: ActaNo. of sets: 1SWL: 4 tonnes at 12 metres radius

Description

Electro hydraulically driven deck cranes are provided for handling the cargohoses, fuel hoses and provisions and stores. The hose handling cranes arepositioned above the port and starboard manifolds and the provisions crane ispositioned on the main deck at the port aft end of the engine casing.

Crane ControlThe crane is controlled from an open platform above the slewing ring.Entrance to the platform is by ladder. All motions have stepless speed controlfrom 0 to maximum. Two motions can be operated at the same time with fullcapacity, but with reduced speed.

Load Limiting SystemEach hydraulic circuit is provided with equipment for limiting hydraulicpressure to preset values corresponding to the crane capacity. These do not stopthe electric motor but divert the oil supply back to the holding tank.

Limit SwitchesThe crane is provided with an automatic hook stop when the hook reaches themaximum top and bottom positions.

Electro-Hydraulic Power Pack

The crane is provided with a built in power pack. The electric pump/motor islocated in the centre of the pedestal with the output shaft pointing upwards anddriving the hydraulic pump through a flexible coupling and shaft. The resevoirfor the hydraulic oil is located in the upper rotating part of the crane pedestal.The hydraulic oil circuit has a full flow suction filter with a changeable filterinsert.

The starter panels for the hose handling cranes are situated in the LPG electricmotor room, aft of the LPG switchboard and the starter panel for the provisionscrane is situated on the distribution board on the No.1 deck cross alleyway.

The local start and stop pushbuttons for each crane are on the lower pedestal.The wire rope is of 20mm nominal diameter and should be lubricated regularlywith an appropriate lubricant.

The wire sheaves are provided with roller bearings on steel axles. All bearingshave grease nipple lubrication.

Hoisting MachineryThe winch unit consists of:

Drum with bearing and brackets

Winch gear with spring operated/pressure release fail safe brake

Hydraulic motor with safety valve to freeze movement in case of pressure drop

Starting Procedure

a) Check that the control levers are in NEUTRAL.

b) Check that the wire is run correctly in the sheaves and that thewire rope ends are securely clamped.

c) Check the oil level and condition of the hoses and connections.

d) Start up the electric motor/hydraulic pump.

e) If the ambient temperature is less than 10ºC, let the crane run untilthe oil temperature is a minimum of 10ºC.

f) Check that all movements (hoist-luffing-slewing) are operationalwithout load.

g) The crane is ready for use.

Parking the Hose Handling Crane

a) Park the crane with the jib in a horizontal position and resting onthe jib support cradle.

b) Stop the pump/motor.

c) Fit the jib securing bracket.


Issue: 1

Deck - 2

BoilerCasing

IncineratorRoom

EngineCasing

Cabin140

Cabin136

Cabin128

Cabin132

Cabin120

Cabin116

Cabin230

Cabin226

Cabin222

Cabin218

Cabin214

Cabin208

CrewDay Room

CrewMess Room

P.O.Mess RoomGalley

Pantry

Vent

Vent Linen

lift wc

Cabin236

Cabin108

Cabin104

Cabin103

Cabin107

Cabin113

Cabin117

Cabin125

Cabin131

Cabin135

BoundedStore

Vent

Vent

Lift

DryingRoom

Laundry

AB SeamChangeRoom

wc

Cabin112

Lifeboat

LifeboatDeck - 1

AccVent

AccVent

EngineCasing

BoilerCasing

SwimmingPool

AccVent

AccVent

Illustration 5.5.1a Fire Detection and Alarms - Decks 1 and 2

Alarm Bell

Alarm Pushbutton

Key

Alarm Horn

Acet.Store

Oxy.Store

Chem.Store

OilStore



Issue: 1

Deck - 4

2nd Officer'sCabin

3rd Officer'sCabin

Electrician'sCabin

CargoEngineer'sDay Room

CargoEngineer'sBedroom

3rdEngineer'sBedroom

3rdEngineer'sDay Room

2ndEngineer'sDay Room

2ndEngineer'sBedroom

Luggage

AlternatorRoom

BattRoom

Catering OfficerDay Room

CateringOfficer'sBedroom wc

ChangingRoom

lift wc

wc

Deck - 3

Hatch

EngineVent

EngineVent

Vent

Vent

Store Laundry

Hospital 2nd Officer

Cadet

Cadet

Officer TV Room

ConferenceRoom

Officer'sDay Room

Officer'sDining Room

wc

Bath

Dispensary

DryingRoom

lift wc

EngineCasing

BoilerCasing

AirConditioning

AccVent

EngineVent

EngineVent

AccVent

AirConditioning

Illustration 5.5.1b Fire Detection and Alarms - Decks 3 and 4

Alarm Bell

Alarm Pushbutton

Key



Issue: 1

Deck - 6Deck - 5

lift wc

wc

wc

wc

wc

wc

Hatch

ChiefOfficer'sBedroom Chief

Officer'sDay Room

Captain'sBedroom

Captain'sOffice

Captain'sDay Room

Chief Engineer'sDay Room

Chief Engineer'sBedroom

Accessories

PantrySpareCabin

ChiefEngineer's

Office

ChiefOfficer'sOffice

Illustration 5.5.1c Fire Detection and Alarms - Decks 5 and 6

Key

Alarm Bell

Alarm Pushbutton

General Alarm PushbuttonG

G

Gas Detector Points



Issue: 1

Illustration 5.5.1d Fire Detection and Alarm - Upper Deck and Engine Room

Alarm Bell

CO2 Siren-Air Operated Alarm Horn

Alarm Pushbutton O2 Indicator

Gas Detector - Portable

Key

Gas Detector Points



Issue: 1

Deck - 2

BoilerCasing

Acet.Store

Oxy.Store

Chem.Store

OilStore

IncineratorRoom

EngineCasing

Cabin140

Cabin136

Cabin128

Cabin132

Cabin120

Cabin116

Cabin230

Cabin226

Cabin222

Cabin218

Cabin214

Cabin208

CrewDay Room

CrewMess Room

P.O.Mess RoomGalley

Pantry

Vent

Vent Linen

lift wc

Cabin236

Cabin108

Cabin104

Cabin103

Cabin107

Cabin113

Cabin117

Cabin125

Cabin131

Cabin135

BoundedStore

Vent

Vent

Lift

DryingRoom

Laundry

AB SeamChangeRoom

wc

Cabin112

Lifeboat

LifeboatDeck - 1

AccVent

AccVent

EngineCasing

BoilerCasing

SwimmingPool

AccVent

AccVent

Illustration 5.5.2a Fire Fighting Equipment - Decks 1and 2

Key

Stop Duct Keel Fans

Fire Flaps

Hose Boxes with 18m - 2"/20m 1½ Hoseand with Unifire V-16 Jet / Fog Nozzle

Fire Hydrant 2 1.2"

Fire Hydrant 2 1.2"

CO2 Nozzle

6.8kg CO2

9L Water/CO2

12kg Powder



Issue: 1

Deck - 4

2nd Officer'sCabin

3rd Officer'sCabin

Electrician'sCabin


CargoEngineer'sBedroom

3rdEngineer'sBedroom



2ndEngineer'sBedroom

Luggage

AlternatorRoom

BattRoom


CateringOfficer's

Bed Room wc

ChangingRoom

lift wc

wc

Deck - 3

Hatch

EngineVent

EngineVent

Vent

Vent


Cadet

Cadet

Officer TV Room

ConferenceRoom

Officer'sDay Room


wc

Bath

Dispensary

Store Laundry

DryingRoom

lift wc

EngineCasing

BoilerCasing

AirConditioning

AccVent

EngineVent

EngineVent

AccVent

AirConditioning

Illustration 5.5.2b Fire Fighting Equipment - Decks 3 and 4


Fire Hydrant 2 1.2"

Key

6.8kg CO2

9L Water/CO2

12kg Powder

Fire Flaps



Issue: 1

Deck - 6Deck - 5

lift wc

wc

wc

wc

wc

wc

Hatch


Officer'sDay Room

Captain'sBedroom

Captain'sOffice

Captain'sDay Room



Accessories

PantrySpareCabin

ChiefEngineer's

Office


Illustration 5.5.2c Fire Fighting Equipment - Decks 5 and 6


Fire Hydrant 2 1.2"

Key

6.8kg CO2

9L Water/CO2

12kg Powder

Release Quick Closing Valve

Emergency Stop Gas Valves

Stop Duct Keel Fans

Fire Flaps



Issue: 1

Illustration 5.5.2d Fire Fighting Equipment - Upper Deck and Engine Room

Fire Flaps in all Vent Ducts

750 Dry Powder 750kg Container

250 Dry Powder 250kg Container

Dry Powder Hose Boxwith Remote Control

Key

Dry Powder Room


Dry Powder Room

Fire Hydrant 2 1.2"

Hose Reel W/20m - 1½ Hoseand Unifire V-16 Jet / Fog Nozzle

International ShipShore ConnectionHold Eductors

CO2 Nozzle

CO2 Remote Release

6.8kg CO2

9L Water/CO2

34kg/CO2

12kg Powder

Fire Hydrant 2 1.2"

12kg Dry Powder

2.5kg Dry Powder

Stop Fuel Oil Pumpsand Gas Supply Boilers

Release Quick Closing Valve


Stop Accommodation Fans

Stop Deck Fans


Stop Duct Keel Fans

Fire Flaps

Fire Pumps2x100m3/h 120mwg

Emergency Fire Pump50m3/h 113mwg

Low Velocity SprayApplicator

Fire Hydrant 2 1.2"

Fire Spray Line

A

A 250 250 250

250 250

250

250



Issue: 1

Deck - 2

BoilerCasing

IncineratorRoom

EngineCasing

Cabin140

Cabin136

Cabin128

Cabin132

Cabin120

Cabin116

Cabin230

Cabin226

Cabin222

Cabin218

Cabin214

Cabin208

CrewDay Room

CrewMess Room

P.O.Mess RoomGalley

Pantry

Vent

Vent Linen

lift wc

Cabin236

Cabin108

Cabin104

Cabin103

Cabin107

Cabin113

Cabin117

Cabin125

Cabin131

Cabin135

BoundedStore

Vent

Vent

Lift

DryingRoom

Laundry

AB SeamChangeRoom

wc

Cabin112

Lifeboat

LifeboatDeck - 1

AccVent

AccVent

EngineCasing

BoilerCasing

SwimmingPool

AccVent

AccVent

Acet.Store

Oxy.Store

Chem.Store

OilStore

Smoke Mask

Illustration 5.5.3a Lifesaving Equipment - Decks 1 and 2

Key

Life Jacket

Liferaft6

620

20

6

2020

Survival Suits



Issue: 1

Deck - 4

2nd Officer'sCabin

3rd Officer'sCabin

Electrician'sCabin


CargoEngineer'sBed Room

3rdEngineer'sBed Room



2ndEngineer'sBed Room

Luggage

AlternatorRoom

BattRoom


CateringOfficer's

Bed Room wc

ChangingRoom

lift wc

wc

Deck - 3

Hatch

EngineVent

EngineVent

Vent

Vent

Store Laundry


Cadet

Cadet

Officer TV Room

ConferenceRoom

Officer'sDay Room


wc

Bath

Dispensary

DryingRoom

lift wc

EngineCasing

BoilerCasing

AirConditioning

AccVent

EngineVent

EngineVent

AccVent

AirConditioning

Illustration 5.5.3b Lifesaving Equipment - Decks 3 and 4

Key

Smoke Mask

Life Jacket



Issue: 1

Deck - 6Deck - 5

lift wc

wc

wc

wc

wc

wc

Hatch


Officer'sDay Room

Captain'sBedroom

Captain'sOffice

Captain'sDay Room



Accessories

PantrySpareCabin

ChiefEngineer's

Office


Illustration 5.5.3c Lifesaving Equipment - Decks 5 and 6

Key

Lifebuoys

MOB Lifebouy

MOB Lifebouy

Line Throwing Device

Parachute Distress Red Signal

GMDSS VHF

Survival Suits

Life Jacket



Issue: 1

Illustration 5.5.3d Lifesaving Equipment - Upper Deck and Engine Room

Survival Suits

Lifebuoys

Liferafts6

6

6

6

Line Throwing Device

Emergency Exit

Emergency Headquarters Smoke Mask

Key



Part 6Cargo Operations

Issue: 2

Illustration 6.1a Operating Procedures Schedule

Void Spaces Cargo Tanks

Normal Operational Cycle

Post/pre Dry Docking Operations

Precooling of cargo tanksbefore loading

Precooling of liquid lines (45 mins)

DISCHARGING(approximately 12 hours) Preparing To Leave Dry Dock

Drainage of liquid lines (45 mins)

LOADING(approximately 12 hours)

LOADED VOYAGE(1-16 days)

Drainage of liquid lines (45 mins)


BALLAST VOYAGE(1-16 days)

Precooling of cargo tanks (10 hours)

Precooling of cargo tanks

Cooling of cargo tanks (ongoing)


Evaporation of liquid residuefrom cargo tanks.

(approximately 12 hours)

Warming of cargo tanks.(approximately 72 hours)

Gas freeing of cargo tanks.(approximately 24 hours)

DRY DOCK

Inerting of the cargo tankswith inert gas.


Purging and dryingof cargo tanks

with warm methane.(approximately 20 hours)

Drying of thevoid spaces

with air.

Nitrogen bleedingto wedge spaces.

Drying of void spaceatmosphere.

Recirculation

Drying of void spaceatmosphere.

LOADED VOYAGE(1-16 days)

BALLAST VOYAGE(1-16 days)

Drying of void spaceswith air.

(approximately30 hours)

Aerating of voidspaces.


Aerating of the cargo tanks.


Preparing for dry dock

Recommence normal operations

Drying of cargo tankswith air

during entire dry dock period



Issue: 2


Part 6 Cargo Operations

6.1 Operating Procedures Overview

The cargo control system is designed to be operated from the cargo controlroom. However, some operations are required locally.

Equipment and plant such as compressors and pumps are protected by meansof tripping devices which will shut down the plant in the event of an abnormaltemperature, pressure or other condition which may be harmful to the plant orequipment if left unattended. In most cases an alarm will be raised before theshutdown, giving personnel time to attend to the problem before a shutdownoccurs.

It should be emphasised that personnel should conduct their own routineinspections of running machinery in line with recommendations issued by theindividual equipment manufacturers.

There are certain cargo operating parameters that are worthy of specialmention, as follows:

Void Space Pressure

To avoid even a remote possibility that the cargo tank shell may buckle, thepressure of the void spaces should never exceed 0.05 bar over that of the cargotanks. There are void space pressure relief valves fitted to avoid this possibility,see section 4.11.3 Void Space Relief Valves for further information.

Cargo Tank Temperature

To avoid thermal stress on the cargo tank shell and piping, sudden coolingdown must be avoided. The cooling down rates shown in section 6.2.4 shouldbe strictly followed.

Overfilling of Cargo Tanks

The greatest care must be taken to ensure that the cargo tanks are neveroverfilled.

General Guidelines

Except in special circumstances (described in section 7) where a single tank orvoid space may need to be isolated, the cargo tanks should be connectedtogether through the vapour line and the void spaces should be connectedtogether via the recirculation loop by keeping the valves in these lines open.

When the ship returns to cargo duties after a dry docking or refit, the tanks andlines will be full of ambient air. Before liquid cargo is reintroduced into thesystem, the tanks and lines must be oxygen (O2) and carbon dioxide (CO2) free.

The tanks and lines should be oxygen free to avoid the formation of anyexplosive mixture.

The tanks, lines and void spaces should be carbon dioxide free as this willsolidify at -78.5ºC.

There should be no humidity in the tanks and lines as this will lead to theformation of ice.

The void spaces should be free from any moisture as this may penetrate thetank insulation.

The methods of drying and inerting the tanks, void spaces and lines isdescribed in the appropriate following sections.


Issue: 2

Key

Nitrogen

Dry Air

Moist Air

V2303 V2303

Illustration 6.2.1a Drying Cargo Tanks and Void Spaces

Cargo Tank Cross-Section

Moist Air Drawn Off

to Recirculation Fans

Nitrogen

Bleed

Dried/Heated

Air

Dried/Heated

Air Ducts

V2209V2303

V2306

V2306V2306

V2303V2303V2303

V2306V2306V2306

From

Nitrogen

Generator

System

Starboard

Nitrogen

Buffer

Tank

15m3

Port

Nitrogen

Buffer

Tank

25m3

IG Connection at Starboard Manifold

IG Outlet

at Starboard Manifold

Recirculation

Fans 2,000m3/h

Void Space

Dryers

LNG

Compressors

LNG

Compressor

Room

V2310 V2310

V2311

V2314 V2314

V2315 V2315

V2311

V2209V2213Boiler Purging

/CompressorSealing

V2352 V2352 V2352A

V2209 V2209

V2216V2216V2216V2216 V2216

V2209

No.1

Cargo Tank

No.2

Cargo Tank

No.3

Cargo Tank

No.4

Cargo Tank

No.5

Cargo Tank

Purging

Outlets

at Dome

From

Engine Room

IG Plant



6.2 Post Dry Dock Operation

6.2.1 Drying Cargo Tanks and Void Spaces

During a dry docking or inspection, cargo tanks which have been opened andcontain wet air must be dried primarily to avoid the formation of ice when theyare cooled down and secondly, the formation of corrosive agents if thehumidity combines with the sulphur and nitrogen oxides, which might becontained in the inert gas. The tanks are inerted in order to prevent thepossibility of any flammable air/LNG mixture. Normal humid air is displacedby dry-air. Dry-air is displaced by inert gas produced from the dry-air/inert gasplant.

Dry-air is introduced at the bottom of the tanks through the filling piping. Theair is displaced from the top of each tank through the dome and the vapourheader, and is discharged from the vent mast.

The operation, carried out from shore or at sea, and will take approximately 20hours to reduce the dew point to between -25°C to -45°C.

During the time that the inert gas plant is in operation for drying and inertingthe tanks, the inert gas is also used to dry (between -25°C to -45°C) and to inertall the other LNG and vapour pipework. Before the introduction of LNG orvapour, any pipework not purged with inert gas must be purged with nitrogen.

