ABS Guide for Access to Tanks and Holds for Inspection

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Guide for Means of Access to Tanks and Holds for Inspection

GUIDE FOR

MEANS OF ACCESS TO TANKS AND HOLDSFOR INSPECTION

MARCH 2007 (Updated February 2009 see next page)

American Bureau of ShippingIncorporated by Act of Legislature ofthe State of New York 1862

Copyright 2007American Bureau of ShippingABS Plaza16855 Northchase DriveHouston, TX 77060 USA


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Updates

February 2009 consolidation includes:

June 2007 version plus Corrigenda/Editorials

June 2007 consolidation includes:

March 2007 version plus Corrigenda/Editorials


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ABS GUIDE FOR MEANS OF ACCESS TO TANKS AND HOLDS FOR INSPECTION . 2007 iii

Foreword

Background

The maritime industry has long recognized that periodic surveys/inspections are the primary meansfor ensuring that a vessels structure is maintained within applicable requirements throughout itsoperational life. These surveys/inspections help ensure that the vessel is free from damage such ascracks, buckling, corrosion and overloading, and that material thickness are within established limits.For surveys/inspections to be carried out effectively, suitable means of access to the vessels structureare required.

To address the issue of suitable access, the Maritime Safety Committee (MSC) adopted the followingresolutions into SOLAS Regulation II-1/3-6 on Access to and within spaces in the cargo area of oiltankers and bulk carriers:

MSC.151(78) Adoption of Amendments to the International Convention for the Safety Of Life

At Sea, 1974, and MSC.158(78) Adoption of Amendments to the Technical Provisions for Means of Access for

Inspections.

To assist in the implementation of these new IMO resolutions, the International Association ofClassification Societies (IACS) developed the Unified Interpretation (UI) SC 191, for the applicationof amended SOLAS Regulation II-1/3-6 (Resolution MSC.151(78)) and revised Technical Provisionsfor Means of Access for Inspections (Resolution MSC.158(78)).

Application

The vessel types and sizes listed below, if constructed on/after 1 January 2006 are required to comply

with SOLAS Regulation II-1/3-6 and Resolutions MSC.151(78) and MSC.158(78): Oil tankers of 500 gross tonnage

Bulk carriers (as defined in SOLAS regulation IX/1) of 20,000 gross tonnage and over.

ScopeIn support of the Statutory and IACS guidance, ABS has prepared the Guide for Means of Access toTanks and Holds for Inspection. This Guide provides graphical illustrations and additional textualclarification of the means of access requirements. The goal is to improve the comprehension andapplication of the Statutory and IACS guidance.

This Guide presents two (2) levels of means of access guidance. The first provides the base criteria to

meet the IMO requirements. The second, and preferred , level of guidance incorporates the applicationof current ergonomics practices to the means of access requirements. The application of ergonomicsto the means of access requirements will enhance levels of safety as well as quality of work by

providing appropriate access for survey, inspection and maintenance activities for tanks and holds.

This Guide also presents the process to obtain ABS approval for the use of alternative materials forthe construction of means of access as presented in MSC.151(78), MSC.158(78) and SOLAS RegulationII-1/3-6.

Associated Notations

This Guide offers two optional notations related to means of access, PMA and PMA+ . The PMA notation is awarded for compliance with all IMO permanent means of access requirements. The PMA+

notation is awarded for compliance with the enhanced ergonomic level of means of access guidancecontained in this Guide.


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ABS GUIDE FOR MEANS OF ACCESS TO TANKS AND HOLDS FOR INSPECTION . 2007 v

Table of Contents

GUIDE FOR

MEANS OF ACCESS TO TANKS AND HOLDS FORINSPECTION

CONTENTSSECTION 1 Introduction .......................... .............................. .................... 1

1 Introduction ............................................................................ 1 2 Application ............................................................................. 1

3 Scope..................................................................................... 2

4 Notations................................................................................ 2 4.1 PMA Notation.................................................................... 2

4.2 PMA+ Notation.................................................................. 2

5 PMA+ Notation....................................................................... 3 5.1 Overview............................................................. .............. 3

5.2 Example of the Application of the PMA+ Notation ............ 3

5.3 Examples of PMA+ Notation Opportunities....................... 3

5.4 IMO Means of Access Requirements verses ErgonomicPractices ............................................................ ............... 4

6 Surveys after Construction .................................................... 6 6.1 Annual Surveys........... ...................................................... 6

6.2 Intermediate Survey .......................................................... 6

6.3 Special Periodical Surveys................................................ 6

6.4 Requirements for Vessel Alterations ................................. 7

7 Units of Measure.................................................................... 7

SECTION 2 Means of Access Requirements and Interpretations ......... 9

1 Introduction ............................................................................ 9 2 Associated Documentation .................................................... 9

3 Overview of Means of Access Requirements...................... 10

4 Specific Means of Access Requirements for OilTankers................................................................................ 11 4.1 Means of Access Requirements for Table 1/1.1 of

MSC.158(78) for Oil Tankers (Tanks with a Height> 6 m and Containing Internal Structures)....................... 12

4.2 Means of Access Requirements for Table 1/1.1.1 ofMSC.158(78) for Oil Tankers (Tanks with a Height> 6 m and Containing Internal Structures)....................... 13



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4.5 Means of Access Requirements for Table 1/1.1.4 ofMSC.158(78) for Oil Tankers (Tanks with a Height

> 6 m and Containing Internal Structures)....................... 16 4.6 Means of Access Requirements for Table 1/1.1.5 of

MSC.158(78) for Oil Tankers (Tanks with a Height> 6 m and Containing Internal Structures)....................... 17


4.8 Means of Access Requirements for Table 1/1.2 ofMSC.158(78) for Oil Tankers (Tanks with a Height< 6 m) .............................................................. ................ 18

4.9 Means of Access Requirements for Table 1/1.3 ofMSC.158(78) for Oil Tankers (Fore Peak Tanks) ............ 18

4.10 Means of Access Requirements for Table 1/1.3.1 ofMSC.158(78) for Oil Tankers (Fore Peak Tanks) ............. 19

4.11 Means of Access Requirements for Table 1/1.3.2 ofMSC.158(78) for Oil Tankers (Fore Peak Tanks) ............. 19

4.12 Means of Access Requirements for Table 1/ 2.1 ofMSC.158(78) for Oil Tankers (Water Ballast WingTanks 5 m Width Forming Double Side Spacesand their Bilge Hopper Sections)..................................... 19

4.13 Means of Access Requirements for Table 1/2.1.1 ofMSC.158(78) for Oil Tankers (Double Side Spaces< 5 m in Width Above the Upper Knuckle Point ofthe Bilge Hopper Sections).............................................. 20

4.14 Means of Access Requirements for Table 1/2.1.2 of

MSC.158(78) for Oil Tankers (Continuous LongitudinalMeans of Access)............................................................ 21

4.15 Means of Access Requirements for Table 1/2.1.3 ofMSC.158(78) for Oil Tankers (Continuous LongitudinalMeans of Access)............................................................ 21

4.16 Means of Access Requirements for Table 1/2.2 ofMSC.158(78) for Oil Tankers (Access for Distances 6 m from the Tank Bottom to the Upper KnucklePoint)............................................................................... 22

4.17 Means of Access Requirements for Table 1/2.2.1 ofMSC.158(78) for Oil Tankers (Continuous LongitudinalMeans of Access)............................................................ 23

4.18 Means of Access Requirements for Table 1/2.2.2 of

MSC.158(78) for Oil Tankers (Continuous LongitudinalMeans of Access)............................................................ 24

4.19 Means of Access Requirements for Table 1/2.3 ofMSC.158(78) for Oil Tankers (Access for Distances< 6 m from the Tank Bottom to the Upper KnucklePoint)............................................................................... 25

