Bulk Carriers for Service on the Great Lakes - Eagle.org

Rules for Building and Classing

Bulk Carriers for Service on the Great Lakes

July 2022

RULES FOR BUILDING AND CLASSING

BULK CARRIERS FOR SERVICE ON THE GREAT LAKESJULY 2022

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

© 2022 American Bureau of Shipping. All rights reserved.ABS Plaza1701 City Plaza DriveSpring, TX 77389 USA

Foreword (1 January 2008)In 2008, Part 1, "Conditions of Classification" was consolidated into a generic booklet, entitled Rules forConditions of Classification (Part 1) for all vessels other than those in offshore service. The purpose of thisconsolidation was to emphasize the common applicability of the classification requirements in "Part 1" toABS-classed vessels, other marine structures and their associated machinery, and thereby make"Conditions of Classification" more readily a common Rule of the various ABS Rules and Guides, asappropriate.

Thus, this supplement specifies only the unique requirements applicable to bulk carriers for service on theGreat Lakes. This supplement is always to be used with the aforementioned Rules for Conditions ofClassification (Part 1).

ABS RULES FOR BUILDING AND CLASSING BULK CARRIERS FOR SERVICE ON THE GREAT LAKES •2022

ii

Hull Construction and Equipment

CONTENTSCHAPTER 1 General..................................................................................................1

Section 1 Definitions.......................................................................... 2Section 2 General Requirements ......................................................3

CHAPTER 2 Hull Structures and Arrangements.................................................. 12Section 1 Longitudinal Strength ......................................................17Section 2 Shell Plating ....................................................................32Section 3 Decks ..............................................................................34Section 4 Bottom Structure .............................................................41Section 5 Framing ...........................................................................44Section 6 Watertight Bulkheads ......................................................49Section 7 Tank Boundary Bulkheads .............................................. 56Section 8 Superstructures and Deckhouses ...................................61Section 9 Protection of Deck Openings (9 May 1996) ....................67Appendix 1 Calculation of Shear Stresses ........................................ 71

CHAPTER 3 Equipment.......................................................................................... 75Section 1 Anchoring, Mooring and Towing Equipment ................... 76

PART 3


iii

C H A P T E R 1General

CONTENTSSECTION 1 Definitions............................................................................................ 2

1 Length ............................................................................................23 Breadth........................................................................................... 25 Depth ............................................................................................. 27 Draft................................................................................................29 Strength Deck ................................................................................2

SECTION 2 General Requirements ........................................................................31 Arrangements ................................................................................ 33 Breaks ............................................................................................35 Structural Sections..........................................................................3

TABLE 1 Scantlings – Inch Units...........................................................3

TABLE 2 ............................................................................................. 10

PART 3


1


S E C T I O N 1Definitions

1 LengthL is the length between perpendiculars, in ft (m), measured on the estimated summer load waterline fromthe fore side of the stem to the centerline of the rudder stock.

3 BreadthB is the greatest molded breadth, in ft (m).

5 DepthD is the molded depth at side, in ft (m), measured at the middle of L, from the molded baseline to the top ofthe strength deck beams.

7 Draftd is the molded draft, in ft (m), from the molded baseline to the summer load waterline.

9 Strength DeckThe strength deck is the deck which forms the top of the effective hull girder at any part of its length. See3-2-1/5.1.

PART 3


2


S E C T I O N 2General Requirements

1 ArrangementsA transverse watertight bulkhead is to be provided at the forward end of the machinery space and acollision bulkhead is to be provided in accordance with Section 3-2-6. An afterpeak bulkhead is to be fittedto enclose the shaft tube in a watertight compartment. In addition, intermediate bulkheads or equivalentsupporting arrangements are to be provided in such number and location which will, when acting inconjunction with the web frames and deep arches, provide adequate transverse strength in the hull.

3 BreaksSpecial care is to be taken throughout the structure to provide against local stress concentrations at the endsof the cargo spaces, superstructures, etc.

5 Structural SectionsThe scantling requirements of these Rules are applicable to structural angles, channels, bars, and rolled orbuilt-up sections. The required section moduli of members; such as girders, webs, etc., supporting framesand stiffeners are to be obtained on an effective width of plating basis as described below unless otherwisenoted. The section is to include the structural member in association with an effective width of platingequal to one-half the sum, of spacing on each side of the member, or 33% of the unsupported span ℓ,whichever is less; for girders and webs along hatch openings, an effective breadth of plating equal toonehalf the spacing or 16.5% of the unsupported span ℓ, whichever is less, is to be used. The requiredsection modulus of each frame and stiffener is assumed to be provided by the stiffener and one frame spaceof the plating to which it is attached.

TABLE 1 Scantlings – Inch Units

1 2 3 4 5 6 7 8 9

Length ofVessel

BasicDepth

BasicDesignDraft

Bottom &Side Shell

(1,7)

ImmersedBox &Stern

Plating

Shell atEnds

Forecastleand Poop

Sides

CenterKeelson (8)

Floors &Side

Keelson

400 26.67 16.0 0.40 0.45 0.42 0.36 3312 × 0 . 42 0.30

410 26.97 16.4 0.41 0.45 0.42 0.36 3414 × 0 . 42 0.30

PART 3


3

1 2 3 4 5 6 7 8 9

Length ofVessel

BasicDepth

BasicDesignDraft

Bottom &Side Shell

(1,7)

ImmersedBox &Stern

Plating

Shell atEnds

Forecastleand Poop

Sides

CenterKeelson (8)

Floors &Side

Keelson

420 27.27 16.8 0.42 0.46 0.42 0.36 3434 × 0 . 43 0.31

430 27.56 17.2 0.43 0.46 0.42 0.36 3512 × 0 . 43 0.31

440 27.85 17.6 0.44 0.47 0.42 0.36 36 × 0 . 44 0.32

450 28.13 18.0 0.45 0.47 0.42 0.36 3634 × 0 . 44 0.32

460 28.40 18.4 0.46 0.47 0.43 0.37 3712 × 0 . 44 0.32

470 28.66 18.8 0.47 0.48 0.43 0.37 38 × 0 . 45 0.33

480 28.92 19.2 0.48 0.48 0.43 0.37 3834 × 0 . 45 0.33

490 29.17 19.6 0.49 0.48 0.43 0.37 3914 × 0 . 46 0.34

500 29.41 20.0 0.50 0.49 0.43 0.37 40 × 0 . 46 0.34

510 29.65 20.4 0.50 0.49 0.43 0.37 4034 × 0 . 46 0.34

520 29.89 20.8 0.51 0.49 0.44 0.38 4112 × 0 . 47 0.35

530 30.11 21.2 0.52 0.49 0.44 0.38 42 × 0 . 47 0.35

540 30.34 21.6 0.53 0.50 0.44 0.38 4212 × 0 . 48 0.36

550 30.56 22.0 0.54 0.50 0.44 0.38 4114 × 0 . 48 0.36

560 30.77 22.4 0.55 0.51 0.44 0.38 44 × 0 . 48 0.36

570 30.98 22.8 .056 0.51 0.45 0.39 3412 × 0 . 49 0.37

580 31.18 23.2 0.57 0.52 0.45 0.39 4514 × 0 . 49 0.37

590 31.38 23.6 0.58 0.52 0.45 0.39 4534 × 0 . 50 0.38

600 31.58 24.0 0.59 0.53 0.45 0.39 4612 × 0 . 50 0.38

610 31.77 24.4 0.60 0.53 0.45 0.39 4714 × 0 . 50 0.38

620 31.96 24.8 0.61 0.53 0.46 0.40 4712 × 0 . 51 0.39

630 32.14 25.2 0.62 0.54 0.46 0.40 4812 × 0 . 51 0.39

640 32.32 25.6 0.63 0.54 0.46 0.40 49 × 0 . 52 0.40

650 32.50 26.0 0.64 0.54 0.46 0.40 4534 × 0 . 52 0.40

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


4

1 2 3 4 5 6 7 8 9

Length ofVessel

BasicDepth

BasicDesignDraft

Bottom &Side Shell

(1,7)

ImmersedBox &Stern

Plating

Shell atEnds

Forecastleand Poop

Sides

CenterKeelson (8)

Floors &Side

Keelson

660 32.67 26.4 0.65 0.55 0.46 0.40 4812 × 0 . 52 0.40

670 32.84 26.8 0.66 0.55 0.47 0.41 51 × 0 . 53 0.41

680 33.1 27.2 0.67 0.55 0.47 0.41 4534 × 0 . 53 0.41

690 33.17 27.6 0.68 0.56 0.47 0.41 4714 × 0 . 54 0.42

700 33.33 28.0 0.69 0.56 0.47 0.41 53 × 0 . 54 0.42

710 33.81 28.0 0.69 0.57 0.47 0.41 5314 × 0 . 54 0.42

720 34.29 28.0 0.70 0.57 0.48 0.42 5312 × 0 . 55 0.43

730 34.76 28.0 0.71 0.58 0.48 0.42 5334 × 0 . 55 0.43

740 35.24 28.0 0.72 0.58 0.48 0.42 54 × 0 . 56 0.44

750 35.71 28.0 0.73 0.58 0.48 0.42 5414 × 0 . 56 0.44

760 36.19 28.0 0.74 0.59 0.48 0.42 5412 × 0 . 56 0.44

770 36.67 28.0 0.75 0.59 0.49 0.43 5434 × 0 . 57 0.45

780 37.14 28.0 0.76 0.59 0.49 0.43 55 × 0 . 57 0.45

790 37.62 28.0 0.77 0.60 0.49 0.43 5514 × 0 . 58 0.46

800 38.10 28.0 0.78 0.60 0.49 0.43 5512 × 0 . 58 0.46

810 38.57 28.0 0.79 0.60 0.49 0.43 5534 × 0 . 58 0.46

820 39.05 28.0 0.80 0.61 0.50 0.44 56 × 0 . 59 0.47

830 39.52 28.0 0.81 0.61 0.50 0.44 5614 × 0 . 59 0.47

840 40.00 28.0 0.82 0.61 0.50 0.44 5612 × 0 . 60 0.48

850 40.48 28.0 0.83 0.62 0.50 0.44 5634 × 0 . 60 0.48

860 40.95 28.0 0.84 0.62 0.50 0.44 57 × 0 . 60 0.48

870 41.43 28.0 0.85 0.62 0.50 0.44 5714 × 0 . 61 0.49

880 41.90 28.0 0.86 0.62 0.50 0.44 5712 × 0 . 61 0.49

890 42.38 28.0 0.87 0.62 0.50 0.44 5734 × 0 . 62 0.50



5

1 2 3 4 5 6 7 8 9

Length ofVessel

BasicDepth

BasicDesignDraft

Bottom &Side Shell

(1,7)

ImmersedBox &Stern

Plating

Shell atEnds

Forecastleand Poop

Sides

CenterKeelson (8)

Floors &Side

Keelson

900 42.86 28.0 0.88* 0.62 0.50 0.44 58 × 0 . 62 0.50

910 43.33 28.0 0.88* 0.62 0.50 0.44 5814 × 0 . 62 0.50

920 43.81 28.0 0.89* 0.62 0.50 0.44 5812 × 0 . 62 0.50

930 44.29 28.0 0.90* 0.62 0.50 0.44 5834 × 0 . 62 0.50

940 44.76 28.0 0.91* 0.62 0.50 0.44 59 × 0 . 62 0.50

950 45.24 28.0 0.92* 0.62 0.50 0.44 5914 × 0 . 62 0.50

960 45.71 28.0 0.93* 0.62 0.50 0.44 5912 × 0 . 62 0.50

970 46.19 28.0 0.94* 0.62 0.50 0.44 5934 × 0 . 62 0.50

980 46.67 28.0 0.95* 0.62 0.50 0.44 60 × 0 . 62 0.50

990 47.14 28.0 0.96* 0.62 0.50 0.44 6014 × 0 . 62 0.50

1000 47.62 28.0 0.97* 0.62 0.50 0.44 6012 × 0 . 62 0.50

1100 52.38 28.0 0.97* 0.62 0.50 0.44 6034 × 0 . 62 0.50

1200 57.14 28.0 0.97* 0.62 0.50 0.44 61 × 0 . 62 0.50

* The tabular thickness for side shell plating for vessels 900 ft and over in length may be taken as 0.88 in.

Notes

1) Frame Spacing Correction. Where the spacing of transverse or longitudinal frames is less than 36in., the thickness of shell plating within 0.67L may be reduced 0.01 in. for each in. of decrease inspacing.

2) Depth Correction. Where the depth of vessel is greater than the basic depth, col. 2, the thicknessof bottom and side plating may be reduced at the rate of 0.005 in. for each additional ft of depth inexcess of the tabular value.

3) Draft Correction. The thickness of bottom and side plating is to be increased 0.01 in. for each ft ofdraft in excess of the basic draft, col. 3.

4) Transverse Framing Correction. Where the bottom shell is transversely framed, the thickness ofbottom plating and the spacing of side keelsons is to be specially considered.

5) Minimum Thickness. The thickness tmin of shell plating within 0.67L amidships, after allcorrections have been made, is not to be less than obtained from the following equation.tmin = st/36 inwhere



6

t = thickness from Col. 4.s = spacing of frames not to be taken as less than 36 in. at L = 400 ft and 30 in. at L ≥ 1000ft; intermediate values to be obtained by interpolation.

6) Bilge Plating. The thickness of the bilge plating is to be in all cases 0.06 in. greater than thethickness required for the bottom shell plating.

7) Longitudinal Bulkheads. Where continuous longitudinal side tank bulkheads are not fitted betweenthe freeboard deck and the bottom shell, the thickness of side shell plating is to be increased 0.04in.

8) Center Keelson. Where drafts exceed the basic draft, col. 3, the depth of center keelson is to beincreased at the rate of 1 in. per ft of excess draft.

TABLE 1 (Continued) Scantlings – Metric Units

1 2 3 4 5 6 7 8 9

Length ofVessel

BasicDepth

BasicDesignDraft

Bottom &Side Shell

(1,7)

ImmersedBox &Stern

Plating

Shell atEnds

Forecastleand Poop

Sides

CenterKeelson (8)

Floors &Side

Keelson

122 8.13 4.88 10.0 11.5 10.5 9.0 850 × 10 . 5 7.5

125 8.22 5.00 10.5 11.5 10.5 9.0 870 × 10 . 5 7.5

128 8.31 5.12 10.5 11.5 10.5 9.0 885 × 11 . 0 8.0

131 8.40 5.24 11.0 11.5 10.5 9.0 900 × 11 . 0 8.0

134 4.49 5.36 11.0 12.0 10.5 9.0 915 × 11 . 0 8.0

137 8.57 5.49 11.5 12.0 10.5 9.0 935 × 11 . 0 8.0

140 8.66 5.61 11.5 12.0 11.0 9.5 950 × 11 . 0 8.0

143 8.74 5.73 12.0 12.0 11.0 9.5 965 × 11 . 5 8.5

146 8.81 5.85 12.0 12.0 11.0 9.5 985 × 11 . 5 8.5

149 8.89 5.97 12.5 12.0 11.0 9.5 995 × 11 . 5 8.5

152 8.96 6.10 12.5 12.5 11.0 9.5 1015 × 11 . 5 8.5

155 9.04 6.22 12.5 12.5 11.0 9.5 1035 × 11 . 5 8.5

158 9.11 6.34 13.0 12.5 11.0 9.5 1050 × 12 . 0 9.0

162 9.18 6.46 13.0 12.5 11.0 9.5 1065 × 12 . 0 9.0

165 9.25 6.58 13.5 12.5 11.0 9.5 1080 × 12 . 0 9.0

168 9.31 6.71 13.5 12.5 11.0 9.5 1100 × 12 . 0 9.0

171 9.38 6.83 14.0 13.0 11.0 9.5 1120 × 12 . 0 9.0

174 9.44 6.95 14.0 13.0 11.5 10.0 1130 × 12 . 5 9.5

177 9.50 7.07 14.5 13.0 11.5 10.0 1150 × 12 . 5 9.5

180 9.56 7.19 14.5 13.0 11.5 10.0 1160 × 12 . 5 9.5

183 9.63 7.31 15.0 13.5 11.5 10.0 1180 × 12 . 5 9.5



7

1 2 3 4 5 6 7 8 9

Length ofVessel

BasicDepth

BasicDesignDraft

Bottom &Side Shell

(1,7)

ImmersedBox &Stern

Plating

Shell atEnds

Forecastleand Poop

Sides

CenterKeelson (8)