Operating Procedure for Drying Tanks

Dry-air with a dew point of between -25°C to -45°C, is produced by the dry-air/inert gas plant at a flow rate of 5000Nm3/h.

a) Prepare the dry-air/inert gas plant for use in the dry-air mode. Seesection 4.7.1 Inert Gas Generator and illustration 6.2.2a InertingCargo Tanks.

b) Install the flexible connection between the flange at the end of theinert gas/dry-air feeder line and the liquid manifold or access tothe liquid header.

c) Install the flexible connection between the flange on the vapourheader line and the inlet flange at each tank’s vent mast.

d) Open valves V2016, V2016A, V2004, V2008, V2012, V2020 andV2024 to supply dry-air to the liquid header.

e) Open tank filling valves V2003, V2007, V2012, V2019 andV2003.

f) Open tank vapour valves V2100, V2101 V2103, V2108 andV2109, to vent through the vent mast on each tank.

g) Start the dry-air production. When the dew point is between -25°C to -45°C, open valve V2354 upstream of the two non-returnvalves V2352 and valve V2352A to allow the dry-air to pass intothe liquid header.

h) Monitor the dew point of each tank by taking a sample at thevapour domes. When the dew point is between -25°C to -45°C orless, close the filling and vapour valves of the tank. Disconnectthe flexible hose and return the blank to the vapour header flange.

(Note: No.1 tank should be the final tank to be dried to ensure the system isalways full of dry-air.)

i) Wet air which may be contained in the discharge lines from thecargo pumps, float level piping and any associated pipework inthe cargo compressor room must be purged with dry-air. This isnormally carried out in conjunction with the drying of the cargotanks.

j) When all the tanks and pipework have been dried out, stop theplant. Close the supply valves V2354, V2352, V2352A and valveV2016 to the LNG header.

k) Disconnect the flexible hose at No.1 vent mast and replace theblank flange on the vapour header.

(Note: It is necessary to lower the tank’s dew point by dry-air to between -25°C to -45°C before feeding the tanks with inert gas. This is in order to avoidany formation of corrosive agents.)

Drying Void Spaces

The procedure for drying the void spaces is as follows:

a) Install the flexible connection between the flange at the end of thedry-air feeder line and the main aeration header.

b) Prepare the inert gas plant for use in the dry-air mode.

c) Remove the blank flange in pipe 2305 at the top of the void space.

d) Open the inlet valve to the void space bottom, valve V2303.

e) Start the inert gas generator and ensure the generator is running inthe dry-air mode (see section 4.7.1, Inert Gas Generator). Whenthe oxygen content is satisfactory (approximately 21%) and thedew point is down to between -25°C to -45°C, open valve V2353upstream of the two non-return valves V2352 and valve V2352Ato allow the inert gas to pass into the main aeration header. Ensurethe spoon blank at the IG outlet at the starboard manifold area isin the correct position.

View of Void Space IG ConnectionShowing Spoon Blank in Place

f) Monitor the dew point of each void space by taking a sample atthe outlet pipe. When the dew point is between -25°C to -45°C,close the filling valves and replace the blank flange at the top ofthe void spaces.

(Note: It is possible to dry the void spaces at the same time as drying the tanks.Dry-air is introduced to each tank via the vapour header and the moist airdischarged from the tank bottom through the filling pipe, led into the voidspace aerating header through a flexible hose, and introduced to the void spacebottom. Exhaust air is discharged to atmosphere from the top of the voidspace.)



Issue: 1

Illustration 6.2.2a Inerting Cargo Tanks

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108V2138

V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103

V2138V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2352A

V2352

V2352

Engine RoomIG Plant Key

Inert Gas

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201 V2015A

Liquid

Vapour

Nitrogen

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

From

Recirculating Fans


To Void Spaces

PI

V2200AV2016A


Astern

Liquid

V2200

V2016

V2120

V2120



Issue: 2


6.2.2 Inerting Cargo Tanks

Inert gas, with an oxygen content of between 2% and 3% and a dew point ofbetween -25°C to -45°C, is produced by the dry-air/inert gas plant at a flowrate of 2,500Nm3/h. The inert gas is primarily nitrogen and carbon dioxide,containing between 2% and 3% oxygen with a dew point of between -25°C to-45°C.

Inerting After Refit

Before introducing vapour or liquid cargo into the cargo system, it is essentialthat all air is purged from the system to prevent the formation of flammablemixtures. In this operation, the object is to replace all air in cargo tanks andcargo pipework with inert gas.

Inert gas from the ship’s IG plant is connected to the LNG liquid header andled to the bottom of each cargo tank. The displaced air escapes to atmospherevia the LNG vapour header and vent riser. Oxygen measurement is carried outusing a portable analyser on samples drawn from each of the five samplingpoints in each cargo tank. Venting continues until the oxygen concentration atall points is consistently between 2% and 3% and the dew point between -25°Cto -45°C.

The inerting of LNG liquid and spray lines, including manifold crossovers,pump risers, vaporisers and relief valve lines, is carried out at the same time asthe inerting of the tanks. LNG vapour lines at the manifold crossover and in theLNG compressor room are inerted on completion of the rest of the system.When purging these pipelines, the volume of inert gas being discharged at decklevel can be minimised by routing the displaced gas, via the pressure build-upline, to vent at the vent riser.

This operation would be carried out before the ship’s arrival at the loading port.Other operations which will be carried out in preparation for first loadingwould be:

Purging/filling insulation spaces with nitrogen

Purging/filling hold spaces with dry-air.

As the IG plant is required for this latter operation, it would normally becarried out either immediately before or immediately after inerting. Nitrogenpurging can be carried out at any time before arrival. The inerting operationtakes about 24 hours.

Procedure to Inert after Refit

a) Prepare the dry-air/inert gas plant for operation in the inert gasmode.


c) Install the flexible connection between the flange on the vapourheader line and the inlet flange at each tank’s vent mast.

d) Open the following valves:


Open Aft liquid manifold valve V2016

Open Aft liquid ESD valve V2016A

Open Inert gas supply valve V2352, V2352A

e) Open the following tank filling valves:


Open No.5 cargo tank liquid header block valve V2024

Open No.5 cargo tank liquid filling valve V2023









f) Open the tank vapour valves V2109, V2108, V2103, V2101 andV2100 to vent through the vent mast on each tank.

g) Start the inert gas production. When the oxygen content is 4%(unless oxygen content percentage is specified by the terminal)and the dew point is between -25°C to -45°C, open the valveV2353, upstream of the two non-return valves V2352 on the dry-air/inert gas discharge line. Also open valve V2354A to allow theinert gas to pass into the liquid header.

h) By sampling at the vapour dome, check the atmosphere of eachtank using a portable oxygen analyser. The oxygen content is tobe between 2% and 3% and the dew point is between -25°C to -45°C.

i) During tank inerting, purge the air contained in the lines andequipment for about 5 minutes by using the valves and purgesample points. It is important to ensure that all pipework and deadends are purged.

j) When the inerting of all the tanks and associated pipework andequipment is completed, disconnect the flexible connection to thevent pipes and replace the flange blanks on the vapour line.

k) Pressurise the tanks to 0.15 bar.

l) When all the tanks and pipework have been dried out, stop theplant. Close the supply valves V2353, V2352, V2354A andmanifold valves V2016 and V2016A to the LNG header.Disconnect the flexible hose and replace the flange on the inertgas supply line.

(Note: Until the ship is ready to load LNG for gas filling, the tanks may bemaintained under inert gas for as long as is necessary. If required, pressurisethe tanks to 0.05 bar above atmospheric pressure.)

WARNINGInert gas from this generator and pure nitrogen will not sustain life. Greatcare must be exercised to ensure the safety of all personnel involved withany operation using inert gas of any description in order to avoidasphyxiation due to oxygen depletion.


Issue: 1

Illustration 6.2.3a Gassing Up Cargo Tanks

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

To LNG Vaporiser

From Manifold

Liquid Line

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

Key

LNG Liquid

LNG Vapour

LNG

Vaporiser

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

V2201

V2015A

NitrogenVapour

Liquid

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

From

Recirculating Fans


To Void Spaces

PI

V2016A


Astern

Liquid

Liquid

V2200A

Inert Gas

Inert Gas/Vapour

V2016 V2200



Issue: 2


6.2.3 Gassing Up Cargo Tanks

After a lay up or dry dock period, the cargo tanks are filled with inert gas ornitrogen. If the purging has been done with inert gas, the cargo tanks have tobe purged and cooled down when the vessel arrives at the loading terminal.This is because, unlike nitrogen, inert gas contains 15% carbon dioxide (CO2),which will freeze at around -78°C and produces a white powder which canblock valves, filters and nozzles.

During purging, the inert gas in the cargo tanks is replaced with warm LNGvapour. This is in order to remove any freezable gases such as carbon dioxideand to complete the drying of the tanks.

Description

LNG liquid is supplied from the terminal to the liquid manifold where it passesto the stripping/spray header via the appropriate ESDS liquid valve. It is thenfed to the LNG vaporiser and the LNG vapour produced is passed at +20°C tothe vapour header and into each tank via the vapour domes.

At the start of the operation to fill the cargo tanks, the piping system and LNGvaporiser are vapour locked. The stripping/spray header can be purged into thecargo tanks via the vapour dome through the arrangement of spray valvescontaining the control valve until the liquid reaches the LNG vaporiser. TheLNG vapour is lighter than the inert gas, which allows the inert gases in thecargo tanks to be exhausted up the tank filling line to the liquid header. Theinert gas then vents to the atmosphere via the vent masts.

When 5% methane (the percentage figure will be specified by the particularport authority) is detected at the vent mast riser, the exhaust gas is directedashore via the HD compressors, or to the boilers through the gas burning line.This operation can be done without the compressors, subject to existing backpressure, or with one or more HD compressors in service. If possible, it isbetter not to use the compressors to avoid creating turbulence inside the tanks.

The operation is considered complete when the methane content, as measuredat the top of the cargo filling pipe, exceeds 80% by volume.

The target values for N2 gas and inert gas CO2 is equal or less than 1%. Thesevalues should be matched with the LNG terminal requirements.This normallyentails approximately 2 complete changes of the volume of the atmosphere inthe cargo tank.

On completion of purging, the cargo tanks will normally be cooled down.

There are exceptional cases where it may be necessary to undertake thepurging of one or more tanks at sea using LNG liquid already on board. In thiscase the liquid will be supplied to the LNG vaporiser via the stripping/sprayheader using the stripping/spray pump of No.3 or No.4 cargo tank containingLNG liquid.

Due to local regulations on venting methane gas to the atmosphere, some portauthorities may require the entire operation to be carried out with the exhaustgases being returned to shore facilities.

Operating Procedures to Purge the Cargo Tanks with LNG Vapour

It is assumed, although unlikely, that all valves are closed prior to use.

a) Install the following spool pieces:

Liquid manifold header to vaporiser supply line

Liquid header to vapour line

b) Swing the liquid header to vaporiser supply line spectacle pieceinto position.

c) Prepare the LNG vaporiser for use.

d) Adjust the set point of the temperature control valve to +20°C.

e) Adjust the set point of the pressure control valve V2203A to 6kPa(or required value) by using the inching control (manual control).

f) Open valves V2201 and V2200A to enable the supply to reach theLNG vaporiser.

g) Open LNG vaporiser inlet valve(s) V2203.

h) Open LNG vaporiser outlet valve(s) V2235.

i) Open valve V2118 to allow the supply to the vapour header.

j) Open the following valves to the vapour domes:


Open No.1 tank header valve V2100





(Note: For safety reasons, ensure the water curtain on the connected side is inoperation.)

k) Using the DCS system mimic, open the following cargo tankloading valves:


Open No.1 tank loading valves V2004, V2003





l) Open valve V2120, if using the port vapour manifold, and informthe shore terminal to prepare for receiving gas to shore.

m) Open valve V2016, if using the aft port liquid manifold, andrequest the shore terminal to commence the supply of LNG to theship at a constant pressure of 5 bar.

n) Adjust the tank pressure by decreasing/increasing the flow rate ofLNG from the shore. The pressure can also be released byadjusting the pressure relief valve setting at No.4 vent mast,however, most terminals prefer the gas to be returned to shore.

o) Monitor the inert exhausting gas at each liquid dome. Use the midcargo tank sampling cock initially, followed by the sample cock atthe top of the loading line.

p) Purge all pipework and dead ends with warm LNG vapour ornitrogen if available.

q) When 5% methane is detected at the sampling points at all tanksinform the shore terminal so that they can divert the exhaust gasesto the terminal facilities.


Issue: 1

Illustration 6.2.4a Cargo Tanks Cooldown Rates

PRESSURE AT PI-22 (kg/cm2)

TIME (h)

EQUATORTEMPERATURE

(OC)SPRAYRATE

(kg/h 103)

1 2 3 4

TANK 1 SPRAY RATES TANK COOLDOWN RATES

00.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

2 4

-160

6 8 10 12 14 16 18 20 22 24 26 28 30

1

2

3

4

5

-140

-120

-100

-80

-60

-40

-20

-0

20

40

StartLoading

5 t/h Spray Rate1 t/h

LoadingFinished

Level 1 m Below EquatorTank No.1 & 5 (4.7 Hours)

Level 1 m Below EquatorTank No.2,3 & 4 (5.7 Hours)

Filling Rate1,500 m3/hEach Tank

Cooldown Rate Limitation 9 OC/h

Cargo Temperature (-163 OC)

Maximum Temperature at Equator Before Loading (-113 OC)

Maximum Temperature at Equator When the Liquid Level is 1 m Below (-138 OC)

Spray Pipe1 & 2

Secondary Spray Rate

Initial Spray Rate

4 4

Tons

Spare Units

1

PI22

1

Spray Pipe 1

15.9 Hours



6.2.4 Cooling Down Cargo Tanks

Initial Cooling Down and Loading

The cargo tanks will be filled with inert gas on arrival. Prior to the first loading,and after gassing-up with LNG vapour, the cargo tanks are gradually cooleddown by spraying LNG received from the loading terminal through the spraynozzles located around the centre column. This operation, which produces coldvapour to be returned ashore, must be carried out until the equatorial region ofthe tank is at least -115ºC. The maximum rate of cooldown is 9ºC per hour.

This cooldown must be carried out smoothly to avoid thermal stress on the tankshell.

In normal service, the ship will arrive with the equatorial region of the tanks atabout, but not warmer than, -115ºC. Full rate loading should not commenceuntil this figure is attained.

LNG enters the cargo tanks through the filling line, while vapour is returned toshore using the HD compressors, if necessary, to maintain tank pressureswithin limits. During this time, continuous cooldown spraying may benecessary until the cargo reaches the equatorial level (for initial loading afterdry docking). The initial cooling down operation will take approximately 20hours.

Preparation for Tank Cooldown: Cooldown of Spray Pipes

a) The HD compressors and the valves in the compressor roomshould be prepared for operation to such a level that only theactual starting operation remains.

b) Cool down the spray pipes by firstly opening the following valveson the vapour return lines from the tanks to the manifold:


Open No.1 cargo tank vapour valve V2000





Open Vapour header to LNG compressor room valve V2110

Open LNG compressor room discharge valve V2119

Open Vapour manifold ESD valve V2120

c) Open the following valves on the liquid lines connecting the sprayline header to the liquid manifold:


Open Forward liquid manifold valve V2015

Open Liquid/spray header crossover valve V2061

Open No.1 cargo tank spray ring block valve V2052





d) Open the following shut-off valves to the spray rings at the tankdomes:


Open No.1 cargo tank spray ring valves V2051





e) The spray lines will now be cooled down by the cold LNG beingsupplied from ashore at a limited flow rate.

Cooldown of Cargo Tanks

After the piping is precooled, LNG is introduced through the liquid crossover,the spray main and the branch lines to the spray nozzles. The spraying proceedsas follows:

a) The spray rate should be approximately 1,000kg/h per tank.

b) The pressure in the cargo tanks should be closely monitored as thepressure will start to build up. When the pressure reaches 0.15 bar,start an HD compressor.

c) After approximately two hours, the spray rate can be increased to5,000kg/h per tank by opening further spray ring valves asrequired.

d) The cargo tank is ready for loading when the temperature of thetank shell at the equator (from sensor TI-10) has dropped to atleast -113ºC. This temperature represents a total cooling downtime of approximately 20 hours.

In order to protect the tank shell against thermal stress, a faster cooldown timethan this must be avoided. Correspondingly, loading must not be started if thetemperature of the tank shell at the equator is above -113ºC.

The cargo tank pressure and the tank shell temperatures must be closelymonitored. If the tank pressure decreases to 0.04 bar below the void spacepressure, the HD compressor(s) are automatically shut down. At the same time,the shut-off valves at the domes are closed.

The two aft spray pipes in each tank dome are spare units. However, they maybe used if the other pipes are not providing sufficient capacity. A spray ratehigher than 5,000kg/h may be used, but the cooldown rate must not exceed arate faster than 9ºC per hour.

Whenever a cargo tank is cooled down completely from ambient temperature,the tank shell temperature, measured at the equator (from sensor TI-10), shouldbe recorded on the relevant time/temperature graph form.



Issue: 2

Illustration 6.2.4b Cooling Down Cargo Tanks Before Loading

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

Key

LNG Liquid

LNG Vapour

V2061

V2201

V2061

To N 2 Plant

V2201

Liquid

LiquidVapour

Nitrogen

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2120

V2120

From

Recirculating Fans


To Void Spaces

PI


Astern

Liquid

V2016A

V2016

V2200A

V2015A

V2200

V2015

V2015A

V2016A

V2200A

V2015

V2016V2200



Issue: 2


Procedure to Cool Down the Liquid Pipes

When the temperature of the tank shell at the equator (from sensor TI-10) hasdropped to at least -113ºC, cargo tank filling may be started.

The first step before actual loading is to cool down the cargo loading lines.

This process is usually carried out at the same time as the tanks are beingcooled down.

a) LNG is introduced into the liquid lines by slightly opening valveV2061 to admit a limited flow rate into the aft liquid crossoverand liquid header.

b) The liquid will flash off immediately due to the high temperaturesas it enters the lines. The vapour generated by this will beintroduced into each tank through the filling pipe.

c) Open the liquid line from the crossovers to each cargo tank byopening valves:


Open ESD valve on the aft liquid header V2016A

Open 10% Spray crossover valve to the liquid header V2016

Open No.1 cargo tank filling and block valves V2003, V2004

Open No.2 cargo tank liquid line valves V2008



Open No.5 cargo tank filling and block valves V2024, V2023

The precooling must be closely monitored by observation of the temperaturesand pressures. The temperatures and pressure in the connection between thecrossovers and liquid headers and the temperatures of the tanks are allavailable on the DCS display. If a high pressure rise is observed, the flow ratemust be reduced by throttling in valve V2015 accordingly.

d) When the temperature in the liquid header at all the cargo tankshas fallen to -120ºC, the gate valve V2015 may be fully openedand the loading valves at No.2, 3 and 4 cargo tanks can be opened.

The vessel is now ready to load.

Criteria and Additional Information

Before liquid can be introduced into the cargo tanks, the temperature differencebetween the cargo tank equator and the liquid must be less than 50°C. It istherefore necessary to cool down all the cargo tanks until the equatortemperature average is -115°C before cooling down the aft loading arm andloading lines.