5 Specific Means of Access Requirements for Bulk Carriers . 26 5.1 Means of Access Requirement for Table 2/1.1 of

MSC.158(78) for Bulk Carriers (Cargo Holds Access to Underdeck Structure)...................................... 27

5.2 Means of Access Requirement for Table 2/1.2 ofMSC.158(78) for Bulk Carriers (Cargo Holds

Access to Underdeck Structures).. .................................. 28


Access to Underdeck Structure)...................................... 29


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ABS GUIDE FOR MEANS OF ACCESS TO TANKS AND HOLDS FOR INSPECTION . 2007 vii


Access to Underdeck Structure)...................................... 29


Access to Underdeck Structure)...................................... 29 5.6 Means of Access Requirement for Table 2/1.6 of

MSC.158(78) for Bulk Carriers (Cargo Holds Access to Vertical Structures) ......................................... 30


Access to Vertical Structures) ......................................... 31









5.12 Means of Access Requirement for Table 2/2.1 ofMSC.158(78) for Bulk Carriers (Ballast Tanks Top Side Tanks).............................................................. 33




5.16 Means of Access Requirement for Table 2/2.5 ofMSC.158(78) for Bulk Carriers (Ballast Tanks Bilge Hopper Tanks) ....................................................... 36

5.17 Means of Access Requirement for Table 2/2.5.1 ofMSC.158(78) for Bulk Carriers (Ballast Tanks Bilge Hopper Tanks) ....................................................... 37

5.18 Means of Access Requirement for Table 2/2.5.2 of

MSC.158(78) for Bulk Carriers (Ballast Tanks Bilge Hopper Tanks) ....................................................... 38

5.19 Means of Access Requirement for Table 2/2.5.3 ofMSC.158(78) for Bulk Carriers (Ballast Tanks Bilge Hopper Tanks) ....................................................... 39



5.22 Means of Access Requirement for Table 2/2.8 ofMSC.158(78) for Bulk Carriers (Ballast Tanks

Bilge Hopper Tanks Double-skin Side Tanks).............. 40


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5.23 Means of Access Requirement for Table 2/2.9 ofMSC.158(78) for Bulk Carriers (Ballast Tanks Fore Peak Tanks)............................................................ 41

5.24 Means of Access Requirement for Table 2/2.9.1 ofMSC.158(78) for Bulk Carriers (Ballast Tanks

Fore Peak Tanks)............................................................ 41 5.25 Means of Access Requirement for Table 2/2.9.2 of

MSC.158(78) for Bulk Carriers (Ballast Tanks Fore Peak Tanks)............................................................ 41

TABLE 1 Application of Resolution MSC.158(78) Table 1 forOil Tankers................................................................. 10

TABLE 2 Application of Resolution MSC.158(78) Table 2 forBulk Carriers .............................................................. 11

FIGURE 1 Access at Transverse Bulkhead on Stiffened Side

of an Underdeck Structure for Ballast/Cargo Tanks 6 meters in Height................................................... 13

FIGURE 2 Continuous Longitudinal Access on Each Sideof the Tank of the Underdeck Structure forBallast/Cargo Tanks 6 meters in Height ................. 14

FIGURE 3 Integrated Continuous Longitudinal Access of aLongitudinal Bulkhead of Cargo Tanks or Holds ....... 16

FIGURE 4 Access for Cross-ties 6 m Above the TankBottom of Cargo Tanks or Holds................................ 17

FIGURE 5 Access Where the Vertical Distance Between theHorizontal Uppermost Stringer and Deck Hold is 6 m .......................................................................... 20

FIGURE 6 Access for Bilge Hopper Sections Where theVertical Distance from the Tank Bottom tothe Upper Knuckle Point is 6 m............................... 22

FIGURE 7 Access for Bilge Hopper Tank ................................... 23

FIGURE 8 Alternative Means of Access...................................... 24

FIGURE 9 Access for Vertical Distances < 6 m from the TankBottom to the Upper Knuckle Point........................... 25

FIGURE 10 Access to Underdeck Structures 17 m in Height .... 27

FIGURE 11 Athwartship Access Fitted on the TransverseBulkhead 17 m in Height......................................... 28

FIGURE 12 Bulk Carriers Having Transverse Bulkheads withFull Upper Stools 17 m in Height ............................ 30

FIGURE 13 Upper Topside Tank Access with a Height > 6 m...... 33

FIGURE 14 Transverse Web Access for Bulk Carriers................. 34

FIGURE 15 Bilge Hopper Tank Access with a Height 6 m......... 36

FIGURE 16 Access Ladder between the LongitudinalContinuous Means of Access and theBottom of the Space .................................................. 37

FIGURE 17 Alternate Bilge Hopper Tank Access with a Height 6 m .......................................................................... 38

FIGURE 18 Access for Foremost and Aftmost Bilge HopperTanks ......................................................................... 39


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FIGURE 7 Ladders with Climber Safety Rails or Cables ............ 60

FIGURE 8 Individual Rung Ladder Design.................................. 61

FIGURE 9 Inclined Ladders......................................................... 63

FIGURE 10 Inclined Ladders with Landings.................................. 64

FIGURE 11 Inclined Ladder Landing/Platform .............................. 65

FIGURE 12 Handle Dimensions.................................................... 66

FIGURE 13 Handle Placement (Ladder not Extending ThroughPlatform)..................................................................... 67

FIGURE 14 Handle Placement (Stepping Through a VerticalHatch)......................................................................... 68

FIGURE 15 Handle Placement (Stepping to or from a VerticalLadder)....................................................................... 69

SECTION 5 Hatches.............................. ............................. ...................... 71

1 General ................................................................................ 71 2 General Principles................................................................ 71

3 Hatch Design ....................................................................... 71

4 Hatch Access ....................................................................... 73

FIGURE 1 Hatch Design.............................................................. 72

FIGURE 2 Hatch Design (Alternative Arrangement) ................... 73

FIGURE 3 Ladder Distance from Hatch Coaming....................... 74

FIGURE 4 Access Hatch Heights of 900 mm (35.5 in.) ........... 74

SECTION 6 Alternative Means of Access ............................ .................. 75 1 General ................................................................................ 75

1.1 Definitions........................................................................ 75

2 Application ........................................................................... 75

3 Associated Documentation .................................................. 76

4 Guidance for Alternative Means of Access.......................... 76 4.1 Portable Ladders ....................................................... ...... 76

4.2 Hydraulic Arm Vehicles ................................................... 78

4.3 Wire Lift Platform...... ....................................................... 79

4.4 Portable Platforms ........................................................... 80 4.5 Scaffolding and Staging .................................................. 81

4.6 Rafting............................................................................. 82

4.7 Remotely Operated Vehicle (ROV) ................................. 84

SECTION 7 Alternative Material Selections......... .............................. .... 85 1 General ................................................................................ 85

1.1 Definitions........................................................................ 85

2 Applicability .......................................................................... 85

3 Alternative Materials ............................................................ 86


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4 Material Characteristics ....................................................... 86 4.1 Material Properties Data ................................................. 86

4.2 Coating Specification ...................................................... 86

4.3 Method of Attachment ..................................................... 86

4.4 Environmental Variables ................................................. 86 5 Approval Process................................................................. 87

FIGURE 1 Equivalent or Alternative Materials ApprovalProcess ...................................................................... 87

APPENDIX 1 References......................... .............................. ..................... 89

APPENDIX 2 Acronyms and Abbreviations ............................... .............. 91


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ABS GUIDE FOR MEANS OF ACCESS TO TANKS AND HOLDS FOR INSPECTION . 2007 1

Section 1: Introduction

S E C T I O N 1 Introduction

1 Introduction

The ability to survey/inspect the condition of a vessel is a principal means to help verify that the vesselsstructure is maintained to comply with applicable requirements. These surveys/inspections assistOwners; Flag Administrations and classification societies in determining that vessels are free fromdamage and that material thickness are within established limits. For surveys/inspections to be carried

out safely and effectively, suitable means of access to the vessels structure is required.The most recent adoptions to IMO legislation (SOLAS Reg. II-1/3-6) have established new requirementsfor means of access. Throughout the life of a vessel, this access enables overall and close-up inspectionsand material thickness measurements of the vessels structures. These means of access may be used

by Flag Administrations, classification societies, vessel personnel and others as necessary.

