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ii ABS RULES FOR BUILDING AND CLASSING STEEL VESSELS .2014

R u l e C h a n g e N o t i c e ( 2 0 1 4 )

Rule Change Notice (2014)

The effective date of each technical change since 1993 is shown in parenthesis at the end of the

subsection/paragraph titles within the text of each Part. Unless a particular date and month are shown, the

years in parentheses refer to the following effective dates:

(2000)and after 1 January 2000 (and subsequent years) (1996) 9 May 1996

(1999) 12 May 1999 (1995) 15 May 1995

(1998) 13 May 1998 (1994) 9 May 1994

(1997) 19 May 1997 (1993) 11 May 1993

Listing by Effective Dates of Changes from the 2013 Rules

Notice No. 2 (effective on 1 July 2013) to the 2013 Rules, which is incorporated in the 2014 Rules, issummarized below.

EFFECTIVE DATE 1 July 2013 shown as (1 July 2013)(based on the contract date for new construction between builder and Owner)

Part/Para. No. Title/Subject Status/Remarks

Section 3-7-1 Tank, Bulkhead and RudderTightness Testing

To align the Rules with SOLAS and MSC.194(80) and to allow foralternative testing where hose testing of structural welds or cable

penetrations is not practical. (Incorporates Notice No. 2)

EFFECTIVE DATE 1 January 2014 shown as (2014)(based on the contract date for new construction between builder and Owner)


3-1-2/3 Application of Steel Materials 100mm (4.0 in.) and Under in Thickness

To reflect the thickness range from 51 to 100 mm in the applicationof materials.

3-1-2/Table 1 Material Grades To reflect the thickness range from 51 to 100 mm in the materialgrades table.

3-2-3/5.17 Wheel Loading To obtain the exactKfactor for certain b/sratios.

3-2-9/9.11 Testing Watertight Door atManufacturer

To align the testing requirements for watertight doors prescribed inSOLAS Reg.II-1/16.2 and IACS UI SC156.

3-2-13/Figure 4 Propeller Nozzle Section View To define Zone 2 for tilted nozzles.

3-2-14/1.3 Materials for Rudder, Rudder Stockand Steering Equipment

To address the galvanic compatibility of materials.

3-2-14/3.1 Rudder Blades without Cutouts To clarify that that any appendages (e.g., rudder bulb) will be

included in the rudder area.

3-2-14/3.5(New)

Rudders Blades with TwistedLeading-Edge

To provide requirements for twisted rudders.

3-2-14/Table 1A Coefficient kcfor Ordinary Rudders To provide requirements for twisted rudders.

3-2-14/Table 1B Coefficient kcfor High-Lift/Performance Rudders

To provide requirements for twisted rudders.

3-2-14/5.3 Rudders without Cutouts To clarify that that any appendages (e.g., rudder bulb) will be

included in the rudder area.

3-2-14/Table 3 Coefficient To provide requirements for twisted rudders.

3-2-14/5.7

(New)

Rudders with Twisted Leading-Edge To provide requirements for twisted rudders.

3-2-A5/3 Spade Rudders To provide requirements for rudders with embedded rudder trunk.3-2-A5/Figure 1 Spade Rudder To provide requirements for rudders with embedded rudder trunk.


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ABS RULES FOR BUILDING AND CLASSING STEEL VESSELS .2014 iii


3-2-16/11.7(New)

Testing at Watertight DoorManufacturer

To align the testing requirements for watertight doors prescribed inSOLAS Reg.II-1/16.2 and IACS UI SC156.

3-2-17/Table 1 Acceptable Arrangement for Access To clarify the requirement in line with IMO Resolution MSC.62(67)

interpreted by SOLAS Reg. II-1/3-3 and IACS UI LL50.

3-3-1/3.3 Subdivision and Damage Stability To clarify the application of damage stability criteria to oil tankers.

3-5-1/11.3.2 Sea Loads To align the requirements with IACS UR S27.

3-5-2/7.7.4 Structural Strength To align the requirements with 3-5-1/15 of the Steel Vessel RulesandIACS UR A2 A.2.2.3.2.


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iv ABS RULES FOR BUILDING AND CLASSING STEEL VESSELS .2014

P A R T T a b l e o f C o n t e n t s

3Hull Construction and Equipment

CONTENTS

CHAPTER 1 General .................................................................................................... 1

Section 1 Definitions .............................................................................. 3

Section 2 General Requirements ........................................................... 6

CHAPTER 2 Hull Structures and Arrangements ..................................................... 12

Section 1 Longitudinal Strength ........................................................... 31Section 2 Shell Plating ......................................................................... 61

Section 3 Decks ................................................................................... 70

Section 4 Bottom Structures ................................................................ 77

Section 5 Frames ................................................................................. 87

Section 6 Web Frames and Side Stringers .......................................... 94

Section 7 Beams .................................................................................. 98

Section 8 Pillars, Deck Girders and Transverses .............................. 104

Section 9 Watertight Bulkheads and Doors ....................................... 111

Section 10 Deep Tanks ........................................................................ 123

Section 11 Superstructures, Deckhouses and Helicopter Decks ........ 127

Section 12 Machinery Space and Tunnel ............................................ 134

Section 13 Stems, Stern Frames and Rudder Horns .......................... 136

Section 14 Rudders and Steering Equipment ...................................... 147

Section 15 Protection of Deck Openings ............................................. 184

Section 16 Protection of Shell Openings ............................................. 232

Section 17 Bulwarks, Rails, Freeing Ports, Portlights andVentilators .......................................................................... 245

Section 18 Ceiling, Sparring and Protection of Steel ........................... 254

Section 19 Weld Design ....................................................................... 256

Appendix 1 Calculation of Shear Stresses for Vessels HavingLongitudinal Bulkheads ........................................................ 44

Appendix 2 Loading Manuals and Loading Instruments ......................... 46

Appendix 3 Loading Manuals and Loading Instruments: AdditionalRequirements for Bulk Carriers, Ore Carriers andCombination Carriers 150 meters (492 feet) andAbove in Length (Lf) ............................................................. 50

Appendix 4 Buckling Strength of Longitudinal Strength Members ......... 55

Appendix 5 Guidelines for Calculating Bending Moment and ShearForce in Rudders and Rudder Stocks ................................ 177

Appendix 6 Portable Beams and Hatch Cover Stiffeners of VariableCross Section ..................................................................... 230


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ABS RULES FOR BUILDING AND CLASSING STEEL VESSELS.2014 1

P A R T C h a p t e r 1 : G e n e r a l

3C H A P T E R 1 General

CONTENTS

SECTION 1 Definitions ............................................................................................... 31 Application .......................................................................................... 33 Length ................................................................................................. 3

3.1 Scantling Length (L) ............................................................ ............ 33.3 Freeboard Length (Lf) ...................................................................... 3

5 Breadth (B) .......................................................................................... 37 Depth ................................................................................................... 4

