Section 1 Transverse Framing System

Ch 5

101. Single Bottoms

1. General

In case of single bottoms, the centerline girder that is formed by web and rider plate is to be in- stalled and extended as far forward and afterward as practicable.

2. Center girder

(1) Girder

(A) The thickness of the girder is not to be less than that obtained from the following formula.

However, beyond the midship part, the thickness of the girder at the fore end and aft end part may be gradually reduced and it may be 85 % of the thickness obtained from the formula.

0.065 Ä + 4.2 (mm )

(B) The height of girder is not to be less than the height of the floor.

(2) Rider plates

(A) The rider plates are to be extended from the collision bulkhead to the aft peak bulkhead.

(B) The sectional area of rider plates is not to be less than that obtained from the following.

However, beyond the midship part, the thickness of rider plates may be gradually reduced and it may be 85 % of the thickness obtained from the formula at the fore and aft end part.

0.6 Ä + 9 (cmË )

(C) The breadth of rider plates is not to be less than that obtained from the following formula;

2.3 Ä + 160 (mm )

(D) The girders under the pillars are to be compensated properly by such means as increasing the sectional areas of rider plates of girder.

3. Side girders

(1) Structure and Arrangement

Side girders are to be composed of girders and rider plates, and extended as far forward and afterward as practicable, and to be arranged between the centerline girder and ship's side with the spacing of not more than 2.5 m .

(2) Girders

(A) Girders

The thickness of girders at amidships is not to be less than that obtained from the follow- ing formula. However, it is not to be more than the value obtained from 101. 2 (1) (A). And also, their thickness at the fore and aft end parts may be 85 % of those at amidships.

0.042 Ä + 4.8 (mm )

(B) Rider Plates

The thickness of rider plates is not to sectional areas at the midship parts are formula. And also, their sectional areas

at amidships.

be less than that of the side girder plate, and their not to be less than that obtained from the following at the fore and aft end parts may be 85 % of those

Ch 5

0.45 Ä + 8.8 (cmË)

4. Floors

(1) Arrangement

The standard spacing of floors is to comply with the requirements in 103. 2.

(2) Shape

(A) Upper edges of floors at any part are not to be below the level of upper edge at the centerline.

(B) In the midship part, the depth of floors at the inner edge of frame bracket is not to be less

than 1/2 of ẀŊ specified in the following (3) (A).

(C) The face plates on the upper edge of floors are to be fitted from the upper part of the

bilge at one side to the upper part of the bilge on the opposite side in case of the floors

with curved shape. In case of floors connected by bracket, they are to be continually fitted extending over the floors.

(3) Scantling of floors

(A) The scantling of floors is not to be less than that obtained from the following formula.

Depth of the floor at the centerline (ẀŊ ) : 0.0625 Ŷ (m )

Thickness of the floor : 10 ẀŊ + 3.0 (mm ) and 12 mm , whichever is the smaller. Section modulus of the floor : 4.27 ÅYŶË (cmĖ)

Å : spacing of floor (m )

Y : Ẁ or 0.66 Ǽ, whichever is the greater (m )

Ŷ : span between the inner edge of floor bracket measured at the middle of Ä plus

0.3 m . However, in case of a floor which has curved shape at the upper edge, the length Ŷ may be suitably modified.

(B) The thickness of face plates fitted at the upper edge of floors is not to be less than the thickness of the floors and the breadth of face plates is to be adequate for lateral stability of the floors.

(C) Beyond 0.5 Ä amidships, the thickness of floors may be gradually reduced to 85 % of the

value specified in the above (A) at the end parts of the ship. However, for the strength- ened bottom forward, the following requirements in Item. (4) are to be complied with.

(4) Strengthened bottom forward

At the strengthened bottom forward parts, the depth of floors is to be increased, or the co- efficients of floors specified in (1) are to be increased properly.

(5) Frame brackets

The scantling of frame brackets is to be determined in accordance with the requirements of the followings. And, the free edge of the brackets is to be appropriately flanged.

(A) The height of the bracket measured from the top of keel is not to be less than twice the required depth of the floor plate at the centerline of the ship.

(B) The breadth of the floor plate measured along the upper edge of floor plate from the inner edge of frame is not to be less than the depth of the floor plate required at the centerline

of the ship.

(C) The thickness of frame brackets is not to be less than that of floor plates.

