IACS Common Structural Rules Knowledge Centre

Bulker Q&As and CIs on the IACS CSR Knowledge Centre
KCID
No.

Ref.

Type

Topic

Date
completed119

4/3.2.2.2

Questionwave
bending
moments

2006/8/18

globalstrengthanalysis

The general case for all primary supporting members of both double hull or
single side bulk carriers shoud be 3 elemnts in height. The case of primary
supporting members in hopper tank and top side tank should be a particularcase, once again for both double hull and single side bulk carriers. Then side
frames in single side bulk carriers are covered in a separate item. Considering
that, we suggest to modify the third and fourth bullets in 2.2.4 as follows: "In FE models for global strength analysis, the number of plate elements on the- webs of primary supporting members are to be divided at least threeheight of primary supporting members is not clear.
2006/10/25
elements height-wise. However, for transverse primary supporting members
In particular, for transverse primary members inside the hopper tank and theinside the hopper tank and top wing tank, in case their web height is smaller
upper wing tank.
than the space between longitudinal ordinary stiffeners, two elements on theheight of primary supporting members are accepted- side shell frames in single side bulk carriers and their end brackets are to bemodeled by using shell elements for web and shell/beam/rod elements forface plate. Webs of side shell frames need not be divided along the directionof the depth"

Stiffeners

The requirement [4.2.3] should be applied both to ordinary stiffeners subjected
or not to the lateral pressure. When this requirement is fullfilled for stiffeners
subjected to lateral pressure, the term (cf-pz) which appears in the calculationof M0 in [4.2.2] becomes greater than 0.
In addition, requirements [4.2.1] and [4.2.2] apply only to ordinary stiffeners
subjected to the lateral pressure.

149

161

7/2.2.2.4

6/3.4.2.2

CI

Question

2007/6/11

Question/CI
What is the probability level of the vertical wave bending moments (Mwv.h)and (Mwv.s) used in the formulae defining the design still water bending
moments ?

A point is not clear while calculating the bending moment M0.
What must be done when (cf - pz) is negative or null?

Attachment

Answer
The vertical wave bending moments (Mwv.h) and (Mwv.s) used in theformulae defining the design still water bending moments are at the probability
level of 10-8, i.e. calculated as defined in [3.1] with (fp) equal to 1.0.

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completed

Question/CI

Attachment

AnswerIn order to have the same relation ship between horizontal shear force andhorizontal bending moment as the one between vertical shear force andvertical bending moment, I suggest introducing the following definition:"The horizontal shear force “Qh” is positive in the case of resulting force
towards portside preceding the ship transverse section, and resulting forces
towards starboard following the ship transverse section, and is negative in the
opposite case"This definition is not mentioned in CSR. Therefore, we will submit the following
modification to Hull Panel.
(1) Chapter 4 Section 1 Figure 1
The symbol “Q” in the figure is amended to “Qs” and “Qwv”..
169

7/2.2.5.4&.
Question
6

horizontal
shear force

2006/9/11

The formulae in 2.5.4 and 2.5.6 deal with horizontal shear force, but there isno sign convention for horizontal shear force.

(2) Chapter 7 Section 2 [2.5.4]
The definition of symbols of “QV_FEM, QH_FEM, MV_FEM, and MH_FE“ areamended as follows.
QV_FEM, QH_FEM, MV_FEM, and MH_FEM: Vertical and horizontal shear
forces and bending moments created by the local loads specified on the FEmodel.
Sign of QV_FEM, MV_FEM and MH_FEM are in accordance with sign
convention defined in Ch.4 Sec.3. Sign of QH_FEM is positive in the case of
resulting force towards portside preceding the ship transverse section, andresulting forces towards starboard following the ship transverse section, and isnegative in the opposite case.
(3) Chapter 7 Section 2 [2.5.6]
The definition of symbols of “QV_T, QH_T, MV_T, and MH_T“ are amended
as follows. QV_T, QH_T, MV_T and MH_T:Target vertical and horizontal
shear forces and bending moments, defined in Table 3 or Table 4, as thelocation xeq. Sign of QV_T, MV_T and MH_T are in accordance with sign
convention defined in Ch.4 Sec.3.

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170

Ref.

Ch 7 App
2 2.2.2 &2.2.3

4/App2/Ta
176
b3

Type

Date
completed

Question/CI

Answer

2007/6/11

In chapter 7 App2, 2.2.2 and 2.2.3, the formulae to obtain sigma x, sigma y,
psi x and psi y are given for "longitudinal compression" and "transverse
compression". In case the stress are in tension, psi will become bigger thanone, and the associated stress will be the minimum tension stress. According
to the definition of psi in Ch6 Sec3 and the schemes and formulae in Ch6
Sec3 Table 2 doe, psi is supposed to be smaller than one.
One interpretation is to change the formula for sigma and psi in order that psi
is lower than one and sigma is the maximum tension stress.
The other interpretation is to keep the formulae as they are in order to get theminimum tension stress.