To assist in the implementation of these new requirements, IACS has developed Unified Interpretation(UI) SC 191 for the application of amended SOLAS regulation II-1/3-6 (resolution MSC.151 (78))and revised Technical provisions for means of access for inspections (resolution MSC.158 (78)). Insupport of this document, ABS has prepared the Guide for Means of Access to Tanks and Holds for

Inspection . This Guide provides additional information, via text and graphics, about the means of accessrequirements interpretation and application, as well as the criteria for the PMA and PMA+ notations.

2 Application

The means of access requirements in SOLAS and in this Guide apply to:

Oil tankers of 500 gross tonnage and over constructed on or after 1 January 2006. This regulationis only applicable to oil tankers having tanks integral with the structure of the vessel which areused for carriage of oil in bulk, which is contained in the definition of oil in Annex 1 of MARPOL73/78. Independent oil tanks can be excluded.

Bulk carriers (as defined in SOLAS regulation IX/1) of 20,000 gross tonnage and over, constructedon or after 1 January 2006. SOLAS Regulation IX/1 defines a bulk carrier as a ship which is

constructed generally with single deck, topside tanks and hopper side tanks in cargo spaces, and isintended primarily to carry dry cargo in bulk, and includes such types as ore carriers and combinationcarriers.

Note: Oil tankers of 500 gross tonnage and over constructed on or after 1 October 1994 but before 1 January 2005 shallcomply with the provisions of regulation II-1/12-2 adopted by resolution MSC.27(61). Also, for oil tankers of lessthan 5,000 tonnes deadweight, Administrations may approve, in special circumstances, smaller dimensions foraccess through vertical and horizontal openings, if the ability to traverse such openings or to remove an injured

person can be proved to the satisfaction of the Administration.


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Section 1 Introduction

2 ABS GUIDE FOR MEANS OF ACCESS TO TANKS AND HOLDS FOR INSPECTION . 2007

3 Scope

To enable physical surveys, inspections, and maintenance activities to be conducted effectively,

consideration needs to be given to how the vessel will be designed, in particular, means of accessarrangements. The effectiveness of the design of means of access can be maximized, as illustrated inthis Guide, through the application of ergonomics to the vessels structural designs and arrangements.

This Guide presents two (2) levels of means of access guidance. The first level provides the basecriteria to meet the IMO requirements. The second, and preferred , level of guidance incorporates theapplication of ergonomics to the IMO means of access requirements.

This Guide also presents the process to obtain ABS approval for the use of alternative materials,equivalent in strength and stiffness to steel, for the construction of means of access as allowed for inMSC.151 (78) and MSC.158 (78).

This Guide overlaps, in several areas, with an existing ABS document called the ABS Guidance Notes for the Application of Ergonomics to Marine Systems , which addresses design and layout considerationsfor human-system interfaces at the individual task and workstation levels. This includes physical and

perceptual issues for the design of the personnel interface with controls, displays, alarms, video-displayunits, labeling, and workspace access and workspace arrangement. These Guidance Notes are anexcellent and highly recommended companion document to further promote the application andunderstanding of ergonomics principles to vessel designs.

The application of ergonomics to the means of access requirements can improve overall personnel performance and safety, while reducing the potential for human error.

4 Notations

This Guide offers two optional notations related to means of access, PMA and PMA+ . The PMA notation is awarded for compliance with all IMO permanent means of access requirements. The PMA+ notation is awarded for compliance to the enhanced ergonomic level of means of access guidancecontained in this Guide.

4.1 PMA Notation

The optional PMA notation will be assigned to vessels to signify that the vessels permanent means ofaccess meets the following:

IMO Resolution MSC.151(78) Adoption of Amendments to the International Convention forthe Safety Of Life At Sea, 1974

IMO Resolution MSC.158(78) Adoption of Amendments to the Technical Provisions forMeans of Access for Inspections

IACS Unified Interpretation (UI) SC 191 for the application of amended SOLAS regulationII-1/3-6 (resolution MSC.151 (78)) and revised Technical provisions for means of access forinspections (resolution MSC.158 (78))

Note: The PMA notation does not include IMO requirements for alternative or temporary means of access.

4.2 PMA+ Notation

The optional PMA+ notation will be assigned to vessels meeting the PMA notation requirements plus the additional ergonomic considerations presented in this Guide. The PMA+ notation is discussed inmore detail in the following Subsection.


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5 PMA+ Notation

5.1 Overview

The PMA+ notation applies ergonomics and safety design practices to the design and arrangement ofthe permanent means of access requirements where allowable. These instances include those areaswhere the means of access requirements have prescribed minimums and/or maximums and a preferredergonomic dimension exists within the allowable range. For those means of access requirements whereno specific dimensioning is provided, ergonomic guidance and dimensioning is provided.

Note: If any PMA+ requirements are found to conflict with MSC requirements or IACS interpretations, the MSC requirementsor IACS interpretations take precedence.

5.2 Example of the Application of the PMA+ Notation

For tankers, IMO states Continuous athwartship permanent access arranged at each transverse bulkheadon the stiffened surface, at a minimum of 1.6 m to a maximum of 3 m below the deck head . This 1.6 m

(63.0 in.) minimum is below current ergonomic practices, which is a minimum of 1975 mm (78.0 in.)with a preferred clearance height of 2030 mm (80 in.).

The minimum overhead clearance of 1600 mm (63.0 in.) is approximately 117 mm (4.5 in.) less thanthe mean male stature (height) presented in Appendix 1, Figure 1, Differences in 50 th Percentile MaleStature for 12 Regions, from the Average Stature of 1717 mm (67.6 in.) of the ABS Guidance Notes

for the Application of Ergonomics to Marine Systems . Also, this mean value does not include clothingallowances of approximately 25 mm (1.0 in.) for footwear and 75 mm (3.0 in.) for safety helmets. Bycombining these two clothing allowances to the mean stature we have an average male height of 1817 mm(71.5 in.). This value is approximately 220 mm (8.5 in.) higher than the IMO minimum height.

For a large majority of personnel this 1600 mm (63.0 in.) minimum would increase the likelihood ofhead strikes against overhead surfaces, potentially causing head and neck injuries as well as causing

personnel to work/walk in awkward postures causing potential upper and lower back pain, discomfortor injury.

The current ergonomic practice of a 1975 mm (78.75 in.) minimum overhead clearance will allow thevast majority of personnel to work upright without the potential for head strikes against upper surfacesor from working in awkward postures.

The way IMO states the overhead clearances, from a minimum of 1.6 m to a maximum of 3 m providesdesigners the opportunity to use the PMA+ requirement of 1975 mm (78.0 in.) [Preferably 2030 mm(80.0 in.)] as a design requirement.

5.3 Examples of PMA+ Notation Opportunities

The majority of the dimensional aspects of the means of access requirements are stated in a mannerthat provides the designer with some latitude with respect to dimensioning. Several examples include:

The minimum clear opening shall not be less than 600 mm 600 mm which means that the clearopening can be greater than the dimension specified.