(6) Drainage holes

Drainage holes are to be provided on the floor plates on both sides of the centerline and for

barges with flat bottom, at the low parts of the turn of bilge.

(7) Lightening holes

Lightening holes may be provided on the floors. compensation is to be made by increasing the floor

In this case, however, appropriate strength depth or by some other suitable means.

Ch 5

102. Double bottoms

1. General

(1) Dredger that Ä is 90 meters and above, is to be of double bottom structure. However, it may be constructed with single bottom structure if approved by this Society.

(2) The requirements in 102. may be suitably considered, where longitudinal bulkheads are provided

to reduce the supported breadth of double bottoms or partial double bottoms are provided.

(3) Where the longitudinal framing system is transformed into the transverse framing system, or the depth of the double bottoms changes abruptly, special care is to be taken for the continuity of strength by installing additional girders or floors.

(4) Manholes and lightening holes are to be provided in all non-watertight members to ensure ac- cessibility and ventilation, except where pillars are provided and where such openings are re- stricted in accordance with the rules.

(5) The number of manholes in tank tops is to be kept to the minimum necessary for securing ventilation and ready access to every parts of the inside of double bottom. They are to be so provided that the main watertight compartments are not to be connected each other through the double bottom.

(6) A suitable means is to be provided for freeing bilge at the top of double bottom. The bilge well fitted at the top of double bottom in accordance with the requirement in (1) above is to be such that, as far as practicable, its depth is to be less than 1/2 of the depth of double bot- tom and its bottom is to be situated at a distance of not less than 460 mm from the bottom

shell.

(7) The thickness of the watertight girders and floors and the scantling of the stiffeners attached to them are to comply with the relevant requirements for respective girders and floors as well as the requirements in Ch 7, 301. and 302.

(8) No structural members of the double bottom is to be less than 6 mm in thickness.

2. Center girders

(1) Arrangement and structure

(A) Center girders are to be extended as far forward and afterward as practicable.

(B) In case the center girders are not watertight in double bottom where fuel oil, fresh water or

ballast are carried, the breadth of the compartments are not to exceed 0.5 A . However, such areas that inside of narrow tanks at the fore and aft end and other areas where deemed appropriate by this Society may be considered properly.

(2) Scantling

(A) The height of the center girders are not to be less than B/16 except as specially approved by this Society, but in no case is it to be less than 700 mm .

(B) The thickness of the center girder is not to be less than that obtained from the following formula;

0.05 Ä + 5 (mm )

(3) Manholes

(A) Manholes may be provided on center girders in every frame space beyond 0.75 Ä amidships.

(B) If Ä (length of ship) is less than 90 meters, manholes may be provided on center girders in every two frame spaces within 0.75 Ä amidships. However, the depth of manholes is not to exceed 1/3 of the depth of center girder.

3. Side girders

(1) Arrangement

(A) Side girders, within 0.5 Ä amidships and in between center girders and the ship's side, are to be provided at an interval not more than 4.6 meters.

(B) The arrangement of the side girders and half-height girders at the strengthened bottom for- ward and their forward and afterward parts are to be in accordance with the requirements in

104. 3.

(2) Thickness

The thickness of side girder plating is not to be less than that obtained from the following for- mula;

Ch 5

ŊĦÈÈĬJÄ Ğ ËĦÈ (mm )

(3) Thickness of half-height girders

The thickness of half-height girders is not to be less than that obtained from the above formula in (2).

(4) Scantling of vertical stiffeners and struts

(A) Vertical stiffeners are to be provided on side girders at appropriate intervals, and struts are to be provided on half-height girders at the place of the open floors.

(B) The stiffeners are to be of the flat bars or equivalents with the thickness of the same as

that of the girder plates to which the stiffeners are attached, and the depth of 0.08 ẀŊ or more, where ẀŊ is the height of the center girder(mm ).

(C) The section modulus of struts defined in the above (A) is not to be less than that obtained

from the requirement in 202. 5.

(5) Lightening holes

The diameter of lightening holes on the side girders within 10 % of the length of a hold at the

location of the transverse bulkhead, is not to be exceeded 1/3 of the depth of side girders at

that place. However, a suitable modification may be made at outside of 0.75 Ä

where appropriate compensation has been made and the length of hold is particularly

4. Solid Floors

(1) Arrangement

amidships small.

(A) Solid floors are to be provided within the double bottom at a spacing not exceeding about

3.5 m .

(B) Solid floors are to be provided at the place of the followings regardless of the above re-

quirement the above (A).