As the psi factor will not be used with tension stresses, it seems preferable toretain the minimum tension stress (ie the maximum stress with the sign
convention for stress in the buckling rules) in order to be conservative.
Therefore, the formula for sigma x or sigma y is unchanged, and psi is not
calculated (or limited to one) for tension stress.

2006/9/27

The DSA calculation results in Loading condition No.10 in Table 3 of chapter
4, Appendix 2 are much larger than one in normal, especially for ships whose
length is less than 200m.

The loading condition No.10 in the Tab.3 of Chap.4, App.2 is extracted fromIACS UR S25, which is applicable to “Bulk Carriers” having length of 150m or
above. For ships having notation “BC-A” and length of 200m or less, scantling
impact are very large, comparing to those not applied to IACS UR S25.

weldedshearstrake

2006/9/27

2.5.1 Welded sheerstrake
The net thickness of a welded sheerstrake is to be not less than the actual
thicknesses of the adjacent 2m width side plating, taking into account higher
strength steel corrections if needed.
In this item, does the actual thickness mean actual gross thickness or actual
as-built thickness? Is the word 'net' omitted between 'actual' and 'thicknesses'
as 'the actual net thicknesses'?

The actual thickness of the adjacent side plating is to be understand as being
the actual net thickness, equal to (tas built - tc).

length

2006/10/2

Which length is correct? 150m or 90m?

Both are correct. The CSR for bulk carriers apply to ships of 90m or above in
general. Sub-sec.[3.1.1] corresponds to UR S25 which applies to ships of
150m or above. These definitions are kept as they are.

application of
CSR

2006/10/2

Does CSR apply to the bulk carrier with box shape which does not have bilge
hopper tank and top side tank?

No, the CSR for bulk carriers do not apply to a bulk carrier which does nothave hopper side tank and topside tank in cargo holds length area.

Topic

CI

PSI Factor

Question

DSA
calculation

177

6/1/2.5.1

Question

188

1/1.1.1.1 &Question
1/1.3.1.1

189

1/1.1.1.2

Question

Attachment

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1/1.1.1.2

1/1.1.1.2

Type

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Question

Topicapplication ofCSR

application of
CSR

Date
completed

Question/CI

2006/10/2

With bulk carriers is intended sea going self-propelled ship which areconstructed generally with single deck, double bottom, hopper side tanks andtopside tanks and with single or double side skin construction in cargo lengtharea and intended primarily to carry dry cargoes in bulk. Hybrid bulk carriers,
where at least one cargo hold is constructed with hopper tank and topsidetank, are covered by the present Rules. The structural strength of members inholds constructed without hopper tank and/or topside tank is to comply withthe strength criteria defined in the Rules. (See attachment)

No, the CSR for bulk carriers do not apply to such bulk carriers which areconstructed with topside tank but without hopper side tank in cargo holds
length area.

2006/10/2

Are the following ships not subject to CSR due to their cross section design?
- ore carrier- combination carrier- cement carrier- wood chip carrier- open hatch carrierNo, such ships are not subject to the CSR for bulk carriers.

(1) Yes, the ships with cross sections indicated in figure are defined as bulk
carriers.
(2) The treatment of "Novel features" and "unusual hull shapes" depends onthe discretion of each Classification Society.

Attachment

Answer192
attc

1/1.1.1.5

Question hull materials

2006/10/2

Ships whose hull materials are different than those given in [1.1.4] and ships
with novel features or unusual hull design are to be individually considered by
the society, on the basis of the principles and criteria adopted in the present
Rules.
(1) Is the word “ships” the bulk carriers as defined in [1.1.2]? (see drawing 1 in
attachment)(2) Can “Novel features” and “unusual hull shapes” be used to include vessels
as shown? See drawing 2 in attachment - Can this design the included in theterm novel feature?

193

1/4.3.3.3

Question

2006/10/2

The midship part of a ship is the part extending 0.4L amidship, unlessotherwise specified.” Could you elaborate on what this means?

The midship part is the extent of 0.3L to 0.7L from the aft end (A.E.) of the rule
length L.

194

2/1.1.1.2
Table
2.1.1

2006/10/2

In current design of bulk carrier with ship's length of 169.5m and after peakbulkhead and aft machinery bulkhead being the same, total number ofbulkheads is 7, but CSR requires 8 bulkheads to such ships not required tocomply with subdivision requirements. Regarding this requirements, is it
acceptable for such ships complying with the requirements on damage
stability?

Yes. Ships complying with subdivision requirement need not follow therequirement on the number of watertight bulkhead indicated in Table 1.