7.1 Molded Depth (D) ............................................................................ 47.3 Scantling Depth (Ds) ........................................................................ 4

9 Draft (d) ............................................................................................... 411 Molded Displacement and Block Coefficient ...................................... 4

11.1 Molded Displacement () .................................................... ............ 411.3 Block Coefficient (Cb) ........................................................... ............ 4

13 Decks .................................................................................................. 413.1 Freeboard Deck ................................................................... ............ 413.3 Bulkhead Deck .................................................................... ............ 413.5 Strength Deck ........................................................... ....................... 413.7 Superstructure Deck ............................................................ ............ 5

15 Deadweight (DWT) and Lightship Weight ........................................... 517 Units .................................................................................................... 5FIGURE 1......................................................................................................... 3

SECTION 2 General Requirements ........................................................................... 61 Material and Fabrication ..................................................................... 6

1.1 Material ..................................................................... ....................... 61.3 Application ................................................................ ....................... 63 Application of Steel Materials 100mm (4.0in.) and Under in

Thickness ............................................................................................ 73.1 Selection of Material Grade ............................................................. 73.3 Note for Users ..................................................................... ............ 7

5 Scantlings ........................................................................................... 95.1 General................................................................................ ............ 95.3 Dynamic Loading Approach ............................................................ 9

7 Proportions ........................................................................................ 109 Workmanship .................................................................................... 1011 Drydocking ........................................................................................ 10


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2 ABS RULES FOR BUILDING AND CLASSING STEEL VESSELS.2014

13 Structural Sections ............................................................................ 1013.1 General ............................................................ .............................. 10

13.3 Deep Supporting Members ............................................................ 10

13.5 Frames, Beams and Stiffeners ...................................................... 10

15 Structural Design Details .................................................................. 11

15.1 General ............................................................ .............................. 11

15.3 Termination of Structural Members................................................ 11

15.5 Fabrication .................................................................. ................... 11

TABLE 1 Material Grades ......................................................................... 7TABLE 2 Material Class or Grade of Structural Members ....................... 8


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P A R T S e c t i o n 1 : D e f i n i t i o n s


S E C T I O N 1 Definitions

1 Application

The following definitions of symbols and terms are to be understood (in the absence of other specifications)

where they appear in the Rules.

3 Length

3.1 Scantling Length (L) (1997)Lis the distance in meters (feet) on the summer load line from the fore side of the stem to the centerline ofthe rudder stock. For use with the Rules,Lis not to be less than 96% and need not be greater than 97% of

the length on the summer load line. The forward end ofLis to coincide with the fore side of the stem onthe waterline on whichLis measured.

3.3 Freeboard Length (Lf) (2002)Lfis the distance in meters (feet) on a waterline at 85% of the least molded depth measured from the top ofthe keel from the fore side of the stem to the centerline of the rudder stock or 96% of the length on thatwaterline, whichever is greater. Where the stem is a fair concave curve above the waterline at 85% of the

least molded depth and where the aftermost point of the stem is above the waterline, the forward end of thelength,Lf, is to be taken at the aftermost point of the stem above that waterline. See 3-1-1/Figure 1.

FIGURE 1

0.85D

D

Lf

FBD Deck

F.P.

5 Breadth (B)

Bis the greatest molded breadth in meters (feet).


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Part 3 Hull Construction and EquipmentChapter 1 GeneralSection 1 Definitions 3-1-1


7 Depth

7.1 Molded Depth (D) (1997)

Dis the molded depth at side in meters (feet) measured at the middle ofLfrom the molded base line to the

top of the freeboard-deck beams. In vessels having rounded gunwales,Dis to be measured to the point ofintersection of the molded lines of the deck and side shell plating. In cases where watertight bulkheadsextend to a deck above the freeboard deck and are to be recorded in theRecordas effective to that deck,D

is to be measured to the bulkhead deck.

7.3 Scantling Depth (Ds) (1997)The depthDsfor use with scantling requirements is the distance in meters (feet) from the molded base lineto the strength deck as defined in 3-1-1/13.5.

9 Draft (d)

dis the molded draft, and is the distance in meters (feet) from the molded base line to the summer load line.

11 Molded Displacement and Block Coefficient (1997)

11.1 Molded Displacement ()

is the molded displacement of the vessel in metric tons (long tons), excluding appendages, taken at the

summer load line.

11.3 Block Coefficient (Cb)

Cbis the block coefficient obtained from the following equation:

Cb = /1.025LBwl d (SI & MKS units)

Cb = 35/LBwl d (US units)

where

= molded displacement, as defined in 3-1-1/11.1.

L = scantling length, as defined in 3-1-1/3.1

d = draft,as defined in 3-1-1/9

Bwl = the greatest molded breadth at summer load line

13 Decks

13.1 Freeboard Deck

The freeboard deck normally is the uppermost continuous deck having permanent means for closing all

openings. Where a vessel is designed for a special draft, considerably less than that corresponding to theleast freeboard obtainable under the International Load Line Regulations, the freeboard deck, for the purposeof the Rules, may be taken as the actual lowest deck from which the draft can be obtained under those

regulations.

13.3 Bulkhead Deck

The bulkhead deck is the highest deck to which the watertight bulkheads extend and are made effective.

13.5 Strength Deck

The strength deck is the deck that forms the top of the effective hull girder at any part of its length. See3-2-1/11.1.


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Part 3 Hull Construction and EquipmentChapter 1 GeneralSection 1 Definitions 3-1-1


13.7 Superstructure Deck

A superstructure deck is a deck above the freeboard deck to which the side shell plating extends. Except

where otherwise specified, the term superstructure deck where used in the Rules refers to the first suchdeck above the freeboard deck.

15 Deadweight (DWT)and Lightship Weight (1997)

For the purpose of these Rules, deadweight,DWT, is the difference in metric tons (long tons) between thedisplacement of the vessel at its summer load line in water having a specific gravity of 1.025 and the

lightship weight. For the purpose of these Rules, lightship weight is the displacement of the vessel inmetric tons (long tons) with no cargo, fuel, lubricating oil, ballast water, fresh water nor feed water in

tanks, no consumable stores, and no passengers or crew nor their effects.

17 Units

These Rules are written in three systems of units, viz., SI units, MKS units and US customary units. Each

system is to be used independently of any other system.

Unless indicated otherwise, the format of presentation in the Rules of the three systems of units is as follows:

SI units (MKS units, US customary units)


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P A R T S e c t i o n 2 : G e n e r a l R e q u i r e m e n t s


S E C T I O N 2 General Requirements

1 Material and Fabrication

1.1 Material

1.1.1 Steel

These Rules are intended for vessels of welded construction using steels complying with the

requirements of Part 2, Chapter 1. Use of steels other than those in Part 2, Chapter 1 and the vesselscorresponding scantlings will be specially considered.

1.1.2 Aluminum Alloys

The use of aluminum alloys in hull structures will be considered upon submission of a specificationof the proposed alloys and their proposed method of fabrication.