 Lower part of the transverse bulkhead.

 At the location specified in the requirement 104. 3 between the collision bulkhead and the after end of the strengthened bottom forward.

(C) Watertight floors are to be so arranged that the double bottom compartment may

sponds to that of the ship as far as practicable.

(2) Thickness

corre-

The thickness of solid floors is not to be less than that obtained from the following formula;

ŊĦÈĬJÄ Ğ ËĦÈ (mm )

(3) Vertical stiffeners

(A) In case of transverse framing system, vertical stiffeners are to be provided on the solid floors at a suitable spacing. In case of a longitudinal framing system, however, they are to be provided at every longitudinal frames.

(B) The thickness of the vertical stiffeners prescribed in (1) is to be the same as that of the flat bar attached to them, and the depth is not to be less than 0.08 ẀŊ (m ) or equivalent, where ẀŊ (m ) is the depth of the centerline girder.

(4) Lightening holes

The diameter of lightening holes within 0.1 A from side shell plating, is not to be exceeded

about 1/5 of the depth of the solid floors that are located within 1/2 length from the middle of a hold. This requirements may, however, be suitably modified to solid floors that have been compensated and located beyond the 0.75 Ä from the amidships or in case that the length of holds are exceptionally small.

5. Open floors

(1) Arrangement

Where the double bottom is framed transversely, open floors composed of brackets fitted at center girder and margin plate, and main frames and reverse frames are to be provided at ev- ery hold frame where solid floors are not provided.

(2) Scantling of main frames and reverse frames

(A) The section modulus of main frames is not to be less than that obtained from the following formula.

ÆÅYŶË (cm Ė)

Ch 5

Ŷ : Distance between the bracket attached to the center girder and the bracket attached to the margin plate (m ). However, in case side girders are provided, the distance between vertical and bracket (m ) is may be taken if it is the greater.

Å : Spacing of frames (m )

Y : Vertical distance to a point of 0.026 Ä + Ẁ above the top of keel (m ).

Æ : Coefficient as the following ;

In case where struts as specified in the following (3) are not provided: 6.0 In case where struts as specified in the following (3) are provided:

under the deep tank : 4.4 Other places : 2.9

(B) The section modulus of reverse frame is not to be less than the value obtained from the calculation which taken 85 % of the value of Æ at that main frame as the coefficient Æ in (1). However, where struts are not provided under deep tank, the value as required in Ch 7, 302. is to be taken.

(3) Struts

(A) The struts specified in (2) are to be of rolled sections other than flat bars or bulb plates and to be overlapped sufficiently with main frames and reverse frames.

(B) The section modulus of the struts specified in (A) is not to be less than that obtained from

the requirement in 202. 5.

(4) Brackets

(A) Main frames and reverse frames are to be connected to the center girder and margin plate with brackets whose thickness are not to be less than that obtained from the requirement in 202. 3 (3).

(B) The above brackets are to be overlapped sufficiently with main frames and reverse frames with their breadth not to be less than 5 % of A . And their free edges are to be suitably

stiffened.

6. Inner bottom plating and margin plates

(1) Thickness of inner bottom plating

The thickness of inner bottom plating is not to be less than that obtained form the following formula;

ĖĦĒÅĬJẀ Ğ ËĦÈ (mm)

Å : the spacing of floors in case of transverse framing system (m )

(2) Crossline between margin plates and shell planting

It is recommended that the crossline between margin plate and shell plating is to be of suffi- cient height to protect the bottom up to the turn of the bilge and for forward 0.2 Ä from the stem the margin plates are to extend to the ship's sides horizontally as far as practicable.

(3) Thickness of margin plates

The thickness of margin plates is to be increased by 1.5 mm above that obtained from the for- mula in the above (1).

(4) Breadth of margin plates

Margin plates are to be of adequate breadth and to extend well inward from the inner edge of the outer brackets.

7. Outer brackets

(1) The thickness of outer brackets connecting hold frames to margin plates is to be increased by

1.5 mm above that obtained from the formula in 202. 3 (3).

(2) The free edges of the outer brackets are to be suitably stiffened.

Ch 5

103. Transverse frames

1. General

(1) Transverse strength

Where the

length between transverse bulk heads is long, transverse strength is to be strength-

ened by means of increasing the scantling of frames or additional provision of web frames etc..