The aft arm can be cooled down from shore. This is achieved by opening theloading valve on all the tanks and adjusting each throttle valve to 25% open,before agreeing with shore side and fully opening the ESD liquid valve andopening the manual liquid valve 7 turns. The terminal will then supply aminimum flow of liquid into the chicksan arm which will eventually flow intothe tanks. Both HD compressors are run at a maximum of 14,000 rpm in orderto stabilise the tank pressures at this stage.

It may be necessary to adjust/reduce the opening on the throttle valves andreduce the number of spray nozzles in use for tanks with high pressure. If thisdoes not help, the flow rate from shore will have to be reduced.

(Note: Keep in mind the vapour back pressure from shore and if it exceeds0.22 bar, ask the terminal to open more to the flare. Relief valves will open at0.25 bar but try to keep the pressure below 0.17 bar, which is 70% of reliefvalve setting, throughout the cooldown and loading operation.)

Before the liquid reaches the level of 1 metre below the equator, thetemperature difference between the liquid and the equator must not exceed25°C (equator temperature -138C).

To achieve this:

1. The tanks are recommended to be further cooled down byspraying, preferably from shore. This is achieved by adjusting themanifold back pressure to 2.5 - 3.0 bar, by throttling the manualliquid valve(s) on the manifold, provided the terminal accepts thisback pressure.

2. Or continue loading until there is approximately 3.5m in No.3 orNo.4 cargo tank.

Then start the spray pumps as follows:

a) Open the spray pump discharge valve V2068.

b) Open the 1 and 4 tonne nozzle valves on each tank.

c) Press the Stop pushbutton to reset the spray pump trips.

d) Press the Start pushbutton for the spray pump.

e) Adjust the nozzle valves so that the spray pump load readsapproximately 27 amps.

In order to achieve effective spraying, the nozzle pressure should beapproximately 2.5 bar.

Log all relevant data during the entire operation.


Issue: 1

Illustration 6.3.1a Cooling Down Cargo Tanks Prior To Arrival

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

Key

LNG Liquid

LNG Vapour

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201

V2015A

Liquid

Vapour

Nitrogen

Liquid

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

From

Recirculating Fans


To Void Spaces

PI

V2016A


Astern

Liquid

V2200A

V2200

V2016



Issue: 2


6.3 Ballast Passage

Cooling Down Cargo Tanks During a Ballast Voyage

The spray cooling system is fitted to cool down the cargo tanks before theloading of cargo. This is in order to protect the tank shell against the thermalstresses and shocks of sudden expansion.

The spray system consists of the piping and the spray pumps. The pipingconsists of a main header, running along the ship from tank No.1 to tank No.5.This header is connected to the liquid crossovers for LNG cargo supply fromthe shore and to the two spray pumps. One pump is fitted in tank No.3 and theother in tank No.4, for the supply of LNG when the ship is at sea.

The spray pipe header is connected to each tank dome by four spray pipessupplying the spray nozzles with liquid. Two of the pipes serve as spare units.The LNG is sprayed through the 10 spray nozzles in each tank to obtain auniform distribution within the tank. There are also 10 spray nozzles spare ineach tank. The spray nozzles are connected to the main system by four spraypipes of which pipes No.1 and No.2 would normally be used. Pipe No.1supplies two nozzles and pipe No.2 supplies eight nozzles. The spare units,pipes 3 and 4 also supply the same number of nozzles.

The nozzles connected to pipe No. 1, 2 and 4, each have a spray rate capacityof 500kg of LNG at 1.53kg/cm2 pressure drop across the nozzle. The nozzlesconnected to pipe 3 each have a capacity of 1,000kg of LNG.

If severe flashing occurs, the remaining nozzles may be used in order to keepthe minimum cooldown time. The spray rates are remotely controlled from theDCS system by operation of the shut-off valves. The cooling down rate mustnot exceed 9ºC per hour measured at the equatorial ring.

6.3.1 Cooling Down Cargo Tanks Prior to Arrival

When loading orders are received, the quantity of coolant (heel) has to bedecided, taking into consideration the length of ballast voyage and charteringinstructions.

The coolant is taken in one (#3 or #4). Regarding the temperature restriction tobe kept in the equator profile during the voyage due to low filling-up ratio,refer to the Appendix to Classification Certificate.

A spray programme has to be made in such a way that the cargo tanks’ equatortemperature, on arrival in port, is according to the charter’s instruction/order.

The use of BOG as fuel has to be optimised during the voyage.

The spray pump(s) have to be used at the designed flow when operated. Lowflow will give an unacceptably high down thrust load on the pump lowerbearing.

CAUTIONThe pressure and ampere load for the pump(s) have to be watchedcarefully to avoid a possible breakdown of the bearing.

Preparation for Cooling Down the Cargo Tanks

a) The LD compressor would normally be in operation supplyingBOG to the boilers.

b) Open the following vapour header tank valves:


Open No.1 cargo tank vapour header valve V2100





c) Cool down the spray pipes using the spray pump in No.3 or No.4tank.

d) Open valve V2068, from the spray pump to the spray header.

e) Open valves V2058 and V2057 A and B if using No.3 spray pumpand tank.

f) Start the spray pump and circulate the LNG back to No.3 tank (orNo.4 tank) via the spray nozzles.

g) Open the following spray ring block and nozzle valves to allow aflow to the tanks:



Open No.1 cargo tank spray ring nozzle valves V2051A, V2051B







h) Once the pipelines are cooled down, the flow rate can beincreased by opening up the spray nozzles and shutting No.3’snozzles, ensuring that the pressure build up is controlled at alltimes. In an emergency or critical situation, excess pressure canbe vented through the valve to No.4 vent mast.

i) The cooling down rate must not exceed 9°C per hour, measured atthe equatorial ring.

j) The cargo tank is ready for loading when the temperature of thetank shell at the equator has dropped to at least -113°C. Thistemperature represents a total cooling down time ofapproximately 20 hours.


Issue: 2

Illustration 6.4.1a Preparations for Loading

Prior ToArrival

Arrival

Terminal Ship

Terminal advises ship of armconfiguration to be used

A and C: LNG loadingB: Vapour return

OR

B and D: LNG loadingC: Vapour return

Secure ship at jetty

Pilot/loading master advisesterminal on completion

Secure gangway

Pilot/loading master advisesterminal staff

Ship advises terminal of tankcondition

Ship confirms ETAShip advises systems operationalShip advises changes (if any)

WarmInertedetc

Ship checks communicationsShip continuously monitorsloading frequencyMain propulsion on standbyFire fighting equipment readyFire main pressurised

Check gangwayHand over crew listDisplay appropriate signage

Loading masterRelevant terminal personnelReview loading schedule

PreloadingMeeting Relevant ship's personnel

Review loading schedule

Vapour return arm connected firstPosition safety locksPressure test with N2

ConnectingUp

CheckSystem

Line - Up

SafetyInspection

Loading strainers in placeManifold blanks removed

Terminal control room checkssystem line - Up

If ship inerted, vapour return toline - up with shore flare

Monitor from CCR

Carry out safety inspectionComplete and sign safety checklist

Test ESD(Warm)

Boil - OffTo Shore

Terminal Ship

Witness and log ESD1 operation

Pilot/loading master advisesterminal control room

Cool Down

ESD Test(Warm)

Terminal advises ship when ready CCR requests start

Ship's CCR specifies flow rate

OROR

Carry out safety inspectionComplete and sign safety checklist

before opening ship's manifoldvalves

When ship's vapour return manifoldis open, open loading arm vapourreturn valve

Cool down loading arms and ship's liquid lines as per terminal's requirement

If ship is in inerted condition,advise ship when ready to startcool down of first loading armand liquid line

If ship is in inerted condition,CCR advises terminal when readyto start cool down of first loadingarm and liquid line

Ship advises terminal of readinessTo start cool down of loading armsand ship's liquid lines.

Fully open ship's vapour returnvalve

Logic test of ESD operationWitness and log ESD1 operation

Initiate ESD1 signal from shore viaradio link

Witness and log ESD1 operationof all shore hydraulic valves

of all ship's valvesWitness and log ESD1 operation

Terminal confirms readiness to cooldown ship's pipelines and tanks

Gas Up(If Inerted)

Cool DownTanks Total Gas Up

AndCooldown

TimeApproximately

36 Hours

Total Gas UpTime

Approximately20 Hours

Ready For Loading

Terminal confirms readiness togas up ship's lines and tanks

Vapour return lined up to shoreflare until CO2 content as terminal's requirements then line up for normal vapour return recovery

Ship's CCR confirms readiness togas up lines and tanks

Ship's CCR confirms readiness tocool down tanks

Ship's CCR specifies liquid flow rate

Ship's CCR specifies liquid flow rate

Ship's CCR requests start

Ship's CCR requests startShip's CCR informs terminal whencool down complete

If ship inerted, vapour return toline - up with shore flare

Ship's cargo tanks will balance withshore tank at approximately 0.12 bar

Cool both arms simultaneouslyuntil frosted over entire lengthOperaton controlled by loading

master (approximately 45/60 minutes)

Start side water curtain at manifold

When CO2 content is as per terminal'srequirement, inform terminalContinue gassing up until a CO2content is as per terminal'srequirement

CTS Carry out initial CTS gauging Carry Out Initial CTS GaugingCarry out initial CTS gaugingbefore opening ship's manifoldvalves

Initial cool down flow ratesin accordance to

vessel's requirement



6.4 Loading

6.4.1 Preparations for Loading

Company Directives

(Note: The maximum loading rate is 7,500m3/h with all five tanks open. Seethe appendix to classification certificate.)

a) The chief officer is to prepare a detailed loading and deballastingplan which includes the trim and stability conditions duringloading and the topping up procedures to be included.

b) The pre-arrival meeting is to be held within 72 hours and the pre-arrival checklists are to be completed.

c) A pre-loading meeting is to be held together with the terminalrepresentatives. The ship/shore safety list is to be filled in.

d) The CTM is to be carried out together with the terminalrepresentatives, surveyors and authorities.

e) All connections (bonding wire, telephones, loading and bunkeringarms) at the manifold are to be carried out according to theterminal’s cargo handling manual.

f) The HD compressors are to be made ready for use for sendingvapour to the shore.

g) The chief officer is to supervise all loading operations on board.

h) The sounding, temperature and pressure is to be checked andnoted on all cargo tanks according to the schedule during theloading. The cargo monitoring record is to be filled in.

i) The pressure at the manifold is to be checked and noted accordingto the schedule.

j) When the loading is completed, all valves at the manifold are tobe closed according to the terminal’s procedure. The manifoldsare to be blanked as soon as the loading arms are disconnected.

k) The CTM (custody transfer measurement) is to be carried outtogether with the terminal representatives, surveyors andauthorities.

l) All forms required by LHC or the charterer are to be filled in andsigned by the shipper, the terminal, the surveyor and theauthorities (customs).

Loading Rates

The loading rates are dependant on the capacity of the shore side pumps,below is a guide to the rates which can be safely taken.

5 tanks open: 7,500m3/h





Compressor Vapour Return Capacity

1 HD compressor running: 12,000m3/h

2 HD compressors running: 36,000m3/h

(LD compressor: 3,000m3/h)



Issue: 1

Illustration 6.4.2a Cargo Lines Cool Down

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101

V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100

V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057

V2028

V2012

V2010 (P)

V2057

V2057V2057

V2138V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201

V2015A

Liquid

LiquidVapour

Nitrogen

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

Key

LNG Liquid

LNG Vapour

From

Recirculating Fans


To Void Spaces

PI

V2016A


Astern

Liquid

V2200A

V2200

V2016

V2108

V2103



Issue: 2


6.4.2 Cargo Lines Cooldown

Inerting and Gassing Up

a) Shipboard management (ie, Master, chief officer and chiefengineer) and cargo engineer plan the operation.

b) All gas measuring equipment is to be tested and calibrated.

c) All relevant safety regulations are to be adhered to.

d) The Master will advise when the operation can commence.

e) The cargo engineer is to check the tanks for any leftovers andsecure all hatches in the tanks. The check list for closing down thecargo tanks is to be filled in. The cargo engineer is to be the lastperson to leave the tank.

f) The cargo lines are to be checked for any signs of water byopening the drains, flanges etc.

g) The inert gas generator is to be tested and adjusted in due timebefore the operation is commenced.

h) The dehumidifiers are to be reactivated and made ready for use.

i) The inert gas is to be checked at regular intervals for the correctO2, dew point and CO2 content. The chief officer/cargo engineeris to take the final readings.

j) The chief officer is to prepare a detailed purging, loading anddeballasting plan including trim and stability conditions duringloading.

k) A pre-loading meeting is to be held together with the terminalrepresentatives. The ship/shore safety list is to be filled in.

l) All connections (bonding wire, telephones. loading and bunkeringarm) at the manifolds are to be carried out according to theterminal’s procedure.

m) When the cooldown of the loading arm is completed and thevaporiser is made ready, the purging of the cargo tanks and linescan commence. The outgoing temperature from the vaporiser is tobe set to approximately 10ºC.

n) The gas analyser is to be put into operation at the ship’s vent mastto continuously check the inert gas for any sign of LNG vapourconcentration.

o) When the gas analyser shows 50% Lower Explosion Limit (LEL),the ship’s vent mast must be closed and the vapour must then besent to the boilers for use as fuel and/or to the shore for flaring (orin accordance with terminal requirement).

p) The gasup (purging) is completed when the CO2 readings at alloutletsis <1% by volume (refer to the terminal requirement) at themanifolds, vent mast connections, drains and gauge piping. Alsoall outlets on compressors and adjacent piping must be measuredfor any traces of O2 or CO2.

q) All additional equipment used during the process is to be riggeddown. Blind flanges are to be refitted and drains and test pointsare to be closed before the cooldown is commenced.

r) The cargo engineer is to prepare the HD compressors for usebefore the cooldown is commenced.

s) The cool down of the cargo tanks is to be carried out according tothe respective cargo handling manual and the temperaturerequirements laid down in the appendix to the classificationcertificate.

t) All temperatures, pressures and the cooldown rate are to berecorded according to the cooldown report.

u) The shore terminal is to be advised in due time for cooling downthe remaining loading arm(s).

Pre-Cooling of Liquid Pipes Before Loading

Company Directives

The cargo tanks will normally be maintained at -113ºC during a ballast voyageby regular spraying. As long as the tanks are at this temperature, cooling downof the cargo liquid pipes may now commence. The operation must be startedin due time before loading.

LNG is introduced into the liquid crossover and liquid header at a limited flowrate. The liquid flashes off immediately due to the high temperature within thepipes and the vapour that is generated is introduced to each tank via the fillingpipe. The pre-cooling is then carried out as follows:

a) Set up the HD compressors to discharge vapour ashore via thevapour manifold and prepare for operation.

b) Open the liquid line from the crossovers to each cargo tank byopening the following valves:


Open No.1 cargo tank liquid line valves V2003 V2004





c) Open the port aft ESD valve V2016A and starboard forward ESDvalve V2015A.

d) Open the manifold block valves V2015 and V2016 on the sidearms connected. Open the ESD valve V2015A and V2016A andrequest the shore to supply LNG at a slow rate to cool down theshore arms and liquid header.

e) Open the three gate valves V2061, connecting the spray crossoverto the liquid crossover, allowing a limited flow into the liquidlines.

The pre-cooling must be thoroughly monitored by observation of thetemperatures and pressures. Temperature monitoring at the liquid header andcrossover connection and at each cargo tank is available at the DCS mimic.The pressure at the header between the two crossovers is also available via theDCS system mimics. If a high pressure is observed at this point, the HDcompressor(s) should be started and the flow rate reduced.

f) When the temperature at the liquid header at the tanks has fallento approximately -120°C, the gate valves may be opened slowlyand the last shut-off valve at the manifold/crossover can beopened.


Issue: 2

Illustration 6.4.3a Cargo Loading with Vapour Return to Shore via the High Duty Compressors

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201

V2015A

Nitrogen

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

LNG Liquid

LNG Vapour

From

Recirculating Fans


To Void Spaces

Key

PI

V2016A


Astern

Liquid

V2200A

V2016V2200

Liquid

Liquid

Vapour



Issue: 2


6.4.3 To Load Cargo with Vapour Return to Shore via the HighDuty Compressors

The procedure is as follows:

a) Set up the HD compressors to discharge vapour ashore via thevapour manifold and prepare for operation.

b) Open valve V2010, the vapour header to HD compressors vapoursupply.

c) Open the HD compressors inlet valves, V2113.

d) Open the HD compressors outlet valves, V2115 and V2114A.

e) Open valves V2117 and V2119, the discharge from the HDcompressor to the vapour header manifold.

f) Open valve V2120, the vapour manifold to shore.

Set up the cargo tanks and the liquid header to load as follows:

a) Open the valves V2061, the liquid crossover to spray header.

b) Open the spray ring block valves to each tank V2052, V2055,V2058, V2064 and V2066.

c) Open the manifold liquid valves V2016A, V2016, V2015 andV2015A.

d) Open the cargo tank liquid header block valves V2004, V2008,V2012, V2020 and V2024.

e) Open the following first spray nozzle valve on each tank:


Open No.1 cargo tank spray nozzle valve V2051





In order to get liquid to the spray valves, open cross-connection valve V2961and close in valve V2061A.

Request the shore terminal to start loading at a slow rate and check that allsystems are tight and that LNG cargo is entering the tanks via the spray header.

Confirm that the temperature of the tank shell at the equator for the first tankto be loaded is at least -113°C.

f) On No.1 tank, crack open the tank loading valve V2003 andconfirm that LNG liquid is entering the tank.

g) Start loading slowly into the other four tanks by opening valvesV2007, V2011, V2019 and V2003, continuing spraying tomaintain the temperature and reduce gas generation. As thepressure rises, the HD compressors may be started and gas sentashore.

h) Once loading into all tanks is confirmed and the gas pressure isunder control, the loading rate can be increased as required andthe flow rates to each tank adjusted to allow for the final toppingoff.

i) As the tank temperature reaches -138°C, the spray crossovervalves V2061 can be closed and once the spray line is drained,close the tank spray ring block valves V2052, V2055, V2058,V2064 and V2066.

j) The loading rate is reduced as the tanks near capacity, to allow fora controlled topping off.

Topping Up Procedures

1. The Chief Officer is responsible for carrying out all the stages of LNGloading, including topping of tanks. His attention shall be focused on cargooperations only during the topping up period.

2. The cargo engineer shall assist the chief officer during the topping up of thetanks.

One qualified deck officer shall be stationed at the tank domes during toppingup of the cargo tanks, in order to monitor the actual level.

The deck officer has to report to the CCR when the level is about 30cm belowthe finish level.

Closing of the loading valve(s) shall be visibly checked and confirmed.