Question

lengthdamagestability

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2/1.3.1.1

7/4.3.3

Ch 6

Datecompleted

Attach
ment

Type

Topic

Questionafter peakbulkhead

Are the example case specified below (see attachment) complied with therequirements that “the after peak bulkhead may be stepped below the
2006/10/31
bulkhead deck, provided the degree of safety of ships as regards subdivision
is not thereby diminished.

simplified
methodYour understanding is right. The simplified method is applicable to theintersection of inner bottom plate and sloping plate of lower stool as well as
the intersection of inner bottom plate and hopper slant plate. That’s was theoriginal intention of the requirement. In applying the requirement of Ch.7 Sec 4
We understand that the methodology used in the simplified method is[3.3], therefore, the following interpretation is prepared in order to be in line
commonly applicable to the intersection of inner bottom plate and sloping plate with the original intention. Common Interpretations for:2006/10/31 of lower stool as well as bilge knuckle part. Therefore, Common Interpretation Chapter 7/Section 4/3.3Simplified method for the bilge hopper knuckle partshould be prepared as soon as possible so that this method can be applied to [The text of the Rules] The words “bilge hopper knuckle parts” , “bilge knuckle
the intersection of sloping plate of lower stool and inner bottom platepart” and “hopper slope plate” in the title of [3.3], the text of [3.3.1] and [3.3.3],
the title of Fig.6 and the text in the top of column of the Table 1. Common
Interpretation The requirements of [3.3] are applicable to the knuckle part not
only bilge knuckle part but also lower stool knuckle part such as theintersection of the inner bottom plate and sloping plate of lower stool.

CI

CI

Stiffeners

2007/6/11

Question/CI

Sniped stiffeners, requirement to buckling capacity - please see attachment for
full query as it included diagrams and equations.

AnswerYes, if the fire door may be regarded as safe for the purpose of subdivision.

Ya)Section 3 covers buckling of ordinary stiffeners and stiffened panels.
Therefore sniped buckling stiffeners are subject to Ch. 6 Sec. 3 [4].
b)No. Ch.6 Sec. 2[1], [2] and [3] are applicable to ordinary stiffeners and [4] isapplicable to web stiffeners.
Y
Buckling stiffeners as shown are subject to1.Ch. 3 Sec.6 [5.2.1]
2.Ch. 6 Sec.2 [4.1.2]
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3/3.1.2.1

3/6.2.3.1

Type

Question

Question

Question

Topic

thickness

Corrosion
additionhatchcoamingDatecompleted

Question/CI

Attachment

Answer

The reason of this requirement is the same as the one requiring D/DH for the
SPECIAL elements i.e. Class III) with notes (4), (5) and (6), which are highly
In case of bulk carriers, thicker plates greater than 20 mm are normally usedstressed elements. In this requirement, the notion of thickness greater than 20
for main structural members. Since this requirement is vague, we would like to
mm is added to the notion of highly stressed element. This corresponds in fact
2006/11/30 ask you to clearly explain your intention of the regulation 2.3.11 and to make
D/DH for Class III elements according to Table 3.However, since theclear the application of this requirement or criteria. If there is no criteria, it isapplication of this requirement is already covered by Table 1 and otherbetter to delete the requirement to avoid confusion in design approval stage.
requirements such as 2.3.2, we propose that this requirement should bedeleted according to your suggestion.

2006/11/8

2006/11/30

According to our understanding on CSR, rules relating to corrosion addition
have been harmonized with JTP.
However, there is a difference in definition of tank top between JTP and JBP.
Note (3) in Table 1 should be revised as follows:"Note (3) Only applicable to ballast tanks with weather deck as the tank top"from CSR for Tankers

As for hatch coamings, ClassNK approves hatch coamings having lower steel
grade than that of upper deck plating, in case of the hatch coaming length
being less than 0.15L. We therefore propose to delete hatch coamings fromthe last sentence.

Note (3) to be kept as it is. Example is Hopper Side Tk. not connected to
TSWB Tk. Air-/Water-Mixture will be below top of tank.
"This question and answer are superseded by KC ID 638. Please refer to
KC ID 638."

First, it is to be noticed that this requirement is not dealing with steel grade,but with yield strength of the steel. Secondly, the stress in shorter hatchcoamings (length much more less than 0,15L) is generally equivalent to theone in the deck. It becomes negligible only for very short hatch coaming.
Some criteria could be developed, including parameters such as length andheight of hatch coaming and their position along the ship. It seems quite
complicated to solve this easy problem. Finally we have to keep in mind astress check is to be carried out for the hatch coaming. Consequently, we
prefer to keep the text as it is, or we may suggest to open a door by adding
the word "generally" between "The same requirement" and "is applicable".