1.1.3 Design Consideration

Where scantlings are reduced in association with the use of higher-strength steel or where aluminumalloys are used, adequate buckling strength is to be provided. Where it is intended to use material

of cold flanging quality for important longitudinal strength members, this steel is to be indicatedon the plans.

1.1.4 Guidance for Repair

Where a special welding procedure is required for special steels used in the construction, includingany low temperature steel and those materials not encompassed in Part 2, Chapter 1, a set of plans

showing the following information for each steel is to be placed aboard the vessel:

Material Specification

Welding procedure

Location and extent of application

These plans are in addition to those normally placed aboard the vessel, and are to show all material

applications.

1.3 Application

The requirements of the Rules apply to steel vessels of all welded construction. Riveted hull construction, where

used, is to comply with the applicable parts dealing with riveting in the 1969 edition of the Rules.


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Part 3 Hull Construction and EquipmentChapter 1 GeneralSection 2 General Requirements 3-1-2


3 Application of Steel Materials 100mm (4.0in.) and Under in

Thickness (2014)

3.1 Selection of Material Grade

Steel materials for particular locations are not to be of lower grades than those required by 3-1-2/Table 1 forthe material class given in 3-1-2/Table 2.

3.3 Note for Users

The attention of users is drawn to the fact that when fatigue loading is present, the effective strength ofhigher-strength steel in welded construction may not be greater than that of ordinary-strength steel.

Precautions against corrosion fatigue may also be necessary.

TABLE 1Material Grades (2014)

Thickness t

mm (in.)

Material Class

I II III

t15 (t0.60) A(2), AH A, AH A, AH

15


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TABLE 2Material Class or Grade of Structural Members (1 July 2009)

LineNo.

Structural MembersWithin 0.4L Amidships Outside 0.4L amidships

Material Class(8)or Grade Material Class or Grade

A Secondary

A1 Longitudinal bulkhead strakes, other than those belonging to thePrimary category

I A(10)/AHA2 Deck plating exposed to weather, other than that belonging tothe Primary or Special category

A3 Side plating (12)

B Primary

B1 Bottom plating, including keel plate

II A(10)/AH

B2 Strength deck plating, excluding that belonging to the Specialcategory (13)

B3 Continuous longitudinal members above strength deck,

excluding hatch coamings (13)

B4 Uppermost strake in longitudinal bulkhead

B5 Vertical strake (hatch side girder) and uppermost sloped strakein top wing tank

C Special

C1 Sheer strake at strength deck (1, 9, 13)

IIIII

(I outside 0.6Lamidships)

C2 Stringer plate in strength deck (1, 9, 13)

C3 Deck strake at longitudinal bulkhead (2, 9, 13)

C4 Strength deck plating at outboard corners of cargo hatch openingsin container carriers and other ships with similar hatch openingconfigurations (3, 13)

C5 Strength deck plating at corners of cargo hatch openings in bulk

carriers, ore carriers, combination carriers and other ships withsimilar hatch opening configurations (4, 13)

C6 Bilge strake (5, 6, 9)

C7 Longitudinal hatch coamings of length greater than 0.15L(7)

C8 End brackets and deck house transition of longitudinal cargohatch coamings (7)

D Other Categories

D1 Stern frames, rudder horns, rudders and shaft brackets - II(11)

D2 Strength members not referred to in A to C and D1 A(10)/AH A(10)/AH


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TABLE 2 (continued)Material Class or Grade of Structural Members (1 July 2009)

Notes:1 Not to be less than grade E/EH(9)within 0.4Lamidships in ships with length exceeding 250 m (820 ft).

2 Excluding deck plating in way of inner-skin bulkhead of double hull ships.

3 Not to be less than class III within the length of the cargo region.

4 Not to be less than class III within 0.6Lamidships and class II within the remaining length of the cargo region.

5 May be of class II in ships with a double bottom over the full breadth and with length less than 150 m (492 ft).

6 Not to be less than grade D/DH within 0.4Lamidships in ships with length exceeding 250 m (820 ft).

7 Not to be less than grade D/DH.

8 Special consideration will be given to vessels of restricted class.

9 Single strake required to be class III or E/EH are to have breadths not less than 800 + 5Lmm (31.5 + 0.06Lin.),but need not exceed 1800 mm (71 in.), unless limited by the geometry of the vessels design.

10 ASTM A36 steel otherwise tested and certified to the satisfaction of ABS may be used in lieu of Grade A for athickness up to and including 12.5 mm (0.5 in.) for plates and up to and including 40 mm (1.57 in.) for sections.

11 For rudder and rudder body plates subjected to stress concentrations (e.g., in way of lower support or at upper part

of spade rudders), class III is to be applied.

12 (1 July 2009)Single side strakes for ships exceeding 150 m (492 feet) without inner continuous longitudinal; bulkheads

between bottom and the single strength deck are not to be less than grade B/AH within cargo region in ships.

13 (1 July 2009)Not to be less than grade B/AH within 0.4Lamidships in ships with length exceeding 150 m (492

feet) and single strength deck.

5 Scantlings (2013)

5.1 General

The midship scantlings specified in the Rules are to apply throughout the midship 0.4L. End scantlings are

not to extend for more than 0.1L from each end of the vessel. Reduction in scantlings from the midship tothe end scantlings is to be effected in as gradual a manner as practicable. Sections having appropriate section

moduli or areas, in accordance with their functions in the structure as stiffeners, columns or combinationsof both, are to be adopted, due regard being given to the thickness of all parts of the sections to provide a

proper margin for corrosion. It may be required that calculations be submitted in support of resistance tobuckling for any part of the vessels structure.

5.3 Dynamic Loading Approach

The symbols SH-DLAare assigned to vessels which have been reviewed based upon an acceptable load

and structural analysis procedure, taking into consideration the dynamic load components acting on the vessel.

The dynamic load components considered are to include the external hydrodynamic pressure loads, dynamicloads from cargoes and inertial loads of the hull structure. The magnitude of the load components and their

combinations are to be determined from appropriate ship motion response calculations for loading conditionswhich represent the envelope of maximum dynamically induced stresses in the vessel.

The adequacy of the hull structure for all combinations of the dynamic loadings is to be evaluated using anacceptable finite element analysis method.

In no case are the structural scantlings to be less than those obtained from other requirements in the Rules.


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7 Proportions

In general, these Rules are valid for all vessels not exceeding 500 m (1640 ft) in length, L, and having abreadth, B, not exceeding one-fifth of the length, L, nor 2.5 times the depth, Ds, to the strength deck.Vessels beyond these proportions will be specially considered.

9 Workmanship (2008)

All workmanship is to be of commercial marine quality and acceptable to the Surveyor. Welding is to be in

accordance with the requirements of Part 2, Chapter 4. See also 3-7-3/1.