3. Deballasting should be completed/interrupted one hour prior to the toppingup procedure. This is to avoid alarms being activated from the ballast panelduring during the topping up procedure.

Any alarms sounding would then clearly be cargo alarms.

4. Notify the terminal one hour prior to the topping up of the first LNG cargotank. Reduce the loading rate to about 3,500m3/h.

5. At the passing of the 95% alarm (or corresponding level) of the first tank,stop the BOG to the engine room (if used) and physically check that the maingas valve is closed.

6. Topping up of the cargo tanks shall be carried out with no less than 10minute intervals between each tank. At about 15 minutes before startingtopping up, the communication with the shore control room/loading mastershall be confirmed.

7. When two of the tanks have been completed, reduce the loading rate to about2,500m3/h. Reduce the loading rate to about 1,000m3/h prior to topping up thelast cargo tank.

8. The tank filling valve of the last tank to be topped up must remain in theOPEN position for liquid draining purposes. Stop the last loading pump whenthe tank level reaches about 25-30cm from the finish level. When the drainingof the loading arm is completed, all liquid valves must be closed at themanifold and confirmed closed.

9. The loading is not completed until all the valves at the manifold are closed.

10. If necessary, never hesitate to use the ESD.

11. If the Chief officer or his deputy at any time feels he needs assistance atany time, he is free to call for it.

If at any time during the cargo transfer procedure, including the topping upprocedure, when reaching an alarm status without such an alarm beingactivated, the cargo transfer should be stopped immediately until the reason(s)for the failure has been identified.

(Note ! This topping up procedure is to be included in the loading plan.)

k) When all the shore loading pumps have stopped, stop the HDcompressors and prepare for the draining of the liquid lines to thefinal tank.

l) All LNG remaining in the downward leg of the loading arms andthe manifold connection is to be drained to the tanks through thespray line assisted by nitrogen pressure from ashore. The LNGand vapour manifolds are then purged with nitrogen until anacceptable hydrocarbon content is reached.

m) Close vapour manifold valve V2120.


Issue: 2

Illustration 6.4.3b Completing Loading

Loading

Topping Off

Terminal Ship

Terminal confirms readiness

Loading rate is running atmaximum rate approx. 7,500 m3/h

CCR giving hourly reports toterminal of cargo received andloading rate

CCR ready to give terminal15 minutes notice of any changesrequired

CCR gives 15 minutes notice oftopping off and according to toppingoff procedure

Stopping CCR requests stop

Draining

InertLoading Arms

Final CTSGauging

DisconnectLoading Arms

Terminal Ship

RemoveGangway Terminal staff action Ship's staff witness

Complete documentation Complete documentation

Disconnect and park armsEngage storm locks

Fit blanks to ship's manifoldflanges

Carry Out Initial CTS GaugingOpen ship's manifold valve to displace vapour

Purge and inert liquid loadingarms and vapour return arm:Complete when hydrocarboncontent is less than 2%

Terminal stops flow at ship'srequest

Terminal stops flow Loading pumps shut down

Terminal shuts terminal liquidloading valves

Terminal drains shore line tosurge drum system using N2 todisplace liquid

Terminal pressurises loading armusing N2

CCR shuts manifold liquidloading valves

Line up for draining through sprayline

Open spray/cool down valve todisplace liquid in shipside sectionof loading arm

When pressure in loading armdrops to 0.12 bar close manifioldvalve. Check for liquid and repeatif required until outboard sectionis free of liquidRepeat for other loading arm

Vapour return line to shore andall spray nozzles on all tanks

to remain open during draining

Close all manifold valves

Final CTS gauging byloading master/surveyor

Final CTS gauging by ship's designated cargo officer

Fit blanks to liquid loading andvapour return arm flanges



Issue: 2


n) Close the liquid manifold ESD valves V2015a and V2016A.

o) Open the spray line crossover valves V2061.

p) Open the spray header block and spray inlet valves to No.4 tanksV2064 and V2063A.

q) Request the shore terminal to pressurise the loading arms withnitrogen gas and check that there is no liquid at the manifold drainvalves.

r) On completion of liquid drainage, carry out vapour purging. Thehydrocarbon content in the liquid and vapour manifoldconnections at the purge valves should be confirmed as 2% orbelow. Shut all manifold, tank loading and spray line valves.

s) Carry out the final custody transfer.


Issue: 1

PI1

HC1A

80120a

HC1

SI1

PI2

HC2A

80120b

HC2

SI2

Illustration 6.4.4a Deballasting

Key

Sea Water

Bilge

Electrical Signal

V66

V55A V55

V54A V54 V52 V52

V58 V59A

V57

V57

V63

V33

From

Bilge System

Ballast

Pump

1,200 m3/h

Ballast

Pump

1,200 m3/h

From

Fire and Deck

Wash System V33

V53

V64 V59

V64 V59

V13

V96

No.5 Side Tank

(Port)

No.4 Side Tank

(Port)

No.3 Side Tank

(Port)

No.2 Side Tank

(Port)

No.1 Side Tank

(Port)

No.5 Side Tank

(Starboard)

No.4 Side Tank

(Starboard)

No.3 Bottom Wing

Tank (Starboard)

No.2 Bottom Wing

Tank (Starboard)

No.1 Bottom Wing

Tank (Starboard)

No.3 Bottom Wing


Tank (Port)

No.1 Bottom Wing

Tank (Port)

No.1

Lower Cross

Tank

No.2

Lower Cross

Tank

No.3

Lower Cross

Tank

No.2

Double Bottom

Spare Water

Ballast Tank

No.3 Side Tank

(Starboard)

No.2 Side Tank

(Starboard)

No.1 Side Tank

(Starboard)

V94 V92 V90 V88 V86 V84 V82 V80 V78 V74

V72

V95 V93 V91 V89 V87 V85 V83 V81 V79 V77 V77V72

V23 V99 V69

V97V98

V53

V61

V56 V60


Emergency

Connection For

Backflushing

Main Condenser

Sea Suction

Emergency

Bilge Suction

Overboard

V70

V71

V71



Issue: 2


6.4.4 Deballasting

Company Directives

a) Carefully follow the instructions in the trim and stabilityparticulars booklet and the instruction book for the DCS systemas per the discharge/loading plan.

b) It should be remembered that free liquid surfaces seriously reducethe stability of the vessel.

c) Ensure that all ballast operations are under full control, ie, thereshould be no water in any empty spaces and ensure that tankswhich are supposed to be empty are in fact empty. The operator(s)should make reference to the vessel’s trim and stabilityparticulars.

d) Local conditions such as mud etc, should be taken intoconsideration when ballasting.

e) Gravity ballasting and deballasting should be used whereverpossible.

(Note: Ensure the maximum draught is regularly checked duringballasting/deballasting, especially alongside during low tide.)

Ballast Pumps

Maker: WeirType: Mark 3 UXLCapacity: 1,200m3/hNo. of sets: 2

Ballast Operations

In the ballast system there are two ballast pumps with suction from all ballasttanks. Each pump is of the electric vertical centrifugal type with a dischargecapacity of 1200m3/h.

In normal service, the port pump is connected to all port tanks and thestarboard pump to all the starboard tanks. However, it is possible to draw fromboth sides with one pump.


The ballast eductor works as a stripping pump for the ballast tanks and as apriming unit for the ballast pumps. This is a water driven unit with a dischargecapacity of 100m3/h, using drive water from the engine room bilge ejectorpump.

Procedure to Set Up for Deballasting: To Run to Sea

a) Open sea suction valves V60, V61 and sea crossover valve V58.

b) Open block valves V52 and V53.

c) Open the tank valve (e.g. for No.3 side tank port and starboard)V90/V84 and V89/V83.

d) Run ballast to sea, keeping the vessel upright and ensure that thevessel’s trim and stability is maintained at all times.

e) Once the level in the tanks has equalised with the sea level it willbe necessary to use the pumps to continue with the ballastdischarge.

Procedure to Set Up for Deballasting: To Pump to Sea

a) Shut sea suction valves V60, V61 and sea crossover valve V58.

b) Open the pump overboard valve V56.

c) Open the pump discharge valves V54 and V55.

d) Open the pump suction valves V52 and V53. Block valves V52and V53 should be still open.

e) Open the tank suction valves. The tanks are taken down one pairat a time, as required, to maintain draught, trim and stability. Theloading of the cargo tanks should counteract the amount of ballastdischarged.

f) Start the ballast pumps. Should the discharge rate require the useof only one pump, the crossover line could be used by openingvalve(s) V59 and V59A, making the tank discharge linescommon. The main ballast pump is used to take as much aspossible out of the tanks, leaving the final draining to becompleted via the eductor.

g) Open the eductor discharge valve V66.

h) Open the eductor drive water supply valve V33 and start thefire/bilge pump.

i) Stop the main ballast pumps and shut the suction, dischargevalves and overboard valves, V52, 53, 54, 55 and 56.

j) Shut the block valves, V52 and V53.

k) Open the suction crossover valves V59 and V59A.

l) Open the tank valve(s) as required, one set at a time.

m) On completion of draining the tanks, ensure that the tank suctionsare closed before shutting off the drive water to avoid water goingback to the tank. Shut down the eductor system.


Issue: 1

Illustration 6.5.1a Loaded Voyage with Normal Boil-Off Gas Burning

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

From

Recirculating Fans


To Void Spaces

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201V2015A

Liquid

Vapour

Nitrogen

Liquid

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

Key

Dry Air

Moist Air

Cold LNG Vapour

Warm LNG Vapour

PI

V2016A


Astern

Liquid

V2200A

V2016V2200



6.5 Loaded Voyage With Boil-Off Gas Burning

6.5.1 Loaded Voyage With Normal Boil-Off Gas Burning

During the laden voyage, the movement of the vessel and the external heatpassing through the tank insulation generates convection currents within thebulk cargo, causing the hot LNG to rise to the surface. This is then boiled off.This natural boil-off amounts to 0.25% per day and is used as fuel in the ship’sboilers.

The boil-off gas is drawn from the common vapour head with the LDcompressor and then passed through an LNG heater before being sent to theengine room where it either supplements or replaces the fuel oil depending onthe ship’s requirements.

The procedure for sending gas to the boilers is as follows:

a) Set up the LD compressor to discharge to the boilers (as describedin section 4.4.2) and prepare for operation. Check the steam andlubrication systems are set up correctly. The LD compressorshould be ready to start.

b) Open each of the vapour tank valve V2100, V2101, V2103,V2108 and V2109 to make the vapour header common.

c) Open valve V2110, the vapour header to compressor inlet supplyline.

d) Open the LD compressor inlet valve V2128.

e) Open the LD compressor outlet valve V2130.

f) Set up the LNG cargo heater(s) to discharge to the boiler, set pointat +45°C and ready to start.

CAUTIONWhen using cargo as fuel for the boilers, the vapour heater used must bethoroughly preheated by steam before the compressor is started andmethane vapour is admitted. This prevents ice forming. If necessary, theoperator should use the bypass valve in the steam inlet pipe.

g) Open the heater LNG outlet valve V2132.

h) Start the LD compressor; the amount of gas drawn off is regulatedvia the DCS system to the ship’s requirements.

Void Spaces: Dry-air Circulation

The dew point in the void spaces is to be kept as low as practicable to avoidcondensation and corrosion to the metal structure as well as providing a drybarrier around the main insulation.

Air is drawn by means of the recirculation fans, situated in the LNGcompressor room, from the void spaces to the void space dryer then throughthe heater for the void space atmosphere, before being returned back to thevoid spaces.

The available ‘cold’ in the boil-off vapour is used for drying the void spaceatmosphere. Drying is carried out in two heat exchangers of the shell and tubetype, in which cargo vapour flows through the tubes. Any moisture in the voidspace atmosphere will condense outside the tubes and freeze to ice. The iceformation will reduce the heat exchange in the dryer. When the atmospherecoming out from the dryer is higher than -50°C, regeneration is necessary. Thesupply of void space atmosphere and cold cargo vapour is shut off and heatedcargo vapour is introduced through the tubes. The ice will now melt and thewater produced is drained off through a drain pipe.

(Note: The dryers are used one at a time, when one is in service the other isregenerated.)

After the flow has passed the dryer, it will be heated to about 30°C in a steamheater before being introduced back to the void space.

Procedure to Circulate the Void Space Atmosphere

The LD compressor is set up to supply cold vapour to the void space dryerfrom the vapour header.

Steam is supplied to the void space atmospheric heater to warm through beforeuse.

Refer to illustration 6.2.1a. The procedure is as follows:

a) Open valves V2125 and V2126, the supply of cold vapour to andfrom the void space dryer in use.

b) Open valve V2314, the air supply to the void space dryers fromthe recirculation fans.

c) Open valve V2315, the air outlet from the void space dryer.

d) Open valves V2306 on all the void spaces, the outlet to therecirculation fan supply line.

e) Open valves V2310 and V2311, the inlet and outlet to/from therecirculation fans.

f) Open valves V2303 on all void spaces, the inlet to the void spaceair supply duct.

g) Start the recirculation fan(s).

h) Monitor the dew point and the temperature of the air beingreturned to the void space by means of the dew point detectorinstalled in the cargo control room. These are connected to sensorelements situated in the top of the void spaces and the outlet dryerfor the void space atmosphere.

i) The pressure in the void spaces is controlled by the pneumaticallyoperated safety valves situated on each void space outlet pipe.

j) On completion of drying the void space atmosphere to therequired levels, shut down the system and continue to monitor.

Nitrogen Circulation in the Wedge Space

Nitrogen is used as a seal gas in the cargo turbine compressor glands, forpurging the gas line to the ship’s boilers, the gas freeing of level indicators andfor bleeding to the wedge space of the cargo tank. This is the tank skirtconnection at the equator ring.

Nitrogen vapour is bled into the wedge space via valve V2209, from thenitrogen generator, where it is introduced into the upper insulation space at thetop of the tank. The nitrogen vapour then flows down along the surface of thetank shell to a drainpipe. The nitrogen vapour and any leaked LNG gas isexhausted into the void space where it mixes with the dry-air atmosphere inthis space (see illustration 6.2.1a for information).

A gas detection sample point is situated in the vicinity of the drain pipe exitwhich will give an early warning of any gas leakage from the shell into theinsulation space.

In the unlikely event of an LNG liquid leakage, this liquid will be drainedthrough additional drain pipes, which are protected by bursting discs. Thesediscs will burst when exposed to cold liquid, activating the gas detectorthrough the sample points located adjacent to these rupture disc outlets.



Issue: 2

Illustration 6.6.1a Preparations for Discharging

Prior ToArrival

Arrival

Terminal Ship

Terminal advises ship of armconfiguration to be used:LNG unloadingVapour return

Secure ship at jetty

Pilot/loading master advisesterminal on completion

Cargo lines at -100ºC (as required by theterminal).Ship checks communications.

Ship continuously monitorsloading frequency.Main propulsion on standby.Firefighting equipment ready.Fire main pressurised.ESD system checked.Gas/fire detection system checked.Valve remote control system tested.CTS activated.Water in manifold spill trays.Cargo pumps insulation tested.

Firefighting equipment readyCheck fender systemCheck ship/shore communicationsPosition spotting lineCheck speed of approach meter

Main propulsion on standby.Hand over crew list.Display appropriate signage.

PredischargeMeeting

RigGangway

Check systemline - up

ConnectArms

SafetyInspection

Terminal staff

Terminal staffreview discharge schedule and confirm safety checks.

Witness and check rigging of gangway.

Continuously check mooringtension and fire wires approximately2m above water line at all times

Start manifold water curtain.

Carry out safety inspection.Complete and sign safety checklist.

Test ESD(warm)

Terminal Ship

Cool Down

Open VapourManifold Valve

ESD Test(cold)

Terminal advises ship when ready. CCR advises terminal and sendslow flow of cargo by spray pump.

Carry out safety inspection.Complete and signsafety checklist

Cool down unloading arms.Ship advises terminal of readinessto start cool down of loading arms.

Relevant ship's personnel.Terminal staff.

Initiate ESD1 signal from ship/shore.Witness and log ESD1 operation ofall shore hydraulic valves. Witness and log ESD1 operation

of all ship valves.

of all ship's valves.Witness and log ESD1 operationof all shore valves.

Witness and log ESD1 operation

Ready For Discharging

Fully open shore vapour ESD valve.

When shore vapour ESD valve isopen, open ship's vapour ESD valve.

Ship's cargo tanks will balancewith shore tank at approx. 0.12 bar.

Cool both arms simultaneouslyuntil frosted over entire length.Operation controlled by loadingmaster (approx. 45/60 minutes).

Check O2 levels at sampling points.

Use of Main CommunicationEquipment and Radars Prohibited

Hot Work ProhibitedObserve Port Regulations

VHF/AIS in low power mode

Relevant ship's personnelreview discharge schedule andconfirm safety checks.

Ship confirms ETA.Ship advises systems operational.Ship advises changes (if any).

Vapour return arm connected first.Position safety locks.Pressure test with N2.Inert to <1% O2.Connect pneumatic hose.

Loading strainers in place.Manifold blanks removed.

CTS Carry out initial CTS gauging.Carry Out Initial CTS GaugingCarry out initial CTS gaugingbefore opening ship's manifoldvalves.

Terminal advises ship when ready.

Initiate ESD1 signal from ship/shore.

SafetyChecks

Carry out safety checks jointlywith ship.

Check through terminal safetychecks jointly with terminal staff.





6.6 Discharging with Gas Return to Shore

6.6.1 Preparations for Discharging

Company Directives

a) The chief officer is to prepare a detailed discharging andballasting plan which includes the trim and stability conditionsduring discharging.

b) The pre-arrival meeting is to be held within 72 hours and theship/shore safety list is to be completed. The pre-arrival checklists are to be completed.

c) A pre-loading meeting is to be held together with the terminalrepresentatives.

d) The CTM is to be carried out together with the terminalrepresentatives, surveyors and authorities.

e) All connections (bonding wire, telephones, loading and bunkeringarms) at the manifold are to be carried out according to theterminal’s cargo handling manual.

f) The chief officer is to supervise all discharging operations onboard.

g) The start-up sequence of the cargo pumps is to take placeaccording to the terminal’s cargo handling manual.

h) Soundings are to be checked and noted on all the cargo tanksduring discharging. Whessoe gauge readings are to be checkedand noted on all the cargo tanks during discharging. The cargomonitoring record is to be completed.

i) When discharging is completed, all valves at the manifold to beclosed according to the terminal’s cargo handling manual. Thedisconnection must follow the terminal’s cargo handling manual.The manifolds must be blanked as soon as the loading arms aredisconnected.

j) The CTM (custody transfer measurement) is to be carried outtogether with the terminal representatives, surveyors andauthorities.

k) All forms required by LHC or the charterer are to be completedand signed by the shipper, terminal, surveyor and the authorities(customs).