Floors &Side

Keelson

186 9.68 7.44 15.0 13.5 11.5 10.0 1200 × 12 . 5 9.5

189 9.74 7.56 15.5 13.5 11.5 10.0 1215 × 13 . 0 10.0

192 9.80 7.68 15.5 13.5 11.5 10.0 1230 × 13 . 0 10.0

195 9.85 7.8 16.0 13.5 11.5 10.0 1245 × 13 . 0 10.0

198 9.91 7.92 16.5 13.5 11.5 10.0 1265 × 13 . 0 10.0

201 9.96 8.05 16.5 14.0 11.5 10.0 1285 × 13 . 0 10.0

204 10.01 8.17 17.0 14.0 12.0 10.5 1295 × 13 . 5 10.5

207 10.06 8.29 17.0 14.0 12.0 10.5 1315 × 13 . 5 10.5

210 10.11 8.41 17.5 14.0 12.0 10.5 1325 × 13 . 5 10.5

213 10.16 8.53 17.5 14.0 12.0 10.5 1345 × 13 . 5 10.5

216 10.30 8.53 17.5 14.5 12.0 10.5 1355 × 13 . 5 10.5

219 10.45 8.53 18.0 14.5 12.0 10.5 1360 × 14 . 0 11.0

222 10.59 8.53 18.0 14.5 12.0 10.5 1365 × 14 . 0 11.0

226 10.74 8.53 18.5 14.5 12.0 10.5 1370 × 14 . 0 11.0

229 10.88 8.53 18.5 14.5 12.0 10.5 1380 × 14 . 0 11.0

232 11.03 8.53 19.0 15.0 12.0 10.5 1385 × 14 . 0 11.0

235 11.18 8.53 19.0 15.0 12.5 11.0 1390 × 14 . 5 11.5

238 11.32 8.53 19.5 15.0 12.5 11.0 1395 × 14 . 5 11.5

241 11.47 8.53 19.5 15.0 12.5 11.0 1405 × 14 . 5 11.5

244 11.61 8.53 20.0 15.0 12.5 11.0 1410 × 14 . 5 11.5

247 11.76 8.53 20.0 15.0 12.5 11.0 1415 × 14 . 5 11.5

250 11.90 8.53 20.5 15.5 12.5 11.0 1420 × 15 . 0 12.0

253 12.05 8.53 20.5 15.5 12.5 11.0 1430 × 15 . 0 12.0

256 12.19 8.53 20.5 15.5 12.5 11.0 1435 × 15 . 0 12.0

259 12.34 8.53 21.0 15.5 12.5 11.0 1440 × 15 . 0 12.0

262 12.48 8.53 21.5 15.5 12.5 11.0 1450 × 15 . 0 12.0

265 12.63 8.53 21.5 15.5 12.5 11.0 1455 × 15 . 5 12.5

268 12.77 8.53 22.0 15.5 12.5 11.0 1460 × 15 . 5 12.5

271 12.92 8.53 22.0 15.5 12.5 11.0 1465 × 15 . 5 12.5

274 13.06 8.53 22.5* 15.5 12.5 11.0 1475 × 15 . 5 12.5



8

1 2 3 4 5 6 7 8 9

Length ofVessel

BasicDepth

BasicDesignDraft

Bottom &Side Shell

(1,7)

ImmersedBox &Stern

Plating

Shell atEnds

Forecastleand Poop

Sides

CenterKeelson (8)

Floors &Side

Keelson

277 13.21 8.53 22.5* 15.5 12.5 11.0 1480 × 15 . 5 12.5

280 13.35 8.53 22.5* 15.5 12.5 11.0 1485 × 15 . 5 12.5

283 13.5 8.53 23.0* 15.5 12.5 11.0 1490 × 15 . 5 12.5

286 13.64 8.53 23.0* 15.5 12.5 11.0 1500 × 15 . 5 12.5

290 13.79 8.53 23.5* 15.5 12.5 11.0 1505 × 15 . 5 12.5

293 13.93 8.53 23.5* 15.5 12.5 11.0 1510 × 15 . 5 12.5

296 14.08 8.53 24.0* 15.5 12.5 11.0 1520 × 15 . 5 12.5

299 14.22 8.53 24.0* 15.5 12.5 11.0 1525 × 15 . 5 12.5

302 14.37 8.53 24.5* 15.5 12.5 11.0 1530 × 15 . 5 12.5

305 14.51 8.53 24.5* 15.5 12.5 11.0 1535 × 15 . 5 12.5

335 15.96 8.53 24.5* 15.5 12.5 11.0 1545 × 15 . 5 12.5

366 17.42 8.53 24.5* 15.5 12.5 11.0 1550 × 15 . 5 12.5

* The tabular thickness for side shell plating for vessels 274 m and over in length may be taken as 22.5mm

Notes

1) Frame Spacing Correction. Where the spacing of transverse or longitudinal frames is less than915 mm, the thickness of shell plating within 0.67L may be reduced 1.0 mm for each 100 mm ofdecrease in spacing.

2) Depth Correction. Where the depth of vessel is greater than the basic depth, col. 2, the thicknessof bottom and side plating may be reduced at the rate of 0.04 mm for each additional 100 mm ofdepth in excess of the tabular value.

3) Draft Correction. The thickness of bottom and side plating is to be increased 0.09 mm for each100 mm of draft in excess of the basic draft, col. 3.

4) Transverse Framing Correction. Where the bottom shell is transversely framed, the thickness ofbottom plating and the spacing of side keelsons is to be specially considered.

5) Minimum Thickness. The thickness tmin of shell plating within 0.67L amidships, after allcorrections have been made, is not to be less than obtained from the following equation.tmin = st/915 inwheret = thickness from Col. 4.s = spacing of frames not to be taken as less than 915 mm at L = 122 m and 760 mm at L ≥

305 m; intermediate values to be obtained by interpolation.

6) Bilge Plating. The thickness of the bilge plating is to be in all cases 1.5 mm greater than thethickness required for the bottom shell plating.



9

7) Longitudinal Bulkheads. Where continuous longitudinal side tank bulkheads are not fitted betweenthe freeboard deck and the bottom shell, the thickness of side shell plating is to be increased 1.0mm.

8) Center Keelson. Where drafts exceed the basic draft, col. 3, the depth of center keelson is to beincreased at the rate of 8.4 mm per 100 mm of excess draft.

TABLE 2Thickness and Flanges of Brackets

Where brackets at end connections of girders, webs and stringers are fitted having thicknesses not less than the girder orweb plates, the value for t may be modified in accordance with the following:

● Where the face area on the bracket is not less than one-half that on the girder or web and the face bar or flange on thegirder or web is carried to the bulkhead or base, the length ℓ may be measured to a point 6 in. (150 mm) on to thebracket.

● Where the face area on the bracket is less than one-half that on the girder or web and the face bar or flange on thegirder or web is carried to the bulkhead or base, ℓ may be measured to a point where the area of the bracket and itsflange, outside the line of the girder or web, is equal to the flange area on the girder.

● Where the flange area of the girder or web is carried along the face of the bracket, which may be curved for thepurpose, ℓ may be measured to the point of the bracket.

● Brackets are not to be considered effective beyond the point where the length of arm on the girder or web is 112 timesthe length of the arm on the bulkhead or base; in no case is the allowance in ℓ at either end to exceed one-quarter ofthe overall length of the girder or web.

● Brackets are not to be considered effective beyond the point where the depth of longer arm exceeds 112 times thedepth of the shorter arm.

Inches Millimeters

Depth ofLonger Arm

Thickness Width ofFlange

Depth ofLonger Arm

Thickness Width ofFlangePlain Flanged Plain Flanged

6.0 0.26 150 6.5

7.5 0.28 175 7.0

9.0 0.30 0.26 114 200 7.0 6.5 30

10.5 0.32 0.26 114 225 7.5 6.5 30

12.0 0.34 0.28 112 250 8.0 6.5 30

13.5 0.36 0.28 112 275 8.0 7.0 35

15.0 0.38 0.30 134 300 8.5 7.0 35

16.5 0.40 0.30 134 325 9.0 7.0 40

18.0 0.42 0.32 2 350 9.0 7.5 40

19.5 0.44 0.32 2 375 9.5 7.5 45



10

Inches Millimeters

Depth ofLonger Arm

Thickness Width ofFlange

Depth ofLonger Arm

Thickness Width ofFlangePlain Flanged Plain Flanged

21.0 0.46 0.34 214 400 10.0 7.5 45

22.5 0.48 0.34 214 425 10.0 8.0 45

24.0 0.50 0.36 212 450 11.5 8.0 50

25.5 0.52 0.36 212 475 11.0 8.0 50

27.0 0.54 0.38 234 500 11.0 8.5 55

28.5 0.56 0.38 234 525 11.5 8.5 55

30.0 0.58 0.40 3 550 12.0 8.5 55

33.0 0.42 314 600 12.5 9.0 60

36.0 0.44 312 650 13.0 9.5 65

39.0 0.46 334 700 14.0 9.5 70

42.0 0.48 4 750 14.5 10.0 75

45.0 0.50 414 800 10.5 80

850 10.5 85

900 11.0 90

950 11.5 90

1000 11.5 95

1050 12.0 100

1100 12.5 105

1150 12.5 110

1200 13.0 110



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

CONTENTSSECTION 1 Longitudinal Strength .......................................................................17

1 General.........................................................................................173 Longitudinal Hull Girder Strength .................................................17

3.1 Strength Standard............................................................173.3 Total Bending Moment..................................................... 183.5 Permissible Shear Stress................................................ 21

5 Strength Deck and Other Effective Decks.................................... 225.1 Strength Deck.................................................................. 225.3 Effective Lower Decks..................................................... 23

7 Loading Guidance (14 May 1991) ............................................... 239 Higher-Strength Materials ............................................................23

9.1 General............................................................................ 239.3 Hull-girder Section Modulus.............................................239.5 Permissible Shear Stress................................................ 249.7 Hull-girder Moment of Inertia........................................... 24

TABLE 1 Combined Dynamic Bending Moment Distribution Factor... 25TABLE 2 Values of Z, in in2, for Q = 1.0 (Ordinary Strength Steel)......26TABLE 2 Values of Z, in in2, for Q = 0.78 ............................................27TABLE 2 Values of Z, in in2, for Q = 0.72.............................................28TABLE 2 Values of Z, in cm2, for Q = 1.0 (Ordinary Strength Steel)....29TABLE 2 Values of Z, in cm2, for Q = 0.78...........................................30TABLE 2 Values of Z, in cm2, for Q = 0.72...........................................31

FIGURE 1 Envelope of Wave-Induced Shearing Forces.......................25

SECTION 2 Shell Plating ...................................................................................... 321 Amidships..................................................................................... 323 Sheerstrake.................................................................................. 325 End Plating .................................................................................. 327 Compensation ..............................................................................32

PART 3


12

9 Special Material ........................................................................... 3211 Higher-strength Steel ...................................................................33

11.1 Bottom Plating................................................................. 3311.3 Side Shell Plating.............................................................3311.5 End Plating...................................................................... 33

SECTION 3 Decks ................................................................................................. 341 General ........................................................................................343 Testing.......................................................................................... 345 Plating ..........................................................................................34

5.1 Freeboard Deck............................................................... 345.3 Lower Decks.................................................................... 345.5 Superstructure Decks and Tops of Houses..................... 355.7 Special Material Requirements........................................35

7 Beams...........................................................................................359 Deep Beams and Girders............................................................. 36

9.1 Strength Requirements....................................................369.3 Proportions...................................................................... 369.5 Proportions of Deep Beams and Girders in Tanks...........369.7 Arch Beams..................................................................... 36

11 Special Heavy Beams and Girders ..............................................3713 Openings ..................................................................................... 3715 Higher-strength Steel ...................................................................37

15.1 Freeboard Deck Plating................................................... 3715.3 Lower Decks, Superstructure Decks, Deckhouse

Tops, and Girder Webs.................................................... 3715.5 Section Modulus.............................................................. 38

17 Continuous Longitudinal Hatch Coamings (14 May 1991) .......... 3819 Hopper Slope (1 July 2017)..........................................................38

19.1 Hopper Slope as a Part of a Tank....................................3819.3 Hopper Slope not a Part of a Tank...................................38

TABLE 1 Minimum Thickness of Deck Plating ................................... 40

SECTION 4 Bottom Structure .............................................................................. 411 General.........................................................................................413 Center Keelson ............................................................................415 Side Keelsons ..............................................................................417 Floors ...........................................................................................41

7.1 Bilge Brackets..................................................................419 Lightening and Access Holes....................................................... 4211 Inner Bottom Plating .................................................................... 4213 Bottom Structure in Self-unloading Vessels..................................42


13

13.1 Inner Bottom Plating........................................................ 4213.3 Floors...............................................................................4213.5 Longitudinal Girders.........................................................42

15 Higher-strength Materials ............................................................ 4315.1 General............................................................................ 4315.3 Inner Bottom Plating........................................................ 4315.5 Center Girders, Side Girders, and Floors........................ 4315.7 Bottom Girders in Self-unloading Vessels....................... 43

SECTION 5 Framing ..............................................................................................441 General ........................................................................................443 Scantlings..................................................................................... 445 Frame Spacing ............................................................................ 447 Bottom ......................................................................................... 449 Inner Bottom Longitudinals ..........................................................4511 Stringers and Webs ..................................................................... 45

11.1 Strength Requirements....................................................4511.3 Proportions...................................................................... 4611.5 Stiffeners and Tripping Brackets......................................46

13 Special Strengthening ..................................................................4615 Topside Tunnel or Side Tank Structure ........................................4617 Higher-strength Steel ...................................................................46

17.1 Section Modulus.............................................................. 4617.3 Plating..............................................................................47

19 Struts............................................................................................ 47

SECTION 6 Watertight Bulkheads ....................................................................... 491 General.........................................................................................493 Arrangement of Watertight Bulkheads .........................................49

3.1 Collision Bulkheads......................................................... 493.3 After Peak Bulkheads...................................................... 493.5 Machinery Space............................................................. 49

5 Chain Lockers ..............................................................................497 Construction of Watertight Bulkheads ......................................... 49

7.1 Plating..............................................................................497.3 Stiffeners..........................................................................507.5 Stringers and Webs......................................................... 507.7 Watertight Doors..............................................................517.9 Testing............................................................................. 51

9 Higher-strength Steel ...................................................................519.1 Section Modulus.............................................................. 519.3 Plating..............................................................................52

11 Construction of Screen Bulkheads (1 July 2017)..........................52


14

13 Construction of Corrugated Bulkheads (Not in way of CargoHolds)........................................................................................... 5513.1 Self-propelled Vessels..................................................... 5513.3 Barges............................................................................. 55

FIGURE 1 Curves for Watertight Bulkhead Plating Thickness –Inch Units ............................................................................ 53

FIGURE 1 Curves for Watertight Bulkhead Plating Thickness –Metric Units ......................................................................... 54

FIGURE 2 Screen Bulkhead Section Modulus Calculation –Double Hulls (1 July 2017)...................................................55

SECTION 7 Tank Boundary Bulkheads ...............................................................561 General ........................................................................................563 Construction of Tank Boundary Bulkheads...................................56

3.1 Plating..............................................................................563.3 Stiffeners..........................................................................563.5 Stringers and Webs......................................................... 573.7 Attachments.....................................................................573.9 Corrugated Bulkheads..................................................... 57

5 Testing ......................................................................................... 587 Topside Tunnel or Side Tank Bulkheads ......................................589 Higher-strength Steel....................................................................58

9.1 Section Modulus.............................................................. 589.3 Plating..............................................................................58

FIGURE 1 Curves for Tank Bulkhead Plating Thickness – Inch Units ..59FIGURE 1 Curves for Tank Bulkhead Plating Thickness – Metric

Units ....................................................................................60

SECTION 8 Superstructures and Deckhouses ...................................................611 Superstructures ........................................................................... 61

1.1 Side Plating......................................................................611.3 Side Frames.................................................................... 611.5 Decks...............................................................................621.7 Superstructure Bulkheads and Deckhouse

Bulkheads on Freeboard Deck........................................ 621.9 Windlass Room Bulkhead................................................63

3 Deckhouses on Superstructure Decks ........................................ 633.1 Bulkheads........................................................................ 633.3 Stacks.............................................................................. 643.5 House Tops......................................................................64

5 Openings...................................................................................... 655.1 .........................................................................................65


15

5.3 .........................................................................................657 Higher-strength Steel ...................................................................65

7.1 Section Modulus.............................................................. 657.3 Deck Plating.....................................................................657.5 Side and Bulkhead Plating...............................................65

FIGURE 1 Swage Panel........................................................................63

SECTION 9 Protection of Deck Openings (9 May 1996) .................................... 671 General.........................................................................................672 Position of Deck Openings .......................................................... 675 Hatchway Coamings ....................................................................67

5.1 Height of Coamings......................................................... 675.3 Coaming Plates............................................................... 675.5 Coaming Stiffening.......................................................... 685.7 Continuous Longitudinal Hatch Coamings.......................68

7 Hatchways Closed by Sectional Sliding Covers and SecuredWeathertight by Tarpaulins and Battening Devices ..................... 687.1 Sliding Steel Hatch Covers.............................................. 687.3 Cleats...............................................................................687.5 Wedges............................................................................687.7 Battening Bars................................................................. 687.9 Tarpaulins........................................................................ 687.11 Security of Hatchway Covers...........................................68

9 Hatchways Closed by Covers of Steel Fitted with Gasketsand Clamping Devices .................................................................699.1 Strength of Covers...........................................................699.3 Other Materials................................................................ 699.5 Means for Securing Weathertightness.............................69

11 Miscellaneous Openings in Freeboard and SuperstructureDecks ...........................................................................................7011.1 Manholes and Scuttles.................................................... 7011.3 Other Openings............................................................... 7011.5 Escape Openings............................................................ 7011.7 Companionway Sills........................................................ 70

APPENDIX 1 Calculation of Shear Stresses ......................................................... 711 General ........................................................................................713 Shear Stress ................................................................................715 Allowable Still-water Shearing Force............................................72

FIGURE 1 Shear Distribution Configurations Type 1.............................72


16


S E C T I O N 1Longitudinal Strength

1 GeneralVessels of 400 ft (122 m) to 1200 ft (366 m) in length, intended to be classed for Great Lakes service, areto have longitudinal strength in accordance with the requirements of this Section. The equations in thisSection are valid for vessels having depths not less than L/15 at 400 ft (122 m) length and L/21 at 700 ft(213 m) length and over. Intermediate values will be determined by interpolation. Vessels whose depths areless than this, or which have an arrangement departing from those specified by the Rules, will be subject tospecial consideration. In general, the breadth of the vessel is not to exceed 2.6 times the depth of thevessel.