11 Drydocking

Consideration is to be given to drydocking the vessel within twelve months after delivery. For vessels228.5 m (750 ft) in length,L,and over, information indicating docking arrangements is to be prepared andfurnished onboard the vessel for guidance.

13 Structural Sections (1993)

13.1 General

The scantling requirements of these Rules are applicable to structural angles, channels, bars, and rolled orbuilt-up sections.

13.3 Deep Supporting Members (1993)

The required section modulus of members such as girders, webs, etc., supporting frames, beams andstiffeners, is to be obtained on an effective width of plating basis in accordance with this subsection. Thesection is to include the structural member in association with an effective width of plating not exceedingone-half of the sum of the spacing on each side of the member or 33% of the unsupported span ,whichever is less. For girders and webs along hatch openings, an effective breadth of plating not exceedingone-half of the spacing or 16.5% of the unsupported span , whichever is less, is to be used.

13.5 Frames, Beams and Stiffeners (1993)13.5.1 Section Modulus

The required section modulus is to be provided by the stiffener and a maximum of one framespace of the plating to which it is attached.

13.5.2 Web Thickness

The depth to thickness ratio of the web portion of members is not to exceed the following:

Members with flange 50C1C2

Members without flange 15C1C2

where

C1 = 0.95 (horizontal web within a tank)

= 1.0 (all other cases)

C2 = 1.0 (ordinary strength steel)

= 0.92 (HT32)

= 0.90 (HT36)


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P A R T C h a p t e r 2 : H u l l S t r u c t u r e s a n d A r r a n g e m e n t s

3C H A P T E R 2 Hull Structures and Arrangements

CONTENTS

SECTION 1 Longitudinal Strength .......................................................................... 311 Application ......................................................................................... 313 Longitudinal Hull Girder Strength ...................................................... 31

3.1 Sign Convention of Bending Moment and Shear Force ................. 313.3 Still-water Bending Moment and Shear Force ............................... 313.5 Wave Loads ................................................................. .................. 333.7 Bending Strength Standard ............................................................ 363.9 Shearing Strength .................................................................... ...... 37

5 Longitudinal Strength with Higher-Strength Materials ...................... 395.1 General ............................................................. ............................. 395.3 Hull Girder Moment of Inertia ......................................................... 395.5 Hull Girder Section Modulus .......................................................... 395.7 Hull girder Shearing Force ............................................................. 39

7 Loading Guidance ............................................................................. 397.1 Loading Manual and Loading Instrument ....................................... 397.3 Allowable Stresses .................................................................. ...... 39

9 Section Modulus Calculation ............................................................. 409.1 Items Included in the Calculation ................................................... 409.3 Effective Areas Included in the Calculation .................................... 409.5 Section Modulus to the Deck or Bottom ......................................... 409.7 Section Modulus to the Top of Hatch Coamings ............................ 40

11 Strength Decks.................................................................................. 4111.1 Definition ........................................................... ............................. 4111.3 Tapering of Deck Sectional Areas ................................................. 41

13 Continuous Longitudinal Hatch Coamings and Above DeckGirders .............................................................................................. 41

15 Effective Lower Decks ...................................................................... 4117 Longitudinal Deck Structures Inboard of Lines of Openings ............ 41

17.1 General ............................................................. ............................. 4117.3 Effectiveness ............................................................... .................. 42

19 Buckling Strength .............................................................................. 42FIGURE 1 Sign Convention ...................................................................... 34FIGURE 2 Distribution FactorM............................................................... 34FIGURE 3 Distribution FactorF1............................................................... 35FIGURE 4 Distribution FactorF2............................................................... 35FIGURE 5 Shear Force Distribution ......................................................... 38FIGURE 6 Effective Area of Hull Girder Members ................................... 43


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SECTION 2 Shell Plating .......................................................................................... 611 Application ........................................................................................ 613 Shell Plating Amidships .................................................................... 61

3.1 Vessels with No Partial Superstructures Above UppermostContinuous Deck ........................................................................... 61

3.3 Superstructures Fitted Above Uppermost Continuous Deck(Side Plating Extended) ................................................................. 61

3.5 Superstructures Fitted Above Uppermost Continuous Deck(Side Plating Not Extended) ........................................................... 61

3.7 In Way of Comparatively Short Superstructures ............................ 613.9 Side Shell Plating ................................................................ .......... 623.11 Sheer Strake ............................................................ ..................... 623.13 Bottom Shell Plating Amidships ..................................................... 623.15 Flat Plate Keel ..................................................................... .......... 643.17 Minimum Thickness ............................................................. .......... 64

5 Shell Plating at Ends ......................................................................... 65

5.1 Minimum Shell Plating Thickness .................................................. 655.3 Immersed Bow Plating................................................................... 655.5 Bottom Forward ................................................................... .......... 665.7 Forecastle Side Plating ................................................................. 665.9 Poop Side Plating ................................................................ .......... 665.11 Bow and Stern Thruster Tunnels ................................................... 675.13 Special Heavy Plates .......................................................... .......... 67

7 Bottom Shell Plating for Special Docking Arrangement ................... 679 Compensation ................................................................................... 6811 Breaks ............................................................................................... 6813 Bilge Keels ........................................................................................ 6815 Higher-strength Materials .................................................................. 68

15.1 General................................................................................ .......... 6815.3 Bottom Plating of Higher-strength Material .................................... 6915.5 Side Plating of Higher-strength Material ........................................ 6915.7 End Plating ............................................................... ..................... 69

SECTION 3 Decks..................................................................................................... 701 General ............................................................................................. 70

1.1 Extent of Plating .................................................................. .......... 70

3 Hull Girder Strength .......................................................................... 703.1 Longitudinal Section Modulus Amidships ...................................... 703.3 Strength Deck ........................................................... ..................... 703.5 Longitudinally Framed Decks ........................................................ 703.7 Superstructure Decks .......................................................... .......... 703.9 Deck Transitions .................................................................. .......... 703.11 Deck Plating ............................................................. ..................... 71

5 Deck Plating ...................................................................................... 715.1 Thickness ................................................................. ..................... 715.3 Effective Lower Decks ................................................................... 715.5 Reinforcement at Openings ........................................................... 71


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13 Fore-end Strengthening .................................................................... 8313.1 General................................................................................ .......... 8313.3 Extent of Strengthening ................................................................. 8313.5 Longitudinal Framing ........................................................... .......... 8313.7 Transverse Framing ............................................................ .......... 84

15 Higher-strength Materials .................................................................. 8415.1 General................................................................................ .......... 8415.3 Inner-bottom Plating ............................................................. ......... 8515.5 Bottom and Inner-bottom Longitudinals ......................................... 8515.7 Center Girders, Side Girders, and Floors ...................................... 85

17 Structural Arrangements and Details ................................................ 8517.1 Structural Sea Chests ................................................................... 8517.3 Drainage ................................................................... ..................... 8517.5 Manholes and Lightening Holes .................................................... 8617.7 Air and Drainage Holes ................................................................. 8617.9 Fixed Ballast ............................................................. ..................... 86