(2) Frames in deep tanks

The frames in deep tanks are to have the same strength as the stiffeners on the deep tank bulk- heads have.

(3) Connection of the frames

The frames and brackets at the turn of the bilges or tank side brackets in the double bottom are to be effectively connected by overlapping over l.5 times the depth of frame.

2. Frame spacing

(1) The standards spacing of transverse frame is obtained from the following formula;

Ä < 40 m : 530 (mm ), Ä ≧ 40 m : 2 Ä + 450 (mm )

(2) Transverse frame spacing in fore and after peaks is not to exceed 610 mm or the standard spacing in (1), whichever is the smaller.

(3) The requirement in (2) may be modified, where structural arrangements or scantlings are suit- ably considered.

3. Scantling of frames

(1) The section modulus of transverse frames under the upper deck between the collision bulkhead and aft peak bulkhead is not to be less than that obtained from the following formula. It should not, however, be less than 30 cmĖ.

ÆÅYŶË (cmĖ )

Å : Spacing of frames (m )

Ŷ : Vertical distance from top of inner bottom plate or floor of single bottoms at side to the upper edge of the deck beam at the top of frames (m )

Y : Vertical distance for each frame from the lower part of Ŷ to the following points;

30 m < Ä ≦ 90 m

Ä > 90 m

: top of the keel

: top of the keel

Ẁ + 0.004 Ä - 0.54

Ẁ + 0.038 Ä

Æ : Coefficient as the following ;

Frames in between 0.15 Ä from the collision bulkhead and aft peak bulkhead: 2.6 Frames in between 0.15 Ä from the collision bulkhead and the collision bulkhead: 3.4

(2) Where the height of floors in the ship's centerline is less than A /16, the scantling of frames in the requirement of (1) is to be suitably increased.

4. Fore and aft peak tank frames

(1) Transverse frames in fore peak tank

The section modulus of transverse frames under the upper deck at forward of the collision bulk- head is not to be less than that obtained from the following formula. It should not, however, be less than 30 cmĖ .

ĒÅYŶË (cm Ė)

Å : Spacing of frames (m )

Ŷ : Vertical distance between frames (m ). However, it is to be taken 2 m where the dis- tance is less than 2 m .

Ch 5

Y : Vertical distance between the middle of Ŷ and 0.12 Ä on top of the keel. However, it is to be taken 0.06 Ä (m ) where the distance is less than 0.06 Ä .

(2) Transverse frames in aft peak tank

The section modulus of transverse frames under the upper deck at aftward of the aft peak bulk- head is not to be less than that obtained from the following formula. It should not, however, be less than 30 cmĖ .

ĒÅYŶË (cm Ė)

Å : Spacing of frames (m )

Ŷ : Vertical distance between frames (m ). However, it is to be taken 2 m where the dis- tance is less than 2 m .

Y : Vertical distance between the middle of Ŷ and the following points.

30 m < Ä ≦ 90 m

Ä > 90 m

: top of the keel

: top of the keel

Ẁ + 0.044 Ä - 0.54

Ẁ + 0.038 Ä

104. Fore and aft end construction

1. General

(1) For the bottom and ship's side structures at the fore and aft end parts, the requirements are to be applied, and for ship's side frames, the requirements in 103. are to be applied.

(2) Where fore and aft end parts are used for deep tank, the requirements in Ch 7, Sec 3 are also to be applied.

(3) Wash plates

In the fore and aft holds which are used for deep tank, the effective wash plating is to be pro- vided on the centerline or scantling of structural members is to be suitably increased.

2. Constructions forward collision bulkhead

(1) Construction and Arrangement

(A) Deep center girders or longitudinal bulkhead on the ship's centerline are to be provided for- ward the collision bulkhead, or center girders and deck structure are to be of truss structure that connects each other with strut and diagonal.

(B) In the transverse framing system, floors having sufficient height are to be provided at every frames. And those floors are to be supported by side girder provided with spacing of 2.5 m or less. The frames are to be supported by structures specified in 104. 2 (1) (E) to (G) at vertical interval of 2.5 m .

(2) Scantling of structural members

(A) Thickness of center girder and floor plate is not to be less than that obtained from the fol- lowing formula. However, it does not need to exceed 11 mm .

0.045 Ä + 4.5 (mm )

(B) Floor plates are to have appropriate depth, and stiffeners are suitably provided as necessary.

(C) The upper edge of the floor plates and center girders are suitably stiffened.