3 Longitudinal Hull Girder Strength

3.1 Strength Standard3.1.1 Section Modulus

The hull-girder section modulus amidships SM expressed in inches squared-feet (centimeterssquared-meters), is not to be less than obtained from the following equation:SM = Mt/fpwhereMt = total vertical bending moment, in long tons-feet (metric tons-meters), see 3-2-1/3.3fp = permissible bending stress, in long tons per inch squared (metric tons per centimeter

squared), for ordinary strength steel= 12 . 367 + 1 . 4 L1000 − 2 . 667 L1000 2 400 ≤ L ≤ 700 ft = 12 . 709 + 0 . 287 L1000 − 1 . 788 L1000 2 700 < L ≤ 850 ft= 11 . 479 + 3 . 2 L1000 − 3 . 5 L1000 2 850 < L ≤ 1050 ft= 15 . 74− 4 . 533 L1000 1050 < L ≤ 1200 ft= 1 . 948 + 0 . 221 L305 − 0 . 42 L305 2 122 ≤ L ≤ 213 m

PART 3


17

= 2 . 001 + 0 . 045 L305 − 0 . 28 L305 2 213 < L ≤ 259 m= 1 . 808 + 0 . 504 L305 − 0 . 551 L305 2 259 < L ≤ 320 m= 2 . 478− 0 . 714 L305 320 < L ≤ 366 mL = length of vessel, in ft (m), as defined in 3-1-1/1

The required hull-girder section modulus at locations other than amidships is to be obtained usingthe fp, values given above and the maximum total bending moment Mt determined from theenvelope curves of still-water and combined dynamic bending moments (see 3-2-1/3.1.2 and3-2-1/3.3). In general, the hull-girder section modulus throughout 0.67L amidships is to be not lessthan that required at amidships. Special consideration will be given to the approval, away fromamidships, of still-water bending moments greater than the maximum permissible midship value.

3.1.2 Minimum Section ModulusThe hull-girder section modulus amidships, expressed in inches squared feet (centimeterssquaredmeters), for all vessels with lengths from 400 ft (122 m) to 1200 ft (366 m) is not to be lessthan the minimum determined SM from 3-2-1/9.7 TABLE 2.

Where the maximum still-water bending moment is not greater than the minimum value Ms, givenin 3-2-1/3.1.1, the required section modulus amidships as specified in 3-2-1/3.1.1 may bedetermined directly from 3-2-1/9.7 TABLE 2.

3.1.3 Section Modulus Calculation● Deck plating (strength deck and other effective decks)

● Shell and inner-bottom plating

● Deck and bottom girders

● Plating and longitudinal stiffeners of longitudinal bulkheads

● All longitudinals of deck, sides, bottom and inner bottom

● Deep longitudinal bottom girders and crown plates in self-unloading vessels

The items included in the hull-girder section modulus amidships are generally to be extendedthroughout the 0.67L, amidships and gradually tapered beyond. In general, the net sectional areasof longitudinal strength members are to be used in the hull-girder section modulus calculations.

The section modulus to the deck or bottom is obtained by dividing the moment of inertia by thedistance from the neutral axis to the molded deck fine at side or to the base line respectively.

3.1.4 Section Modulus with Continuous Coaming (14 May 1991)Where longitudinal coamings of length greater than 0.14L are provided, they are to comply withthe requirements of 3-2-3/17. Such continuous coamings may be included in the calculation ofhull girder inertia which is to be divided by the sum of the distance from neutral axis to deck atside and the height of continuous hatch coaming, to obtain the section modulus to the top of thecoaming.

3.3 Total Bending MomentThe total bending moment Mt, expressed in long tons-feet (metric tons-meters), is to be obtained from thefollowing equation:Mt = Msw+Mc

Part 3 Hull Construction and EquipmentChapter 2 Hull Structures and ArrangementsSection 1 Longitudinal Strength 3-2-1


18

whereMsw = sill-water bending moment, in long tons-feet (metric tons-meters), see 3-2-1/3.3.1Mc = maximum combined dynamic bending moment, in long tons-feet (metric tons-meters), see3-2-1/3.3.2

3.3.1 Still-water Bending Moment and Shear ForceFor all vessels, still-water bending moments Msw and shear force Fsw calculations for theanticipated loaded and ballasted conditions are to be submitted. The results of these calculationsare to be submitted in the form of curves showing hull-girder shear forces and bending momentvalues along the entire ship length.

In determination of the total bending moment Mt amidships, the value of Msw, is not to be taken asless than the value of Ms obtained from the following equation:Ms = [2 . 64L − 336] B 400 ≤ L ≤ 650 ft = [3 . 0L − 570]B 650 < L ≤ 750 ft = [3 . 2L − 720]B 750 < L ≤ 850 ft = [3 . 867L − 1287]B 850 < L ≤ 1000 ft = [74 . 34(L/100)2− 10 . 34L+ 5482]B 1000 < L ≤ 1200 ft = [8 . 8L − 341]B 122 ≤ L ≤ 198 m = [10 . 0L − 579]B 198 < L ≤ 229 m = [10 . 67L − 732]B 229 < L ≤ 259 m = [12 . 89L − 1308]B 259 < L ≤ 305 m = [75 . 54(L/30 . 5)2− 34 . 47L+ 5571]B 305 < L ≤ 366 m

3.3.2 Combined Dynamic Bending Moment AmidshipsThe combined dynamic bending moment Mc amidships, in long tons-feet (metric tons-meters),may be obtained from the following equation:Mc = Cs Mw2 +Msp2

where

Mw = maximum-wave-induced bending moment amidships, in long tons-feet (metric tons-meters), see 3-2-1/3.3.3Msp = maximum springing bending moment amidships, in long tons-feet (metric tons-meters), see 3-2-1/3.3.4Cs = correlation coefficient= 0 . 995 – 0 . 172[(L/1000) – 0 . 4]2 inch/poundunits = 0 . 995− 0 . 172[(L/305)− 0 . 4]2 metricunitsL = length of vessel, in ft (m), as defined in 3-1-1/1



19

The maximum combined dynamic bending moment at locations other than amidships may bedetermined in accordance with the distribution factor given in 3-2-1/9.7 TABLE 1.

Consideration will be given to the combined dynamic as well as the wave-induced and springingbending moments calculated by means of a statistical analysis based on ship motion and vibrationcalculations in realistic sea states. In such cases, the calculations, computer programs used, and thecomputed results are to be submitted for review.

3.3.3 Wave-induced Bending Moment AmidshipsThe maximum wave-induced bending moment amidships, in long tons-feet (metric tons-meters),may be obtained from the following equations:Mw = CwB(L/1000)2 t − ft Mw = CwB(L/305)2 t −mwhereCw = 9113− 1 . 410L 400 ≤ L ≤ 600 ft = 8850− 0 . 972L 600 < L ≤ 800 ft = 8663− 0 . 738L 800 < L ≤ 1000 ft = 8518− 0 . 593L 1000 < L ≤ 1200 ft = 9261− 4 . 700L 122 ≤ L ≤ 183 m = 8993− 3 . 240L 183 < L ≤ 244 m = 8803− 2 . 460L 244 < L ≤ 305 m = 8656− 1 . 977L 305 < L ≤ 366 m L and B are as defined in Section 3-1-1.

3.3.4 Springing Bending Moment AmidshipsThe maximum springing bending moment amidships, in long tons-feet (metric tons-meters), maybe obtained from the following equations.Msp = CCspB(L/1000)3 t − ft Msp = CCspB(L/305)3 t −mwhereC = 2296− 0 . 3839L 400 ≤ L ≤ 600 ft = 2224− 0 . 2640L 600 < L ≤ 800 ft = 2173− 0 . 2001L 800 < L ≤ 1000 ft = 2134− 0 . 1606L 1000 < L ≤ 1200 ft = 2333− 1 . 2798L 122 ≤ L ≤ 183 m= 2260− 0 . 8800L 183 < L ≤ 244 m



20

= 2208− 0 . 6670L 244 < L ≤ 305 m= 2168− 0 . 5353L 305 < L ≤ 366 m Csp = 5 . 58− ω 1 . 0 ≤ ω ≤ 2 . 0= 5 . 06/ ω 2 . 0 < ωω = Cf ID2Y / B3d/ 0 . 1L 2 inch/ pounds units

= Cf27 . 33 ID2Y / B3d / 0 . 1L 2 metric unitsCf = 1645− 0 . 7549L 400 ≤ L ≤ 600 ft = 1483− 0 . 4836L 600 < L ≤ 800 ft = 1374− 0 . 3479L 800 < L ≤ 1000 ft = 1294− 0 . 2678L 1000 < L ≤ 1200 ft = 1645− 2 . 4768L 122 ≤ L ≤ 183 m = 1483− 1 . 5867L 183 < L ≤ 244 m = 1374− 1 . 1411L 244 < L ≤ 305 m= 1294− 0 . 8784L 305 < L ≤ 366 mY = distance from the neutral axis to the strength deck at side or to the bottom shell, in ft(m), whichever is greaterI = moment of inertia of the midship section, in in 2 - ft2 (cm2 - m2)L,B,D,d are as defined in Section 3-1-1.

The actual moment of inertia Iof the vessel is to be used for calculating Msp. When the value of Iis changed as a result of section modulus modifications, the modified I is to be used forcalculating the new Msp and new section modulus requirements. When the actual value of I is notknown at the early design stages, the I values determined from 3-2-1/9.7 TABLE 2 may be takenas initial value.

3.5 Permissible Shear StressIn general, the thicknesses of the side shell and longitudinal bulkhead, where fitted, are to be such that thetotal shear stresses as obtained from 3-2-1/3.5.1 are not greater than 6.75 long tons per inch squared (1.065metric tons per centimeter squared) provided the critical shear buckling stress of the plating is satisfactory.

3.5.1 Calculation of Shear StressesIn calculating the total shear stresses due to still-water and dynamic loads in the side shell andlongitudinal bulkhead plating, the maximum numerical sum of the shearing force in still waterFsw and that induced by wave and springing Fd at the station examined, is to be used. For vesselswithout continuous longitudinal bulkheads, the total shear stress fs in the side shell plating clear ofthe wing tanks may be obtained from the following equation:fs = Fsw+ Fd m/ 24tI t/in2fs = (Fsw+ Fd)m/(200tI) t/cm2



21

wherefs = total shear stress, in long tons per inch squared (metric tons per centimeter squared)I = moment of inertia, in in2- ft2 (cm2- m2) of the hull girder section at the section underconsiderationm = first moment, in in2- ft2 (cm2- m2), about the neutral axis, of the area of the effectivelongitudinal material, taken at the section under considerationt = thickness, in in. (cm), of the side shell plating at the position under considerationFsw = as specified by 3-2-1/3.5.2Fd = as specified by 3-2-1/3.5.2

The total shear stress in the side shell in way of wing tanks, and for vessels having continuouslongitudinal bulkheads, the total shear stress in the side shell and longitudinal bulkhead plating isto be calculated by an acceptable method. One simplified method is shown in Appendix A.Consideration will be given to alternative methods for shear stress calculations.

3.5.2 Hull-girder Shearing ForceThe hull-girder shearing forces in still water Fsw, are to be submitted as required by 3-2-1/3.3.1.The envelope curve of maximum shearing forces induced by wave and springing Fd as shown in3-2-1/9.7 TABLE 1 may be obtained from the following equation:Fd = KMc/LwhereFd = maximum shearing force induced by wave and springing, in long tons (metric tons)Mc = maximum combined dynamic hull-girder bending moment amidships, in long tons-

feet (metric-tons-meters), as specified by 3-2-1/3.3.2L = length of vessel, in ft (m), as defined in 3-1-1/1K = 3.4 between 0.85L and 0.70L= 2.3 between 0.60L and 0.45L= 3.2 between 0.35L and 0.20L= 0.0 at FP and AP

The length range is measured from the AP, and at intermediate locations the K value may beobtained by interpolation.

5 Strength Deck and Other Effective Decks

5.1 Strength DeckThe uppermost deck to which the side shell plating extends for any part of the length of the vessel is to beconsidered the strength deck for that portion the length. The thickness of the stringer plates and deckplating are to comply with the requirement of 3-2-3/5. In general, the effective sectional area of the deckfor calculating the section modulus is to exclude hatchways and other openings in the deck and is to bemaintained throughout 0.67L amidships.



22

5.3 Effective Lower DecksTo be considered effective for use in calculating the hull-girder section modulus, the thickness of the deckplating is to comply with the requirement of 3-2-3/5. The sectional areas of effective lower decks used incalculating the section modulus are to be generally maintained throughout 0.67L amidships.

7 Loading Guidance (14 May 1991)A loading manual based on still-water bending conditions is to be provided on all vessels and submitted forreview. This manual is to show the effect of the various loaded and ballasted conditions upon thelongitudinal bending. The loading manual is to indicate the still-water bending moments at amidships andat other locations along the length of the vessel as necessary.

A loading instrument where installed is to be of a type suitable for the intended service. The checkconditions and other relevant data are to be submitted for review. The accuracy of the loading instrument isto be checked at regular intervals by applying approved test loading conditions. In the event the loadinginstrument malfunctions, the loading manual is to be used, for assessing the suitability of the intendedloading condition.

9 Higher-Strength Materials

9.1 GeneralVessels in which the effective longitudinal material of the upper, lower, or both flanges of the main., hullgirder are constructed of materials having mechanical properties greater than those of ordinary-strengthhull structural steel are to have longitudinal strength generally, in accordance with the precedingparagraphs of this section, except as modified by 3-2-1/9. Applications of higher-strength material are tobe continuous throughout the midship 0.67L of the vessel, and are to be extended to suitable locationsbelow the strength deck and above the bottom, so that the stress levels will be satisfactory also for the mildsteel structure. Longitudinal framing members are to be essentially of the same material as the plating theysupport. Calculations showing that adequate strength has been provided against buckling are to besubmitted for review. Care is to be taken against the adoption of reduced thicknesses of members whichmay be subject to damage during normal operation.

9.3 Hull-girder Section ModulusWhen either the top or bottom of the hull girder, or both, is constructed of higher-strength material, thesection modulus SMℎts may be obtained from 3-2-1/3.3.1 by substituting the permissible stress fp withfp/Q.SMℎts = Mt/(fp/Q) whereQ = 70900/ Y+ 2U/3 inch/pound units

= 49 . 92/(Y+ 2U/3) metric units

Y =specified minimum yield point for the higher-strength material or its specified minimum yieldat 0.2% offset, or 72% of the specified minimum strength, in psi (kg/mm2), whichever is thelesserU = specified minimum tensile strength of the higher-strength material, in psi (kg/mm2)Mt = total bending moment, in long tons-feet (metric tons-meters), see 3-2-1/3.3

For determining the maximum total bending moment Mt, the actual moment of inertia of thehigherstrength midship section is to be used to calculate Mspa s specified in 3-2-1/3.3.4.



