SHIP TO SHIP (STS) TRANSFER OF CARGO: LATEST DEVELOPMENTS AND OPERATIONAL RISK ASSESSMENT

SHIP TO SHIP (STS) TRANSFER OF CARGO: SHIP TO SHIP (STS) TRANSFER OF CARGO: LATEST DEVELOPMENTS AND LATEST DEVELOPMENTS AND

OPERATIONAL RISK ASSESSMENTOPERATIONAL RISK ASSESSMENT

N.P. Ventikos1 , D.I. Stavrou2

National Technical University of AthensSchool of Naval Architecture & Marine Engineering

1. Assistant Professor, Laboratory for Maritime Transport, School of Naval Architecture and Marine Engineering, NTUA2. PhD Candidate, Laboratory for Maritime Transport, School of Naval Architecture and Marine Engineering, NTUA

OUTLINE

1. Introduction 2. Legislative regime 3. Factors in consideration 4. Risk assessment 5. Lessons learned from accidents 6. Conclusions

4th Int. Symposium of MASSEP.

STS transfer operation

INTODUCTION

Significant development due to:

•Operational factors (optimization of the distribution plan)

•Trading factors (offshore storage - contango situation)


INTRODUCTION

AIM OF THIS STUDY :

Describe the latest developments,

Preliminary risk analysis/assessment of the procedure,

Importance of lessons learnt from case studies

PhD: development of a dynamic risk framework for STS transfers.


INTRODUCTION


STS transfer of cargo

Ore lightering (Rarely)

Petroleum products (Usaly)

LNG, LPG transfer(Under

development)

INTRODUCTION


• Initially used on the decade of 1960s in the Gulf of Mexico.

• Transfer of cargo between seagoing ships positioned alongside.

• “Constant heading vessel” moves on a study direction with slow speed, while the other ship called “maneuvering vessel” approach the first ship

• Objective cause for both ships is to come on parallel courses with similar speed and their manifolds in line so to continue with the transfer procedure.

• Stationary or underway.• “Lightering” transshipment from a larger ship to a smaller one or “Reverse Lightering” transshipment vice versa

PHASES OF A STS TRANSFER OPERATION


LEGISLATIVE REGIME FOR STS OPERATIONS

The STS transfer operations were initially based on guidelines or recommendations made primarily from:

•ICS •OCIMF •IMO

Although few accidents or spills, public concerns about consequences of oil spills led to the adoption of international regulations

First significant action:

Addition of Chapter 8 to MARPOL Annex I of the Protocol of 1978 related to the International Convention for the Prevention of Pollution from ships.


LEGISLATIVE REGIME FOR STS OPERATIONS The IMO resolution MEPC 186(59)/2009 entered into force on April 1st, 2012 and it comprises three regulations of interest;

Regulation 40. Scope of Application: •Apply to oil tankers above 150 GT•exceptions: Bunkering, FPSOs & FSUs, offshore platforms, warships.

Regulation 41. General Rules on Safety and Environmental Protection: •STS operation Plan•Qualified Person in Overall Advisory Control (POAC)•Records for inspection. Regulation 42. Notification: •Applies to territorial waters/ EEZ •notification to the Party 48 hours prior to the operation.


FACTORS THAT AFFECT AN STS TRANSFER OPERATION

The development of an STS transfer operation depends on different factors:

•The vessels and their technical specifications (dimensions, compatibility issues, propulsion installations, mooring and anchorage equipment etc.).

•The human factor (master’s experience, training skills and qualifications, preparation of the crew for emergency conditions etc.).

•The special STS equipment (transfer hoses, fenders etc.).



•The Person of the Overall Advisory Control (POAC) and his assistants; complete the operation safely and in accordance with the regulations set by IMO; criteria to abort/suspend the operation. •Other external factors such as the selected transfer area (traffic density, geological factors, security threat, underwater pipelines and/or cables, water depth), prevalling weather and environmental conditions (sea state, wind, tidal currents, visibility etc.).