(D) The thickness of side girder is to be the same as that of center girder and its height is to be appropriately modified according to the height of floor plates.

(E) Stiffening beam is to be provided on each frame, and where steel plates having lightening

holes are provided from the ship's side to the other side, scantling of stiffening beams and steel plates is not to be less than that obtained from the following formula;

Sectional area of stiffener : 0.1 Ä + 5 (cmË) Thickness of steel plate : 0.02 Ä +4.5 (mm )

Ch 5

(F) In case that a ship's side stringer is installed, its scantling is not to be less than that ob- tained from the following formula.

Depth of stringer : 0.2 Ŷ (m ) or 2.5 times the depth of slot for penetrating longitudinal

frames, whichever is the greater. However,

following formula;

it is not to be less than that obtained from the

Ä < 90 m : 0.0053 Ä + 0.25 (m ), Ä ≥ 90 Ŷ : 0.0025 Ä + 0.5 (m )

Section modulus of stringer Thickness of Web

: ĒÅYŶË (cmĖ)

: 0.02 Ä + 5.5 (mm )

Å : Width supported by ship's side stringer (m )

Y : Vertical distance from the middle of Å to 0.12 Ä on the top of keel.

However, 0.06 Ä (m ) is taken, in case the distance is less than 0.06 Ä (m )

Ŷ : Length between supporting points including Connection part of the ship's side stringer (m )

(G) Stiffening beam is to be provided on every other frame, and the scantling of stiffening

beam and stringer plate in case that the stringer plate is connected to shell plating is to be as follows;

 Stiffening beam : Sectional area of stiffening beam is not to be less than that obtained from the following formula.

0.3 Ä (cmĖ )

 Stringer plate :

Width : Ä < 90 m : 5.3 Ä + 250 (mm ),

Thickness : 0.02 Ä + 5.5 (mm )

Ä ≧ 90 m : 2.5 Ä + 500 (mm )

(3) Truss

Where applied.

bottom structures and deck structures are connected by truss, the followings are to be

(A) The sectional area of the strut is not to be less than that obtained from the following for- mula

ŊĦĖĖÅẄÄ (cmĖ)

JŶ

ËĦĒË G JÝ

Å : Distance between the center of span extending from one strut to its next strut or to the bulkhead (m )

Ẅ : Distance between the center of span extending from one strut to its next strut or

to the inside of bracket at ship's side (m )

Ŷ : Length of strut (m )

Ĭ

JÂ

Ý G JA

 : Moment of inertia of strut (cm Ė)

A : Sectional area of strut (cmË)

Ch 5

(B) Diagonal

An angle with the horizontal line is to be about 45° and the sectional area is not to be less than 75 % of the sectional area of strut as required in (1).

(C) Where fore peak tank is to be used as deep tank, the strut and diagonal are to be of solid type one.

3. Construction of strengthened bottom forward

(1) General

These requirements are to be applied in ships having a fore draught of less than 0.037 Ä in ballast condition.

(2) Structure

(A) Side girders or half side girders are to be provided in accordance with Table 5.1 in be-

tween the collision bulkhead and 0.2 Ä from the fore provided in between the collision bulkhead and 0.175 Ä

end. However, half girders may be from the fore end.

(B) Solid floors are to be provided in accordance with Table 5.1 in between the collision bulk- head and the 0.15 Ä from the fore end.

(C) In ships where the fore draught in ballast condition is more than 0.025 Ä and less than

0.037 Ä and the arrangement of the structures in the compensated parts at the forward bot- tom is such that it may be hard to comply with the requirements prescribed in previous paragraphs, floors and side girders are to be suitably compensated. However, exception is to be made for ships having tugging and pushing speed exceptionally low, compared with Ä.

Table 5.1 Structure of the compensated parts at the forward bottom

4. Structures at the afterward of the Aft peak bulkhead

(1) Floor

Scantling and construction of floors in aft peak tank are to be in compliance with the require- ments in 104. 2 (2).

(2) Frames

Where the distance measured from the outside of the frame to the supporting point of the frame is over 2.5 m , either the scantling of frame may be increased or stiffening of the ship's side be increased by a suitable mean.

(3) Other structural members

Where the structures in the aft peak tank are of the same as those in the fore peak tank as required in 104. 2, the scantlings of transverses, stringers, longitudinal frames, struts and diago- nals may be reduced with 30% that required in 104. 2.