Issue: 1

Illustration 6.6.2a Liquid Line Cooldown

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201

V2015A

Liquid

Vapour

Nitrogen

Liquid

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

From

Recirculating Fans


To Void Spaces

Key

LNG Liquid

LNG Vapour

PI

V2016A


Astern

Liquid

V2200A

V2200

V2016



Issue: 2


6.6.2 Liquid Line Cooldown

Company Directives

The cargo lines are cooled down and the cargo plant is prepared to the highestpossible level before arrival at the loading/discharging port as per terminalrequirement. This is in order to commence the discharging as soon as the vesselis moored and all procedures have been completed. At the same time as thecargo lines are cooled down, the cargo lines are pressure tested for any leakageby increasing the pressure to 5 bar. Spool pieces/reducers with their requiredfilters are to be mounted.

Liquid line cool down is carried out using the spray pump in No.3 or No.4 tankto pump LNG from No.3 or No.4 cargo tank through the spray header to theliquid manifold pipework.

Vapour displaced from the crossover pipework passes through the liquidheader and spray bypass and return valves of No.1, 2, 4 and 5 cargo tanks andthen back to No.3 or No.4 tank via the filling line.

Vapour from the tanks will be burned in the boilers using the LD compressorand gas heaters.

Although the text and illustration indicate No.4 tank spray pump being used,No.3 pump could be used.

Procedure to Cool Down the Liquid Lines

a) Open valve V2068, the discharge valve from No.4 spray pump,approximately 15%.

b) At the manifold, open the liquid/spray header crossover valvesV2061 and the forward and aft liquid ESD valves V2016A andV2015A.

c) Open the liquid line from the crossovers to each cargo tank byopening following butterfly valves:


Partly open No.1 cargo tank liquid line valves V2004



Fully open No.4 cargo tank liquid line valves V2020


d) At the discharge side manifold, open valve V2015A, the liquid

manifold block valve.e) At the non-discharge manifold, open valves V2061, the spray line

crossover.

f) Open filling valve V2011 on the No.3 tank or filling valve V2019on the No.4 tank.

g) Using No.3 or No.4 spray pump, LNG is passed via the sprayheader to the spray line tank manifold, then through the crossovervalve into the liquid header, returning to No.3 or No 4 tank via theloading line.

h) After the spray pump is started, slowly fully open valve V2068,the spray pump discharge valve into the spray header andcommence spray line cooldown and then liquid line cooldown, inturn.

i) During line cooldown, monitor the following;

Cargo tank levels

Liquid crossover pressure

Liquid crossover temperature

Liquid header temperature

Vapour header pressure

j) Line cooldown will be complete when the liquid headertemperature falls below -100°C.

k) When the cooldown is completed, stop the spray pump. If the timebetween cooldown completion and berthing is extensive, thespray pump may be restarted.

(Note: Return of cooldown liquid to the bottom of the tank via the loading linecan give rise to localised temperature increase at the tank bottom sensor.Sufficient time should be allowed for this to stabilise prior to gauging.)


Issue: 1

Illustration 6.6.3a Arm Cooldown Before Unloading

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201

V2015A

Vapour

Nitrogen

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

From

Recirculating Fans


To Void Spaces

Key

LNG Liquid

PI

V2016A


Astern

Liquid

Liquid

Liquid

V2200A

V2200

V2016



Issue: 2


6.6.3 Arm Cooldown Before Unloading

Company Directives

After the discharging arms are connected to the ship’s manifold, thedischarging arms are pressurised with N2. This is delivered from the shore atup to 3 bar. The connections are then tested for leaks using soapy water.

The cooldown procedure of the discharging arms follows the terminal’sprocedure and is carried out using the ship’s spray pumps in co-operation withthe shore terminal. Reference should be made to the terminal’s cargo operationmanual.

On completion of testing the discharge arm connections, the vessel uses itsspray pump(s) to cool down the shore arms.

The ship/shore safety checks will have been completed; the BOG burning shutdown, custody transfer completed and the ship/shore vapour line opened.

Procedure to Cool Down the Arms

a) Open the spray pumps discharge valve V2068 and V2108approximately 15%.

b) Open the spray line to No.3 tank valves V2058 and V2057 andestablish a 3 bar recirculating pressure before discharging to thearm.

c) Open the liquid/spray line crossover valves V2061.

d) Open the ship’s liquid manifold valves V2015 and V2016.

e) After starting the spray pumps, slowly open the spray pumpdischarge valves V2068 and V2108, to cool down the sprayheader back to No.3 or No.4 tank via the spray line.

f) Once the spray header has cooled down, increase the flow rate atshore terminal request by opening valve V2068 and closing thespray valve V2057.

g) Once the shore arms are cooled down and the shore terminalrequest the spray pump to be stopped, close the spray headercrossover valves V2034.

h) Drain the spray line back to No.3 tank via valves V2058 andV2057.


Issue: 1

Illustration 6.6.4a Discharging Cargo

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201V2015A

Nitrogen

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

From

Recirculating Fans


To Void Spaces

Key

LNG Liquid

LNG Vapour

PI

V2016A


Astern

Liquid

Liquid

V2200A

V2200

V2016

LiquidVapour



Issue: 2


6.6.4 Discharging Cargo

Company Directives

In co-operating LNG operations, the ship must be compatible with theterminals and the ship and shore personnel must be familiar with each other’sequipment and the division of all responsibilities.

Each terminal has its own procedures, which have to be strictly followed,regarding the following operations:

Approaching the terminal

Mooring

Connecting

Loading

Disconnecting

Departure

CAUTIONIt is of the utmost importance that the cargo pumps are never allowed torun dry, even for short periods, as this will result in motor failure. Amomentary loss of priming during cargo stripping should not beconsidered as running a pump dry. Up to 30 seconds of operation with drysuction but with fluid in the discharge pipe will not damage the pump orthe motor.

Discharging Cargo with Vapour Return From Shore

Using No.1 tank as the first tank to commence discharging.

Vapour Return

a) Open the crossover valves between compressor supply line andvapour header V2118 and V2119.

b) Open vapour manifold valve V2120.

Liquid Header

c) Open the cargo tank liquid header block valves V2004, V2008,V2012, V2020 and V2024.

d) Open the discharge valve V2002 on the No.1 tank approximately25%.

e) Open the liquid manifold block valves, V2016 and V2015.

f) Open the liquid manifold ESD valves, V2016A and V2015A.

g) When the shore terminal is ready to receive cargo, start the firstpump. With the pump running, open the discharge valve slowlyinto the fully open position to obtain a discharge pressure of 2 bar.

h) Check the motor current at the ammeter, the current should besteady after the motor has been running for 3 seconds. Duringstarting, while the discharge line is being filled, the current maybe over the ammeter red line. Do not exceed the maximum ratedcurrent by 50% for more than 2 or 3 seconds when the tank is full.If the running current after this time is more than 150% above themaximum rated current, stop the pump immediately anddetermine the cause of high current (possible blockage).

i) Before starting the remainder of the cargo pumps with 5 minuteintervals, or according to shore terminal instruction, ensure thatthere three generators connected to the main switchboard. Onceall the pumps are in operation, adjust the discharge valves toobtain the required flow or pressure.

j) Request the shore terminal to supply return gas to the ship.


Issue: 2

Illustration 6.6.4b Discharging

Terminal

StartDischarge

Ship

Reducing

Stopping

Drain Arms

Ship stops cargo pumps: Discharge complete.

Close ship's liquid manifold valves.Open ship's manifold valves todisplace liquid in outboard (shipside)section of arm.

Close terminal liquid arm valves.

Ship must advise terminal at 1 hourbefore reducing unloading rate.

Terminal confirms readiness.

Terminal supplies return gasat ship's request.

Ship's CCR must notify terminal ofall activities.Ship's CCR confirms readinessand starts first cargo pump.

Progressively increase loading rateto full rate by mutual agreementwith terminal, at about 5 minuteintervals between each pump.

Ship's CCR makes hourly reportsof quantities discharged anddischarge rates.

Discharge rate, ramp up andramp. down in accordance

with the discharge plan

Drain shoreside section to surgedrum system using N2 to displaceliquid.

Pressurise liquid arm with N2.

When pressure in loading arm dropsto 0.12 bar close manifold valve. Check for liquid and repeat ifrequired until outboard section isfree of liquid.

Repeat for other loading arm.

Vapour Return Line To Shore To Remain Open During Draining

Final CTSGauging

InertArms

Terminal Ship

Complete documentation. Complete documentation.

Final CTS gauging byloading master.

Final CTS gauging by ship's designated cargo officer.

Purge and inert liquid arms andvapour return arm.

DisconnectArms

RemoveGangway

Unmoor and Depart

Terminal staff action. Ship's staff disconnectcommunications cables

Carry OutSafety Checks Terminal staff jointly with ship's

staff.

Disconnect and park arms.Engage storm locks.

Remove strainers and fit blanksto ship's manifold flanges.

Fit blanks to liquid loading andvapour return arm flanges.

Post DischargeMeeting Terminal staff.

Fit blanks to liquid loading andvapour return arm flanges.

Complete when hydrocarboncontent reaches 1%.

Stop Water Curtain

Pre discharging meetingShip's staff work through terminalsafety check list jointly withterminal staff



Issue: 2


Completion of Discharge

Towards the end of the discharge, the flow of the pumps will diminish. In orderto maintain the pressure differential over the pump, the discharge valve willhave to be throttled in. This should be done at the low level alarm, about 1metre above the non pumpable level.

If any fluctuations are observed on the motor ammeter or the pump dischargepressure gauge during final pumping, the discharge flow rate should be furtherreduced until the readings stabilise. When the flow is throttled down to about230m3/h the required non pumpable level will be about 10cms. This levelrepresents the minimum level attained by pumping.

(Note: When the liquid level reaches 1 metre or less, avoid stopping the pumpif at all possible until the cargo has been fully discharged. If the shore facilityis unable to accept the liquid for intermittent periods it is better to keep thepump going and recirculate back into the tanks until discharge can be resumedand completed.)

All LNG remaining in the downward leg of the loading arms and manifoldconnection is to be drained to the tanks through the spray line assisted bynitrogen pressure from ashore. The LNG and vapour manifolds are then purgedwith nitrogen until an acceptable hydrocarbon content is reached.

Procedure to Drain the Loading Arms

a) Close vapour manifold valve V2120.

b) Close the liquid manifold block valves V2016 and V2015.

c) Open the liquid/spray line crossover valves V2061.

d) Open the spray header valves to No.5 tank V2065.

e) Request the shore terminal to pressurise the loading arms withnitrogen gas and check that the liquid manifold drain valves areliquid-free.

f) On completion of liquid drainage, carry out vapour purging. Thehydrocarbon content in the liquid and vapour manifoldconnections at the purge valves should be confirmed as 2% orbelow.

g) Close all manifold, tank loading and open one cargo tank sprayline to reduce the pressure in the cargo lines.

h) Carry out the final custody transfer.

i) Start the LD compressor and resume BOG burning to the boilers.


Issue: 1

PI1

HC1A

80120a

HC1

SI1

PI2

HC2A

80120b

HC2

SI2

Illustration 6.6.5a Ballasting

Key

Sea Water

Bilge

Electrical Signal

V66

V55A V55

V54A V54 V52 V52

V58 V59A

V57

V57

V63

V33

From

Bilge System

Ballast

Pump

1,200 m3/h

Ballast

Pump

1,200 m3/h

From

Fire and Deck

Wash System V33

V53

V64 V59

V64 V59

V13

V96

No.5 Side Tank

(Port)

No.4 Side Tank

(Port)

No.3 Side Tank

(Port)

No.2 Side Tank

(Port)

No.1 Side Tank

(Port)

No.5 Side Tank

(Starboard)

No.4 Side Tank

(Starboard)

No.3 Bottom Wing

Tank (Starboard)

No.2 Bottom Wing

Tank (Starboard)

No.1 Bottom Wing

Tank (Starboard)

No.3 Bottom Wing


Tank (Port)

No.1 Bottom Wing

Tank (Port)

No.1

Lower Cross

Tank

No.2

Lower Cross

Tank

No.3

Lower Cross

Tank

No.2

Double Bottom

Spare Water

Ballast Tank

No.3 Side Tank

(Starboard)

No.2 Side Tank

(Starboard)

No.1 Side Tank

(Starboard)

V94 V92 V90 V88 V86 V84 V82 V80 V78 V74

V72

V95 V93 V91 V89 V87 V85 V83 V81 V79 V77 V73

V23 V99 V69

V97V98

V53

V61

V56 V60


Emergency

Connection For

Backflushing

Main Condenser

Sea Suction

Emergency

Bilge Suction

Overboard

V70

V71

V71

V72



Issue: 1


6.6.5 Ballasting

Company Directives

a) Carefully follow the instructions in the trim and stabilityparticulars booklet and the instruction book for the DCS system.

b) It should be remembered that free liquid surfaces seriously reducethe stability of the vessel.

c) Ensure that all ballast operations are under full control, ie, thereshould be no water in any empty spaces and ensure that tankswhich are supposed to be empty are in fact empty. The operator(s)should make reference to the vessel’s trim and stabilityparticulars.

d) Local conditions such as mud etc, should be taken intoconsideration when ballasting.

e) Gravity ballasting and deballasting should be used whereverpossible.

(Note: Ensure the maximum draught is regularly checked duringballasting/deballasting, especially alongside during low tide.)

Ballast Pumps

Maker: WeirType: Mark 3 UXLCapacity: 1,200m3/hNo. of sets: 2

There is an automatic ballasting sequence available via the DCS system, referto section 3.2.6a DCS System: Cargo and Ballast Operations.

Ballast Operations

Ballast operations can be carried out in the automatic mode via the DCSsystem, the following is a manual procedure for deballasting.

In the ballast system there are two ballast pumps with suction from all ballasttanks. Each pump is of the electric vertical centrifugal type with a dischargecapacity of 1200m3/h.

In normal service, the port pump is connected to all port tanks and thestarboard pump to all the starboard tanks. However, it is possible to draw fromboth sides with one pump.


The bottom wing tanks can be filled directly through the sea suction.

Procedure to Set Up for Ballasting: To Run From the Sea

a) Open the sea suction valves V60, V61 and sea crossover valveV58.

b) Open the block valves V52 and V53.

c) Open the tank valve (eg, for No.3 bottom tank port and starboard)V93 and V94.

d) Run ballast from the sea, keeping the vessel upright and ensuringthat the vessel’s trim and stability is maintained at all times.

e) Once the level in the tanks has equalised with the sea level it willbe necessary to use the pumps to continue with the ballastloading.

Procedure to Set Up for Ballasting: To Pump From the Sea

a) Open the sea suction valves V60, V61 and sea crossover valveV58.

b) Open the pump suction valves V52 and V53.

c) Open the pump discharge valves V54 and V55.

d) Shut the block valves V52 and V53.

e) Open the drop valve(s) V57.

f) Open the tank suction valves. The tanks are filled one pair at atime as required to maintain draught, trim and stability. Theloading of the ballast tanks counteracts the amount of LNG cargodischarged.

g) Start the ballast pumps. Should the loading rate require the use ofonly one pump, the crossover line could be opened via valve(s)V59 and V59A, making the tank filling lines common.

On completion of loading ballast, shut down the ballast system.


Issue: 1

Illustration 6.7.1a Stripping and Line Draining

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201

V2015A

Liquid

Liquid

Vapour

Nitrogen

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

From

Recirculating Fans


To Void Spaces

Key

LNG Liquid

PI

V2016A


Astern

Liquid

V2200A

V2200

V2016





6.7 Pre Dry Dock Operations

This section describes the operations for the period leading up to a dry dock.

6.7.1 Stripping and Line Draining

It is assumed that the cargo tanks have been discharged to their maximumusing the main cargo pumps which have been shut down. The stripping/spraypumps are situated in No.3 and No.4 tanks and it will only be possible todischarge these two tanks. Discharge is via the port side manifold and theprocedure is as follows:

a) At the manifold crossover:Open valve V2015 on the forward manifold.Close valves V2016A and V2015A on both manifolds and V2016on the aft manifold.

b) At the stripping/spray header:Open valve V2061, the spray header to the liquid forwardmanifold.

c) At No.3 and No.4 tanks:Open the stripping/spray discharge valves V2068 for No.3 andNo.4 tanks. Start the stripping/spray pumps.

Whenever possible the spray pumps should be started early enough to avoidany possible starting problems due to very low tank levels (about 0.5mminimum).

On completion:

d) Stop the final pump.Close valve V2015 on the forward manifold.Open valves V2066 and V2065 to drain the spray header lineback to No.5 tank.

Purging and Draining of Loading Arms

Purging is carried out one line at a time as follows:

a) Open valve V2061, the spray header to the forward liquidmanifold.

b) Open the following spray line valves:


Open Port and starboard manifoldspray/liquid header valves V2061

Closed Port and starboard manifold liquid header ESD valves V2016A, V2015A

Open No.1 cargo tank spray line valves V2052, V2051





c) Open the forward manifold valve V2015.

d) Close the liquid/spray header crossover valve V2061 when themanifold pressure drops to 0 bar. Repeat this operation a furthertwice. On the last operation, shut the forward manifold liquidvalve V2015 at approximately 0.1 bar in order to eliminate therisk of liquid flowing back from the ship’s liquid line.

e) Open the test drain valve on the loading arm to ensure that thereis no liquid present. Repeat the operation with the other liquidarm.

f) Once the arms are empty of liquid, continue to purge withnitrogen, checking the methane content at the drain valve. Whenthe required amount of methane (usually less than 1%) isindicated at the drain valve, inform the shore terminal and theywill close the shore terminal ESD valves.

g) When purging is complete, proceed with the disconnection of theliquid arms.

h) Complete the ballasting operations for final measurement andsailing condition.

Shortly before departure:

i) Vapour line disconnection:

Close manifold vapour ESD valve V2120.

Open the vapour bypass valve.

Purge the vapour line with nitrogen at 0.2 bar.

Close the drain valve.

Confirm that the gas content at the drain valve is less than 1% volume ofmethane.

j) Disconnect the vapour arm.

k) Open the following valves to allow the lines to warm up:


Open Port and starboard manifoldspray/liquid header valves V2061

Open Port and starboard manifold liquid header ESD valves V2016A, V2015A






Open Liquid header block valves on all cargo tanks V2004V2008,V2012V2020, V2024

Open Liquid header block valves on all cargo tanks V2003V2007, V2011V2019, V2003

l) When the lines are warmed up, the valves should be closed again.

m) Prepare the cargo system for warming up the cargo tanks.