Elevated passageways forming sections of a permanent means of access, where fitted, shall havea minimum clear width of 600 mm which means the passageway can have a greater clear width.

Stanchions shall be not more than 3 m apart this establishes a maximum distance only. A shorterdimension is allowed.

Permanent inclined ladders shall be inclined at an angle of less than 70 degrees which meansthat inclined ladders cannot exceed 70 degrees, but inclined ladders can be at less of an angle.

Additionally, there are instances where no dimensional aspects of the means of access requirementsare provided.


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Inclined ladders shall be provided with handrails of substantial construction on both sides fittedat a convenient distance above the treads No dimensional requirements are provided for thesize of the handrail or the handrails height above the tread or any intermediate rails.

5.4 IMO Means of Access Requirements verses Ergonomic PracticesThere are other instances of IMO means of access requirements, which could be enhanced through theapplication of ergonomic practices, but cannot because the specific wording of the IMO means ofaccess requirements prohibits any modification of these requirements. These instances include thedesign of guardrail heights, openings in horizontal stringers, and the tread design and spacing ofinclined ladders. These are discussed in more detail in the following Subparagraphs.

Note: The discussion in the following Subparagraphs (1/4.4.1, Guardrail Heights, 1/5.4.2 , Openings in HorizontalStringers, 1/5.4.3 , Tread Spacing (Inclined Ladders) and 1/5.4.4 , Tread Design (Inclined Ladders)) are notPMA+ requirements. These Subparagraphs discuss examples of where ergonomics practices should be applied butcannot due to the specific wording of the IMO means of access requirements.

5.4.1 Guardrail Heights

MSC.158 (78), Technical Provisions 3.3, requirement states that Guardrails shall be 1,000 mmin height and consist of a rail and an intermediate bar 500 mm in height and of substantialconstruction... This specific wording allows no opportunity to apply ergonomic principles tothe design of guardrails.

From an ergonomics and safety perspective a guardrails height should be 1070 mm (42.0 in.).The rational for this change in guardrail height is based on the biomechanics (including centerof gravity) of a worker leaning or falling over a guardrail. Biomechanical analyses show thatthe center of gravity of a human body is approximately 75 mm (3.0 in.) above the midpoint ofa persons stature (the center of gravity varies slightly among individuals and genders).

Biomechanical analyses also show that if the center of gravity of a human body acts above aguardrail, a person falling against the rail would have a higher tendency to rotate over the top of the railing. Additionally, if the center of gravity of a human body acts below the top of arail, a person would have a tendency to rotate under the railing. This action (rotating under)along with intermediate rail(s) will help prevent a fall to a lower surface.

To illustrate this point, a person 1830 mm (72.0 in.) tall would have a center of gravity ofapproximately 1000 mm (39.0 in.). This means that persons with a stature greater than 1830 mm(72.0 in.), including footwear, would have a higher likelihood of rotating over the top of a1000 mm (39 in.) guardrail than a 1070 mm (42.0 in.) guardrail.

The requirement for a guardrail height of 1000 mm (39.0 in.) is more effective for personnelless than 1830 mm (72.0 in.) tall (including footwear), leaving those workers who are taller ata safety disadvantage. Current ergonomics design practices for the height of guardrails take

into consideration taller potential workers (up to 1975 mm (78.0 in.) in height). When consideringthe taller potential worker population, a guardrail height of 1070 mm (42.0 in.) will help protect approximately 99% of all workers.

5.4.2 Openings in Horizontal StringersMSC.158 (78) Table 1 requirement 2.3, To facilitate the operation of the alternativemeans of access, in-line openings in horizontal stringers shall be provided From a personnelsafety perspective, openings in stringers should not be in-line with each other.

The use of in-line openings allows the potential for a worker who falls through one opening,to fall through the in-line openings on lower stringer levels, possibly even to the bottom of thetank or hold. Current safety practices discourage the use of in-line openings. Staggering the

openings as depicted in the following figure is a preferred design alternative.


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6 Surveys after Construction

Surveys after construction of the means of access are to be in conjunction with, or prior to, HullClassification Surveys.

6.1 Annual Surveys

In order to maintain the PMA or PMA+ notation, an Annual Survey shall be made within three (3)months before or after each annual anniversary date of the crediting of the previous Special PeriodicalSurvey or original construction date. The following information shall be reviewed by the attendingABS Surveyor for issues that could impact the PMA or PMA+ notation.

i) Vessels log book since previous hull survey or date of build

ii) Hull maintenance records since previous hull survey or date of build

iii) Repair and damage reports since previous hull survey or date of build

iv) Previous hull classification reports

v) Approved copy of the Ships Structure Access Manual

vi) A list of all means of access alterations/repairs to the vessel since the previous hull survey ordate of build

vii) General condition of means of access as accessible in any tanks that are internally examinedas part of the applicable annual survey

The attending Surveyor will review the above information to determine if any changes or alterationshave been made that could affect the PMA or PMA+ notation. As a result, the details of any modificationor alterations may need to be submitted for review and approval to one of the ABS Technical Offices.

6.2 Intermediate Survey

In order to maintain the PMA or PMA+ notation, an Intermediate Survey shall be completed either ator between the second and third Annual Surveys after Special Periodical Survey No. 1 and subsequentSpecial Periodical Surveys.

In addition to the requirements of the Annual Survey, means of access are to be surveyed as part ofthe Intermediate Survey Hull, as follows:

Examination of means of access in all tanks that are examined internally as part of the intermediatehull survey.

6.3 Special Periodical Surveys

In order to maintain the PMA or PMA+ notation, a Special Periodical Survey shall be completedwithin five (5) years after the date of build or after the crediting date of the previous Special PeriodicalSurvey. A Special Periodical Survey will be credited as of the completion date of the survey but notlater than five (5) years from date of build or from the date recorded for the previous Special PeriodicalSurvey. If the Special Periodical Survey is completed within three (3) months prior to the due date, theSpecial Periodical Survey will be credited to agree with the effective due date. The Special PeriodicalSurvey may be commenced fifteen (15) months prior to the due date and be continued with completion

by the due date.

6.3.1 Special Periodical SurveysIn addition to the requirements of the Annual Survey, means of access are to be surveyed as

part of the Special Periodical Survey Hull, as follows:

Examination of all means of access in all tanks.


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Section 2: Means of Access Requirements and Interpretations

S E C T I O N 2 Means of Access Requirementsand Interpretations

1 Introduction

This Section presents the means of access requirements set forth in MSC Resolution MSC.151(78),MSC Resolution MSC.158(78), and the associated IACS Unified Interpretations.

Subsection 2/3, Overview of Means of Access Requirements presents a summary of the IMOrequirements in tabular form. Subsection 2/4, Specific Means of Access Requirements for Oil Tankersand Subsection 2/5, Specific Means of Access Requirements for Bulk Carriers present the actualrequirements and interpretations contained in the MSC and the IACS documentation.

Where appropriate, additional guidance, via text and graphics, has been provided to further promotethe interpretation and application of the means of access requirements.

2 Associated Documentation

The following documents provide specific details about the IMO requirements for means of access

contained in this Section: SOLAS regulation II-1/3-6, Access to and Within Spaces in, and Forward of, the Cargo Area of

Oil Tankers and Bulk Carriers

MSC Resolution MSC.151 (78) (adopted on 20 May 2004), Adoption of Amendments to theInternational Convention for the Safety of Life at Sea, 1974, as amended

MSC Resolution MSC. 158 (78) (adopted 20 May 2004), Amendments to the Technical Provisionsfor Means of Access for Inspections

IACS Unified Interpretation (UI) SC 191 for the application of amended SOLAS regulationII-1/3-6 (resolution MSC.151 (78)) and revised Technical provisions for means of access forinspections (resolution MSC.158 (78))

Note: There have been several recent revisions to IACS Unified Interpretation (UI) SC 191. The information containedin this document is current as of Revision 3 from March 2006. It is the responsibility of the reader to check if therehave been any revisions since March 2006. If so, the revised UI SC 191 should be used in conjunction with thisGuide.