105. Beam

1. General

(1) Camber

The standard camber of weather decks is to be

(2) Connection of beam

A

JÈŊ

at the middle of Ä of barge.

(A) Transverse beam is to be connected to frame by brackets

(B) Transverse beam, which is provided at a place where frame is not provided, in between decks or superstructures, is to be connected to shell plating by beam bracket.

Ch 5

(3) Place where longitudinal beam system is transformed to transverse beam system

Special care is to be taken to keep the continuity of strength at the place where longitudinal beam system is transformed to transverse beam system.

2. Transverse beams

(1) Arrangement and shapes

(A) Transverse beams are to be provided on every frames. The length-depth ratio of the trans- verse beam is preferably to be of 30 or less at strength deck.

(B) 40 or less at superstructure deck as far as practicable.

(2) Section modulus

The section modulus of transverse beam is not to be less than that obtained from the following formula;

ŊĦĖĖ ÅYŶË (cm Ė)

Å : Spacing of beams (m )

Y : Deck loads as required in Ch 4, 202. (kNĤmË )

Ŷ : Distance between the inner end of the beam bracket and the nearest deck longitudinal girder or between each deck longitudinal girders (m ).

3. Beams at bulkhead recess

Section modulus of beam provided for the deck which forms the bulkhead recesses, is to be in compliance with this chapter as well as the requirement in Ch 7, 203.

4. Beams on top of deep tank

Section modulus of beam provided for the deck which forms deep tank is to be in compliance with this chapter as well as the requirement in Ch 7, 302.

5. Deck beam supporting especially heavy weight

Superstructure or end parts of deckhouse, and deck beams supporting mast, ladder, dredging ma- chineries, auxiliary machinery or especially heavy weight are to be properly reinforced by increasing the scantling of beams, or by installing additional deck girders or pillars.

106. Deck girders

1. Arrangement

(1) Longitudinal girders under the deck are to be provided to support the transverse beams.

(2) In way of the bulkhead recess and the top of tank, deck girders are to be arranged at an inter- val not exceeding 4.6 m as far as practicable.

2. Construction

(1) Deck girders are to be composed of face plate provided along the lower edge.

(2) Tripping brackets are to be provided at an interval of about 3 m and where the breadth of face plate exceeds 180 m in either side, the tripping brackets are to be so arranged as to support the face plate as well.

(3) The thickness of face plates forming girders is not to be less than that of web plates and the width of the face plates is not to be less than that obtained from the following formula.

ĒÈĦĖĬJẀ

ŊŶ (mm)

d0 l

: depth of girder (m )

: span of girders (m ). If there is a effective tripping brackets, it is considered between supporting points

(4) The depth of girder is to be kept constant between two adjacent bulkheads and is to be more

Ch 5

than 2.5 times of slot depth for beam.

(5) The girders are to have sufficient rigidity to prevent excessive deflection of decks and excessive additional stresses at the end of beams.

3. Section Modulus

(1) The section modulus of deck girders outside the lines of hatchway opening of the strength deck for midship part is not to be less than that obtained from the following formula.

ËĦËŊ ẄYŶË (cm Ė)

Ẅ : Distance between the centres of two adjacent spans of beams supported by the girders or the beam bracket (m)

Y : Deck loads specified in Ch 4, Sec 2 (kNĤmË)

Ŷ : Distance between the supports of longitudinal girders (m)

(2) The section modulus of deck girders outside the lines of hatchway opening of the strength deck for the part forward and aftward the midship part may be gradually reduced. In no case, how- ever, the section modulus is not to be less than that obtained from the following formula.

ŊĦĖĒĖẄYŶË (cm Ė)

Ẅ, Y and Ŷ : as specified in (1)

(3) The section modulus of deck girders other than (1) and (2) is not to be less than that obtained from (2).

4. Web thickness

The thickness of web plate of longitudinal girder is not to be less than that obtained from the fol- lowing formula.

10 ÅË + 1.5 (mm )

ÅË : spacing of web stiffeners or depth of girders, whichever is the smaller (m )

5. End connection

(1) Where Girder ends are connected to bulkhead plating or top plating of tank, effective supporting members are to be provided on the opposite side of bulkhead plating or top plating of tank.

(2) The bulkhead stiffeners or stiffening girders which are connected to the deck girders are to have

sufficient strength to support the deck girders

(3) Longitudinal deck girders are to be continuous or to be effectively connected so as to maintain the continuity at ends.