23

The value of fp/Q is not to be taken greater than the critical buckling stress of the deck and bottomplating. Special consideration will be given to the application of Q less than 0.72.

In addition, the hull-girder section modulus amidships of a vessel constructed of higher-strength materialsis also not to be less than the minimum SM given in 3-2-1/9.7 TABLE 2 for Q = 0.78 or 0.72. Forintermediate Q values, the minimum SM may he obtained by interpolation.

9.5 Permissible Shear StressWhere the side shell or longitudinal bulkhead is constructed of higher-strength material, the permissibleshear stresses indicated in 3-2-1/3.5 may be increased by the factor 1/Q, provided the critical bucklingstress of the plating is satisfactory.

9.7 Hull-girder Moment of InertiaAs specified in 3-2-1/3.3.4, the actual moment of inertia of the midship section for a vessel constructed ofhigher-strength material is to be used to calculate the springing bending moment. A set of initial values of Iis shown in 3-2-1/9.7 TABLE 2, for ordinary-strength steel Q = 1 . 0 and for higher-strength materialswith Q = 0.78 and 0.72 respectively. For higher-strength materials with Q values between 0.72 and 1.00,the initial I values may be obtained by interpolation. The inertia of a vessel constructed of higher-strengthmaterial in the top, bottom or both flanges of the hull girder is to be not less than obtained from thefollowing equation:Iℎts = 0 . 45 SM DawhereIℎts = hull girder moment of inertia of higher-strength material, in in2- ft2 (cm2-m2)SM = minimum hull-girder section modulus of an ordinary strength steel vessel of the same

dimensions as determined from 3-2-1/3.1.2Da = basic depth from 3-1-2/5 TABLE 1, column 2



24

FIGURE 1 Envelope of Wave-Induced Shearing Forces

TABLE 1Combined Dynamic Bending Moment Distribution Factor

Intermediate values of distribution factor may be determined by interpolation.

Position Distribution Factor

Station 0 AP 0

2 0.17

4 0.57

6 0.76

8 0.95

9 1.00

10 1.00

11 1.00

12 0.96

14 0.76

16 0.44

18 0.12

20 FP 0



25

TABLE 2 Values of Z, in in2, for Q = 1.0 (Ordinary Strength Steel)

ZB = Minimum SMZBD/2 = Initial Values of IB,D, and d are as defined in Section 3-1-1, in ft, Q is as defined in 3-2-1/9.3.



26

TABLE 2 Values of Z, in in2, for Q = 0.78

ZB = Minimum SM



27

ZBD/2 = Initial Values of IB,D, and d are as defined in Section 3-1-1, in ft, Q is as defined in 3-2-1/9.3.

TABLE 2 Values of Z, in in2, for Q = 0.72




28

TABLE 2 Values of Z, in cm2, for Q = 1.0 (Ordinary Strength Steel)




29

TABLE 2 Values of Z, in cm2, for Q = 0.78




30

TABLE 2 Values of Z, in cm2, for Q = 0.72




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S E C T I O N 2Shell Plating

1 AmidshipsThe thickness of the shell plating within the midship 0.67L is not to be less than is required for purposes oflongitudinal hull girder strength in accordance with 3-2-1/1 nor is it to be less than is required by 3-2-1/9.7TABLE 1, column 4, with associated footnotes. The thickness of the bilge plating is to be in all cases 0.06in. (1.5 mm) greater than the thickness required for the bottom shell plating.

3 SheerstrakeThe thickness of the sheerstrake within the midship 0.67L, is to approximate that of the stringer plate onthe freeboard deck. The top edge of the sheerstrake is to be smooth and, in general, fittings are not to bewelded to the top edge of the sheerstrake within the midship 0.75L.

5 End PlatingThe thickness of shell plating at ends, and immersed bow and stern plating is to be in accordance with3-1-2/5 TABLE 1, columns 6 and 5, respectively. End thicknesses are not to extend for more than 0.1L, atends and are to be gradually tapered to the midship thickness. Plate thickness and connections to the sternframe and boss are to be specially considered. In the vicinity of the hawse pipes and below the anchorpockets, the plating is to be increased in thickness over a width sufficient to provide added protection inway of the anchor flukes.

7 CompensationAll shell openings are to have well-rounded corners and are to be kept well clear of breaks insuperstructures or other highly stressed areas and local compensation may be required to maintain thelongitudinal and transverse strength of the hull.

9 Special MaterialVessels with a length of 450 ft (137 m) and above are to be provided with sheerstrakes of special materialin accordance with the Marine Vessel Rules. Where a radiused gunwale plate is fitted, the aboverequirements for special material may be modified. Strakes of the same special material are also to beprovided at the lower turn of the bilge in vessel of 450 ft (137 m) in length and above. These strakes ofspecial material are to be extended throughout the midship 0.67L. Riveted seams as an alternative thematerial requirements of this paragraph will be specially considered. See also 3-2-3/5.7.

PART 3


32

11 Higher-strength Steeln general, applications of higher-strength materials for shell plating are to take into consideration thesuitable extension of the higher-strength material above and below the bottom and deck respectively, asrequired by 3-2-1/9.1. Care is to be exercised against the adoption of reduced thickness of material thatmight he subject to damage during normal operation. Calculations showing that adequate, bucklingstrength is provided may be required to be submitted. The thicknesses of longitudinal bottom and. sideshell are not to be less than required for longitudinal strength by Section 3-2-1. The requirement of thepreceding paragraphs of Section 4 may be modified but are not to be less obtained from 3-2-4/15.3 through3-2-4/15.7.

11.1 Bottom PlatingWhere constructed of higher strength steel, the bottom plating is to be not less in thickness than obtainedfrom the following equation:tℎts = (t – c)Q+ cwheretℎts = thickness of higher-strength steel, in in. (mm)t = thickness of ordinary-strength steel, in in. (mm), as required by the preceding paragraphs of this Sectionc = 0.06 in. (1.5 mm)Q is as defined in 3-2-1/9.3.

11.3 Side Shell PlatingWhere constructed of higher-strength steel, the side shell plating is to be not less in thickness than obtainedfrom the following equation:tℎts = (t – c)[(Q+ 2 Q )/3] + c wheretℎts, t, c are as defined in 3-2-2/11.1.Q is as defined in 3-2-1/9.3.

11.5 End PlatingWhere constructed of higher-strength steel, the thickness of end plating, immersed bow, and, stern platingbe subject to special consideration.

Part 3 Hull Construction and EquipmentChapter 2 Hull Structures and ArrangementsSection 2 Shell Plating 3-2-2


33


S E C T I O N 3Decks

1 GeneralStrength decks are to be effectively continuous, preferably in one plane; should they change level, thechange is to be accomplished by a gradually sloping section or by the deck material at each level beingextended so as to provide a suitable overlap and being effectively tied together by diaphragms or webs. Alldecks exposed to the weather are to be weathertight.

3 TestingRiveted boundaries of weathertight decks are to be subjected to hose testing after all fittings affecting theweathertightness are fastened in position, and the pressure of water in the hose is not to be less than 30 psi(2.1 kg/cm2). Decks forming the top of tanks are to be tested as required by Section 3-2-7 and decksforming steps in watertight bulkheads are to be tested as required by Section 3-2-6.

5 Plating

5.1 Freeboard DeckThe exposed plating of the freeboard deck, outboard of the cargo hatchways within the midship 0.67L, is tohave the sectional area required for purposes of longitudinal hull-girder strength as required by 3-2-1/1 andbe of approximately the same thickness as the sheer strake. The stringer plate is to be of sufficient width toextend well inboard of the line of the hatch openings to allow for a generous radius at the corners of theopenings, but where the inboard seam is riveted, this requirement may be modified. At the ends of thevessel, the stringer plate thickness is not to be less than the shell plating thickness at ends, see 3-1-2/5TABLE 1, Column 6. End thicknesses are not to extend for more than 0.1L and are to be gradually taperedto the midship thickness. Local increases in thickness in way of breaks at superstructures may be requiredand will be subject to special consideration. Exposed plating within the line of the hatchway openings is tobe of the thickness required by 3-2-3/19 TABLE 1, line 1. However, the thickness in way of the archbeams is not to be less than that required to provide an efficient top flange for these members. Withinenclosed spaces, the plating thickness within the line of openings is not to be less than required by 3-2-3/19TABLE 1, lines 2 or 3, for platform decks.

5.3 Lower Decks5.3.1 Strength Decks

Lower decks which are considered as effective members of the hull girder (see 3-2-1/1) are to betreated as strength decks (see 3-2-3/1). The thickness of the plating is not to be less than given in

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3-2-3/19 TABLE 1, line 1, or where the deck forms the top of a tank, as required for tankboundary bulkhead plating at that level, see 3-2-7/3.1 whichever is greater.

5.3.2 Platform DecksLower decks which are not considered to be effective decks for longitudinal strength are termedplatform decks. The plating which forms the top of a tank is to be of the thickness required fortank boundary bulkhead plating at that level (see 3-2-7/3.1). Elsewhere, the thickness is not to beless than required by 3-2-3/19 TABLE 1, lines 2 or 3, in way of boilers and within coal hunkers,the thickness is to be increased 0.06 in. (1.5 mm). Platform decks which have a length greater than0.1L are to be fitted with tapering brackets to the shell, the thickness of which may be speciallyconsidered.

5.5 Superstructure Decks and Tops of Houses5.5.1 Forecastle and Poop Decks

Exposed plating of the forecastle and poop decks is to be of the thickness required by 3-2-3/19TABLE 1, line 1,and within enclosed spaces, the thickness is not to be less than given in 3-2-3/19TABLE 1, lines 2 or 3, for platform decks. Where the length of the forecastle or poop exceeds 0.1L, the thickness of the stringer and adjacent plating beyond 0.1L may be required to be increased.In all cases, the thickness of the stringer plate in way of the forecastle or poop bulkhead is to bespecially considered.

5.5.2 Tops of HousesThe plating thickness of the tops of houses is not to be less than required by 3-2-3/19 TABLE 1,line 2, where the house top is at the first level above the freeboard deck, or as required by line 3,where it is at the second level above the freeboard deck, Where deck houses have a length greaterthan 0.1L, the thickness of deck plating may be required to be increased.

5.7 Special Material RequirementsVessels are to have stringer plates of special material in accordance with the Marine Vessel Rules. Thesestrakes are to extend throughout the midship 0.67L. Riveted seams as an alternative to the materialrequirements of this paragraph will be specially considered. See also 3-2-2/9.

7 BeamsBeams supporting decks which form the tops of tanks are to be of the sizes required for tank boundarybulkhead stiffeners at the same level (see 3-2-7/3.3). Elsewhere, each deck beam is to have a sectionmodulus SM not less than obtained from the following equation.SM = 0 . 0041cℎsℓ2 in3

SM = 7 . 9cℎsℓ2 cm3

wherec = 1.00 for longitudinal beams considered as part of the effective hull girder (see 3-2-1/3.1.3)= 0.54 for all other beamsℎ = 7.0 ft (2.13 m) for beams in way of exposed plating of freeboard and forecastle decks= 6.0 ft (1.83 m) for beams of the freeboard and forecastle decks within superstructures of deck houses, and forbeams of effective lower decks and platform decks in machinery spaces= 5.0 ft (1.52 m) for beams of the poop deck and for the tops of houses located aft, forming the first level abovethe freeboard deck

Part 3 Hull Construction and EquipmentChapter 2 Hull Structures and ArrangementsSection 3 Decks 3-2-3


35

= 4.0 ft (1.22 m) for beams of tops of houses forming the second level above the freeboard deck, and for beamsof platform decks outside machinery spaces= 3.0 ft (0.915 m) for beams of tops of houses forming the third and higher levels above the freeboard decks = spacing of the beams, in ft (m)ℓ = span between girders or deep beams or between toes of brackets where fitted in accordance with 3-1-2/5TABLE 2, in ft (m)

9 Deep Beams and Girders

9.1 Strength RequirementsDeep beams and girders are to be so located in relation to webs, bulkheads, etc., as to provide thenecessary continuity for the strength and stiffness of the hull. Those located under decks which form thetops of tanks are to be as required for the stringers of tank boundary bulkheads at the same level.Elsewhere, each is to have section modulus SM not less than obtained from the following equation:SM = 0 . 0025 cbh ℓ2 in3

SM = 4 . 74 cbh ℓ2cm3

wherec = 1.0b = sum of the half breaths of the area supported, in ft (m)ℎ = appropriated value for the location as given in 3-2-3/7ℓ = span between bulkheads or stanchions or other supports, in ft (m)

Where effective brackets are fitted, ℓ may be modified as described in 3-1-2/5 TABLE 2.

9.3 ProportionsIn general, girders and deep beams, except arch beams as given in 3-2-3/9.7, are to have depths not lessthan 0.7 in. per ft (6 mm per 100 mm) of span ℓ. The depth is to be not less than twice the depth of theslots, and the thickness is not to be less than 0.01 in. per in. (1 mm per 100 mm) of depth, plus 0.12 in. (3mm), and may be required to be increased in way of concentrated loads.

9.5 Proportions of Deep Beams and Girders in TanksGirders and deep beams are to have depths not less than 1 in. per ft (8.4 mm per 100 mm) of span ℓ. Thedepth is not to be less than 2.5 times the depth of the slots, and the thickness is not to be less than 0.01 in.per in. (1 mm per 100 mm) of depth plus 0.12 in. (3 mm), but need not exceed 0.44 in. (11 mm).

9.7 Arch BeamsEach arch beam under the freeboard deck is to have a section modulus SM not less than obtained from thefollowing equation:SM = 0 . 0025csℓ2 in3

SM = 4 . 74csℓ2 cm3

where



36

c = 7.0 ft (2.13 m)s = spacing of arch beams, in ft (m)ℓ = span, in ft or m, between longitudinal bulkheads or between the inboard faces or web frames


The depth of arch beams is to be 1 in. per ft (8.4 mm per 100 mm) of span ℓ. The web thickness is not tobe less than 0.38 in. (9.5 mm) in association with brackets and panel stiffeners spaced 36 in. (915 mm).

11 Special Heavy Beams and GirdersSpecial heavy beams and girders are to be arranged as may be required to carry concentrated loads.

13 OpeningsOpenings in decks are to be framed so as to provide efficient support and are to have well rounded corners.Access openings in the freeboard deck, such as companionways or trunks, are to be located well within theline of cargo hatchways. Openings in the stringer plate of the freeboard deck for scuppers and air pipes areto be well rounded and smooth, and generally compensation will not be required.

15 Higher-strength SteelIn general, proposed applications of higher-strength steel for decks are to be accompanied by submissionof calculations in support of adequate strength against buckling. Higher-strength steel members are to becontinuous at their intersection with those of ordinary strength steel. Care is to be exercised to avoid theadoption of reduced thicknesses of material such as might be subject to damage during normal operation.The deck supporting members and the deck plating to which they are attached are to generally have thesame strength properties and strength decks are to be generally longitudinally framed. Subject to theforegoing and compliance with the longitudinal strength requirement of 3-2-1/9, the scantlings given in thepreceding paragraphs of this section may be modified as permitted by 3-2-3/15.1 through 3-2-3/15.5.

15.1 Freeboard Deck PlatingWhere constructed of higher-strength steel, the plate thickness is to be not less than obtained from thefollowing equation.tℎts = (t – c)Q+ cwheretℎts = thickness of higher-strength steel, in in. (mm)t = thickness of ordinary-strength steel, as required by 3-2-3/5.1, in in. (mm)c = 0.06 in. (1.5 mm)Q is as defined in 3-2-1/9.3.

15.3 Lower Decks, Superstructure Decks, Deckhouse Tops, and Girder WebsWhere constructed of higher-strength steel, the plate thickness is not to be less than obtained from thefollowing equation.tℎts = (t – c)[(Q+ 2 Q)/3] + cwhere



37

tℎts = thickness of higher-strength steel, in in. (mm)t = thickness of ordinary-strength steel, in in. (mm), for which a requirement is given in the preceding paragraphsof this sectionc = 0.06 in. (1.5 mm)Q is as defined in 3-2-1/9.3.

15.5 Section ModulusThe section modulus of each higher-strength steel member is not to be less than obtained from thefollowing equation:SMℎts = SM(Q)whereSMℎts = section modulus of higher-strength steel member, in in3 (cm3)SM = section modulus of ordinary-strength steel member, in in3 (cm3), as required by the preceding paragraphs

of this SectionQ is as defined in 3-2-1/9.3.