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Section 2 Mean of Access Requirements and Interpretations


3 Overview of Means of Access Requirements

This Subsection summarizes the means of access requirements for oil tankers and bulk carriers as

presented in MSC.158(78).The following two (2) tables, Section 2, Table 1 Application of Resolution MSC.158(78) Table 1 forOil Tankers and Section 2, Table 2, Application of Resolution MSC.158(78) Table 2 for Bulk Carrierswere created to simplify the use and application of the extensive tables containing the MSC means ofaccess requirements.

These tables are arranged with column and row headings for different areas of vessel tanks andholds/spaces as well as tank or hold/space dimensions (heights and widths). This format allows for thequick identification of means of access requirements.

To reduce potential confusion for users of this Guide who may already be familiar with the MSC.158(78)tables, the requirements contained in this Guides Section 2, Table 1 summarize the requirementscontained in the MSC.158(78) Table 1. This Guides Section 2, Table 2 summarizes the requirementscontained in the MSC.158(78) Table 2.

To further simplify the use of these tables, the numbering scheme used in the MSC tables has been preserved. For example, in Section 2, Table 1, in the Underdeck Structure row, tanks with a height of6 meters or more are required to meet MSC.158(78) Table 1 requirements of 1.1.1, 1.1.2, and 1.1.3.The same rational has been applied to MSC.158(78) Table 2.

TABLE 1Application of Resolution MSC.158(78) Table 1 for Oil Tankers*

Cargo/Ballast Tanks Tank Height

6 m Tank Height < 6 mUnderdeck Structure 1.1.1, 1.1.2, 1.1.3

Longitudinal Bulkhead 1.1.4 or 1.1.6 +

Cross Tie ( 6 m above tank bottom) 1.1.5

1.2

Tank/Space Width < 5 m Ballast Tank and Double Side Skin Space Tank/Space Width

5 m Height 6 m Height < 6 m

Wall-sided Mid-Depth Portion(Between Topside and Hopper Portions) 2.1 Not Applicable

Lower Hopper Portion/Tank

1.1.4 or 1.1.6 +

1.1.5 2.2 2.3

Fore Peak Tanks 1.3 1.3

* = Numbers in this table correspond to MSC.158 (78) Table 1, Means of Access for Ballast/Cargo Tanks of Oil Tankers.

+ = If Height < 17 m


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TABLE 2Application of Resolution MSC.158(78) Table 2 for Bulk Carriers*

Cargo Holds Hold Height 17 m Hold Height < 17 m

Underdeck Structure 1.1, 1.2, 1.3, 1.4 1.5

Side Shell 1.6 + or 1.8, 1.7, 1.9 +, 1.10 +

Vertical Bulkhead 1.7 Not Applicable

Ballast and Double Side Skin Spaces Tank/Space Height 6 m Tank/Space Height < 6 m

Wall-sided Mid-Depth Portion(Between Topside and Hopper Portions) 2.8 2.8

Upper Topside Tank 2.1, 2.2, 2.3 2.4

Lower Hopper Portion/Tank 2.5 and 2.6 2.7


* = Numbers in this table correspond to MSC.158 (78) Table 2, Means of Access for Bulk Carriers.+

= Single side skin construction only.

4 Specific Means of Access Requirements for Oil Tankers

The specific means of access requirements for oil tankers displayed in Section 2, Table 1 Applicationof Resolution MSC.158(78) Table 1 for Oil Tankers, as interpreted by IACS UI SC 191, are presentedin this Subsection.

Note: Those requirements that relate to permanent means of access are prerequisites for the PMA notation. The PMA notation does not include the IMO requirements or allowances for alternative or temporary means of access.

Each MSC requirement is presented in its entirety along with any associated IACS unified interpretation.Graphical representations for some of the means of access requirements have been provided to helpclarify or demonstrate the requirements intent. Also, additional guidance related to the design of themeans of access is provided.

Note: Graphics are for demonstrative purposes only and are not to scale.

In some of the figures, specific dimensions are provided. These dimensions will help clarify the meansof access requirement and/or the interpretation. Where appropriate, IMO, PMA and PMA+ dimensional requirements are provided. These dimensions are to be used in conjunction with the additional guidancecontained in the following Sections:

Section 3, Walkways, Ramps and Work Platforms,

Section 4, Vertical Ladders, Inclined Ladders and Handles, and Section 5, Hatches.


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4.1 Means of Access Requirements for Table 1/1.1 of MSC.158(78) for Oil Tankers(Tanks with a Height > 6 m and Containing Internal Structures)

Means of Access Requirements for Table 1/1.1 of MSC.158(78) for Oil Tankers

Means ofAccess

Requirement

For tanks of which the height is 6 m and over containing internal structures, permanent means of access shall be provided in accordance with .1 to .6:

PMA Requirement

IACSInterpretation

Sub-paragraphs .1, .2 and .3 define access to underdeck structure, accessto the uppermost sections of transverse webs and connection betweenthese structures.

Sub-paragraphs .4, .5 and .6 define access to vertical structures only andare linked to the presence of transverse webs on longitudinal bulkheads.

If there are no underdeck structures (deck longitudinals and decktransverses) but there are vertical structures in the cargo tank supportingtransverse and longitudinal bulkheads, access in accordance with sub-

paragraphs from .1 through to .6 is to be provided for inspection of theupper parts of vertical structure on transverse and longitudinal bulkheads.

If there is no structure in the cargo tank, section 1.1 of Table 1 is not to beapplied.

Section 1 of Table 1 is also to be applied to void spaces in cargo area,comparable in volume to spaces covered by the regulation II-1/3-6, exceptthose spaces covered by Section 2.

The vertical distance below the overhead structure is to be measured fromthe underside of the main deck plating to the top of the platform of themeans of access at a given location.

The height of the tank is to be measured at each tank. For a tank the heightof which varies at different bays, item 1.1 is to be applied to such bays ofa tank that have height 6 m and over.

PMA + Requirement No additional PMA+ requirements.

Additional Guidance

Detailed walkway design guidance is available in Section 3, Walkwaysand Ramps.

Detailed ladder and handle guidance is available in Section 4, guidanceVertical Ladders, Inclined Ladders, and Handles

Detailed guidance for hatch design is available in Section 5, Hatches.


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4.2 Means of Access Requirements for Table 1/1.1.1 of MSC.158(78) for Oil Tankers(Tanks with a Height > 6 m and Containing Internal Structures)

Means of Access Requirements for Table 1/1.1.1 of MSC.158(78) for Oil Tankers

Continuous athwartship permanent access arranged at each transverse bulkhead onthe stiffened surface, at a minimum of 1.6 m to a maximum of 3 m below the deckhead.

Dimension MSC.158(78) Requirement

Means ofAccess

Requirement

A Distance below deckhead 1600 mm (63.0 in.) and 3 m (10.0 ft) PMA

Requirement

IACSInterpretation

The vertical distance below the overhead structure is to be measured from theunderside of the main deck plating to the top of the platform of the means of accessat a given location.

Dimension PMA+ RequirementPMA+ Requirement

A Distance below deckhead 1975 mm (78.0 in.) and 3 m (10.0 ft)

Additional Guidance

Section 2, Figure 1, Access at Transverse Bulkhead on Stiffened Side of anUnderdeck Structure for Ballast/Cargo Tanks 6 meters in Height is

provided to help illustrate this requirement. Detailed walkway design guidance is available in Subsection 3/2, Walkways

and Ramps.