Issue: 2

Illustration 6.7.2a Tank Warm Up

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101 V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057

V2028

V2012

V2010 (P)

V2057

V2057V2057

V2138V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2Plant

V2201

V2015A

Liquid

Vapour

Nitrogen

Liquid

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

From

Recirculating Fans


To Void Spaces

Key

LNG Vapour (Cold)

LNG Vapour (Warm)

PI

V2016A


Astern

Liquid

V2200A

V2200

V2016

V2108

V2103



6.7.2 Tank Warm Up

Company Directives

When the cargo tanks are completely emptied of liquid residue, they can bewarmed up with warm cargo vapour.

The cargo vapour is sucked from the bottom of the cargo tanks through thefilling line by the HD compressors, heated by the vapour heaters andintroduced to the top of the tanks through the loading line. Excess vapourgenerated during the evaporation process should be delivered to the ship’sboilers as fuel.

As the filling line in the tank ends 1.5m above the bottom of the tank, a flexiblehose is fitted to the hot vapour line which will increase the warming effect.This line directs the warm vapour down to the centre and bottom of the tank.

The flexible hose is fitted, with a reducer, from the blind flange situatedbetween the throttle valve and the filling valve on the liquid filling line, to thehot vapour line valve blind flange.

The heating operation is continued until the equator profile and the tank bottomshell temperature are at least +5ºC, ie, higher than the dew point of the inertgas. This is to avoid the water content in the inert gas condensing at the tankshell.

If not all tanks have to be warmed up, the same procedure as for all tanks hasto be followed. Tank(s) that are to be inspected have to be completely separatedfrom the other tank(s).

Warming Up the Cargo Tanks

The maximum amount of cargo should be discharged from all the tanks toreduce the time necessary to vaporise the remaining liquid. The ship returns tosea and the tanks are circulated with warm vapour supplied (through theloading lines) by the HD compressor, via the gas heaters, at a maximum outlettemperature of about 75ºC. The remaining LNG is vaporised and the excessvapour generated will be vented via the vapour line and the vent mast. Duringthis time, insulation and hold space pressures must be carefully monitored, aspressures will increase due to warming up. Warming up is considered completewhen the temperature of the tank bottom (internal) and equarorial ringtemperatures are +5ºC, i.e. well above the dew point of the inert gas. Thewarming up operation should normally take about 72 hours.

Tank warm-up is part of the gas freeing operations carried out prior to a drydocking or when preparing tanks for inspection purposes.

The maximum amount of cargo will be discharged from all the tanks to reducethe time necessary to vaporise the remaining liquid.

The warm up operation requires a period of time dependent on both the amountand the composition of liquid remaining in the tanks and the temperature of thetanks.

Initially, the tank temperatures will rise slowly as evaporation of the LNGproceeds, accompanied by high vapour generation and venting. On completionof evaporation, tank temperatures will rise rapidly. Temperatures within thetank are monitored via the DCS system.

Gas burning should continue as long as possible, normally until all the liquidhas evaporated, venting has ceased and the tank pressures have started to fall.

Operating Procedure to warm Up the Tanks

During the tank warm up, gas burning may be used by directing some vapourfrom the heater outlet to the boilers and by manually controlling the operation.

a) Install the spool piece and open valves V2121 and V2125 todischarge heated vapour to the liquid header.

b) Install the flexible hose from the liquid filling line, to the LPGline valve blind flange on each tank.

c) Prepare gas heaters A and B for use.

CAUTION The vapour heaters should be thoroughly preheated with steam before theadmission of methane vapour. This is to prevent ice formation.

d) Adjust the temperature set point for about +75°C.

CAUTION When returning heated vapour to the cargo tanks, the temperature at theheater outlet should not exceed +85°C. This is to avoid possible damage tothe cargo piping insulation and safety valves.

e) Prepare No.1 and No.2 HD compressors for use as required.

f) Open valve V2110, the compressor(s) suction from the vapourheader.

g) Open the compressor(s) inlet and outlet valve(s), V2113 andV2114A.

h) Open the heater inlet and outlet valves V2131 and V2132.i) Open the following valves on each tank:







Open No.1 cargo tank LPG valve V2138





Open No.1 cargo tank filling valves V2003, V2004





j) Start one or two HD compressors manually and gradually increasethe flow.

k) Send boil-off gas to the boilers. Carry out steam dump and ventcontrol in parallel to obtain stable boiler combustion.

l) Monitor the tank pressure and adjust the compressor(s) tomaintain tank pressure between 0.04 and 0.2 bar.

m) When the tank pressure starts to decrease, stop the BOG burning.

n) Monitor the temperatures in each tank. Warm up is completedwhen the cargo tank equator temperature is higher than +5°C.

o) Stop the warm up. Shut off steam to the gas heaters and allowcirculation for 10 minutes.

p) Shut down the HD compressors and initiate the set up for inertingthe cargo tanks.



Issue: 1

Illustration 6.7.3a Inerting

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2352A

V2352

V2352


Inert Gas

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201V2015A

Liquid

Vapour

Nitrogen

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

From

Recirculating Fans


To Void Spaces

PI

V2016A


Astern

Liquid

V2200A

V2200

V2016



Issue: 2


6.7.3 Inerting

Inerting Before a Dry Dock Period

Before air is introduced into the cargo system, it is essential that allhydrocarbons are purged from the system to prevent the formation offlammable mixtures. The objective of this operation is to replace all themethane gas in the cargo tanks and cargo pipework with inert gas. This iscarried out as an intermediate step between warming up and aeration.

This procedure is basically the same as for inerting after refit, but with thefollowing differences:

1) Completion of each step in purging has the object of achievinga hydrocarbon concentration of 1% volume or less.

2) Before starting the operation, it should be verified that the tankequator temperatures are above +5ºC.

At the end of the inerting process, aeration immediately follows. The inert gasplant is not completely shut down, but is vented via the funnel while beingchanged over to the air production mode. During the changeover to airproduction, the valves will be lined up ready for aeration.

Company Directives

After heating the tanks, they are to be purged with inert gas to remove the cargovapour before air is admitted. This is to avoid the formation of an explosivemixture. This gas freeing is to be accomplished by means of the inert gas plant,the R22 cooler, with a dew point +5ºC, and an additional dehumidifier with adew point of -25ºC or lower.

Before the inert gas line is connected to the cargo system, the inert gas linemust be blown through with air using the inert gas blower to avoid any debrisentering the cargo system. The inert gas must not be introduced to the cargotanks before the tank shell temperature is above +5ºC, the inert gas systemcontaining between 2% - 3% O2 and the dew point is less than -25ºC.

The O2 content of 2% normally ensures zero ppm CO, however the inert gasmust be checked for the presence of CO (carbon monoxide/soot) prior toinerting the tanks.

The inert gas generator must not be forced to run in such a way that thetemperature after the R22 cooler increases to a temperature above 10ºC, +5ºCis recommended. If the temperature of the inert gas is above 10ºC, some saltfrom the sea water will be liberated (mostly chloride) and this will follow theinert gas flow into the tanks.

All cargo tanks are to be inerted in parallel if possible, to take advantage of thepiston effect due to the difference in specific gravity between the LNG vapourand the inert gas.

Before the inert gas operation is stopped, it should be carefully checked that all‘blind ends’ in the cargo system have been opened, such as cargo compressors,heaters, vaporiser, manifolds not in use, Whessoe gauge heads etc.

The readings of the methane content in the cargo tanks and cargo lines, takenby a portable gas detector, must be between 2% and 3% by volume at alllocations.

WARNINGIf any piping or components are to be opened, the inert gas or nitrogenmust first be flushed out with dry-air. Take precautions to avoidconcentrations of inert gas or nitrogen in confined spaces which could behazardous to personnel.


Issue: 1

Illustration 6.7.3a Inerting

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2352A

V2352

V2352


Inert Gas

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201V2015A

Liquid

Vapour

Nitrogen

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

From

Recirculating Fans


To Void Spaces

PI

V2016A


Astern

Liquid

V2200A

V2200

V2016



Issue: 2

Norman Lady Cargo Operating Manual Inerting After a Dry Dock Period: Tanks Returning to Service

Company Directives

LNG vapour must not be introduced into the cargo tanks, lines or equipmentbefore they are inerted with inert gas.

Before closing down the tanks, the cargo engineer must visually check thetanks for any leftover items or debris. The cargo engineer must close andsecure all entry hatches and must be the last person to leave the tank. Thegasket on the tank hatch must be renewed every time the hatch is used toensure integrity and avoid leakages.

Before commencing purging, all cargo and spray lines are to be checked forany water content in any traps, blind ends, U-bends etc. in the system.

The purging of cargo tanks and lines is to be carried out using the inert gasplant, the R22 cooler (dew point +5ºC) and an additional de-humidifier (dewpoint -25ºC or lower at the outlet).

The purging operation is complete when the measured O2 content is below 3%by volume and dew point below -25ºC at all locations in the cargo system.

Operating Procedure to Inert the Cargo Tanks

a) Install the flexible connection between the flange at the end of theinert/dry-air feeder line and the liquid manifold or access to theliquid header.

b) Install the flexible connection between the flange on the vapourheader line and the flange at each tank vent mast.

c) Open the following valves to supply inert gas to the liquid header:





Open No.1 cargo tank filling valve V2003










d) Open the following tank vapour valves to vent through the ventmast on each tank:



Open No.1 cargo tank vent mast valve V2137





e) Start the inert gas plant. When the oxygen content is between 2%- 3% and the dew point is below -25°C, open the IG plantdischarge valve V2353 and open the deck valves V2352 andV2352A to allow the inert gas to pass into the liquid header.

f) Monitor the tank pressures and adjust the opening of the fillvalves to maintain a uniform pressure in all tanks.

g) Approximately once an hour, take samples of the discharge fromthe vapour dome at the top of each tank and test for hydrocarboncontent. Measurements to be taken at the sample point at themanifold inlet. Verify that the O2 stays between 2% - 3% and thedew point is better than -25°C.

h) By sampling at the domes (bottom - middle - top) for HC content,check and record the process developments, i.e. monitoring the‘layer’ of the HC and the inert gas mixture which is graduallyrising during the process..

i) During tank inerting, the flow must be directed through thesample points, gauge connections, compressor and vaporisertogether with adjacent piping. Safety valves on the cargo tanksand pipelines, which may have ‘dead ends’ must also be purged.

j) When the hydrocarbon content sampled from a tank outlet fallsbelow 1.5%, closed in the tank. On completion of inerting of allthe tanks and associated pipework and equipment, stop the inertgas supply and shut down the inert gas plant. Line up for aeratingthe tanks.

If the tanks are not to be inerted:

a) Close the following vapour header valves and pressurise the tanksto 10.0kPa:


Close No.1 cargo tank vapour valve V2100

Close No.1 cargo tank vent mast valve V2137





b) Close the IG supply valves V2353, V2352A and the manifoldvalves V2016A and V2016 to the LNG header and shut down theinert gas plant.

c) Close the following tank filling valves:


Close No.1 cargo tank liquid header block valve V2004

Close No.1 cargo tank filling valve V2003









d) Disconnect the flexible hose and replace the flange on the inertgas supply line.


Issue: 1

Illustration 6.7.4a Aerating

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201V2015A

Liquid

Vapour

Nitrogen

Liquid

Liquid

V2061

V2061

V2015

V2120

V2120

From

Recirculating Fans


To Void Spaces

Key

Inert Gas/Air Mixture

Dry Air

Inert Gas Plant inDry-Air Mode

V2352A

V2352V2352

PI

V2016A


Astern

Liquid

V2200A

V2200

V2016

V2006 (P)



6.7.4 Aerating

This is carried out immediately after inerting before dry dock. The objective isto replace all the inert gas in the cargo tanks with air. The procedure is basicallythe same as for inerting after dry dock, but with the following differences:

1) Completion of each step in the aeration procedure has the objectof achieving an oxygen content of 20% or more. At the same time,the carbon dioxide content should be 0.5% or less and the carbonmonoxide content should not exceed 50 ppm. Aerating progress ismonitored by taking regular samples and measuring the oxygencontent. Only after the oxygen content is confirmed at 20% ormore at all sampling points, should the CO2 and CO contentmeasurements be made. The portable gas analyser is providedwith CO2 and CO detector tubes of various ranges.

2) In preparation, almost all checks have already been covered bythose made in the preparation for inerting after dry dock. Inaddition, the nitrogen bleed to the insulation spaces would be shutoff and the nitrogen generator shut down. It should be verifiedthat the inert gas plant has been changed over to air productionmode and that the unit has settled down and is producing goodquality dry-air before changing the delivery back to the cargosystem. The aeration procedure normally takes at least 24 hours.

Prior to entry into the cargo tanks, the inert gas must be replaced with air. Withthe IG system in dry-air production mode, the cargo tanks are purged with dry-air until a reading of 20% oxygen by volume is reached.

Operation

The IG and dry-air system produce dry-air with a dew point of between -25°Cand -45°C. The dry-air enters the cargo tanks via the vapour header, to theindividual vapour domes.

The inert gas/dry-air mixture is exhausted from the bottom of the tanks to theatmosphere at the vent mast via the tank filling pipes, the liquid header, andspool piece and valve V2132. During aerating, the pressure in the tanks mustbe kept low to maximise the piston effect.

The operation is complete when all the tanks have a 20% oxygen value and amethane content of less than 0.2% by volume (or whatever is required by therelevant authorities) and a dew point between -25°C and -45°C.

Before entry, test for traces of noxious gases (carbon dioxide less than 0.5% byvolume, and carbon monoxide less than 50ppm) which may have beenconstituents of the inert gas. In addition, take appropriate precautions as givenin the Tanker Safety Guide and other relevant publications.

The pressure in the tanks is adjusted to 0.012 bar. Aeration carried out at sea asa continuation of gas freeing will take approximately 20 hours.

WARNINGTake precautions to avoid concentrations of inert gas or nitrogen inconfined spaces, which could be hazardous to personnel. Before enteringany such areas, test for sufficient oxygen > 20% and for traces of noxiousgases: CO2 < 0.5% and CO < 50 ppm.

Operating Procedure for Aerating the Cargo Tanks

Dry-air with a dew point of between -25°C and -45°C, is produced by the dry-air/inert gas plant at a flow rate of 5000 Nm3/h using two generators.

a) Prepare the dry-air/inert gas plant for use in the dry-air mode (Seesection 4.7.1).

b) Install the flexible connection between the flange at the end of theinert/dry-air feeder line and the vapour manifold.

c) Install the flexible connection between the flange on the liquidheader line and the flange at each tank vent mast.

d) Open the following valves to supply dry-air to the liquid header:














e) Open the following tank vapour valves to vent through the ventmast on each tank:



Open No.1 cargo tank vent mast valve V2137





f) Set the control valve V2137, to No.1 vent riser, to 0.16 bar aboveatmospheric pressure.

g) Start the dry-air production. When the dew point is between -25°C and -45°C, open the IG plant discharge valve V2353 andopen the deck valves V2352 and V2352A to allow the dry-air topass into the liquid header.

h) Observe the tank pressures and void space pressures, to ensurethat the tank pressures are higher than the void space pressures by0.01 bar gauge at all times.

i) Every hour, take samples from the filling pipe test connections totest the discharge from the bottom of the tank for oxygen content.

j) When the oxygen content reaches above 20%, isolate and shut inthe tank.

k) When all the tanks are completed and all piping has been aired out,raise the pressure to 0.1 bar gauge on each tank and shut thefilling and vapour valves. Restore the tank pressure controls andvalves to vent from the vapour header.

l) During the time that dry-air from the inert gas plant is supplied tothe tanks, use the dry-air to flush out inert gas from the vaporisers,compressors, gas heaters, crossovers, pump risers and theemergency pump wells. Pipes containing significant amounts ofinert gas should be flushed out. Smaller piping can be left filledwith inert gas or nitrogen.

m) During the time a tank is opened for inspection, dry-air will bepermanently blown through the vapour header line in order toprevent the entry of humidity from the ambient air.



Issue: 1

Illustration 6.7.4a Aerating

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201V2015A

Liquid

Vapour

Nitrogen

Liquid

Liquid

V2061

V2061

V2015

V2120

V2120

From

Recirculating Fans


To Void Spaces

Key


Dry Air


V2352A

V2352V2352

PI

V2016A


Astern

Liquid

V2200A

V2200

V2016

V2006 (P)



Issue: 1


Precautions to be Taken During the Periods the Tanks are Open

To avoid corrosion during the periods that the cargo tanks are open, it is veryimportant that the tanks are vented with dry-air at all times. This is of vitalimportance with 9% nickel steel tanks.

In relative humidity of less than 50%, corrosion will rarely take place.However, the speed of corrosion increases rapidly when the relative humidityexceeds 60%.

At all times during dry docking, the dew point temperature is to be kept morethan 3ºC lower than the cargo tank steel surface temperature and the relativehumidity is to be kept at 40% or lower.

During the dry docking period when the tanks may be open, air should be bledinto the cargo tanks and hold spaces through the ‘bottom’ line(s) and ventedout via the top.

To avoid any humid air being introduced into the cargo tank during this period,the following additional precautions are to be taken:

A tent is to be rigged above all tank domes to avoid rainfrom entering the tank

A prefabricated wooden hatch to cover the manhole is tobe fitted on all tanks which have to be entered

Avoid any more than two tanks being open at the same time

All entries into the cargo tanks are to be controlled by the vessel

Dry-air is to be bled into the tanks when entered

All tanks are to be closed when no work is taking place

A slight air overpressure is to be maintained


Part 7Emergency Procedures

Issue: 2

Skirt

Insulation

Tank Top Showing Nitrogen Bleed to Insulation Space Pipe

View Showing Tank Upper Hemisphere Insulation and Walkway

Rupture DiscRemoved

Rupture Disc

RuptureDisc

PolystyreneInsulation withStainless SteelCover

Blank Flange

Catch Basin

Leakage Pipes

NitrogenBleed

Illustration 7.1a Vapour Leakage to Insulation Space



Part 7 Emergency Procedures

7.1 LNG Vapour Leakage to Insulation Space

1. Leak before failure concept.

The Moss spherical cargo tank system is based on the ‘leak before failure’concept, which means:

a) The stress level even at the welding seams is kept low enough soas not to cause initial fatigue cracks during the lifetime of thevessel.

b) Even if there is a dent or crack-like due to some accidental reason,the crack will not penetrate the tank shell throughout the life ofthe vessel. (The crack propagation speed of 9% Nickel-steel isslow enough not to penetrate the tank shell.)

c) In the next assumption, a penetrating crack is considered andcrack propagation analysis is executed.

d) In summary, no penetrating crack will be expected in the lifetimeof the vessel. Even if the crack penetrates, the speed of crackgrowth and leak increase is moderate and there will be ample timeto take action before failure.

e) The ‘small leak protection system’ consists of the following:Cargo tank insulationPartial secondary barrier (drip pan)Gas detection system

2. Cargo tank insulation.

The cargo tank insulation is designed to meet the requirements of the ‘smallleak protection system’ i.e;

1. Gas detection in the insulation space.

A leak starts as a ‘gas leak’. The tank insulation is not glued to the tank plate,therefore it allows movement of a gas leak and thus the early detection ofleakage.