17 Continuous Longitudinal Hatch Coamings (14 May 1991)Where longitudinal hatch coamings of length greater than 0.14L, are supported by longitudinal bulkheadsor deep girders, they are in general to be longitudinally stiffened. The coaming plates and stiffeners are tohave scantlings as required for decks. Special consideration will be given where calculations are submittedto show adequate buckling strength in the maximum expected sagging conditions.

19 Hopper Slope (1 July 2017)

19.1 Hopper Slope as a Part of a TankWhere the hopper slope forms a part of a tank, the plating and strength requirements are as required fortank boundary bulkhead, see 3-2-7/3.

19.3 Hopper Slope not a Part of a TankWhere hopper slope is not a part of a tank, the hopper slope plating has to meet the minimum thicknessrequirement for inner bottom plating, see 3-2-4/11. In lieu of meeting the inner bottom plating thicknessrequirement 3-2-4/11, the hopper slope plating and stiffeners are to meet 3-2-3/19.3.1 and 3-2-3/19.3.2.

19.3.1 PlatingIn lieu of meeting the inner bottom plating thickness requirement 3-2-4/11, the net thickness of thehopper slope plating is not to be less than t1, t2, and t3, as obtained from the following equations:t1 = 0 . 73s(k1p/f1)1/2 mm(in . )t2 = 0 . 73s(k2p/f2)1/2 mm(in . )t3 = 6 . 35 mm(0 . 25 in . )where



38

s = stiffener spacing, in mm (in.)k1 = 0.342k2 = 0.500p = nominal pressure due to gravity at the lower edge of each plate, in N/cm2 (kgf/cm2, lbf/in2)

= k3ρgℎc[cos2α+ (1 – sinαο)sin2α]k3 = adjustment factor to account for the Great Lakes environment

= 0.870ρg = specific weight of the bulk cargo considered, in N/cm2-m (kgf/cm2-m,lbf/in2-ft).ρg is not to be takenless than 1.471 N/cm2-m (0.15 kgf/cm2-m, 0.6503 lbf/in2-ft)α = slope of wall measured from horizontal plane, in degreesαο = angle of repose for the bulk cargo considered, normally 30 degrees (Re: “Code of Safe Practice forSolid Bulk Cargoes” published by IMO)ℎc = vertical distance from the top cargo surface to the wall point considered in upright condition, in m (ft)f1 = permissible bending stress, in the longitudinal direction, in N/cm2(kgf/cm2, lbf/in2)

= 0 . 60SmYf2 = permissible bending stress, in the vertical direction, in N/cm2 (kgf/cm2,lbf/in2)

= 0 . 85SmYSm = strength reduction factor

= 1 for Ordinary Strength Steel, as specified in 2-1-2/15.9 TABLE 2 of the ABS Rules for Materialsand Welding (Part 2)

= 0.95 for Grade H32, as specified in 2-1-3/7.3 TABLE 2 of the ABS Rules for Materials and Welding(Part 2)

= 0.908 for Grade H36, as specified in 2-1-3/7.3 TABLE 2 of the ABS Rules for Materials and Welding(Part 2)

= 0.875 for Grade H40, as specified in 2-1-3/7.3 TABLE 2 of the ABS Rules for Materials and Welding(Part 2)Y = minimum specified yield point of the plating, in N/cm2 (kgf/cm2, lbf/in2)

Nominal Design Corrosion Value (NDCV) is to be taken as 2 mm (0.08 in.).

19.3.2 StiffenersEach stiffener is to have sufficient section modulusSM to withstand the pressure ρ as defined in19.3.1.



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TABLE 1 Minimum Thickness of Deck Plating

Spacing of Longitudinal orTransverse

in. mm

24 27 30 33 36 610 685 760 835 915

1

Freeboard decks withinline of hatch openings;exposed forecastle andpoop decks; effectivelower decks 0

0.28 0.31 0.33 0.35 0.37 7.00 8.00 8.50 9.00 9.50

2

House tops, first levelabove freeboard deck;platform decks withinenclosed cargo ormachinery spaces

0.25 0.28 0.29 0.30 0.31 6.50 7.00 7.50 8.00 8.00

3

Platform decks withinenclosed passenger orcrew spaces; house tops atsecond level abovefreeboard deck

0.21 0.22 0.24 0.24 0.28 5.50 5.50 6.00 6.50 7.00



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S E C T I O N 4Bottom Structure

1 GeneralA double bottom is to be fitted between peak bulkheads where practicable. In general, it is to be arrangedwith a center keelson and a system of side keelsons and plate floors in accordance with the followingparagraphs.

3 Center KeelsonThe depth and thickness of the center keelson is not to be less than given in 3-1-2/5 TABLE 1, column 8,nor is the depth to be less than 0.75 in. per ft (6.3 mm per 100 mm) of beam B, where B may be measuredbetween longitudinal side tank bulkheads. Where plate floors are spaced more than 3 ft (0.915 m),intermediate stiffening of the keelson may be required. Where floors are spaced more than 7.5 ft (2.3 m),intermediate docking brackets of the same thickness as the floors are to be provided. Docking brackets areto extend and be attached to the first longitudinals outboard. For depth of double bottom requirements forself-unloading vessels, see 3-2-4/13.3.

5 Side KeelsonsFull depth side keelsons, spaced not more than 10 ft (3 m), are to be not less in thickness than given in3-1-2/5 TABLE 1, column 9. Where plate floors are spaced more than 3 ft (0.915 m), intermediatestiffening may be required.

7 FloorsFull depth floors of the thickness given in 3-1-2/5 TABLE 1, column 9, are to be fitted at maximumintervals of 6 ft (1.8 m) in way of the cargo spaces and stiffeners are to be fitted in line with each bottomlongitudinal. Within the machinery space the floors are to be spaced at every frame under the engine,boiler, and major auxiliary foundations. Within the peaks, the spacing of floors is not to be greater than 24in. (610 mm) and the depth, thickness, and stiffening arrangements are to be specially considered. Tankend floors are to meet the requirements for tank bulkheads in the same location.

7.1 Bilge BracketsWhere floors are spaced more than 4 ft (1.2 m), intermediate bilge brackets are to be fitted. Alternatively,the shell at the bilge may be reinforced by one or more suitably spaced longitudinal frames havingscantlings intermediate between the adjacent bottom and side shell longitudinals.

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9 Lightening and Access HolesIn general, the center keelson in way of the double bottom is to be intact, except this requirement may bemodified near the ends of the vessel or where other intact longitudinal divisions are provided. Lighteningand access holes in floors and side keelsons are generally to be located at mid-depth of the member and arenot to have a vertical dimension greater than one-half of the depth of the member. Where lightening oraccess holes are in close proximity to drainage Cut-out or longitudinal frames, chocks or othercompensation may be required. Lightening or access holes are not to be cut in the floors in the panelimmediately inboard of plane of side tank bulkhead or in other location subject to high shear or bucklingloads.

11 Inner Bottom PlatingFlush inner-bottom plating is to be adopted throughout the cargo space and the least thickness is to be 0.50in. (12.5 mm) where stiffeners are spaced 24 in. (610 mm) or less, and 0.75 in. (19 mm) with 36 in. (915mm) stiffener spacing. Other method of construction, such as associated with the use of the channels, willbe specially considered.

13 Bottom Structure in Self-unloading Vessels

13.1 Inner Bottom PlatingWhere the inner bottom is longitudinally framed, plating thicknesses may be determined in accordancewith Section 3-2-7 for tank bulkheads. Where transverse frames are fitted, the plating thicknesses will bespecially considered, taking into account the buckling characteristics of the inner bottom plating.

13.3 FloorsIn vessels where the bottom is supported by a deep centerline girder or a system girders, the depth of thedouble bottom is not to be less than 30 in. (760 mm) or 1.5 in. per ft (12.6 mm per 100 mm) of span,whichever is greater, where the span may be measured between deep girders or between a deep girder andside tank bulkheads. Full-depth floors may be fitted at intervals of not more than 8 ft (2.44 m) andstiffeners are to be fitted in line with each longitudinal. The thickness of the floors may be required to beincreased over the thickness required by 3-1-2/5 TABLE 1, column 9, or intermediate floors added wheresubject to high shear leads.

13.5 Longitudinal GirdersEach longitudinal girder, when fitted, is to have a depth not less than 1.5 in. per ft (12.6 mm per 100 mm)of span ℓ. The required section modulus, SM, is to be not less than obtained from the following equation:SM = 0 . 0025cbℎℓ2 in3

SM = 4 . 74cbℎℓ2 cm3

wherec = 1.5b = sum of half-lengths (on each side of girder) of floors supported, in ft (m)ℎ = one-half the distance from the base line to the load line, in ft (m)

ℓ = span between transverse bulkhead or other supports, in ft (m)

Where effective brackets are fitted,ℓ may be modified as described in 3-1-2/5 TABLE 2.

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15 Higher-strength Materials

15.1 GeneralIn general, proposed application of higher-strength materials for bottom structures are to meet therequirements of this section, but may be modified as permitted by 3-2-4/15.3 through 3-2-4/15.7. Care is tobe exercised to avoid the adoption of reduced thickness of material such as might be subject to damageduring normal operation, and calculations showing adequate buckling strength is provided may be requiredto be submitted. Longitudinal framing members are to be of essentially the same material as the platingthey support.

15.3 Inner Bottom PlatingInner bottom plating ,where constructed of higher-strength material and where longitudinally framed, is tobe not less in thickness than required by preceding paragraphs of this section as modified by the followingequation:tℎts = (t – c)[(Q+ 2 Q)/3] + c wheretℎts = thickness of higher-strength material, in in. (mm)t = thickness of mild steel, as required by preceding paragraphs of this Section, in in. (mm)c = 0.06 in. (1.5 mm)Q is as defined in 3-2-1/9.3.

15.5 Center Girders, Side Girders, and FloorsCenter girders, side girders, and floors, where constructed of higher strength materials, are generally tocomply with requirements of 3-2-4/3, 3-2-4/5, 3-2-4/7, or 3-2-4/13.3 but may be modified as permitted bythe following equation:tℎts = (t – c)[(Q+ 2 Q)/3] + cwheretℎts ,t, c, are as defined in 3-2-4/15.3Q is as defined in 3-2-1/9.3.

15.7 Bottom Girders in Self-unloading VesselsThe section modulus required by 3-2-4/13.5 may be modified provided the plating to which the higherstrength steel girder is attached has the same strength properties. The section modulus of the higherstrength steel girder is not to be less than obtained from the following equation.SMℎts = SM(Q)whereSMℎts = section modulus of higher strength steel members, in in3 (cm3)SM = section modulus of ordinary strength steel members as required by 3-2-4/13.5, in in3 (cm3)Q is as defined in 3-2-1/9.3.

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S E C T I O N 5Framing

1 GeneralThe sizes and arrangement of frames are to be as required by this Section. The equations apply to vesselshaving bulkhead and web frame arrangements as outlined by 3-1-2/1.

3 ScantlingsThe frames may be flat bars, inverted angles, flanged plates, or other rolled structural sections, Holes cut inwebs or outstanding flanges may require compensation.

5 Frame Spacing3-1-2/5 TABLE 1 is based on a 36 in. (915 mm) spacing of frames throughout the midship portion of thevessel, longitudinal framing of the bottom shell, and either transverse or longitudinal framing of the sideshell.

The spacing in peaks and the distance from the stem to the first frame is not to exceed 24 in. (610 mm).

7 BottomEach structural section for bottom longitudinals and shell frames in the side tanks is to have a sectionmodulus SM not less than obtained from the following equation:SM = 0 . 0041cℎsℓ2 in3


wherec = 1.30 for bottom longitudinals= 1.00 for longitudinal or vertical side shell framesℎ = distance from the longitudinal, or from the middle of ℓ for vertical members, to the loadline, or to a pointlocated at two-thirds of the distance from the top of the tank to the top of the overflow, in ft (m), whichever isgreater. ℎ is not to be taken at less than 6 ft (1.83 m).

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44

s = spacing of frames, in ft (m)ℓ = span between floors, between decks or supporting stringers, between transverse bulkheads or webs, or betweenthe toes of brackets where fitted in accordance with 3-1-2/5 TABLE 2, in ft (m). The value of ℓ is not to betaken as less than 6 ft (1.83 m).

It is recommended that the longitudinal system of framing of the bottom be carried at least to the lowerturn of the bilge. Longitudinals around the bilge, if fitted, are to be graded in size from that required for thelowest side longitudinal to that required for bottom longitudinals. Where the hull-girder section modulus tothe bottom is in excess of the required hull-girder section modulus, the c value of 1.30 for bottomlongitudinals may be modified.

9 Inner Bottom LongitudinalsWhere cargo is carried on the inner bottom, the section modulus SM for inner-bottom longitudinals is notto be less than 85% of that required for bottom longitudinals as described in 3-2-5/7 nor is the sectionmodulus for inner-bottom longitudinals throughout the cargo space of bulk carriers where subject tomechanical damage to be less than obtained from the following equation:SM = 0 . 0041cℎsℓ2 in3


wherec = 1.75ℎ = distance from the inner bottom to the deck at the center, in ft (m)s = spacing of frames, in ft (m)ℓ = span between floors, in ft (m)

Where the density of the cargo to be carried is greater than 150 lb/ft3 (2400 kg/m3), the section modulus isto be increased in the ratio of the actual density to 150 lb/ft3 (2400 kg/m3). Where cargo is not carried onthe inner bottom, the required section modulus is to be obtained from the above equation using a value of cequal to 1.00, and a value of h equal to the distance, in ft (m), from the inner bottom to the load line, or to apoint located at two-thirds of the distance from the top of the tank to the top of the overflow, whichever isgreater. However, h is not to be taken as less than 6 ft (1.83 m).

11 Stringers and Webs

11.1 Strength RequirementsEach stringer and web which supports frames in the side tanks is to have a section modulus SM not lessthan obtained from the following equation:SM = 0 . 0025cℎsℓ2 in3


wherec = 1.5ℎ = distance from the center of the area supported to the load line, or to a point located at two-thirds of the distancefrom the top of the tank to the top of the overflow, in ft (m), whichever is greater

Part 3 Hull Construction and EquipmentChapter 2 Hull Structures and ArrangementsSection 5 Framing 3-2-5


45

s = sum of the half-lengths on each side of the stringer or web of the frames supported, in ft (m)ℓ = span between floors, between transverse bulkheads or webs, or between decks or other supports, in ft (m)


Transverse webs are to be arranged in line with solid floors. Where efficient struts are fitted between theside shell web and a web on the side tank bulkhead, the combined section moduli of the webs may be used.

In self-unloading vessels where web frames serve as the only supporting structure for the arch beams, theweb-frame section modulus is to be not less than 75% of that required for the arch beam.

11.3 ProportionsStringers and webs are to have depths not less than 1.5 in. per ft (12.6 mm per 100 mm) of span ℓwhen nostruts are fitted and 1 in. per ft (8.4 mm per 100 mm) when struts are fitted. The depth is not to be less than2.5 times the depth of the slots and the thickness is not to be less than 0.01 in. per in. (1 mm per 100 mm)of depth plus 0.12 in. (3 mm), but need not exceed 0.44 in. (11 mm).

11.5 Stiffeners and Tripping BracketsStiffeners are to extend for the full depth of the stringer or web on alternate frames, and where stringers orwebs do not directly support frames, the stiffeners are to be spaced at about 6 ft (1.83 m). Trippingbrackets are to be fitted at intervals of about 10 ft (3 m). Where the breadth of the flange on either side ofthe stringer or web exceeds 8 in. (200 mm), the brackets are to be arranged to support the flange.

13 Special StrengtheningSpecial consideration is to be given to local strengthening to suit particular operating conditions.Closelyspaced shell webs and stringers are to be arranged forward and aft in those areas which are mostsubject to dock damage. Suitable fenders are recommended and, where fitted, they are to be supported bydecks, stringers, or other internal stiffening.

15 Topside Tunnel or Side Tank StructureThe structural members stiffening the side shell, side tank, and freeboard and lower decks are to be of suchsize as to meet local strength requirements and of such thickness as to be compatible with the plating towhich they are attached. Web frames are to be arranged to support the longitudinal members and the archbeams and they are to develop continuity between the arch beams and the structure below the lower deck.

17 Higher-strength SteelWhere constructed of higher-strength steel and provided the steel to which they are attached generally hasthe same properties, the scantlings given in the preceding paragraphs of Section 3-2-5 may be modified aspermitted by 3-2-5/17.1 and 3-2-5/17.3. Higher-strength steel members are to be continuous where theyintersect with members of ordinary-strength steel.