Continuous athwartship PMA is usually arranged at the same level as integratedstructural members (horizontal girders).

FIGURE 1Access at Transverse Bulkhead on Stiffened Side of an Underdeck

Structure for Ballast/Cargo Tanks 6 meters in Height

A


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Means ofAccess

Requirement

Continuous longitudinal permanent means of access which are integrated in the structural memberon the stiffened surface of a longitudinal bulkhead, in alignment, where possible, with horizontalgirders of transverse bulkheads are to be provided for access to the transverse webs unless permanentfittings are installed at the uppermost platform for use of alternative means, as defined in

paragraph 3.9 of the Technical provisions, for inspection at intermediate heights.

PMA Requirement

IACSInterpretation

The permanent fittings required to serve alternative means of access such as wire lift platform,that are to be used by crew and Surveyors for inspection shall provide at least an equal levelof safety as the permanent means of access stated by the same paragraph. These means ofaccess shall be carried on board the ship and be readily available for use without filling ofwater in the tank . Therefore, rafting is not acceptable under this provision.

Alternative means of access are to be part of Access Manual, which is to be approved on behalf of the Flag State.


Additional Guidance

Section 2, Figure 3, Integrated Continuous Longitudinal Access of a Longitudinal Bulkheadof Cargo Tanks or Holds, shows two views of this requirement.

Graphic A shows the intent of this requirement.

Graphic B shows an alternative design if permanent fittings (e.g., to accommodate a wirelift platform) are installed at the uppermost platform to obtain access to the vertical web.

Detailed walkway design guidance is available in Subsection 3/2, Walkways and Ramps.

FIGURE 3Integrated Continuous Longitudinal Access of a

Longitudinal Bulkhead of Cargo Tanks or Holds

BA


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Means of Access RequirementAlternative means as defined paragraph 3.9 in the Technical provisions may be providedfor small ships as an alternative to 1.1.4 for cargo oil tanks of which the height is lessthan 17 m.

IACS Interpretation No interpretation provided.


Additional Guidance Additional guidance on the design and selection of alternative means of access is availablein Section 6, Alternative Means of Access.

4.8 Means of Access Requirements for Table 1/1.2 of MSC.158(78) for Oil Tankers(Tanks with a Height < 6 m)


Means of Access RequirementFor tanks of which the height is less than 6 m, alternative means as defined in paragraph3.9 of the Technical provisions or portable means may be utilized in lieu of the permanentmeans of access.



Additional Guidance Additional guidance on the design and selection of alternative means of access is availablein Section 6, Alternative Means of Access.

4.9 Means of Access Requirements for Table 1/1.3 of MSC.158(78) for Oil Tankers(Fore Peak Tanks)


Means ofAccess

Requirement

For fore peak tanks with a depth of 6 m or more at the center line of the collision bulkhead,a suitable means of access shall be provided for access to critical areas such as theunderdeck structure, stringers, collision bulkhead and side shell structure.PMA

RequirementIACS

Interpretation No interpretation provided.


Additional Guidance Detailed walkway design guidance is available in Subsection 3/2, Walkways and

Ramps.

Detailed hatch design guidance is available in Section 5, Hatches.


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4.10 Means of Access Requirements for Table 1/1.3.1 of MSC.158(78) for Oil Tankers(Fore Peak Tanks)


Means ofAccess

Requirement

Stringers of less than 6 m in vertical distance from the deck head or a stringer immediatelyabove are considered to provide suitable access in combination with portable means ofaccess.PMA

RequirementIACS



Additional Guidance

Detailed walkway design guidance is available in Subsection 3/2, Walkways andRamps.

Additional guidance on the design and selection of alternative means of access isavailable in Section 6, Alternative Means of Access.

4.11 Means of Access Requirements for Table 1/1.3.2 of MSC.158(78) for Oil Tankers(Fore Peak Tanks)


Means of Access RequirementIn case the vertical distance between the deck head and stringers, stringers or the loweststringer and the tank bottom is 6 m or more, alternative means of access as defined in

paragraph 3.9 of the Technical provisions shall be provided.



Additional Guidance


Additional guidance on the design and selection of alternative means of access isavailable in Section 6, Alternative Means of Access.

4.12 Means of Access Requirements for Table 1/ 2.1 of MSC.158(78) for Oil Tankers(Water Ballast Wing Tanks 5 m Width Forming Double Side Spaces and theirBilge Hopper Sections)


Means ofAccess

Requirement

For double side spaces above the upper knuckle point of the bilge hopper sections, permanent means of access are to be provided in accordance with .1 to .3:PMA

RequirementIACS

InterpretationSection 2 of Table 1 (The above requirement 4.10 MSC Requirement 1.3.2 (Fore PeakTanks) is also to be applied to wing tanks designed as void spaces.


Additional Guidance Detailed walkway design guidance is available in Subsection 3/2, Walkways and

Ramps.



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4.14 Means of Access Requirements for Table 1/2.1.2 of MSC.158(78) for Oil Tankers(Continuous Longitudinal Means of Access)


Continuous longitudinal permanent means of access, which are integrated in thestructure, at a vertical distance not exceeding 6 m apart.


Means ofAccess

RequirementA Access height 6 m (19.5 ft)

PMA Requirement

IACSInterpretation

This paragraph (2.1.2) is a requirement for access for survey and inspection ofvertical structures on longitudinal bulkheads (transverse webs).

The continuous permanent means of access may be a wide longitudinal, which provides access to critical details on the opposite side by means of platforms asnecessary on web frames. In case the vertical opening of the web is located inway of the open part between the wide longitudinal and the longitudinal on theopposite side, platforms shall be provided on both sides of the web to allowsafe passage through the web. A "reasonable deviation" as noted in TP/1.4, ofnot more than 10% may be applied where the permanent means of access isintegral with the structure itself.


Additional Guidance

Detailed walkway design guidance is available in Subsection 3/2, Walkwaysand Ramps and Subsection 3/3, Platforms.


With the Administrations approval, reasonable deviations may be applied tofacilitate this means of access. IACS UI (SC) 191 has interpreted this to be nomore than 10% for vertical distances exceeding 6 m (19.5 ft).


Means of Access Requirements for Table 1/ 2.1.3 of MSC.158(78) for Oil Tankers

Means ofAccess

Requirement

Plated stringers shall, as far as possible, be in alignment with horizontal girders oftransverse bulkheads.PMA

RequirementIACS



Additional Guidance Detailed walkway design guidance is available in Subsection 3/2, Walkwaysand Ramps.


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Means of Access Requirements for Table 1/2.2.1 of MSC.158(78) for Oil Tankers The longitudinal continuous permanent means of access may be installed at a minimum1.6 m to maximum 3 m from the top of the bilge hopper section. In this case, a platformextending the longitudinal continuous permanent means of access in way of the web framemay be used to access the identified structural critical areas.


A Distance from the top of the bilgehopper 1600 mm (63 in.) and 3 m (10.0 ft)

Means ofAccess

Requirement

B Hopper height 6 m (19.5 ft)

PMA Requirement

IACSInterpretation

The bilge hopper tanks at fore and aft of cargo area narrow due to raised bottom platingand the actual vertical distance from the bottom of the tank to hopper plating of the tank ismore appropriate to judge if a portable means of access could be utilized for the purpose.

Dimension PMA+ RequirementPMA + Requirement

ADistance from the top of the bilgehopper 1975 mm (78.0 in.) and 3 m (10.0 ft)

Additional Guidance

Section 2, Figure 7, Access for Bilge Hopper Tank is provided to help illustrate thisrequirement.

Distance A from the top of the bilge hopper is measured from the underside of the plating to the top of the platform.