The insulation space (upper and lower hemisphere) is purged by N2 and theoutlet is monitored by the gas analyser regularly.

2. Insulation as a splash barrier.

With the growth of the crack size, the leaked cargo will change its form to aliquid-gas mixture, then to liquid.

In this case, the cargo tank insulation acts as a splash barrier for the inner hullstructure.

The insulation material itself has enough chemical/mechanical strength toresist the leaked cargo. The aluminium sheet applied on the warm side surfaceof the insulation also acts as a splash barrier and as protection for moisturepenetration.

3. Draining of leaked cargo.

The annular space between the cargo tank and the cargo tank insulation leadsthe leaked cargo to the drip pan. The leaked cargo opens a rupture disc on thedrain pipe (normally for the prevention of moisture migration during normalservice) and the cargo liquid flows out to the drip pan.



Issue: 2

Key

LNG Liquid

Illustration 7.2.1a Use of Eductors for LNG Removal

Cargo DischargePump

CargoTank

Tank CrossSection

VoidSpace

BottomWater Ballast

Tank

SideWater Ballast

Tank

Ejector FeedPump

Overboard

Turnable SpoolPiece

Ejector

V40

V41

V30

V2014

V2004 V2015

V30A V20A

V31

V1429V1429

V42

Catch Basin

Tank Void Eductor Well

Eductor Inlet Spool Piece Arrangement on Deck

Spool Piece

Eductor Inlet

Eductor Outlet

Driving Water



7.2 LNG Liquid Leakage to Insulation and Void Space

7.2.1 Use of Eductors for LNG Removal

A serious failure of the tank structure, allowing liquid into the insulation spaceor void space, will be indicated as follows:

1) A rapid increase in the methane content of the affected space.

2) Low temperature alarms at the temperature sensors in thesurrounding areas.

3) A general lowering of inner hull steel temperatures.

4) Possible liquid alarms in the surrounding areas.

5) Possible gas alarms in the surrounding areas.

Any liquid flow from the upper hemisphere will be collected in the drainchannel formed by the upper ring stiffener of the skirt. There are four drainpipes, port, starboard, forward and aft of the tanks, which lead any cargoleakage to the catch basin. Any liquid flow in the lower hemisphere will be ledto the catch basin by a drain pipe at the south pole.

Any liquid collecting in the catch basin will raise a liquid alarm via the DCSsystem. Whether the liquid is LNG cargo due to a tank leakage, or water dueto leakage from the water ballast tanks, can be determined by observing the gasdetector and the temperature indicators. A low temperature (-100º to -163ºC forLNG) indicates cargo leakage, while temperatures above 0ºC indicate waterleakage.

A bilge ejector is installed in the catch basin to empty the area when required.If the basin has to be emptied of water, water supplied from the driving linefrom the ejector feed pump is used as the driving force. The exhausted wateris delivered overboard. After use, the flexible hoses must be disconnected andthe pipe ends blind-flanged. A needle valve, V1429, is located at each flange.Pressurised air from the working air system on deck is introduced to the ejectorpipe through these valves by means of quick connecting couplings and the airwill empty the ejector pipe of water through the drainpipe.

Depending on the size of the leak, liquid may find its way to the catch basinlocated centrally below the affected tank.

When LNG cargo has to be removed from the catch basin, the cargo is alsoused as the eductor driving force.

The eductor driving force LNG is fed from the starboard side cargo pump ofthe tank concerned, through the ejector pipe in the tank dome.

Connect the tank dome ejector pipe to the cargo hold ejector pipe using theturntable spool piece located on the port side of the main deck.

The cargo from the catch basin must be returned to the damaged cargo tank asshown in illustration 7.2.1a. It is also possible to deliver the cargo overboardby the cargo piping discharge system, if necessary.

Procedure to Educt Back to the Cargo Tank

a) Install the spool piece on the void space eductor return line to theliquid header.

b) Swing the spool piece on the LNG eductor drive line from thecargo pump discharge.

c) Open valve V2014, the LNG drive.

d) Open valves V2005 and V2015, the return from the void spaceeductor.

e) Open valve V2005 - the filling valve to the tank.

f) Open valves V311 and V41 - the eductor inlet and outlet.

g) Start the cargo pump. LNG is drained from the catch basinthrough valve V40 and discharged back to the cargo tank.

On completion, the lines are allowed to warm up and vent back to the cargotank before being purged with nitrogen to ensure no LNG vapour remains.

Inerting the Void Space

If the leakage of cargo into the void space is observed, the oxygen content ofthis space must be reduced to below the explosive limit by the use of inert gasor nitrogen.

Inert gas is introduced via the void space aeration header to the void spacebottom and is exhausted to the atmosphere from the top of the void space.

Procedure to Inert the Void Space

a) Prepare the inert gas plant in inert gas mode (see section 4.7.1 forfurther detailed information) and start the inert gas production.When the oxygen content is between 2% and 3% and the dewpoint between -25°C and -45°C, open valve V2354, upstream ofthe two non-return valves on the dry air/inert gas discharge line.

b) Ensure the spoon blank between the IG outlet at the starboardmanifold and the void space aeration header is in the correctposition.

c) Open the void space air inlet valve V2303.

d) Take samples from the outlet pipe at the top of the void space totest for hydrocarbon content. Also verify that the oxygen contentof the inert gas remains between 2% and 3%.

e) When the hydrocarbon content sampled from the void spaceoutlet falls below 1.5%, shut in the space, stop the inert gas supplyand shut down the inert gas plant. Reset the valve system foraerating.

Aeration is carried out in the same manner as inerting, using the inert gas plantoperating in the dry air mode to supply dry-air.

The aeration operation is continued until the oxygen content, measured with aportable oxygen indicator, is about 21%.

In order to save time, the aeration of the void spaces can be carried outsimultaneously with gas freeing of the cargo tanks.

It is very important that the aeration of the void spaces must not start beforethe warming up of the cargo tanks has been completed.



Issue: 2

Illustration 7.3.1a Use of Eductors for Water Removal

Tank Void Eductor Well

Eductor Inlet Spool Piece Arrangement on Deck

Spool Piece

Eductor Inlet

Eductor Outlet

Driving Water

Cargo DischargePump

CargoTank

Tank CrossSection

VoidSpace

BottomWater Ballast

Tank

SideWater Ballast

Tank

Ejector FeedPump

Overboard

Turnable SpoolPiece

Ejector

V40

V41

V30

V2014

V2004 V2015

V30A V20A

V31

V1429V1429

V42

Key

Sea Water

Catch Basin



Issue: 1


7.3 Water Leakage to Void Spaces

7.3.1 Use of Eductors for Water Removal

Ballast water leakage from the wing tanks to the void spaces can occur throughfractures in the inner hull plating. If the leakage remains undetected and wateraccumulates in these spaces, ice may be formed. Ice accumulation can causedeformation, and possible rupture, of the tank insulation. The resultant coldconduction paths forming in the insulation may cause cold spots to form.

To reduce the risk of damage from leakage, each cargo tank void space isprovided with water/leakage detection units.

The leakage protection system also includes a method of collecting andaccumulating small leaks of liquid cargo as well as water. This liquid iscollected in the catch basin under the cargo tank. The water leakage collects inthis basin, where the monitoring equipment is installed. The equipmentconsists of a sample point for the gas detector, a liquid indicator and atemperature indicator to raise alarms in the CCR via the DCS system.

Any liquid collecting in the catch basin will raise a liquid alarm via the DCSsystem. Whether the liquid is LNG cargo due to a tank leakage, or water dueto leakage from the water ballast tanks, can be determined by observing the gasdetector and the temperature indicators. A low temperature (-100º to -163ºC forLNG) indicates cargo leakage, while temperatures above OºC indicate waterleakage.

Procedure to Use the Eductors for Water Removal

A bilge ejector is installed in the catch basin to empty the area when required.If the basin has to be emptied of water, the procedure is as follows:

a) Turn the spool pieces on the drive and outlet pipes and connect tothe drive water inlet line and overboard discharge.

b) Open valve V20A, the ejector feed pump suction valve.

c) Open valves V30 and 30A, the pump discharge valves.

d) Open valve V41, the outlet to the overboard discharge line.

e) Open valve V311, the eductor inlet.

f) Start the ejector feed pump.Water is drained from the catch basinthrough valve V40 and discharged overboard.

g) On completion, shut valves V311 and V41. Swing the spoolpieces. An air outlet valve is located at each flange enabling airfrom the working air system on deck to be introduced by meansof the quick connecting couplings. The air will empty the ejectorpipe of water through the drain line and valve V42.


Issue: 1

Illustration 7.4a Emergency Discharge

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100

V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Emergency

Discharge

To Astern

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To LNG

Vaporiser

From

Manifold

V2201

V2016A

V2200A

V2015A

Liquid

Vapour

Nitrogen

Liquid

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061V2016

V2015

V2120

V2120

V2200

From

Recirculating Fans


To Void Spaces

Key

LNG Liquid

LNG Vapour

Displaced LNG

Liquid



Issue: 1


7.4 Failure of Cargo Pumps - Emergency Discharge

If the two cargo pumps in any one cargo tank fail, the remaining cargo can betransferred to any other tank by vapour pressurisation above the liquid in theaffected tank. The rate of transfer is controlled by regulating the pressurewithin the tank.

The transfer operation would normally take place at sea after the completion ofunloading and gauging of the tanks. The ship would then return to complete theunloading operation prior to the inerting, aerating and replacement of thedefective cargo pumps.

Control of this operation would be by remote manual control from the DCSsystem in the CCR, with personnel available on deck for local monitoring. Fullsafety precautions are to be implemented as for any normal cargo transferoperation. These include:

Fire hoses: laid out, pressurised

Dry powder system availableSafety personnel patrolling the cargo areas during the fulloperations of purging, cooldown and pressurised transferof LNG.

Using this method, cargo is pressed up and displaced into the filling line bymeans of increased vapour pressure above the liquid. The increased pressure isobtained by pumping LNG from cargo tanks No.3 or 4 using the spray pumpto the vaporisers. The vapour is introduced into the required tank through thevapour line. The flow lines for LNG vapour, liquid LNG and for the displacedLNG are shown in illustration 7.4a. The illustration also shows the vapoursupply line to the other cargo tanks if required and the spray liquid suctionfrom cargo tank No.3 if required.

In order to avoid opening the safety valves, due to the increased pressure, thevalves are set for operation on the HP pilot. This is carried out by operating thetwo-way three port ball valve via the interlock device. The opening set point isthus increased to 2.15 bar.

The high pressure alarm is set to sound at 0.22 bar, so this alarm should beinhibited.

For this example, it is assumed the pumps have failed in cargo tank No.5. Thetransfer of cargo from No.5 cargo tank to No.4 cargo tank is explained.

Procedure for an Emergency Discharge

a) Discharge the contents of No.1, 2, 3 and 4 cargo tanks, leavingapproximately 1500m3 in No.3 or No.4 cargo tanks. This quantityof liquid will provide the required volume of vapour.

b) Complete normal unloading procedures and final gauging of thecargo, then sail from the port to an open sea area.

c) Connect spool pieces at the inlet and outlet of the vaporiser.

d) Open the manifold valves V2061, V2201 and V2200A and cooldown the transfer lines as required.

e) Select the Cargo Primary Window on the DCS display and carryout the normal safety checks.

(Note: Under normal operating conditions, the LD compressor will besupplying boil-off gas to the boilers from all tanks through the gas heater. Thisoperation will be continued for No. 1, 2, 3 and 4 cargo tanks.)

The Transfer of Cargo

a) Supply steam to the LNG vaporiser, opening steam supply valveV937A and when the LNG supply is stabilised, place the controlvalve V2203 in automatic control.

b) Adjust the vapour temperature out set point to -60ºC. Adjustingthe set point is described in the vaporiser manufacturer’s manual.

c) Set the safety valves for operation on the HP pilot in order toadjust the opening set point to 2.15 bar.

d) When the LNG liquid line header has cooled down, Set thesevalves as in the following table:


Open LNG vaporiser supply valve V2203

Open LNG vaporiser discharge valve V2235

Open LNG vaporiser supply to vapour header valve V2118

Open No.4 cargo tank filling valves V2020, 2019


Open Cargo tank No.5 vapour supply valve V2108

Open Cargo tank No.4 spray pump discharge valve V2068

No. 4 spray pump will now supply the LNG vaporiser to pressurise No.5 cargotank through valve V2109.

e) Start No.4 cargo tank spray pump.

f) Monitor No. 5 cargo tank pressure increase and the cargo transferrate. The tank pressure will rise rapidly during the first hour or so,then, as the tank level falls, the vapour pressure will have to beincreased to maintain the flow. Regulate the cargo tank pressureby throttling the liquid flow into the vaporiser.

(Note: The vaporiser must be monitored locally during this operation.)

g) Ensure that the tank pressure does not rise too close to the settingof the safety valve.

h) When the tank liquid level falls to approximately 2 metres, stopthe transfer of cargo by stopping No. 4 spray pump.

i) Shut down the steam supply to the vaporiser.

j) Set the valves as in the following table:


Close LNG vaporiser supply valve V2203

Close LNG vaporiser discharge valve V2235

Close LNG vaporiser supply to vapour header valve V2118

Close Cargo tank No.5 vapour supply valve V2109

Close Cargo tank No.4 spray discharge valve V2068



k) Reset No. 5 tank safety valves to their normal operating positions.

l) The adjustment and readjustment of the safety valves is to becarried out under the supervision of the Master and recorded inthe ship’s log book.

m) Restore all alarms to their normal operating settings.

n) Remove the spool pieces at the inlet and outlet of the vaporiser.


7.5 Fire and Emergency Breakaway

All terminals have their own requirements regarding when it is unsafe for avessel to remain alongside a terminal. These are normally outlined in theterminal handbook.

In case of a fire or emergency developing, either on board or ashore thefollowing basic procedures will be followed:

a) All cargo operations will be stopped and emergency signalssounded as per the terminal’s requirements (as detailed in theship/shore checklist). Ship’s personnel should move away fromthe manifold areas immediately.

b) Ship and shore emergency procedures will be put into operation.

c) The ESD1 system will be activated, resulting in the cargo armsbeing disconnected.

d) In the event of fire, the water spray system on ship/shore will beactivated.

e) Fire parties would attempt to deal with the situation.

f) The vessel would prepare for departure from the berth.

g) Liaison with shore personnel to arrange for pilot and tugs andadditional support.

h) A standby tug would assist with fire fighting/movement of thevessel from the berth.

i) The vessel would either move away from the berth to a safe area,under its own power with assistance of a standby tug or withadditional tugs/pilot summoned from shore.

j) The owners/charterers and other interested parties would beinformed of the situation.



Issue: 1

Illustration 7.6.1a One Tank Warm Up

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201V2015A

Liquid

Vapour

Nitrogen

Liquid

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

From

Recirculating Fans


To Void Spaces

Key

LNG Vapour

LNG Vapour (Warm)

V2137

V2200AV2016A

Liquid

V2016 V2200



Issue: 2


7.6 One Tank Operation

It may be necessary for in-tank repairs to be carried out with the vessel inservice, in which one tank can be warmed up, inerted, aerated, entered andwork undertaken on the tank internals, i.e. change cargo pump, investigate andcure problems with tank gauging systems etc.

The warm up, inerting and aeration can be carried out with the remaining coldtanks providing boil-off gas for burning in the boilers.

Aeration should be continued throughout the repair period to prevent ingressof humid air to the cargo tank.

Tank venting is carried out by means of the gas header line.

Operation

At the discharge port, the tank to be worked on is discharged to the lowestmeasurable level and after completion of custody transfer, as much as possibleis drained to another tank using the spray/stripping pump, if possible.Sufficient heel for the voyage, together with an extra amount for cooling downthe tank after completion of repairs, is retained in one of the other tanks.

7.6.1 One Tank Warm Up

Normal gas burning is continued during this operation using vapour from allfive tanks. In the first instance, normal boil-off gas procedures are followeduntil this operation has stabilised, then the operation for warming up one tankusing an HD compressor can be carried out.

Warm Up Procedure (No.3 Tank)

It is assumed that all valves are closed prior to use.

a) Install the spool piece and open valves V2121 and V2125 todischarge the heated vapour to the liquid header.

b) Prepare the upper or lower gas heater for use.

CAUTION The vapour heaters should be thoroughly preheated with steam before theadmission of methane vapour. This prevents ice formation.

c) Adjust the heater temperature set point for +75ºC.

CAUTION When returning heated vapour to the cargo tanks, the temperature at theheater outlet should not exceed +85ºC to avoid possible damage to thecargo piping insulation and safety valves.

d) At the vent mast, set valve V2137 for 0.3 bar.

e) Prepare the HD compressor(s) for use.

f) Open valve V2110, the compressor(s) suction from the vapourheader.

g) Open the compressor(s) inlet valves V2113 and dischargevalve(s) V2114A and V2115 to the heaters.

h) Open the heater inlet and outlet valves V2131 and V2132.

i) Open the vapour outlet valves on each tank - V2100, V2101,V2103, V2108 and V2109.

j) Open the filling valves V2012 and V2011 on tank No.3.

k) Start one or two HD compressors manually. Gradually increasethe flow by adjusting the speed accordingly.

l) Send boil-off gas to the boilers; carry out steam dumping and ventcontrol in parallel to obtain stable boiler combustion.

m) Monitor the tank pressure and adjust the compressor(s) tomaintain the tank pressure between 0.04 bar and 0.2 bar.

n) When the tank pressure tends to decrease, stop the BOG burning.

o) Monitor the tank temperatures, warm up is completed when thecargo tank equator temperature is higher than -20°C.

p) Stop the warm up, shut off the steam to the gas heaters and allowvapour to circulate for 10 minutes.

q) Shut down the HD compressor(s) and set up for inerting andaerating the tank.


Issue: 1

Illustration 7.6.2a One Tank Gas Freeing

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2352A

V2352

V2352


Inert Gas

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201

V2015A

Liquid

Vapour

Nitrogen

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

V2120

From

Recirculating Fans


To Void Spaces

V2137

* 1-5 Cargo Tank Valves 2100, 2101, 2103, 2108 and 2109Must Be Shut On Tanks Not being Inerted

Liquid

V2016

V2200AV2016A

V2200



Issue: 2


7.6.2 One Tank Gas Freeing

The tank pressure in all tanks is to be reduced as much as possible prior toinerting as it is not possible to use the boil-off gas from the four remainingtanks during the inerting of No.3 cargo tank.