17.1 Section ModulusThe section modulus of each higher-strength steel member is not to be less than obtained from thefollowing equation:SMℎts = SM(Q)whereSMℎts = sections modulus of higher-strength steel member, in in3 (cm3)SM = section modulus of ordinary-strength steel member, in in3 (cm3), as required by the preceding paragraphs

of this Section



46

Q is as defined in 3-2-1/9.3.

17.3 PlatingWhere constructed of higher-strength steel, the thickness of stringers and webs is not to be less thanobtained from the following equation.tℎts = (t – c)[(Q+ 2 Q)/3] + c wheretℎts = thickness of higher-strength steel, in in. (mm)t = thickness of ordinary-strength steel, in in. (mm), as required by 3-2-5/11.3 for the depth of the webc = 0.06 in. (1.5 mm)Q is as defined in 3-2-1/9.3.

19 Struts (2021)The value of W for struts is not to be less than obtained from the following equation:W = 0 . 03bℎs long tonsW = 1 . 07bℎs metric tons

whereb = mean breadth of the area supported, in ft (m)ℎ = distance from the center of the area supported to the load line, or to a point located at two-thirds of the distancefrom the top of the tank to the top of the overflow, in ft (m), whichever is greaters = spacing of stringers or webs, in ft (m)

The sizes of struts are to satisfy the following equation.W = (k − nℓ/r′)A LtfW = (k − nℓ/r′)A tfwherek = 7.83 (1.232) ordinary strength steel

= 10.43 (1.643) HT32 strength steel

= 11.73 (1.848) HT36 strength steeln = 0.345 (0.452) ordinary strength steel

= 0.581 (0.762) HT32 strength steel

= 0.699 (0.918) HT36 strength steelℓ = unsupported span of the strut, in ft (m)r′ = least radius of gyration, in in. (cm)A = area of the strut, in in2 (cm2)



47

Struts within tanks are to be of solid section. Special attention is to be given to the end connections fortension members.



48


S E C T I O N 6Watertight Bulkheads

1 General (1 July 2022)All vessels are to be provided with watertight bulkheads in accordance with this section and as outlined by3-1-2/1; in vessels of special type where adherence to these requirements is found to be impracticable, thearrangements will be specially considered. In all cases, the plans submitted are to show clearly the locationand extent of the bulkheads. Watertight bulkheads which serve as tank boundaries are to have scantlingsnot less than obtained from Section 3-2-7.

3 Arrangement of Watertight Bulkheads

3.1 Collision BulkheadsCollision bulkheads are to be fitted in all vessels. They are to be approximately 20 ft (6.1 m) abaft the stemat the load line in vessels 400 ft (122 m) in length and 30 ft (9.15 m) abaft the stem in vessels 1000 ft (305m) and over in length; values for lengths between 400 ft (122 m) and 1000 ft (305 m) are to be obtained byinterpolation. They are to extend to the freeboard deck preferably in one plane, and in vessels withsuperstructures at the forward end, the bulkheads are to be extended weathertight to the superstructuredeck. The extension need not be fitted directly over the bulkhead below provided the part of the freeboarddeck which forms the step is made effectively weathertight.

3.3 After Peak BulkheadsAfter peak bulkheads are to be arranged to enclose the shaft tubes in watertight compartments.

3.5 Machinery SpaceBulkheads are to be fitted at the forward ends of machinery spaces and are to extend to the freeboard deck.

5 Chain LockersChain lockers which extend into the forepeak tank are to be made watertight.

7 Construction of Watertight Bulkheads

7.1 Plating (2021)Plating is to be of the thickness obtained from 3-2-6/11 FIGURE 1 for the spacing of stiffeners and thedistance ℎ measured from the lower edge of the plate to the bulkhead deck at center. The plating of

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collision bulkheads is obtained from the same Figure using a spacing 6 in. (150 mm) greater than actuallyadopted. In way of the stern tube, the after peak bulkhead plating is to be increased in thickness, ordoubled, to provide suitable support for the tube. However, the minimum required plate thickness is not tobe less than 0.25 in. (6.35 mm) for stiffener spacing of 27 in. (0.685 m) or less. For stiffener spacing morethan 27 in. (0.685 m), the minimum required plate thickness is to be in accordance with the 3-2-6/11FIGURE 1.

7.3 Stiffeners (2022)Each stiffener is to have a section modulus SM not less than obtained from the following equation.SM = 0 . 0041cℎsℓ2 in3


wherec = 0.54 for stiffeners between stringers or for stiffeners having bracketed or clipped end connections= 0.60 for stiffeners having no end attachmentsℎ = distance from the middle oft to the bulkhead deck at center, in ft (m). Where that distance is less than 20 ft (6.1m), ℎ to be taken as 0.8 times the distance in ft plus 4 (m plus 1.22).s = spacing of the stiffeners, in ft (m)ℓ = span between supporting stringers or decks or between the toes of brackets where fitted in accordance with3-1-2/5 TABLE 2, in ft (m)

The section modulus of stiffeners on collision bulkheads is to be at least 25% greater than required forordinary bulkheads. Stiffeners on watertight bulkheads in way of the cargo holds are to have endattachments. Stiffening arrangements on the after-peak bulkhead are to be specially considered,particularly in way of the stern tube; additional stiffening may be required to minimize the effect ofvibration.

Watertight bulkheads in way of cargo holds are to comply with the hopper slope requirements in 3-2-3/19.The specific weight is not to be taken less than 1.471 N/cm2-m (0.15 kgf/cm2-m, 0.6503 lbf/in2-ft). If thespecific weight of the cargo is higher than 1.471 N/cm2-m (0.15 kgf/cm2-m, 0.6503 lbf/in2-ft), then thehigher specific weight is to be used for evaluating the bulkhead scantlings.

7.5 Stringers and Webs7.5.1 Strength Requirements

Each stringer and web which supports bulkhead stiffeners is to have a section modulus SM notless than obtained from the following equation:SM = 0 . 0025cℎsℓ2 in3


wherec = 1.0ℎ = distance from the center of the area supported to the bulkhead deck at center, in ft (m). Where thatdistance is less than 20 ft (6.1 m), the value of ℎis to be 0.8 times the distance in ft plus 4 (m plus1.22).

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s = sum of half-lengths (on each side of the stringer or web) of the stiffeners supported, in ft (m)ℓ = span between bulkheads or webs or between decks or other supports, in ft (m)


The section modulus of stringers and webs on collision bulkheads is to be at least 25% greaterthan required for similar supporting members on ordinary bulkheads.

7.5.2 ProportionsStringers and webs are to have depths not less than 1 in. per ft (8.4 mm per 100 mm) of span ℓ.The depth is not to be less than two times the depth of the slots, and the thickness is not to be lessthan 0.01 in. per in. (1 mm per 100 mm) of depth plus 0.12 in. (3 mm), but need not exceed 0.44in. (11 mm).

7.5.3 Tripping BracketsTripping brackets arranged to support the flanges are to be located at intervals of about 10 ft (3 m).

7.5.4 AttachmentsWhere stiffeners cross decks or bulkheads on the opposite side of the plating, chocks are to befitted.

7.7 Watertight DoorsWatertight doors of an approved type are to be of ample strength for the water pressure to which they maybe subjected, and fitted with gaskets and dogs spaced and designed to insure that the opening may beclosed thoroughly watertight. Those doors below the freeboard deck which may require to be opened at seaare to have either audible or visual alarms located in the pilot house to indicate whether the doors are in theopen or closed position. Where stiffeners are cut in way of watertight doors, the openings are to be framedand bracketed so as to maintain the full strength of the bulkhead without taking the strength of the doorframes into consideration. Where doors are hinged, they are to be quick-acting type. The doors are to beclosed and dogs secured at all times except when the vessel is in port or when the door is used for access.Where used at sea for access the door is to be closed and dogs secured immediately access is gained. Signsinforming of this requirement are to be posted on either side adjacent to the door.

7.9 TestingTesting of watertight bulkheads, recesses, and decks is to be carried out after the completion of all workaffecting the watertightness. A hose test is to be carried out under simultaneous inspection of both sides ofthe plating and the pressure of the water in the hose is not to be less than 30 psi. (2.1 kg/cm2). Shaft tubecompartments and forepeaks are to be tested with a head of water to the load line. Where shaft tubecompartments and forepeaks are used as tanks, the test heads are not to be less than required in 3-2-7/3.

9 Higher-strength SteelWhere constructed of higher-strength steel, the scantlings given in the preceding paragraphs may bemodified as permitted by 3-2-6/9.1 and 3-2-6/9.3.

Care is to be taken to avoid the adoption of reduced thicknesses of members that might be subject todamage during normal operation. Calculations, showing that adequate buckling strength is provided, maybe required to be submitted. The structural members and the plating to which they are attached are togenerally have the same strength properties.

9.1 Section ModulusThe section modulus of each higher-strength steel member is not to be less than obtained from thefollowing equation:



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SM = SM QwhereSMℎts = section modulus of higher-strength steel member, in in3 (cm3)SM = section modulus of ordinary-strength steel member, in in3 (cm3), as required by the preceding paragraphs


9.3 PlatingWhere constructed of higher-strength steel, the plate thickness required by the preceding paragraphs of thisSection may be modified but is not to be less than obtained from the following equation:tℎts = (t – c)[(Q+ 2 Q)/3] + cwheretℎts = thickness of higher-strength steel, in in. (mm)t = thickness of ordinary-strength steel, in in. (mm), as required by 3-2-5/11.3 for the depth of the webc = 0.06 in. (1.5 mm)Q is as defined in 3-2-1/9.3.

11 Construction of Screen Bulkheads (1 July 2017)Screen bulkheads are non-watertight bulkheads often used to separate cargoes. Strength requirements forscreen bulkhead plating, stiffeners, stringers, and webs are to be obtained from 3-2-6/7 with thecorresponding h value reduced by half for thickness and section modulus calculations. However, in nocase, is the screen bulkhead plating thickness to be taken less than 0.25 in. (6.35 mm).

In lieu of applying the requirement indicated above, the “U” shaped part, which runs along the deck andside tanks for double hulls or the deck and side shell for single hulls, is to have section modulus SM notless than obtained from 3-2-5/11.1. See 3-2-6/11 FIGURE 2 for an example of screen bulkhead sectionmodulus calculation.



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FIGURE 1 Curves for Watertight Bulkhead Plating Thickness – Inch Units

Note: Curves are based on the following equation:t = (0 . 0228 h)s+ 0 . 06 in . s = stiffener spacing, in ftℎ = as defined in 3-2-6/7.1



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FIGURE 1 Curves for Watertight Bulkhead Plating Thickness – Metric Units

Note: Curves are based on the following equation:t = (3 . 45 h)s+ 1 . 5 mm s = stiffener spacing, in mℎ = as defined in 3-2-6/7.1



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FIGURE 2Screen Bulkhead Section Modulus Calculation – Double Hulls (1 July 2017)

13 Construction of Corrugated Bulkheads (Not in way of Cargo Holds)(2022)

13.1 Self-propelled VesselsConstruction of corrugated bulkheads for self-propelled vessels is to be in accordance with 3-2-9/7 of theMarine Vessel Rules.

13.3 BargesConstruction of corrugated bulkheads for barges is to be in accordance with 3-2-6/5.7 of the ABS Rules forBuilding and Classing Steel Barges (Barge Rules).

The thickness of the plating is not to be less than 0.25 in. (6.35 mm).



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S E C T I O N 7Tank Boundary Bulkheads

1 GeneralAll tank boundary bulkheads are to be constructed in accordance with the requirements of this section.Tanks are to be arranged with swash bulkheads in such number and location as to minimize the dynamicstress of the structure. The arrangements of all tanks, together with their intended service and the height ofthe overflow pipes, are to be clearly indicated on the plans submitted for approval.

3 Construction of Tank Boundary Bulkheads (2021)Where the specific gravity of the liquid exceeds 1.05, the design head, ℎ, in this section is to be increasedby the ratio of the specific gravity of the liquid to be carried to 1.05.

3.1 Plating (2021)The thickness of the plating is to be obtained from 3-2-7/9.3 FIGURE 1 for the spacing of the stiffenerswith the distance ℎ, in ft (m), measured from the lower edge of the plating to a point located at two-thirdsof the distance from the top of the tank to the top of the overflow. However, the minimum required platethickness is not to be less than 0.25 in. (6.35 mm) for stiffener spacing of 24 in. (0.610 m) or less. Forstiffener spacing more than 24 in. (0.610 m), the minimum required plate thickness is to be in accordancewith the 3-2-7/9.3 FIGURE 1. The thickness of plating of side tank bulkheads when subject to mechanicaldamage, and the hopper slopes forming tank boundaries in self-unloading vessels, is to be increased 0.06in. (1.5 mm).

3.3 StiffenersEach stiffener is to have a section modulus SM not less than obtained from the following equation.SM = 0 . 0041cℎsℓ2 in 3


wherec = 1.0ℎ = distance from the middle of ℓ to a point two-thirds of the distance from the top of the tank to the top of theoverflow, in ft (m). The value of ℎ is not to be taken at less than 6 ft (1.83 m).

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s = spacing of the stiffeners, in ft (m)ℓ = span between supporting stringers or decks or between the toes of brackets where fitted in accordance with3-1-2/5 TABLE 2, in ft (m).

All stiffeners which pass through decks, girders, or stringers are to be attached to these members, andelsewhere they are to be fitted with brackets or clips which are to extend to the adjacent frame or beam.

3.5 Stringers and Webs3.5.1 Strength Requirements

Each stringer and web which supports stiffeners in deep tanks is to have a section modulus SM notless than obtained from the following equation:SM = 0 . 0025cℎsℓ2 in3


wherec = 1.5ℎ = distance from the center of the area supported to a point located at two-thirds of the distance from thetop of the tank to the top of the overflow, in ft (m). The value of ℎ is not to be taken at less than 6.0 ft(1.83 m)s = sum of half-lengths (on each side of the stringer or web) of the stiffeners supported, in ft (m)ℓ = span between bulkheads or webs or between decks or other supports, in ft (m)

Where effective brackets are fitted,ℓ may be modified as described in 3-1-2/5 TABLE 2. Whereefficient struts are fitted between stringers or webs, the combined section moduli of the stringersor webs may be used.

3.5.2 ProportionsStringers and webs are to have depths not less than 1.5 in. per ft (12.6 mm per 100 mm) of span ℓwhen no struts or ties are fitted, and 1 in. per ft (8.4 mm per 100 mm) when struts are fitted. Thedepth is not to be less than 2.5 times the depth of the slots, and the thickness is not to be less than0.01 in. per in. (1 mm per 100 mm) of depth plus 0.12 in. (3 mm), but need not exceed 0.44 in. (11mm).

3.5.3 Tripping Brackets and Web Plate StiffenersTripping brackets arranged to support the flanges are to be located at intervals of about 10 ft (3 m).Where the bulkhead may be subject to mechanical damage, flat bars or other web plate stiffenersare to be fitted at each stiffener for the full depth of the stringer or web, and elsewhere they are tobe fitted at alternate stiffeners.

3.7 AttachmentsWhere stiffeners cross decks or bulkheads on the opposite side of the bulkhead plating, the stiffeners are tobe attached to the bulkhead by chocks in line with the deck or bulkhead on the opposite side of thebulkhead.

3.9 Corrugated Bulkheads (2021)For corrugated bulkheads:

i) 3-2-10/3.9 of the ABS Rules for Building and Classing Marine Vessels is applicable for all self-propelled vessels.

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ii) 3-2-7/7 of the ABS Rules for Building and Classing Steel Barges is applicable for barges.

The thickness of the plating is not to be less than 0.25 in. (6.35 mm).

5 TestingAll tanks are to be tested with a head of water to the overflow.

7 Topside Tunnel or Side Tank BulkheadsIt is recommended that the uppermost strake of continuous longitudinal side tank or tunnel side bulkheadswhich extend to the freeboard deck not be less than 0.44 in. (11 mm) in vessels of 400 ft (122 m) lengthand 0.62 in. (15.5 mm) in vessels of 700 ft (213 m) length and above. Openings, where cut, are to havewell-rounded corners and may require compensation.

9 Higher-strength SteelWhere constructed of higher-strength steel, the scantlings given in the preceding paragraphs of this sectionmay be modified as permitted by 3-2-7/9.1 and 3-2-7/9.3. The structural members and the plating to whichthey are attached are to generally have the same strength properties.