In this figure, B refers to the height of bilge hopper tank. This is the maximum ofthe clear vertical distance from bottom plating to hopper plating.

Detailed walkway design guidance is available in Subsection 3/2, Walkways and Ramps.


FIGURE 7Access for Bilge Hopper Tank

A

Critical Areafor Inspection

B


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4.19 Means of Access Requirements for Table 1/2.3 of MSC.158(78) for Oil Tankers(Access for Distances < 6 m from the Tank Bottom to the Upper Knuckle Point)


Where the vertical distance referred to in 2.2 is less than 6 m, alternative means as definedin paragraph 3.9 of the Technical provisions or portable means of access may be utilized inlieu of the permanent means of access. To facilitate the operation of the alternative meansof access, in-line openings in horizontal stringers shall be provided. The openings shall beof an adequate diameter and shall have suitable protective railings.


A Handrail height 1000 mm (39.0 in.)

Means ofAccess

Requirement

B Distance between longitudinal stringers < 6 m (19.5 ft)

PMA Requirement

IACSInterpretation No interpretation provided.


Additional Guidance

Section 2, Figure 9, Access for Vertical Distances < 6 m from the Tank Bottom to the

Upper Knuckle Point is provided to help illustrate these requirements. Detailed walkway design guidance is available in Subsection 3/2, Walkways and Ramps.


Detailed ladder design guidance is available in Section 4, Vertical Ladders, InclinedLadders and Handles.

Detailed guidance on the design and selection of alternative means of access isavailable in Section 6, Alternative Means of Access.

With the Administrations approval, reasonable deviations may be applied to facilitatethis means of access. IACS UI (SC) 191 has interpreted this to be no more than 10%for vertical distances exceeding 6 m (19.5 ft).

FIGURE 9Access for Vertical Distances < 6 m from the Tank Bottom

to the Upper Knuckle Point

A

B

B


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5 Specific Means of Access Requirements for Bulk Carriers

The specific means of access requirements for bulk carriers are presented in this Subsection. Thefollowing table, Application of Resolution MSC.158(78) Table 2 for Bulk Carriers, as interpreted

by IACS UI SC 191, has been duplicated (from Subsection 2/3) for the readers convenience. Note: Those requirements that relate to permanent means of access are prerequisites for the PMA notation. The PMA

notation does not include the IMO requirements or allowances for alternative or temporary means of access.

Application of Resolution MSC.158(78) Table 2 for Bulk Carriers*

Cargo Holds Hold Height 17 m Hold Height < 17 m

Underdeck Structure 1.1, 1.2, 1.3, 1.4 1.5

Side Shell 1.6 + or 1.8, 1.7, 1.9 +, 1.10 +

Vertical Bulkhead 1.7 Not Applicable

Ballast and Double Side Skin Spaces Tank/Space Height

6 m Tank/Space Height < 6 m

Wall-sided Mid-Depth Portion(Between Topside and

Hopper Portions)2.8 2.8

Upper Topside Tank 2.1, 2.2, 2.3 2.4

Lower Hopper Portion/Tank 2.5 and 2.6 2.7


* = Numbers in this table correspond to MSC.158 (78) Table 2, Means of Access for Bulk Carriers.+ = Single side skin construction only.

Each MSC requirement is presented in its entirety along with any associated IACS unified interpretation.Graphical representations for some of the means of access requirements have been provided to helpclarify or demonstrate the requirements intent. Also, additional guidance related to the design of themeans of access is provided.

Note: Graphics are for demonstrative purposes only and are not to scale.

In some of the figures, specific dimensions are provided. These dimensions will help clarify the meansof access requirement and/or the interpretation. Where appropriate, IMO, PMA and PMA+ requirementsare provided. These dimensions are to be used in conjunction with the additional guidance containedin the following Sections:

Section 3, Walkways, Ramps and Work Platforms,

Section 4, Vertical Ladders, Inclined Ladders and Handles, and

Section 5, Hatches.


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5.1 Means of Access Requirement for Table 2/1.1 of MSC.158(78) for Bulk Carriers(Cargo Holds Access to Underdeck Structure)

Means of Access Requirement for Table 2/1.1 of MSC.158(78) for Bulk Carriers

Permanent means of access shall be fitted to provide access to the overhead structure at both sides of the cross deck and in the vicinity of the centerline. Each means of access shall be accessible from the cargo hold access or directly from the main deck and installed at aminimum of 1.6 m to a maximum of 3 m below the deck.


Means ofAccess

Requirement

A Distance below deckhead 1600 mm (63 in.) and 3 m (10.0 ft)

PMA Requirement

IACSInterpretation

Means of access shall be provided to the crossdeck structures of the foremost andaftermost part of the each cargo hold.

Interconnected means of access under the cross deck for access to three locations at both sides and in the vicinity of the centerline is acceptable.

Permanent means of access fitted at three separate locations accessible independently,one at each side and one in the vicinity of the centerline is acceptable.

Special attention is to be paid to the structural strength where any access opening is provided in the main deck or cross deck.

The requirement for bulk carrier cross deck structure is also considered applicable toore carriers.



Additional Guidance

Section 2, Figure 10, Access to Underdeck Structures 17 m in Height is providedto help illustrate this requirement.

Distance A below the deckhead is measured from the underside of the deck platingto the top of the platform.


FIGURE 10Access to Underdeck Structures 17 m in Height

A


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5.2 Means of Access Requirement for Table 2/1.2 of MSC.158(78) for Bulk Carriers(Cargo Holds Access to Underdeck Structures)


An athwartship permanent means of access fitted on the transverse bulkhead at a minimum1.6 m to a maximum 3 m below the cross-deck head is accepted as equivalent to 1.1.


Means ofAccess

RequirementA Distance below deckhead 1600 mm (63 in.) and 3 m (10.0 ft)

PMA Requirement

IACSInterpretation No interpretation provided



Additional Guidance

Section 2, Figure 11, Athwartship Access Fitted on the Transverse Bulkhead 17 min Height is provided to help illustrate this requirement.

Distance A below the deckhead is measured from the underside of the deck platingto the top of the platform.


FIGURE 11Athwartship Access Fitted on the Transverse

Bulkhead 17 m in Height

A


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Means ofAccess

Requirement

Access to the permanent means of access to overhead structure of the cross deck mayalso be via the upper stool.PMA

RequirementIACS

InterpretationParticular attention is to be paid to preserve the structural strength in way of accessopening provided in the main deck or cross deck.


Additional Guidance Detailed walkway design guidance is available in Subsection 3/2, Walkways and Ramps.



Means of Access RequirementShips having transverse bulkheads with full upper stools with access from the maindeck which allows monitoring of all framing and plates from inside, do not require

permanent means of access of the cross deck.

IACS Interpretation Full upper stools are understood to be stools with a full extension between top sidetanks and between hatch end beams.


Additional Guidance Detailed walkway design guidance is available in Subsection 3/2, Walkways and Ramps.



Means of Access Requirement Alternatively, movable means of access may be utilized for access to the overheadstructure of cross deck if its vertical distance is 17 m or less above the tank top.

IACS Interpretation

The movable means of access to the underdeck structure of cross deck need notnecessarily be carried on board the vessel. It is sufficient if it is made availablewhen needed.

The requirement for bulk carrier cross deck structure is also considered applicableto ore carriers.

PMA + Requirement No additional PMA+ requirements

Additional Guidance

This movable means of access should not be a vertical ladder, except for heightsunder 6 m (19.5 ft).

Detailed guidance on the design and selection of alternative means of access isavailable in Section 6, Alternative Means of Access.