TABLE 1 ......................................................................................................... 84TABLE 2 Spacing of Floors .................................................................... 84FIGURE 1 Double-bottom Solid Floors .................................................... 79FIGURE 2 Double-bottom Open Floors .................................................... 81

SECTION 5 Frames .................................................................................................. 871 General ............................................................................................. 871.1 Basic Considerations ........................................................... .......... 87

1.3 Holes in Frames .................................................................. .......... 871.5 End Connections ................................................................. .......... 871.7 Standard and Cant Frame Spacing ............................................... 87

3 Hold Frames ..................................................................................... 883.1 Transverse Frames ............................................................. .......... 883.3 Raised Quarter Decks ................................................................... 903.5 Fore-end Frames ................................................................. .......... 903.7 Panting Frames ................................................................... .......... 903.9 Side Stringers ........................................................... ..................... 903.11 Frames with Web Frames and Side Stringers ............................... 903.13 Panting Webs and Stringers .......................................................... 903.15 Hold Frame Brackets ........................................................... .......... 903.17 Longitudinal Frames ............................................................ .......... 913.19 Machinery Space ................................................................. .......... 91

5 Tween-deck Frames ......................................................................... 915.1 General................................................................................ .......... 915.3 Transverse Tween-deck Frames ................................................... 915.5 Longitudinal Tween-deck Frames ................................................. 92

7 Forepeak Frames .............................................................................. 927.1 General................................................................................ .......... 927.3 Frame Scantlings ................................................................ .......... 92


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9 After-peak Frames ............................................................................ 939.1 General ............................................................. ............................. 939.3 Frame Scantlings ..................................................................... ...... 939.5 Vessels of High Power or Fine Form ............................................. 93

FIGURE 1 Zones of Framing .................................................................... 88FIGURE 2 Hold Frames ............................................................................ 89FIGURE 3 Hold Frames ............................................................................ 89FIGURE 4 Hold Frames ............................................................................ 89

SECTION 6 Web Frames and Side Stringers ......................................................... 941 General ............................................................................................. 943 Web Frames ...................................................................................... 94

3.1 Hold Web Frames Amidships and Aft ............................................ 943.3 Hold Web Frames Forward ............................................................ 953.5 Proportions .................................................................. .................. 953.7 Stiffeners........................................................... ............................. 953.9 Tripping Bracket ........................................................... .................. 963.11 Tween-deck Webs ................................................................... ...... 96

5 Side Stringers .................................................................................... 965.1 Hold Stringers .............................................................. .................. 965.3 Proportions .................................................................. .................. 965.5 Stiffeners........................................................... ............................. 965.7 Tripping Brackets ..................................................................... ...... 96

7 Structural Arrangements and Details ................................................ 96

7.1 Brackets of Girders, Webs, and Stringers ...................................... 967.3 End Connections ..................................................................... ...... 97

9 Peak Stringers ................................................................................... 979.1 Peak Stringer-plate Thickness ....................................................... 979.3 Peak Stringer-plate Breadth ........................................................... 97

FIGURE 1 Hold Web-frame Arrangements .............................................. 95SECTION 7 Beams .................................................................................................... 98

1 General ............................................................................................. 981.1 Arrangement ................................................................ .................. 981.3 Design Head ................................................................ .................. 98

3 Beams ............................................................................................... 983.1 Strength Requirement .............................................................. ...... 983.3 Special Heavy Beams .............................................................. .... 1003.5 Beams at the Head of Web Frames ............................................. 1003.7 End Connections ..................................................................... .... 100

4 Deck Fittings ................................................................................... 1004.1 General ............................................................. ........................... 1004.3 Design Loads ............................................................................... 1014.5 Supporting Structures .................................................................. 1024.7 Scantlings ............................................. ....................................... 102


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5 Container Loading ........................................................................... 1035.1 General................................................................................ ........ 1035.3 Strength Requirements ............................................................... 103

7 Higher-strength Materials ................................................................ 1037.1 General................................................................................ ........ 103

7.3 Beams of Higher-strength Materials ............................................ 103

TABLE 1 Values of hfor Beams ........................................................... 100TABLE 2 Values off(Ordinary-strength Steel) .................................... 103FIGURE 1 Application of Design Loads ................................................. 102

SECTION 8 Pillars, Deck Girders and Transverses ............................................. 1041 General ........................................................................................... 104

1.1 Arrangements General ............................................................. 1041.3 Container Loading .............................................................. ......... 104

3 Pillars .............................................................................................. 1043.1 Permissible Load ................................................................. ........ 1043.3 Calculated Load .................................................................. ........ 1053.5 Special Pillars ........................................................... ................... 1053.7 Pillars Under the Tops of Deep Tanks ......................................... 1053.9 Bulkhead Stiffening ............................................................. ........ 1063.11 Attachments ............................................................. ................... 106

5 Deck Girders and Transverses ....................................................... 1065.1 General................................................................................ ........ 1065.3 Deck Girders Clear of Tanks ....................................................... 1065.5 Deck Transverses Clear of Tanks ............................................... 1075.7 Proportions ............................................................... ................... 1075.9 Tripping Brackets ................................................................ ........ 1085.11 End Attachments ................................................................. ........ 1085.13 Deck Girders and Transverses in Tanks ..................................... 1085.15 Hatch Side Girders .............................................................. ........ 108

7 Hatch-end Beams ........................................................................... 1087.1 Hatch-end Beam Supports .......................................................... 1087.3 Weather Deck Hatch-end Beams ................................................ 1097.5 Depth and Thickness ........................................................... ........ 1097.7 Tripping Brackets ................................................................ ........ 1097.9 Brackets ................................................................... ................... 109

9 Higher-strength Materials ................................................................ 1109.1 General................................................................................ ........ 1109.3 Girders and Deck Transverses .................................................... 110

FIGURE 1 Deck Girders and Pillars ....................................................... 107FIGURE 2 Hatch-end Beams ................................................................. 110


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SECTION 9 Watertight Bulkheads and Doors ...................................................... 1111 General ........................................................................................... 111

1.1 Application ................................................................... ................ 1111.3 Openings and Penetrations ......................................................... 1111.5 Sluice Valves and Cocks ............................................................. 111

1.7 Strength Bulkheads ................................................................. .... 1111.9 Testing .............................................................. ........................... 111

3 Arrangement of Watertight Bulkheads ............................................ 1123.1 Collision Bulkhead ................................................................... .... 1123.3 After-peak Bulkhead ................................................................ .... 1123.5 Machinery Spaces ................................................................... .... 1133.7 Hold Bulkheads ............................................................ ................ 1143.9 Chain Lockers .............................................................. ................ 114

5 Construction of Watertight Bulkheads ............................................ 1155.1 Plating ............................................................... ........................... 1155.3 Stiffeners........................................................... ........................... 1155.5 Attachments ................................................................. ................ 1165.7 Girders and Webs .................................................................... .... 118