9.1 Section ModulusThe section modulus of higher-strength steel members is not to be less than obtained from the followingequation:SMℎts = SM(Q) whereSMℎts = section modulus of higher-strength steel member, in in3 (cm3)SM = section modulus of ordinary-strength steel member, in in3 (cm3), as required by the preceding paragraphs of

this SectionQ is as defined in 3-2-1/9.3.

9.3 PlatingWhere constructed of higher-strength steel, the plate thickness required by the preceding paragraphs of thissection may be modified but is not to be less than obtained from the following equation:tℎts = (t – c)[(Q+ 2 Q)/3] + c wheretℎts = thickness of higher-strength steel, in in. (mm)t = thickness of ordinary-strength steel, in in. (mm), as required by the preceding paragraphs of this Sectionc = 0.06 in. (1.5 mm)Q is as defined in 3-2-1/9.3.



58

FIGURE 1 Curves for Tank Bulkhead Plating Thickness – Inch Units

Note:Curves are based on the following equation:t = (0 . 02792 h)s in.s = stiffener spacing, in ftℎ = as defined in 3-2-7/3.1



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FIGURE 1 Curves for Tank Bulkhead Plating Thickness – Metric Units

Note:Curves are based on the following equation:t = (4 . 214 h)s mms = stiffener spacing, in mℎ = as defined in 3-2-7/3.1



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S E C T I O N 8Superstructures and Deckhouses

1 Superstructures

1.1 Side PlatingThe thickness of side plating of the poop and forecastle is not to be less than given in 3-1-2/5 TABLE 1,Column 7, for a distance of 0.1L from the ends of the vessel. Beyond 0.1L, the thickness is to be graduallyincreased. In way of the forecastle and poop bulkheads, a further increase may be required. The plating isto be carried well beyond the end bulkheads and fashioned so as to provide a long gradual taper to thesheerstrake. Where the plating is welded to the sheerstrake, the termination of the joint is to be groundsmooth and faired into the top edge of the sheerstrake.

1.3 Side FramesThe side frames of the poop and forecastle are to be aligned with the frames below the freeboard deck.Each frame abaft the collision bulkhead is to have a section modulus SM not less than obtained from thefollowing equation:SM = 0 . 0041csℓ2 in3SM = 7 . 9csℓ2 cm3

wherec = for forecastle side frames abaft the collision bulkhead= 20 (6.1) for vessels 400 ft (122 m) in length= 30 (9.15) for vessels 800 ft (244 m) or over in lengthc = for poop side frames= 16 (4.9) for vessels 400 ft (122 m) in length= 24 (7.3) for vessels 800 ft (244 m) or over in length Intermediate values of c are to be obtained byinterpolation.s = spacing of the frames, in ft (m)ℓ = span, in ft (m), between decks or between toes of brackets where fitted in accordance with 3-1-2/5 TABLE 2

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Forecastle side frames forward of the collision bulkhead are to be of the same size as those abaft, are to bealigned with each frame below the freeboard deck, and are to be bracketed to the deck beams. Web framesor partial bulkheads are to be lilted over main bulkheads or webs as may be required to provide adequatetransverse rigidity to the superstructures.

1.5 DecksThe thickness of plating on superstructure decks is to be in accordance with the requirements of3-2-3/5.5.1. Deck beams and girders are to be as required by 3-2-3/7, 3-2-3/9, and 3-2-3/11.

1.7 Superstructure Bulkheads and Deckhouse Bulkheads on Freeboard Deck1.7.1 PlatingThe plating is to be not less in thickness than obtained as follows

0.38 in. (9.5 mm) for poop front and deckhouse front bulkheads

0.30 in. (7.5 mm) for deckhouse sides and after bulkhead, poop and forecastle after bulkheads

Where the spacing of stiffeners is greater or less than 30 in. (760 mm), the thickness is to be increased, ormay be reduced, at the rate of 0.02 in. for each 4 in. (0.5 mm per 100 mm) difference in spacing,respectively.

1.7.2 StiffenersEach stiffener is to have section modulus SM not less than obtained from the following equation.SM = 0 . 0041csℓ2 in3

SM = 7 . 9csℓ2 cm3

wherec = 10 (3) at L = 400 ft (122 m) and 14.5 (4.4) at L ≥ 500 ft (152 m) for poop front and deckhouse frontbulkhead. Intermediate values may be obtained by interpolation.= 4.75 (1.45) for deckhouse sides= 4.0 (1.22) for poop and deckhouse after bulkheads= 3.4 (1.04) for forecastle after bulkheads = spacing of the stiffeners, in ft (m)ℓ = tween deck height, in ft (m)

1.7.3 Swage Bulkheads (1 July 2020)Exposed bulkheads in steel superstructures and deckhouses whose sides are not in line with theship’s sides may be constructed of swage panels.

Swages are triangular shaped recesses pressed into plates to form stiffeners (see 3-2-8/Figure 1).

The scantlings of the exposed swage panel bulkheads of superstructures and deckhouses are to bein accordance with the following paragraphs.

The swage panel plating thickness is to satisfy the requirements in 3-2-8/1.7.1 for ordinary-strength steel or 3-2-8/7.5 for higher-strength steel.

The effective width of the swage (see 3-2-8/Figure 1) is to be taken as the sum of one-half of thespacing on either side of the swage centerline. The section modulus of the swage, including the

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flat portion of the plates on either side of the swage within the effective width, is to satisfy therequirements in 3-2-8/1.7.2 for ordinary-strength steel or 3-2-8/7.1 for higher-strength steel, wheres is to be taken as the effective width od the swage. If the flat plate thickness varies, mean flatplate thickness over the effective width is to be used.

Swages are to be oriented vertically. The swage angle, φ, is to be between 40 and 70 degrees.

FIGURE 1Swage Panel

1.7.4 End Attachments for Swage Bulkheads (1 July 2020)The upper and lower edges of swage panels are to be continuously welded to the deck plating. Theflat plating of swage panels is to be aligned with deck girders, deck transverses, or bulkheads. Thebottom ends of swages of all lowest tier bulkheads are to be adequately supported by underdeckstiffeners, brackets, or carlings to prevent stress concentrations.

Special attention is to be paid to connections between horizontal deck stiffeners, deck girders, ordeck transverses and swage panels in order to enable effective load transfer and to minimize stressconcentrations.

Large cutouts for doors, windows, pipes, and ventilation ducts are not to be positioned directlyacross the swages. Appropriate carlings are to be fitted at the edges of such cutouts in order toenable effective load transfer to the adjacent structure of the bulkhead.

The scantlings of swage panels having other types of end connections are to be speciallyconsidered.

1.9 Windlass Room BulkheadWhere the anchor windlass is located on the freeboard deck, a bulkhead is to be fitted abaft the windlassand is to have the scantlings required for forecastle bulkheads. See also 3-2-6/3.1

3 Deckhouses on Superstructure Decks

3.1 Bulkheads3.1.1 Plating

The plating is to be not less in thickness than obtained as follows:

0.30 in. (7.5 mm) for deckhouse fronts

0.28 in. (7.0 mm) for deckhouse sides

0.25 in. (6.5 mm) for deckhouse after ends

Where the spacing of stiffeners is greater or less than 30 in.(760 mm), the thickness is to beincreased, or may be reduced, at the rate of 0.02 in. for each 4 in. (0.5 mm per 100 mm) differencein spacing, respectively.



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3.1.2 StiffenersEach stiffener is to have section modulus SM not less than obtained from the following equation.SM = 0 . 0041csℓ2 in3

SM = 7 . 9csℓ2 cm3

wherec = 7.5 (2.29) at L = 400 ft (122 m) and 10.0 (3) at L ≥ 500 ft (152 m) for house frontbulkhead on forecastle deck. Intermediate values may be obtained by interpolation.= 7.5 (2.29) for house front bulkhead on poop deck= 4.5 (1.37) for house sides on forecastle deck= 4.0 (1.22) for house sides on poop deck= 3.4 (1.04) for house after bulkheadss, ℓ are as defined in 3-2-8/1.7.2.

Stiffeners on the house front bulkheads are to be attached to the decks at their ends, and elsewherethey may have sniped ends.

3.1.3 Swage Bulkheads (1 July 2020)Exposed bulkheads in steel deckhouses, whose sides are not in line with the ship’s sides, and arelocated on superstructure decks, may be constructed of swage panels (see 3-2-8/Figure 1).

The scantlings of the exposed swage panel deckhouse bulkheads are to be in accordance with thefollowing paragraphs.

The swage panel plating thickness is to satisfy the requirements in 3-2-8/3.1.1 for ordinary-strength steel or 3-2-8/7.5 for higher-strength steel.

The effective width of the swage (see 3-2-8/Figure 1) is to be taken as the sum of one-half of thespacing on either side of the swage centerline. The section modulus of the swage, including theflat portion of the plates on either side of the swage within the effective width, is to satisfy therequirements in 3-2-8/3.1.2 for ordinary-strength steel or 3-2-8/7.1 for higher-strength steel, wheres is to be taken as the effective width of the swage. If the flat plate thickness varies, mean flat platethickness over the effective width is to be used.

Swages are to be oriented vertically. The swage angle, φ, is to be between 40 and 70 degrees.

The end attachments of swage bulkheads are to be in accordance with 3-2-8/1.7.4.

3.3 StacksPartially protected stacks and other structures located on the first deck above the freeboard deck and whichenclose openings leading to spaces below are to have scantlings not less than as required for the afterbulkheads of houses.

3.5 House TopsThe plating for the tops of deck houses is to be in accordance with the requirements of 3-2-3/5.5.2. Beamsand girders are to be as required by 3-2-3/7, 3-2-3/9, and 3-2-3/11.



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5 Openings (2022)

5.1Where openings are cut in bulkheads for access and other purposes, they are to have rounded corners andare to be framed so as to maintain the strength of the bulkhead. All openings in the exterior bulkheads ofsuperstructures or deckhouses are to be provided with efficient means of closing. Opening and closingappliances are to be framed and stiffened so that the whole structure is equivalent to the unpiercedbulkhead when closed.

5.3Access openings in bulkheads at the ends of enclosed superstructures, or Category A deckhouses which areleading to access below, are to have sills that are at least 12 inches (300 mm) above the deck. Deckhousesat other locations must have a sill height of at least 6 inches (150 mm).

For companionway sills, see 3-2-9/11.7.

7 Higher-strength SteelIn general, proposed applications of higher-strength materials for superstructures and deckhouses are tomeet the requirements of this section, but may be modified as permitted by 3-2-8/7.1 through 3-2-8/7.5.Care is to be taken to avoid the adoption of reduced thicknesses of members that might be subject todamage during normal operation. Calculations, showing that adequate buckling strength is provided, maybe required to be submitted. The structural members and the plating to which they are attached are togenerally have the same strength properties.

7.1 Section ModulusThe section modulus of each higher-strength steel member is not to be less than obtained from thefollowing equation:SMℎts = SM(Q)whereSMℎts = section modulus of higher-strength steel member, in in3 (cm3)SM = section modulus of ordinary-strength steel member, in in3 (cm3), as required by the preceding paragraphs


7.3 Deck PlatingWhere constructed of higher-strength steel, the thickness of superstructure decks and deckhouse tops is tobe in accordance with the requirements of 3-2-3/15.3.

7.5 Side and Bulkhead PlatingWhere constructed of higher-strength steel, the thicknesses of superstructure sides and of the superstructureand deckhouse bulkheads, as required by the preceding paragraphs of this section, may be modified but arenot to be less than obtained from the following equation:tℎts = (t – c)[(Q+ 2 Q )/3] + cwhere



65

tℎts = thickness of higher-strength steel, in in. (mm)t = thickness of ordinary-strength steel, in in. (mm), for which a requirement is given in the preceding paragraphsof this Sectionc = 0.06 in. (1.5 mm)Q is as defined in 3-2-1/9.3.



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S E C T I O N 9Protection of Deck Openings (9 May 1996)

1 GeneralAll openings in decks are to be framed to provide efficient support and attachment to the ends of the deckbeams. The proposed arrangements and details for all hatchways are to be submitted for approval.

2 Position of Deck OpeningsFor the purpose of the Rules, two positions of deck openings are defined as follows:

Position 1 Upon exposed freeboard decks, and upon exposed superstructure decks or a trunk deck situated forward of apoint located a quarter of the vessel’s length from the forward perpendicular.

Position 2 Upon exposed superstructure decks or trunk of at least standard* height and situated abaft a quarter of thevessel's length from the forward perpendicular.

* Standard height as defined in Load Line Regulations for Great Lakes Vessels

5 Hatchway Coamings

5.1 Height of CoamingsThe height of coamings of hatchways secured weathertight by tarpaulins and battening devices is to be atleast as follows:

18.0 in. (457 mm) if in Position 1

12.0 in. (305 mm) if in Position 2

Where hatch covers are made of steel or other equivalent material and made tight by means of gaskets andclamping devices, these heights may be reduced, or the coamings omitted entirely, provided that the safetyof the vessel is not thereby impaired in any sea condition.

5.3 Coaming PlatesCoaming plates are to be of steel or equivalent material and not less than 0.375 in. (9.5 mm) thick.

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5.5 Coaming StiffeningEfficient brackets or stays are to be fitted from the upper edge of the coaming to the deck at intervals of notmore than 10 ft (3 m). All exposed coamings other than Position 1 which are 30 in. (760 mm) or more inheight are to be similarly supported. Where the height of any exposed coaming exceeds 36 in. (915 mm),the arrangement of the stiffeners and brackets or stays is to be specially considered. Where end coamingsare protected, the arrangement of the stiffeners and brackets or stays may be modified

5.7 Continuous Longitudinal Hatch CoamingsStrength deck longitudinal hatch coamings of length greater than 0.14L are to be effectively supported bylongitudinal bulkheads or deep girders and they are in general to be longitudinally stiffened. Specialconsideration will be given to the coaming scantlings. Calculations showing that adequate bucklingstrength is provided may be required to be submitted.

7 Hatchways Closed by Sectional Sliding Covers and SecuredWeathertight by Tarpaulins and Battening Devices

7.1 Sliding Steel Hatch CoversCovers of the sliding plate type with flanges on one edge or with stiffeners welded to one edge are to havea sufficient number of sections so that when closed, the spacing of the stiffeners does not exceed 42 in.(1070 mm). Plates are not to be less in thickness than required for solid steel covers in association with thespacing of the stiffeners when closed. The stiffening at the edge of the covers is not to be less effectivethan required for solid covers. If hatch covers of the sliding plate type are used for spans exceeding 12 ft-1in. (3.68 m), additional support is to be provided, the detail of which will be specially considered.

7.3 CleatsCleats are to be set to fit the taper of the wedges. They are to be at least 2.5 in. (65 mm) wide and spaced atintervals of approximately 24 in. (610 mm) center to center; the cleats along each side or end are to be notmore than 6 in. (150 mm) from the hatch corners.

7.5 WedgesWedges are to be of tough wood; they are to have a taper of not more than 1 in 6 and are to be not less than0.5 in. (13 mm) thick at the toes.

7.7 Battening BarsBattening bars are to be provided for properly securing the tarpaulins; they are to have a width of 2.5 in.(64 mm) and a thickness of not less than 0.375 in. (9.5 mm).

7.9 TarpaulinsAt least one tarpaulin in good condition thoroughly waterproofed and of ample strength is to be providedfor each exposed hatchway. The material is to be guaranteed free from jute, and is not to be less than No. 4cotton canvas or equal before waterproofing. Synthetic fabrics which have been demonstrated to beequivalent will be specially approved.

7.11 Security of Hatchway CoversAt all hatchways in exposed positions on the freeboard or superstructure decks suitable provision is to bemade for securing the covers after the tarpaulins are battened down.

Part 3 Hull Construction and EquipmentChapter 2 Hull Structures and ArrangementsSection 9 Protection of Deck Openings (9 May 1996) 3-2-9


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9 Hatchways Closed by Covers of Steel Fitted with Gaskets andClamping Devices

9.1 Strength of CoversWhere weathertight covers are of steel, the strength is to be calculated with assumed loads not less than250 pounds per square foot (1.22 metric tons per square meter) on the hatchways in Position 1, and not lessthan 200 pounds per square foot (0.98 metric tons per square meter) on hatchways in Position 2, and theproduct of the maximum stress thus calculated and the factor of 4.25 is not to exceed the minimumultimate tensile strength of the material. They are to be so designed as to limit the deflection to not morethan 0.0028 times the span under these loads. Steel plating forming the tops of covers is to be not less inthickness than 1% of the spacing of stiffeners or 0.24 in. (6 mm) if that be greater. Where higher strengthsteels are used that have a higher resistance to corrosion a minimum thickness of 0.19 in. (4.8 mm) will beacceptable provided the limiting deflection noted above is not exceeded and calculations are submitted toshow adequate provision against buckling. The hatch covers are to be provided with stiffening bar or platesrequired to provide the necessary rigidity to permit the cover being handled without permanentdeformation.