Emergency STS transfer in the strong wind conditions and 2m swells

POACSupervise/control the STS operation

Responsible for the Ship/Ship Interface

STS Superintendent

Coastal Authorities

Vessel Crew

Master of constant heading vessel Responsible for his own vessel


Master of maneuvering vesselResponsible for his own vessel

Vessel Crew STS Superintendent

RISK ASSESSMENT OF AN STS TRANSFER OPERATION


RISK ASSESSMENT OF AN STS TRANSFER OPERATION

minimum level of absolute risk


Analysis conducted in 2004; 1,270 STS transfer operations; a time window of 10 years

•No major pollution incident;

•Oil leakage in 7 cases (5.5‰) from which only two ended up to the sea.

•Minor collisions was 11.81 cases per 1000 operations •Major collisions was 1.57 cases per 1000 operations.

•One fatality and one crew injury occurred.

•A rate of 3.6 accidents /year

LESSONS LEARNED FROM STS ACCIDENTS

Case 1: Collision between VLCC and Aframax tanker at the beginning of STS procedure

Case 2: Collision between two Aframax oil tankers at the end of the STS procedure

CASE 1: COLLISION AT THE BEGINNING OF STS PROCEDURE

Narrative

Two tankers conducted “run-in” procedure for STS operation; helmsman (maneuv. vessel) on the wheel for 1 ½ hours. Operation during the night. Poor exterior helm repeater illumination. When manifolds came in line the superintendent used steering orders to do final approach. The maneuvering vessel start swing towards to the constant heading vessel. The superintendent tried to correct the movement. He then noticed that the indicator of the helm was on the opposite direction to the one he ordered. The two ships collided.

Wrong impression for

steering orders


Investigation analysis

Delay of the initiation led STS to be conducted in darkness. That had adverse affection on the procedure.

Poor visibility of the helm indicator in the wing bridge caused

lack of control at the executed orders.

Superintendent was not checking if his orders were executed correctly.

Helmsman was executing orders to keep courses for 1 1/2h

and during final approach he had to adjust to a different situation in which he had to execute specific helms angle. This led to a lapse of concentration.


Lessons learnt

It is of upmost importance to use persons with special qualifications when difficult operations are conducted including “run-in” or mooring procedures.

The fatigue of the personnel must be taken under serious consideration.

It is preferred that STS transfer operations are conducted with day light.

Bridge instrumentation must be inspected and remedy measures must be taken.

CASE 2: COLLISION AT THE END OF STS PROCEDURE

Narrative

After STS operation completed the ships started procedure so to separate. While moving with 2.5 knots, the last lines slipped, causing movement of the stern of one vessel close towards the other. To correct movement superintendent used propulsion and steering orders. However, the engine did not start. Efforts of the superintendent to avoid collision between the ships using consecutive steering orders were ineffectual; the ships collided

Engine fail to start


Investigation analysis

Main cause of the collision was the engines failure.

The personnel of the engine room were not aware of the emergency procedures when the engine fails to start. Internal poor communications led to the delay of the relay of the engines problem from the officer on bridge to the superintendent;

Superintendent had conducted 8 consecutive STS operations. Fatigue may have affected him adversely.


Lessons learnt

Unmooring procedure has many navigational hazards that must be very carefully examined.

Communication between MCR-Bridge, and Bridge-superintendent is vital to avoid difficult situations.

Training of crew for emergency procedures is very important. Exercises should be conducted prior STS.

The long-time duration of STS transfer procedures in combination with the consecutive operations may adverse superintendent’s ability and alertness (human fatigue).

CONCLUSIONS


IMO resolution MEPC 186(59)/2009 gives to tanker vessels the full operational responsibility of an STS transfer operation.

amendment of the respective IMO resolution so to conclude gas and chemical products.

The law allows masters to perform as superintendents. It seems appropriate to keep the two roles separated and not to cause additional problems with aforementioned combination.

The factor of human fatigue seems to be determinant in the occurrence and escalation of accidents.

CONCLUSIONS


Use of tugs; if tugs are not available then mooring and unmooring is better to happen underway.

The success of an STS transfer operation is based on the experience of the POAC/superintendent and the masters as well as on the good training of the personnel involved.

Guides and practices are to be revised and amended taking into account the lessons learned from the recorded accidents.

THANK U!!

D.I. Stavrou, N. P. Ventikos.

STS transfer operation between three ships underway at Skagen reef in Denmark

SHIP TO SHIP (STS) TRANSFER OF CARGO: LATEST DEVELOPMENTS AND OPERATIONAL RISK ASSESSMENT

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