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5.6 Means of Access Requirement for Table 2/1.6 of MSC.158(78) for Bulk Carriers(Cargo Holds Access to Vertical Structures)


Permanent means of vertical access shall be provided in all cargo holds and built into thestructure to allow for an inspection of a minimum of 25% of the total number of hold frames

port and starboard equally distributed throughout the hold including at each end in way oftransverse bulkheads. But in no circumstance shall this arrangement be less than 3 permanentmeans of vertical access fitted to each side (fore and aft ends of hold and mid-span). Permanentmeans of vertical access fitted between two adjacent hold frames is counted for an accessfor the inspection of both hold frames. A means of portable access may be used to gainaccess over the sloping plating of lower hopper ballast tanks.


Means ofAccess

Requirement

A Distance between rungs 350 mm (13.75 in.)

PMA Requirement

IACSInterpretation

The maximum vertical distance of the rungs of vertical ladders for access to holdframes is to be 350 mm.

If safety harness is to be used, means should be provided for connecting the safetyharness in suitable places in a practical way.


A Distance between rungs 275 mm (11.0 in.) and 300 mm (12.0 in.)

Additional Guidance

Section 2, Figure 12, Bulk Carriers Having Transverse Bulkheads with Full UpperStools 17 m in Height is provided to help illustrate this requirement.

Permanent access can be a vertical ladder or horizontal bars/rungs in the hold frames.

Ladder rung-to-rung distance consistent for the full run of the ladder.


FIGURE 12Bulk Carriers Having Transverse Bulkheads with

Full Upper Stools 17 m in Height

A

Portable Meansof Access

PermanentAccess


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Means of Access RequirementIn addition to 1.6, portable or movable means of access shall be utilized for access tothe remaining hold frames up to their upper brackets and transverse bulkheads.

IACS Interpretation Portable, movable or alternative means of access also is to be applied to corrugated bulkheads.

PMA+ Requirement No additional PMA+ requirements.

Additional Guidance Detailed guidance on the design and selection of alternative means of access is availablein Section 6, Alternative Means of Access.



Means of Access RequirementPortable or movable means of access may be utilized for access to hold frames up totheir upper bracket in place of the permanent means required in 1.6. These means ofaccess shall be carried on board the ship and readily available for use.

IACS Interpretation No interpretation provided.PMA+ Requirement No additional PMA+ requirements.



Means of Access Requirement for Table 2/1.9 of MSC.158(78) for Bulk CarriersMeans ofAccess

Requirement

The width of vertical ladders for access to hold frames shall be at least 300 mm, measured between stringers.PMA

RequirementIACS



Additional Guidance Detailed ladder design guidance is available in Section 4, Vertical Ladders, InclinedLadders and Handles.


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5.10 Means of Access Requirement for Table 2/1.10 of MSC.158(78) for BulkCarriers (Cargo Holds Access to Vertical Structures)


Means ofAccess

Requirement

A single vertical ladder over 6 m in length is acceptable for the inspection of the holdside frames in a single skin construction.PMA

RequirementIACS



Additional Guidance Climber safety devices (rails) should be used for vertical ladders over 6 m (19.5 ft).


5.11 Means of Access Requirement for Table 2/1.11 of MSC.158(78) for Bulk

Carriers (Cargo Holds Access to Vertical Structures) Means of Access Requirement for Table 2/1.11 of MSC.158(78) for Bulk Carriers

Means ofAccess

Requirement

For double-side skin construction no vertical ladders for the inspection of the cargo holdsurfaces are required. Inspection of this structure should be provided from within thedouble hull space.PMA

RequirementIACS



Addit ional Guidance Detailed walkway design guidance is available in Subsection 3/2, Walkways and Ramps.


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5.13 Means of Access Requirement for Table 2/2.2 of MSC.158(78) for Bulk Carriers(Ballast Tanks Top Side Tanks)


If no access holes are provided through the transverse webs within 600 mm ofthe tank base and the web frame rings have a web height greater than 1 m in wayof side shell and sloping plating, then step rungs/grab rails shall be provided toallow safe access over each transverse web frame ring.


Means ofAccess

Requirement

A Step rungs/grab rails Not Provided

PMA Requirement

IACSInterpretation No interpretation provided.


A Step rungs/grab rails 275 mm (11 in.) and 300 mm (12 in.)

Additional Guidance

Section 2, Figure 14, Transverse Web Access for Bulk Carriers is providedto help illustrate this requirement.

Detailed guidance on the design of handles is available in Subsection 4/4,Handles.

Detailed guidance for individual stairs is available in Paragraph 4/2.2,Individual Rung Ladders.

FIGURE 14Transverse Web Access for Bulk Carriers

A


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Means ofAccess

Requirement

Three permanent means of access, fitted at the end bay and middle bay of each tank,shall be provided spanning from tank base up to the intersection of the sloping platewith the hatch side girder. The existing longitudinal structure may be used as part ofthis means of access.

PMA Requirement

IACSInterpretation

If the longitudinal structures on the sloping plate are fitted outside of the tank a meansof access is to be provided.


Additional Guidance Detailed guidance on the design of handles is available in Subsection 4/4, Handles.



Means of Access RequirementFor topside tanks of which the height is less than 6 m, alternative means as defined in

paragraph 3.9 of the Technical provisions or portable means may be utilized in lieu ofthe permanent means of access.





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5.16 Means of Access Requirement for Table 2/2.5 of MSC.158(78) for Bulk Carriers(Ballast Tanks Bilge Hopper Tanks)


For each bilge hopper tank of which the height is 6 m and over, one longitudinalcontinuous permanent means of access shall be provided along the side shell websand installed at a minimum of 1.2 m below the top of the clear opening of the webring with a vertical access ladder in the vicinity of each access to the tank.


Means ofAccess

Requirement

A Distance below web ring 1200 mm (47.25 in.)PMA

Requirement

IACSInterpretation

The height of a bilge hopper tank located outside of the parallel part of vesselis to be taken as the maximum of the clear vertical height measured fromthe bottom plating to the hopper plating of the tank.

It should be demonstrated that portable means for inspection can be deployedand made readily available in the areas where needed.


A Distance below web ring 1500 mm (59.0 in.)

Additional Guidance

Section 2, Figure 15, Bilge Hopper Tank Access with a Height 6 m is provided to help illustrate these requirements.

Detailed walkway design guidance is available in Subsection 3/2, Walkwaysand Ramps.

FIGURE 15Bilge Hopper Tank Access with a Height 6 m

A


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5.18 Means of Access Requirement for Table 2/2.5.2 of MSC.158(78) for BulkCarriers (Ballast Tanks Bilge Hopper Tanks)

Means of Access Requirement for Table 2/2.5.2 of MSC.158(78) for Bulk Carriers

Alternatively, the longitudinal continuous permanent means of access can belocated through the upper web plating above the clear opening of the web ring,at a minimum of 1.6 m below the deck head, when this arrangement facilitatesmore suitable inspection of identified structurally critical areas. An enlargedlongitudinal frame can be used for the purpose of the walkway.


A Distance below deck head 1600 mm (63.0 in.)

Means ofAccess

Requirement

B Access width 600 mm (23.5 in.)

PMA Requirement

IACSInterpretation

A wide longitudinal frame of at least 600 mm clear width may be used for the purpose of the longitudinal continuous permanent means of access.

Dimension PMA+ Requirement

A Distance below deck head 1975 mm (78.0 in.)PMA+ Requirement

B Access width No additional Requirement

Additional Guidance

Section 2, Figure 17, Alternate Bilge Hopper Tank Access with a Height 6 m is provided to help illustrate these requirements.

Vertical walkway clearance from a PMA+ perspective shall be measured fromthe top of the wa

ABS Guide for Access to Tanks and Holds for Inspection

Documents

Transcript of ABS Guide for Access to Tanks and Holds for Inspection