9.3 Other MaterialsThe strength and stiffness of covers made of materials other than steel is to be equivalent to those of steeland is to subject to special consideration.

9.5 Means for Securing Weathertightness9.5.1 Weathertightness

The means for securing the maintaining weathertightness are to be such that the tightness can bemaintained in any sea condition. The covers are to be hose-tested in position under a waterpressure of at least 30 psi (2.1 kgf/cm2) at the time of construction and, if considered necessary, atsubsequent surveys.

9.5.2 Clamping DevicesWhere the hatch cover edges are stiffened with a horizontal gasket retaining bar, clamping devicesequivalent to the over-the-center type may be fitted at a maximum spacing of 24 in. (610mm)center to center.

Where the hatch cover edges is stiffened by a deep bar to witch the stiffener and gasket retainerare attached the spacing of the clamps may be increased. The inertia of the cover edge is to be notless than:IR = 0 . 0062S14 in4IR = 30S14 cm4whereS1 = spacing of the cleats, in ft (m)IR = inertia of cover edge, in in4 (cm4)



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11 Miscellaneous Openings in Freeboard and Superstructure Decks

11.1 Manholes and ScuttlesManholes and flush scuttles in Position 1 or 2 or within superstructures other than enclosed superstructuresare to be closed by substantial covers capable of being made watertight. Unless secured by closely spacedbolts, the covers are to be permanently attached.

11.3 Other OpeningsOpenings in freeboard decks other than hatchways, machinery-space openings, manholes and flush scuttlesare to be protected by an enclosed superstructure, or by a deckhouse or companionway of equivalentstrength and weathertightness. Any such opening in an exposed superstructure deck or in the top of adeckhouse on the freeboard deck which gives access to a space below the freeboard deck or a space withinan enclosed superstructure is to be protected by an efficient deckhouse or companionway. Doorways insuch deckhouses or companionways are to be fitted with weathertight doors.

11.5 Escape OpeningsThe closing appliances of escape openings are to be readily operable from each side.

11.7 Companionway SillsIn Position 1 the height above the deck of sills to the doorways in companionways is to be at least 18 in.(457 mm). In Position 2 they are to be at least 12 in. (305 mm)



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A P P E N D I X 1Calculation of Shear Stresses

1 GeneralThe shear stresses in the side shell, and longitudinal bulkhead plating for vessels having continuouslongitudinal bulkheads, and in the side shell in way of wing tanks for vessels without continuouslongitudinal bulkheads are to be calculated, as specified by 3-2-1/3.5.1, by an acceptable method. Ingeneral, the shear stresses should be determined based on the shear flow in the transverse section. Theshear stress is the shear flow divided by the plate thickness, at the location considered.

For calculating shear flows, a computer program similar to ABS Hull Girder Section Analysis (HGSA)should be generally used. Information about ABS Hull Girder Section Analysis (HGSA) can be obtainedfrom ABS’s Houston office.

When a computer program is not available, or at the early design stages, the following simplified methodmay be used to calculate shear stresses.

3 Shear StressThe total shear stresses fs, in long tons per inch squared (metric tons per centimeter squared), in the sideshell and longitudinal bulkhead plating may be determined by the following equation:fs = cK1NF/tHwherec = 0.083 inch/pound units= 0.01 metric unitsK1 = 1 + y/8yy = distance, measured from the deck or bottom (depending on whether the strake considered is above or below

the neutral axis of the section) to the point under consideration, in ft (m)y = distance, measured from the deck (bottom) to the neutral axis of the section, when the strake underconsideration is above (below) the neutral axis, in ft (m)N = shear distribution factor as given in 3-2-A1/5 FIGURE 1F = total shearing force, Fsw+ Fd at the location considered, in long tons (metric tons)

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t = plate thickness at the location considered, in in. (cm)H = depth of the side shell or longitudinal bulkhead plating considered, in ft (m), see 3-2-A1/5 FIGURE 1

For vessels having structural configurations departing from those shown in 3-2-A1/5 FIGURE 1, thecalculation of shear stresses will be subject to special consideration.

5 Allowable Still-water Shearing ForceAlternatively, the allowable still-water shearing forces SWSF, in long tons or metric tons, at transversesections of the hull-girder may be determined by the following equation.SWSF = cfstH/(NK1) – fd wherec = 12 inch/pound units= 100 metric unitsfs = permissible shear stress, in long toms/in2 or metric tons/cm2, as specified in 3-2-1/3.5fd = dynamic shearing force, in long tons or metric tons, at the section considered as specified in 3-2-1/3.5.2K1,N, t, and H are as defined in 3-2-A1/3.

The allowable still-water shearing forces are to be determined for both the side shell and longitudinalbulkhead plating at various locations for each transverse section and the lowest value is to be used as theallowable still-water shearing force at the section under consideration.

FIGURE 1 Shear Distribution Configurations

Type 1

Ns1 = 0 . 59H1/D – 0 . 05 Ns2 = 0 . 5 – Ns1 – NbNb = (0 . 21Ab/As2+ 0 . 09)H2/D As2 = total area of side shell plating with the region of H2, in in-ft (cm-m)

Part 3 Hull Construction and EquipmentChapter 2 Hull Structures and ArrangementsAppendix 1 Calculation of Shear Stresses 3-2-A1


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Type 2a

NS= 0 . 5− NbNs1= NsH1/DNs2= Ns− Ns1Nb= 0 . 16Ab/As+ C1Nb1= NbH1/DNb2= Nb H2/D+ C2C2= 0 whenℎ ≤ 0 . 15H2= (0 . 6ℎ/H2− 0 . 09) whenℎ > 0 . 15H2



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Type 2b

C1 = 0.115 for Type 2a= 0.08 for Type 2bA = total area of the vertical projected longitudinal bulkhead plating, in in-ft (cm-m)As = total projected area of the side shell plating for the full depth of the vessel, in in-ft (cm-m)



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C H A P T E R 3Equipment

CONTENTSSECTION 1 Anchoring, Mooring and Towing Equipment ..................................76

1 General ........................................................................................763 Equipment Weight and Size......................................................... 765 Tests ............................................................................................ 777 Anchor Types ...............................................................................779 Windlass....................................................................................... 77

9.1 Windlass Supporting Structure and Chain Stopper......... 7711 Hawse Pipes, Anchor Pockets and Chain Cables........................7713 Mooring and Towing Equipment................................................... 8215 Deck Fittings.................................................................................82

TABLE 1 Equipment Weights and Sizes Inch/Pound Units.................78TABLE 1 Equipment Weights and Sizes Metric Units......................... 80

PART 3


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C H A P T E R 3Equipment

S E C T I O N 1Anchoring, Mooring and Towing Equipment

1 GeneralAll vessels are to have a complete equipment of anchors and chains. The symbol Ⓔ included in theclassification symbols as published in the Record will signify that the equipment is in compliance withthese requirements and has been tested in the presence of the ABS Surveyors in accordance with therequirements of the ABS Rules for Materials and Welding (Part 2). Chains which are intended to form partof the equipment are not to be used as check chains when the vessel is launched. Anchors and their chainsare to be effectively secured and arrangements for stopping each chain as it is paid out are to be provided.The windlass is to be capable of heaving in either chain and suitable arrangements for securing the anchorsand stowing the chains are to be provided.

3 Equipment Weight and SizeEach vessel is to be provided with two bower anchors (stockless) and 180 fathoms (330 m) [90 fathoms(165 m) on each anchor], the weights and sizes of these being in accordance with 3-3-1/11 TABLE 1 andregulated by the tonnage for equipment as obtained from the following equations. Anchors of other typesand chains of other material will be specially considered. Where the calculated tonnage falls between twovalues given in the Table, the lower value may be used.

Tonnage under freeboard deck = 0.01cLBD inch units= 0.35cLBD metric units

wherec = 0.85L = length of vessel, as defined in 3-1-1/1, in ft (m)B = breadth of vessel, as defined in 3-1-1/3, in ft (m)D = depth of vessel to freeboard deck, in ft (m)

Addition for superstructures or deck houses on freeboard deck = 0 . 0066cℓbd inchunits = 0 . 2355 cℓbd metricunits where

PART 3


76

c = 0.75ℓ = length of superstructure or deck house, in m (ft)b = mean breadth of superstructure or deck house, in m (ft)d = mean height of superstructure or deck house, in m (ft)

For the second tier of houses or superstructures the multiplier is to be 0.005 (0.1766) instead of 0.0066(0.2355).

5 TestsTests are to be in accordance with the Table requirements for the respective sizes as set forth in ABS Rulesfor Materials and Welding (Part 2). Anchors and chains are to be tested in an approved machine in thepresence of a Surveyor.

7 Anchor TypesAnchors are to be of the stockless type in which the weight of the head is not less than three-fifths of thetotal weight of the anchor. Where specifically requested by the Owners, the Bureau is prepared to giveconsideration to the use of special types of anchors and where these are of proven superior holding ability,consideration may also be given to some reduction in the weight, up to a maximum of 20%, from theweight specified in 3-3-1/11 TABLE 1. In such cases an appropriate notation will be made in the Record.

9 Windlass (2022)The windlass is to be of good and substantial make, suitable for the size of chain required by 3-3-1/11TABLE 1. Care is to be taken to insure a fair lead for the chain from the windlass to the hawse pipes and tothe chain pipes.

9.1 Windlass Supporting Structure and Chain Stopper (2022)The windlass supporting structure and chain stopper are to meet the following requirements:

i) 3-5-1/11 of the Marine Vessel Rules for self-propelled vessels

ii) 3-3-1/19 of the Barge Rules for barges

11 Hawse Pipes, Anchor Pockets and Chain Cables (2022)Hawse pipes and anchor pockets are to be of ample size and strength. They are to be secured to thickplating and, after installation, are to be hose tested for watertightness, with the pressure of the water in thehose not to be less than 30 psi (2.1 kg/cm2). The hawse pipes are to have the easiest possible lead and fullround flanges so as to minimize the nip on the chains. The anchors are to be shipped and unshipped so thatthe Surveyor may be satisfied that there is no risk of the anchors jamming in the hawse pipes or anchorpockets.

Hawse pipes for stockless anchors are to provide enough clearances to preclude the anchor jamming. Theanchors are to be let go aweigh and heaved up to the satisfaction of the Surveyor, proving that the anchorchain does not get stuck.

Arrangements are to be provided for securing the inboard ends of the bower anchor chain cables. Thechain cables are to be secured to structures by a fastening able to withstand a force not less than 15% normore than 30% of the breaking load of the chain cable. The fastening is to be provided with a meanssuitable to permit, in case of emergency, an easy slipping of the chain cables to sea, operable from anaccessible position outside the chain locker.

Part 3 Hull Construction and EquipmentChapter 3 EquipmentSection 1 Anchoring, Mooring and Towing Equipment 3-3-1


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TABLE 1 Equipment Weights and Sizes Inch/Pound Units

Equipment Tonnage Weight Each Anchorlb

Chain Cable Stud Link Bower Chain

Diameter

Normal Strength Steel(Grade 1), in.

High-Strength Steel(Grade 2), in.

Extra High-StrengthSteel (Grade 3), in.

2000 3750 15/8 17/16 11/4

2500 4000 15/8 17/16 11/4

3000 4500 13/4 11/2 15/16

3500 4750 17/8 15/8 17/16

4000 5000 115/16 111/16 17/16

4500 5250 2 13/4 11/2

5000 5750 21/16 113/16 19/16

5500 6000 21/16 113/16 19/16

6000 6300 21/16 113/16 19/16

6500 6500 21/16 113/16 19/16

7000 6750 21/8 17/8 15/8

7500 7000 21/8 17/8 15/8

8000 7000 21/8 17/8 15/8

8500 7250 23/16 115/16 13/4

9000 7600 23/16 115/16 13/4

9500 7600 25/16 2 113/16

10000 8100 25/16 2 113/16

10750 8600 25/16 2 113/16

11500 8600 23/8 21/16 113/16

12250 9000 23/8 21/16 113/16

13000 9000 27/16 21/8 17/8

13750 9500 27/16 21/8 17/8

14500 10000 27/16 21/8 17/8

15250 10000 21/2 23/16 2

16000 10000 21/2 23/16 2

16750 10000 21/2 23/16 2

17500 11000 29/16 21/4 2

18250 11000 29/16 21/4 2



78



Diameter




19000 11000 29/16 21/4 2

19750 11000 25/8 25/16 2

20500 12000 25/8 25/16 2

21250 12000 211/16 23/8 21/16

22000 12000 211/16 23/8 21/16

23000 13000 211/16 23/8 21/16

24000 13000 23/4 27/16 21/8

25000 13000 23/4 27/16 21/8

26000 14000 23/4 27/16 21/8

27000 14000 27/8 21/2 23/16

28000 14000 27/8 21/2 23/16

29000 15000 27/8 21/2 23/16

30000 15000 215/16 29/16 21/4

31500 16000 215/16 29/16 21/4

33000 16000 215/16 29/16 21/4

34500 16000 3 25/8 25/16

36000 18000 3 25/8 25/16

37500 18000 3 25/8 25/16

39000 18000 3 25/8 25/16

40500 18000 31/16 211/16 23/8

42000 20000 31/16 211/16 23/8

44000 20000 31/16 211/16 23/8

46000 20000 33/16 23/4 27/16

48000 20000 33/16 23/4 27/16

50000 22500 33/16 23/4 27/16

52000 22500 31/4 213/16 27/16

54000 22500 35/16 27/8 21/2

56000 25000 35/16 27/8 21/2

58000 25000 35/16 27/8 21/2

60000 25000 33/8 215/16 29/16



79



Diameter




62000 25000 33/8 215/16 29/16

64000 27500 33/8 215/16 29/16

66000 27500 33/8 215/16 29/16

68000 27500 37/16 3 25/8

70000 27500 37/16 3 25/8

TABLE 1 Equipment Weights and Sizes Metric Units

Equipment Tonnage Weight Each Anchorkg


Diameter

Normal Strength Steel(Grade 1), mm

High-Strength Steel(Grade 2), mm

Extra High-StrengthSteel (Grade 3), mm

2000 1700 42 36 32

2500 1815 42 36 32

3000 2040 44 38 34

3500 2155 48 42 36

4000 2270 49 43 36

4500 2380 50 44 38

5000 2610 52 46 40

5500 2720 52 46 40

6000 2860 52 46 40

6500 2950 52 46 40

7000 3060 54 48 42

7500 3175 54 48 42

8000 3290 54 48 42

8500 3290 56 50 44

9000 3445 56 50 44

9500 3445 58 50 46

10000 3675 58 50 46

10750 3900 58 50 46

11500 3900 60 52 46

12250 4080 60 52 46



80



Diameter




13000 4080 62 54 48

13750 4310 62 64 48

14500 4535 62 64 48

15250 4535 64 56 50

16000 4535 64 56 50

16750 4535 64 56 50

17500 4990 65 57 50

18250 4990 65 57 50

19000 4990 65 57 50

19750 4990 66 58 50

20500 5445 66 58 50

21250 5445 68 60 52

22000 5445 68 60 52

23000 5895 68 60 52

24000 5895 70 62 54

25000 5895 70 62 54

26000 6350 70 62 54

27000 6350 73 64 56

28000 6350 73 64 56

29000 6805 73 64 56

30000 6805 75 65 57

31500 7260 75 65 57

33000 7260 75 65 57

34500 7260 76 66 58

36000 8165 76 66 58

37500 8165 76 66 58

39000 8165 76 66 58

40500 8165 78 68 60

42000 9070 78 68 60

44000 9070 78 68 60



81



Diameter




46000 9070 81 70 62

48000 9070 81 70 62

50000 10205 81 70 62

52000 10205 83 71 62

54000 10205 84 73 64

56000 11340 84 73 64

58000 11340 84 73 64

60000 11340 86 75 65

62000 11340 86 75 65

64000 12475 86 75 65

66000 12475 86 75 65

68000 12475 87 76 66

70000 12475 87 76 66

13 Mooring and Towing Equipment (2022)Mooring and towing equipment are to meet the following requirements:


ii) 3-3-1/17 of the Barge Rules for barges

15 Deck Fittings (2022)Deck fittings are to meet the following requirements:


ii) For the installation of deck fittings on steel barges, the structure in way of cleats, bitts, and chocksis to be suitably reinforced by the installation of headers, additional beams, brackets, or doublingbeams.



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Bulk Carriers for Service on the Great Lakes - Eagle.org

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