Gas Freeing Procedure (No.3 Tank)

a) Prepare the dry-air/inert gas plant for operation in the inert gasmode.


c) Install the flexible connection between the flange on the vapourheader line to the flange at No.3 tank vent mast.

d) Set up the following valves:







Open Liquid manifold valves V2016, V2016A


e) Start the inert gas plant. When the oxygen content is between 2%and 3% and the dew point is between -25°C and -45°C, open theIG plant discharge valve V2353 and open the deck valves V2352and V2352A to allow the inert gas to pass into the liquid header.

f) Monitor the tank pressure and adjust the opening of the fill valveto maintain a uniform pressure.

g) Approximately once an hour, take samples of the discharge fromthe vapour dome at the top of tank and test for hydrocarboncontent. Also verify that the oxygen content of the inert gasremains between 2% and 3%, by testing at a purge valve at thefilling line of the tank being inerted.

h) By sampling at the vapour dome, check the atmosphere of thetank using a portable oxygen analyser. The oxygen content is tobe between 2% and 3% and the dew point less between -25°C and-45°C.

i) When the hydrocarbon content sampled from the tank outlet fallsbelow 1.5%, shut in the tank. On completion of inerting, stop theinert gas supply and shut down the inert gas plant. Reset the valvesystem for aerating.

(Note: If No.3 tank is to remain without inerting shut the vapour header valveV2103 and pressurise the tank to 0.1 bar before shutting down the inert gasplant.)

j) Close the following valves:


Close IG plant discharge valve V2353

Close IG plant deck discharge valves V2352, V2352A

Close Liquid manifold valves V2016, V2016A

Close No.3 cargo tank filling valves V2011, V2012

k) Disconnect the flexible hose and replace the flange on the inertgas supply line.

l) Reset the system to send the boil-off gas in the four remainingtanks to the ship’s boilers.


Issue: 1

Illustration 7.6.3a One Tank Aerating

V2023

V2002 (S)

V2065

V2030

V2024

V2002 (P)

V2065

V2065V2065

V2138V2066

No.5Cargo Tank

VentMast

Dome

V2019

V2018 (S)

V2063

V2029

V2020

V2018 (P)

V2063

V2063V2063

V2108

V2138V2064

No.4Cargo Tank

VentMast

Dome

V2007

V2006 (S)

V2054

V2027

V2008

V2006 (P)

V2054

V2054V2054

V2101V2138V2055

No.2Cargo Tank

VentMast

Dome

V2003

V2002 (S)

V2051

V2026

V2004

V2002 (P)

V2051

V2051V2051

V2100V2138V2052

No.1Cargo Tank

VentMast

Dome

SprayPump

V2011

V2010 (S)

V2057V2028

V2012

V2010 (P)

V2057

V2057V2057

V2103V2138

V2058

No.3Cargo Tank

VentMast

Dome

SprayPump

V2068

V2068

V2109

V2122

V2119

V2118

V2110

LNG Compressor

Room

Void Space

Air Dryer

Void Space

Air Dryer

HD Comp.B

HD Comp.A

LD Comp.

Vapour

Heater

Vapour

Heater

FWD

LNG

Vaporiser

To

Boilers

V2125

V2126

V2139

V2125

V2126

V2315V2315

V2314

V2314

V2139

V2111

V2235V2113

V2139

V2128

V2113 V2136

V2135

V2134

V2132

V2132

V2131

V2130 V2130

V2131

V2115

V2114

V2114A

V2114

V2203

V2203

V2203AV2234 V2117

V2135

Heater For Void

Space Atmosphere

V2061

V2201

V2061

V2016A

V2016

V2200A

V2015A

V2200

V2015

To N 2 Plant

V2201

V2016A

V2200A

V2015A

Liquid

Vapour

Nitrogen

Liquid

Vapour

Nitrogen

Liquid

V2061

V2061

V2015

V2120

From

Recirculating Fans


To Void Spaces

Key


Fresh Air

V2137

V2352A

V2352

V2352


V2200

V2016

Liquid

V2120



Issue: 2


7.6.3 One Tank Aerating

The aeration of a single tank may be carried out in the same manner aspreviously described for inerting a single tank. The supply of air from the dry-air plant is sent to the tank via the liquid header and vented through the vapourtank vent.

It is not possible to use the boil-off gas in the boilers whilst this operation isbeing carried out as the other tanks have to be isolated. However, it is possibleto continue using the boil-off gas in the following alternative method:

Dry-air with a dew point of between -25°C and -45°C, is produced by the inertgas plant operating in the dry-air mode at a flow rate of 5000Nm3/h using twogenerators.

Aeration Procedure (No.3 Tank)

a) Prepare the dry-air/inert gas plant for use in the dry-air mode (Seesection 4.7.1).

b) Install the flexible connection between the flange at the end of theinert/dry-air feeder line and the liquid manifold.

c) Install the flexible connection between the flange on the vapourheader line and the flange on No.3 tank vent mast.

d) Open the following valves to supply dry-air to the liquid header:






e) Start the dry-air production. When the dew point is between -25°C and -45°C, open the IG plant discharge valve V2353 andopen the deck valves V2352 and V2352A to allow the dry-air topass into the liquid header.

f) Observe the tank pressures and void space pressures, to ensurethat the tank pressures are higher than the void space pressures by0.01 bar gauge at all times.

g) Approximately once an hour, take samples from the filling pipetest connections to test the discharge from the bottom of the tankfor oxygen content.

h) When the oxygen content reaches 20%, isolate and shut in thetank

i) During the time a tank is opened for inspection, dry-air will bepermanently blown through the spray header line in order toprevent the entry of humidity from the ambient air.

CAUTION Ensure that the tank pressure in the aerated tank remains higher than theother tanks containing LNG vapour to avoid leakage of toxic gas to thistank. All safety precautions are to be taken to avoid creating aninflammable mixture by fitting blanks to the pipelines surrounding thetank.

j) During the above operation, gas burning can be continued fromthe other four tanks in the usual manner.


7.7 Ship to Ship Transfer

This section is intended to complement the ICS Tanker Safety Guide,(Liquefied Gases) and the ICS Ship to Ship Transfer Guide, (Liquefied Gases)and should be supplemented by the Company’s own instructions and orders.

7.7.1 General Safety

The Master, or other person in overall control of the operation, should beclearly established before the operation commences and the actual transfershould be carried out in accordance with the wishes of the receiving ship.

The means of communication should also be well established before transferand both ships must be in direct contact with each other during the wholeoperation. Radiotelephone contact should be established on VHF Channel 16and thereafter on a mutually agreed working channel. Approach, mooring,transfer and unmooring should not be attempted until fully effectivecommunications are established.

Should there be a breakdown in communications for whatever reason, either onapproach, or during transfer, the operation should immediately be suspended.

CAUTIONThe ignition of gas vapours may be possible by direct or induced radiofrequency energy and no radio transmissions, other than at very highfrequency, should take place during transfer operations. Arrangementsshould be made with an appropriate coast station for blind transmissionswhich would allow reception of urgent messages.

7.7.2 Pre-Mooring Preparations

Prior to mooring, the organisers of the transfer should notify the localauthorities of their intentions and obtain any necessary permits.

The two vessels should liaise with each other and exchange details of the ships,which side is to be used for mooring, the number of fairleads and bitts and theirdistance from the bow and stern of the ship to be used for mooring.

Information should also be exchanged on:

The size and class of manifold flanges to be used.

The anticipated maximum height differential of the manifolds for determininghose length required.

The type of hoses required and their supports to ensure that their allowablebending radius is not exceeded.

The weather conditions should be taken into consideration, as that willdetermine the type and number of fenders to be used and the type of mooringprocedure to be used. Both Masters should be in agreement that conditions aresuitable for berthing and cargo transfer before the operation takes place.

All equipment to be used should be thoroughly prepared and tested, and allsafety equipment should be checked and be ready for use if required.

Cargo Equipment to be Tested

Ventilation of compressor, pump and control room to be fully operational.

Gas detection systems to be correctly set, tested and operating.

Emergency shut down system to be tested and ready for use.

Pressure and temperature control units to be operational.

Cargo tanks to be cooled, if necessary.

Manifolds to be securely blanked.

Cargo hose reducers to be ready in place.

Hose purging equipment to be acceptable.

Safety Precautions

Fire main tested and kept under pressure.

Water spray system tested and ready.

Two additional fire hoses connected near the manifold and ready for use.

Dry powder system ready.

All access doors to the accommodation to be kept closed at all times duringtransfer.

No smoking.

Impressed current cathodic protection system, if fitted, to be switched off atleast three hours before transfer.

First aid equipment etc. to be ready for use.

Fenders should be positioned according to an agreed plan, taking intoconsideration the type and size of both ships, the weather conditions and thetype of mooring that is to take place.

7.7.3 Mooring

The most successful method of berthing is with both ships underway. One ship,preferably the larger, maintains steerage way on a constant heading asrequested by the manoeuvring ship, usually with the wind and sea dead ahead.The manoeuvring ship then comes alongside.

Successful operations have taken place with one ship at anchor in fine weatherconditions, and this is not too difficult if there is an appreciable current and asteady wind from the same direction. If not, then tug assistance may benecessary.

Mooring should be rapid and efficient and can be achieved by good planningby the Masters of both ships.

In general, the following points should be noted.

The wind and sea should be ahead or nearly ahead.

The angle of approach should not be excessive.

The two ships should make parallel contact at the same speed with no asternmovement being necessary.

The manoeuvring ship should position her manifold in line with that of theconstant heading ship and match the speed as nearly as possible.

Contact is then made by the manoeuvring ship, reducing the distance betweenthe two ships by rudder movements, until contact is made by the primaryfenders.

(Note: Masters should be prepared to abort if necessary. The internationalregulations for preventing collisions at sea must be complied with.)

On completion of mooring, the constant heading ship will proceed to ananchoring position previously agreed. The manoeuvring ship will have itsengines stopped and rudder amidships, or angled towards the constant headingship. The constant heading ship should use the anchor on the opposite side tothat on which the other ship is berthed.

From the time that the manoeuvring ship is all fast alongside, to the time theconstant heading ship is anchored, the constant heading ship assumesresponsibility for the navigation of the two ships.



Issue: 1


7.7.4 Transfer Operations

Transfer can begin when the two Masters have ensured that all the pre-transferchecks and precautions have been completed and agreed them. Both shipsshould be prepared to disconnect and unmoor at short notice should anythinggo wrong.

During transfer, ballast operations should be performed in order to keep thetrim and list of both vessels constant. Listing of either vessel should be avoidedexcept for proper tank draining. Checks should also be kept on the weather,traffic in the area, and that all safety equipment is still in a state of readiness.

Transfer can take place whilst the two vessels are at anchor. This is the mostcommon method. Transfer can also take place whilst the two vessels are underway, though this depends on there being adequate sea room, traffic conditionsand the availability of large diameter, high absorption fenders.

Underway Transfer

After completion of mooring, the constant heading ship maintains steerageway and the manoeuvring ship adjusts its engine speed and rudder angle tominimise the towing load on the moorings. The course and speed should beagreed by the two Masters and this should result in the minimum movementbetween the two ships. The Master of the constant heading ship is responsiblefor the navigation and safety of the two vessels.

Drifting Transfer

This should only be attempted in ideal conditions.

Completion of Transfer

After transfer has been completed and before unmooring, all hoses should bepurged, manifolds securely blanked and the relevant authorities informed thattransfer is complete.

7.7.5 Unmooring

This procedure will be carried out, under normal conditions, at anchor, thoughif both Masters agree, unmooring can take place whilst under way.

Before unmooring begins, obstructions from the adjacent sides of both shipsshould be cleared and the sequence and timing of the event be agreed by bothships, and commenced at the request of the manoeuvring ship. Lines should besingled up fore and aft, then let go the remaining forward mooring allowing theships to drift away from each other, at which time the remaining after mooringsare let go and the ships drift clear of each other. Neither ship should, at thispoint, attempt to steam ahead or astern until their mid lengths are about twocables apart.


Issue: 1


7.8 LNG Jettison

WARNINGThe jettisoning of cargo is an emergency operation. It should only becarried out to avoid serious damage to the cargo tank and/or inner hullsteel structure.

A containment or insulation failure in one or more cargo tanks may necessitatethe jettisoning of cargo from that particular cargo tank to the sea. This iscarried out using a single main cargo pump, discharging LNG through aportable nozzle fitted at the ship’s manifold.

As jettisoning of LNG will create hazardous conditions:

a) All the circumstances of the failure must be carefully evaluatedbefore the decision to jettison cargo is taken.

b) All relevant fire fighting equipment must be manned, in a state ofreadiness and maintained so during the entire operation.

c) All accommodation and other openings and all vent fans must besecured.

d) The NO SMOKING rule must be rigidly enforced.

e) The water curtain on the side of the jettison is to be running toprotect the ship’s structure.

Weather conditions, and the heading of the vessel relative to the wind, must beconsidered so that the jettisoned liquid and resultant vapour cloud will becarried away from the vessel. In addition, if possible, avoid blanketing thevapour with exhaust gases from the funnel.

The discharge rate must be limited to the capacity of one cargo pump only and,if necessary, reduced to allow acceptable dispersal within the limits of theprevailing weather conditions.

WARNINGToo rapid a flow of LNG will result in rapid phase transfer (RPT) whenthe liquid hits the sea water.


Issue: 2


7.9 General Emergency Procedures

1. Mooring Failure

If any of the mooring lines should break, or a winch starts to pay out on amooring line, the CCR is to be notified at once. Corrective action is to be takenas soon as possible.

If the vessel starts moving, the CCR has to be informed and ESD to bereleased. The cargo operation shall not resume until the reason why the vesselhas moved is established and the corrective action taken.

If the OOW observes a change in the weather conditions, or recognises anunannounced vessel passing nearby, the CCR shall be notified and themoorings shall be carefully observed.

2. Cargo Leakage on Deck

The CCR is to be informed immediately about the observation and the extentof the leakage is to be reported.

Discharging rate/loading rate is to be reduced or stopped until the situation isunder control. The terminal is to be informed.

If unable to stop the leakage, the cargo operation shall be suspended until theproblem is solved.

Water shall be used to protect the steel and dilute the gas.

3. Cargo Line Burst

The ESD system is to be activated, the CCR is to be informed accordingly andthe general alarm raised.

The terminal is to be informed immediately according to the terminal’s safetychecklist procedures.

All cargo operations are to be suspended, valves closed and if possible thefractured section to be isolated as much as possible.

All ventilation is to be closed, or stopped.

Smoking, naked lights and the use of electric switches everywhere onboard,are not to be used until the area is declared as gas free.

Fire hoses and water sprays must be ready for immediate use in the fracturedarea of the vessel’s hull, in order to protect the mild steel and to disperse theliquid overboard.

Try to control the direction of the dispersion with the fire hose water spray,dilute the gas with water spray, heating the relatively cold gas to increase itsbuoyancy.

The off-duty crew are to be called out to prepare for fire fighting.

4. Fire in the Tank Vent Mast

If vent mast fire, the following to be considered:

1. Stop venting immediate, or detect the gas leakage from the safetyvalves.

2. Inject any kind of inert gas (IG) into the vent mast.

3. Spray the masthead with water.

5. Cargo Tank Overfill

If any sign that a cargo tank is overfilled during a cargo operation, theoperation is to be stopped immediately and the terminal is to be advised.

The situation is to be assessed and corrective action is to be taken.

The vapour line is to be inspected to find out if any liquid has entered it andthe LNG compressors are to be stopped accordingly in order to avoid liquidslugs.

If possible, the excess cargo is to be transferred to another cargo tank.

The ‘overfilled’ cargo tank is to be closely monitored during the remainingloading.

6. Leakage in Cargo Compressor Room

If any alarm comes from the gas detection system, indicating a high gasconcentration in the cargo compressor room, the room has to be inspected withcaution (enclosed space entry procedure is to be followed), and action is to betaken to correct the gas leakage.

Be sure that the ventilation fan is running, and no gas has accumulated.

Be sure that the gas analyser and ventilation are operating at all times.

7. Tank Overpressure

During Cooldown or Loading

If the high-pressure alarm is released and the pressure is still rising afterreducing the cooldown rate/loading rate, the following action shall be taken:

The cooldown/loading is to be stopped immediately and the reason for the hightank pressure is to be investigated. The terminal is to be advised.

The cooldown/loading shall not continue until the tank pressure is undercontrol and accepted by the terminal.

During Discharging

The terminal has to be ordered to stop the return gas blower and vapourmanifold valve to be closed.

The terminal is to be advised that the discharging will be stopped and that themanifold valves will be closed until the situation is clarified.

As soon as agreed with the terminal, open the vapour valve and vent the returngas to the shore flare or burn the excess BOG on the boilers, until the pressurein the cargo tanks is under control.

Continue the discharging when the reason for the high tank pressure isestablished and agreed by the terminal.

8. Uncontrolled Venting

If any uncontrolled venting should take place, all cargo operations are to bestopped immediately.

Check that all openings in the deckhouse and superstructure are closed tominimise the possibility to vapour entry.

If alongside, the terminal is to be advised.

If at sea, try to change course, related to the wind and the vessel’s speed, tominimise the risk for any gas vapour to enter the superstructure.

Identify the gas leakage and try to isolate the gas-leaking source.

Spray the vent mast with water in order to heat and increase the vapourbuoyancy.


Issue: 2


9. Cargo Operations during an Electrical Storm

If an electrical storm is closing on the vessel, the CCR is to be informed.

The terminal safety checklist is to be followed and the cargo operations are tobe stopped while the electrical storm is passing the vessel, terminal and plant.

The cargooperation may continue as soon as the electrical storm has passedand is agreed by the terminal.

10. Fire in the Vicinity of the Vessel

If a fire occurs in the immediate vicinity of the vessel, whether ashore oronboard another vessel, the following action shall be taken:

1. An alarm is to be given according to the terminal’s regulation

2. Contact the terminal and inform that the cargo operation may bestopped.

3. Stand by at the telephone/VHF to await information and/orinstructions.

4. Rig the pilot ladder on the offshore side.

The following actions are also to be considered:

1. Stopping the cargo operation (and bunker operation, if takingplace).

2. Contacting the port authorities to obtain the latest information anddiscuss/decide the best course of action to be taken.

3. Disconnecting the loading/discharging arms.

4. Starting the sprinkler on deck and spraying sea water at exposedlifeboat/liferafts.

5. Preparations for leaving the berth.

6. Muster the fire stations.


Norman Lady Cargo Operating Manual

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