7 Construction of Corrugated Bulkheads ........................................... 1197.1 Plating ............................................................... ........................... 1197.3 Stiffeners........................................................... ........................... 1197.5 End Connections ..................................................................... .... 119

9 Watertight Doors ............................................................................. 1219.1 Doors Used While at Sea ............................................................. 1219.3 Access Doors Normally Closed at Sea ........................................ 1219.5 Doors or Ramps Dividing Large Cargo Spaces ........................... 1219.7 Other Openings Closed at Sea .................................................... 1219.9 Construction ................................................................. ................ 1219.11 Testing Watertight Door at Manufacturer ..................................... 122

TABLE 1 Thickness and Flanges of Brackets and Knees .................... 117FIGURE 1 Collision Bulkhead in Vessels with Bow Door ....................... 113FIGURE 2 Reference Point for Vessels with Bulbous Bow .................... 113FIGURE 2A .................................................................................................. 114FIGURE 2B .................................................................................................. 114FIGURE 3 Corrugated Bulkhead ............................................................ 119FIGURE 4 Corrugated Bulkhead End Connections ................................ 120FIGURE 5 Corrugated Bulkhead Upper Stool Credit ............................. 120

SECTION 10 Deep Tanks ......................................................................................... 1231 General ........................................................................................... 123

1.1 Application ................................................................... ................ 1231.3 Arrangement ................................................................ ................ 1231.5 Construction ................................................................. ................ 1231.7 Drainage and Air Escape ............................................................. 1231.9 Testing .............................................................. ........................... 123


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3 Construction of Deep Tank Bulkheads ........................................... 1233.1 Plating .......................................................... ............................... 1233.3 Stiffeners .................................................................. ................... 1243.5 Tank-top Plating .................................................................. ........ 1253.7 Girders and Webs ............................................................... ........ 1253.9 Corrugated Bulkheads ................................................................. 125

5 Higher-strength Materials ................................................................ 1265.1 General................................................................................ ........ 1265.3 Plating .......................................................... ............................... 1265.5 Stiffeners .................................................................. ................... 126

SECTION 11 Superstructures, Deckhouses and Helicopter Decks ..................... 1271 General Scantlings of Superstructures and Deckhouses ............... 127

1.1 Side Plating .............................................................. ................... 1271.3 Decks ........................................................... ............................... 1271.5 Frames ..................................................................... ................... 1271.7 Breaks in Continuity ............................................................ ........ 127

3 Exposed Bulkheads ........................................................................ 1273.1 General................................................................................ ........ 1273.3 Plating .......................................................... ............................... 1283.5 Stiffeners .................................................................. ................... 1283.7 End Attachments ................................................................. ........ 1293.9 Raised Quarter Deck Bulkheads ................................................. 129

5 Enclosed Superstructures and Deckhouses ................................... 1315.1 Openings in Bulkheads................................................................ 1315.3 Doors for Access Openings ......................................................... 1315.5 Sills of Access Openings ............................................................. 1315.7 Portlights .................................................................. ................... 1315.9 Bridges and Poops .............................................................. ........ 131

7 Open Superstructures ..................................................................... 1319 Forecastle Structures ...................................................................... 13111 Helicopter Decks ............................................................................. 132

11.1 General................................................................................ ........ 13211.3 Structure ................................................................... ................... 13211.5 Safety Net ................................................................. ................... 13311.7 Material ..................................................................... ................... 13311.9 Means of Escape and Access ..................................................... 133

TABLE 1 Values of a............................................................................ 130TABLE 2 Values off............................................................................. 130TABLE 3 Allowable Factors of Safety Based on Yfor Helicopter

Decks .................................................................................... 133SECTION 12 Machinery Space and Tunnel ............................................................ 134

1 General ........................................................................................... 1341.1 Arrangement ............................................................. ................... 1341.3 Testing of Tunnels ............................................................... ........ 134


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3 Engine Foundations ........................................................................ 1343.1 Engine Foundations in Double-bottom Vessels ........................... 1343.3 Boiler Foundations ................................................................... .... 1343.5 Thrust Foundations .................................................................. .... 1343.7 Shaft Stools and Auxiliary Foundations ....................................... 135

5 Tunnels and Tunnel Recesses ....................................................... 1355.1 Plating ............................................................... ........................... 1355.3 Stiffeners........................................................... ........................... 1355.5 Beams, Pillars and Girders .......................................................... 1355.7 Tunnels Through Deep Tanks ..................................................... 135

SECTION 13 Stems, Stern Frames, Rudder Horns, and Propeller Nozzles ......... 1361 Stems .............................................................................................. 136

1.1 Plate Stems ................................................................. ................ 1361.3 Cast-steel Stems ..................................................................... .... 136

3 Stern Frames .................................................................................. 1363.1 General ............................................................. ........................... 1363.3 Rudder Gudgeons ................................................................... .... 1363.5 Scantlings Below the Propeller Boss ........................................... 1363.7 Stern Frames with Shoe Piece .................................................... 1383.9 Scantlings Above the Propeller Boss ........................................... 1383.11 Secondary Members ................................................................ .... 1383.13 Shoe Pieces ................................................................. ................ 138

5 Rudder Horns .................................................................................. 1405.1 Scantlings Single Pintle Rudders .............................................. 1405.3 Scantlings Two Pintle Rudders ................................................. 1415.5 Floors ................................................................ ........................... 1415.7 Shell Plating ................................................................. ................ 1415.9 Water Exclusion ........................................................... ................ 141

7 Propeller Nozzles ............................................................................ 1437.1 Application ................................................................... ................ 1437.3 Design Pressure .......................................................... ................ 1437.5 Nozzle Cylinder ............................................................ ................ 1447.7 Nozzle Section Modulus .............................................................. 1447.9 Welding Requirement .............................................................. .... 146

9 Inspection of Castings ..................................................................... 146TABLE 1 Coefficient c........................................................................... 143TABLE 2 Coefficient ........................................................................... 143TABLE 3 Coefficient cn......................................................................... 144TABLE 4 Corrosion Allowance tc.......................................................... 144FIGURE 1 Stern Frame .......................................................................... 137FIGURE 2 Shoe Piece ............................................................................ 139FIGURE 3 Rudder Horn .......................................................................... 142

FIGURE 4 Propeller Nozzle Section View .............................................. 145


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SECTION 14 Rudders and Steering Equipment .................................................... 1471 General ........................................................................................... 147

1.1 Application ................................................................ ................... 1471.3 Materials for Rudder, Rudder Stock and Steering Equipment ..... 1471.5 Expected Torque ................................................................. ........ 147

1.7 Rudder Stops ........................................................... ................... 148

3 Rudder Design Force ...................................................................... 1483.1 Rudder Blades without Cutouts ................................................... 1483.3 Rudders Blades with Cutouts ...................................................... 1483.5 Rudders Blades with Twisted Leading-Edge ............................... 149

5 Rudder Design Torque .................................................................... 1525.1 General................................................................................ ........ 1525.3 Rudders without Cutouts ............................................................. 1525.5 Rudders Blades with Cutouts ...................................................... 1535.7 Rudders with Twisted Leading Edge ........................................... 1535.9 Trial Conditions ................................................................... ........ 153

7 Rudder Stocks ................................................................................ 1537.1 Upper Rudder Stocks .......................................................... ........ 1537.3 Lower Rudder Stocks .......................................................... ........ 1537.5 Rudder Stock Sealing .......................................................... ........ 154

9 Flange Couplings ............................................................................ 1549.1 General................................................................................ ........ 1549.3 Horizontal Couplings ........................................................... ........ 1559.5 Vertical Couplings ............................................................... ........ 155

11 Tapered Stock Couplings................................................................ 15611.1 Coupling Taper .................................................................... ........ 15611.3 Keyed Fitting ............................................................ ................... 15711.5 Keyless Fitting ..................................................................... ........ 15711.7 Locking Nut .............................................................. ................... 157

13 Pintles ............................................................................................. 15813.1 General................................................................................ ........ 158

15 Supporting and Anti-Lifting Arrangements ...................................... 15815.1 Bearings ................................................................... ................... 15815.3 Rudder Carrier ..................................................................... ........ 15915.5 Anti-lifting Devices ............................................................... ........ 159

17 Double Plate Rudder ....................................................................... 16017.1 Strength .................................................................... ................... 16017.3 Side, Top and Bottom Plating ...................................................... 16217.5 Diaphragm Plates ................................................................ ........ 16217.7 Watertightness .................................................................... ........ 162

19 Single Plate Rudders ...................................................................... 16319.1 Mainpiece Diameter ............................................................ ........ 16319.3 Blade Thickness .................................................................. ........ 16319.5 Arms ............................................................. ............................... 163

21 Steering Nozzles ............................................................................. 16321.1 Application Scope ................................................................ ........ 16321.3 Design Force ............................................................................... 164


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21.5 Design Torque ............................................................. ................ 16521.7 Nozzle Stock ................................................................................ 16521.9 Design Pressure .......................................................... ................ 16621.11 Plate Thickness ........................................................... ................ 16621.13 Section Modulus ...................................................................... .... 16621.15 Locking Device ............................................................ ................ 16621.17 Welding Requirement .................................................. ................ 166

23 Azimuthal Thruster .......................................................................... 16723.1 Plans and Documents .............................................................. .... 16723.3 Application Scope .................................................................... .... 16723.5 Locking Device ............................................................ ................ 16723.7 Design Force ............................................................... ................ 16823.9 Design Torque ............................................................. ................ 16923.11 Design Pressure .......................................................... ................ 16923.13 Nozzle Scantlings .................................................................... .... 16923.15 Steering Tube ................................................... ........................... 16923.17 Section Modulus ...................................................................... .... 17023.19 Welding Requirement .................................................. ................ 170

25 Azimuthing Pod ............................................................................... 17025.1 General Remarks ..................................................................... .... 17025.3 Application Scope .................................................................... .... 17125.5 Plans and Documents .............................................................. .... 17125.7 Material Requirements ............................................................. .... 17225.9 Locking Device ............................................................ ................ 17225.11 Direct Analysis ............................................................................. 17225.13 Strength Criteria ........................................................... ................ 17325.15 Additional Requirements .............................................................. 17325.17 Structural Transition ................................................................. .... 17525.19 Service Accessibility ...... .............................................................. 17525.21 Air and Drainage Escape ............................................................. 17525.23 Watertightness ............................................................. ................ 17625.25 Welding Requirements............................................................. .... 176

TABLE 1A Coefficient kcfor Ordinary Rudders ....................................... 150TABLE 1B Coefficient kcfor High-Lift/Performance Rudders ................. 150TABLE 2 Coefficient kl.......................................................................... 152TABLE 3 Coefficient .......................................................................... 152TABLE 4 Minimum Bearing ForceBmin................................................. 158TABLE 5 Bearing Reaction Force ........................................................ 160TABLE 6 Allowable Bearing Surface Pressure .................................... 160TABLE 7 Permissible Stress Values .................................................... 173FIGURE 1 Rudder Blade without Cutouts .............................................. 151FIGURE 2 Rudder Blade with Cutouts ................................................... 151FIGURE 3 Tapered Couplings ................................................................ 156FIGURE 4 ..................................................................................................... 161


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FIGURE 5 Nozzle Geometry .................................................................. 164FIGURE 6 Azimuthal Thruster ................................................................ 168FIGURE 7 Pod Propulsion Unit .............................................................. 170FIGURE 8 Hull Supporting Structure ...................................................... 175

SECTION 15 Protection of Deck Openings ............................................................ 1841 General ........................................................................................... 1843 Positions and Design Pressures ..................................................... 184

3.1 Positions of Deck Openings ........................................................ 1843.3 Vertical Weather Design Pressures ............................................. 1843.5 Horizontal Weather Design Pressures ........................................ 187

5 Hatchway Coamings ....................................................................... 1885.1 Height of Coamings ............................................................. ........ 1885.3 Coaming Plates ................................................................... ........ 1895.5 Coaming Stiffening .............................................................. ........ 1895.7 Protection of Coaming Edges ...................................................... 1895.9 Continuous Longitudinal Hatch Coamings................................... 189

7 Hatchways Closed by Portable Covers and SecuredWeathertight by Tarpaulins and Battening Devices ........................ 1897.1 Pontoon Covers ................................................................... ........ 1897.3 Wood Hatch Covers ............................................................ ........ 1907.5 Steel Hatch Covers ............................................................. ........ 1917.7 Bearing Surface ................................................................... ........ 1917.9 Materials Other Than Steel .......................................................... 191

9 Hatchways Closed by Covers of Steel Fitted with Gaskets andClamping Devices ........................................................................... 1919.1 Strength of Covers .............................................................. ........ 1919.3 Local Net Plate Thickness ........................................................... 1939.5 Net Scantlings of Secondary Stiffeners ....................................... 1949.7 Net Scantlings of Primary Supporting Members .......................... 1959.9 Cargo Loads ............................................................. ................... 1969.11 Container Loads .................................................................. ........ 1979.13 Loads due to Elastic Deformations of the Vessels Hull .............. 1989.15 Strength Calculations ............................................... ................... 1989.17 Buckling Strength of Hatch Cover Structures .............................. 1999.19 Details of Hatch Covers ............................................................... 2139.21 Hatch Coaming Strength Criteria ................................................. 2149.23 Closing Arrangements ................................................................. 2179.25 Corrosion Addition and Steel Renewal ........................................ 221

11 Hatchways in Decks at Higher Levels ............................................ 22111.1 Gasketless Covers .............................................................. ........ 221

13 Hatchways in Lower Decks or within Fully EnclosedSuperstructures ............................................................................... 22213.1 General................................................................................ ........ 22213.3 Beams and Wood Covers............................................................ 22213.5 Steel Covers ............................................................. ................... 22213.7 Wheel Loading .................................................................... ........ 222


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FIGURE 6 General Arrangement of Panel ............................................. 200FIGURE 7 Stiffening Parallel to Web of Primary Supporting Member ... 205FIGURE 8 Stiffening Perpendicular to Web of Primary Supporting

Member ................................................................................. 206FIGURE 9 Dimensions of Stiffeners ....................................................... 212FIGURE 10 Example for Arrangement of Coaming Plates ...................... 217FIGURE 11 Lifting Forces at a Hatch Cover ............................................ 219FIGURE 12 Arrangement of Stiffeners ..................................................... 225FIGURE 13 Example of Primary Securing Method .................................. 226

SECTION 16 Protection of Shell Openings ............................................................ 2321 Cargo, Gangway, or Fueling Ports ................................................. 232

1.1 Construction ............................................................. ................... 2321.3 Location .................................................................... ................... 2321.5 Subdivision Requirements ........................................................... 232

3 Bow Doors, Inner Doors, Side Shell Doors and Stern Doors ......... 2333.1 General................................................................................ ........ 2333.3 Arrangement ............................................................. ................... 233

5 Securing, Locking and Supporting of Doors ................................... 2335.1 Definitions ................................................................. ................... 233

7 Securing and Supporting Devices .................................................. 2347.1 General................................................................................ ........ 2347.3 Bow Doors ................................................................ ................... 2347.5 Side Shell and Stern Doors ......................................................... 234

9 Securing and Locking Arrangement ............................................... 2349.1 General................................................................................ ........ 2349.3 Operation .................................................................. ................... 234

11 Tightness ........................................................................................ 23511.1 Bow Doors ................................................................ ................... 23511.3 Inner Doors ............................................................... ................... 23511.5 Side Shell and Stern Doors ......................................................... 23511.7 Testing at Watertight Door Manufacturer..................................... 235

13 Bow Door Scantlings ....................................................................... 23513.1 General................................................................................ ........ 23513.3 Primary Structure ................................................................ ........ 235

13.5 Secondary Stiffeners ........................................................... ........ 23513.7 Plating .......................................................... ............................... 23513.9 Securing and Supporting Devices ............................................... 23613.11 Visor Door Lifting Arms and Supports ......................................... 236

15 Inner Door Scantlings ..................................................................... 23615.1 General................................................................................ ........ 23615.3 Primary Structure ................................................................ ........ 23615.5 Securing and Supporting Devices ............................................... 237

17 Side Shell Door and Stern Door Scantlings .................................... 23717.1 General................................................................................ ........ 23717.3 Primary Structure ................................................................ ........ 237


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17.5 Secondary Stiffeners.................................................................... 23717.7 Plating ............................................................... ........................... 23717.9 Securing and Supporting Devices ................................................ 237

19 Bow Door Design Loads ................................................................. 23819.1 External Pressure .................................................................... .... 23819.3 External Forces ............................................................ ................ 23919.5 Visor Door Forces, Moments and Load Cases ............................ 24019.7 Side-Opening Door Load Cases .................................................. 242

21 Inner Door Design Loads ................................................................ 24221.1 External Pressure .................................................................... .... 24221.3 Internal Pressure ..................................................................... .... 242

23 Side Shell and Stern Doors ............................................................. 24223.1 Design Forces for Primary Members ........................................... 24223.3 Design Forces for Securing or Supporting Devices of Doors

Opening Inwards .......................................................... ................ 24223.5 Design Forces for Securing or Supporting Devices of Doors

Opening Outwards ....................................................................... 24225 Allowable Stresses .......................................................................... 243

25.1 Primary Structure and Securing and Supporting Devices ............ 24325.3 Steel Securing and Supporting Devices Bearing Stress .............. 24325.5 Tensile Stress on Threaded Bolts ................................................ 243

27 Operating and Maintenance Manual ............................................... 24427.1 Manual .............................................................. ........................... 24427.3 Operating Procedures .............................................................. .... 244

FIGURE 1 Entry and Flare Angles .......................................................... 238

FIGURE 2 Definition of mandm........................................................... 240FIGURE 3 Visor Type Bow Door ............................................................ 241

SECTION 17 Bulwarks, Rails, Freeing Ports, Portlights, Ventilators,Tank Vents and Overflows ................................................................. 2451 Bulwarks and Guard Rails .............................................................. 245

1.1 Height on Manned Vessels .......................................................... 2451.3 Strength of Bulwarks ................................................................ .... 2451.5 Guard Rails .................................................................. ................ 245

3 Access and Crew Protection ........................................................... 246

3.1 General ............................................................. ........................... 2463.3 Access to Bow on Tankers .......................................................... 246

5 Freeing Ports ................................................................................... 2495.1 Basic Area ................................................................... ................ 2495.3 Vessels with Less than Standard Sheer ...................................... 2495.5 Trunks ............................................................... ........................... 2495.7 Open Superstructures .............................................................. .... 2495.9 Details of Freeing Ports ........................................................... .... 249

7 Portlights ......................................................................................... 2507.1 Application ................................................................... ................ 2507.3 Location ............................................................ ........................... 2507.5 Construction ................................................................. ................ 250


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9 Ventilators, Tank Vents and Overflows ........................................... 2519.1 General................................................................................ ........ 2519.3 Ventilators ................................................................ ................... 2519.5 Tank Vents and Overflows .......................................................... 2519.7 Ventilators, Tank Vents and Overflows on the Fore Deck ........... 251

TABLE 1 Acceptable Arrangement for Access .................................... 247TABLE 2 760 mm (30 in.) High Tank Vents and Overflows

Thickness and Bracket Standards ........................................ 253TABLE 3 900 mm (35.4 in.) High Ventilator Thickness and Bracket

Standards .............................................................................. 253FIGURE 1 Guardrail Stanchion .............................................................. 246

SECTION 18 Ceiling, Sparring and Protection of Steel ......................................... 2541 Close Ceiling ................................................................................... 2543 Sparring........................................................................................... 2545 Corrosion Protection of Steel .......................................................... 254

5.1 All Spaces ................................................................ ................... 2545.3 Cargo Holds on Bulk Carriers (including Combination

Carriers) .............................................................................. ........ 2545.5 Fuel Oil Tanks ..................................................................... ........ 255

FIGURE 1 Extent of Coatings ................................................................. 255SECTION 19 Weld Design ........................................................................................ 256

1 Fillet Welds ..................................................................................... 2561.1 General................................................................................ ........ 256

3 Tee Connections ............................................................................. 2563.1 Size of Fillet Welds .............................................................. ........ 2563.3 Length and Arrangement of Fillet ................................................ 2573.5 Intermittent Welding at Intersection ............................................. 2573.7 Welding of Longitudinal to Plating ............................................... 2573.9