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3/6.2.3.1

3/6.6.1.6

3/6.6.4.2

3/6.9.6.3

6/1.2.5.1

Type

Topic

Date
completed

Question/CI

The last sentence of 2.3.1 is excess and differs from the present application
accepted by many classification societies. Higher strength steels are normallyapplied taking account of not only hull girder bending stresses but also local
stresses. For instance, higher strength steel is used to double bottom girders
taking into account local shearing stresses caused by cargo and external sea
high strengthloads acting on double bottom.And some sniped longitudinal stiffeners not
Question
2006/11/29
steel
contributing hull girder longitudinal strength, which are mild steel, are weldedon the girders to prevent panel buckling. Such design has been alreadyapproved by many classification societies. We consider that the steel grade ofstiffeners not contributing hull girder longitudinal strength can be selected on acase by case basis. We would like to ask you to revise the rule taking into
account the above.

The last sentence in Ch 3, Sec 6, [2.3.1] is not a matter of steel grade, butconcerns the yield strength of the steel. The matter of steel grade is relevant
to Ch 3, Sec 1. Having said that, it is understood that the original question is
not about steel grade. Ch 3, Sec 6, [2.3.1] could be considered as therequirements in general. If the stress level due to hull girder bending, inlongitudinal member not contributing to hull girder longitudinal strength, shouldbe verified as to satisfy the requirement in Ch 5, Sec 1, [3.1.1], application of
the requirements in Ch 3, Sec 6, [2.3.1] might be mitigated. As a matter of
opening the door, the word "generally" should be added between "The samerequirement" and "is applicable...".

2006/11/1

As shown in the caption, main intention of this requirement is continuity ofstrength, not scantling.
In the scantling determination of sloped bulkhead plating, yielding, buckling,grab handling and fatigue strength are taken into account. Continuity ofstrength can be realized by the consideration.
Therefore we would like to ask you to delete the requirement.

In applying the last sentence of 6.1.6, where the scantling of lower strake ofthe sloped bulkhead of hopper tanks and inner bottom plate adjacent thereto
are determined by the requirements on FEA and fatigue strength assessment,such structures are regarded as the satisfaction of the requirement on
continuity of strength.

2006/11/1

At least, please exclude the required material properties and net thickness ofstool side plating by GRAB from this requirement.
It is not necessary to apply the required material properties and net thicknessof stool side plating by GRAB to the supporting floors.

In applying this requirement 6.4.2, the net thickness and material properties
required for the bulkhead plating, or when a stool is fitted, of the stool side
plating mean that they are required by the scantling requirement except for the
grab loading and under flooded condition.

The extent of insert plate is larger than that of present designs. Since thestress concentration occurs in way of corner radius, we consider that therequirement should be reconsidered taking account of your experience.
Please permit us to determine the extent of insert plate taking into accountFEA results.

The following sentence should be added at the end of requirement 9.6.3: "Forships having length L of 150m and above, the extent of insert plate may be
determined by the results of a direct strength assessment, including bucklingcheck and of a fatigue assessment of hatch corners."

Question

scantling
determination

Question

GRAB
notation

Question

extent ofinsert plate

2006/11/1

side shell
plating

There are some cases where the side shell plating adjacent to sheer strake
includes single side part and is increased due to the buckling and hull girder
shear strength.Obviously, its reinforcement is not necessary for sheer strake,
2006/11/22
then please revise the sentence as follows:"...is to be not less than therequired thickness of the adjacent 2 m width side plating, which is calculated
according to Ch.6, Sec.1,..."

Question

Attachment

Answer

Generally, when the side shell plating adjacent to sheer strake includes single
side part and is increased due to the buckling and hull girder shear strength, it
is also the case for the sheer strake, which is located above. Consequently,
we see no reason to modify this requirement.

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6/2.2.3

6/2.3.3.1

Type

Question

Question

QuestionTopichull girder

Datecompleted

Question/CI

Answer

2007/1/11

We consider that this requirement has been introduced taking into accountshear lag.
However, there are some cases where the attached plating is increased dueto the buckling of the plating and hull girder shear strength.
Therefore we would like to ask you to revise the sentence as follows:"The net thickness of the web of ordinary stiffeners, in mm, is to be not lessthan the greater of:・…
・40% of the net required thickness of the attached plating, which is
calculated according to Ch.6, Sec.1."

We agree with the modification proposed in the original question:"The net thickness of the web of ordinary stiffeners, in mm, is to be not lessthan the greater of:- t = 3.0 + 0.015L2- 40% of the net required thickness of the attached plating, to be determinedaccording to Ch.6, Sec.1. and is to be less than 2 times the net required
thickness of the attached plating."
We will consider the Rule change proposal.

Attachment

PMA

If applying this requirement to longitudinal PMA having wide width, therequired scantlings become to be very heavy. This rule seems to be buckling
requirement. Since at least longitudinal structural members, such as deck
plating, skin plating, longitudinal bulkhead plating, inner bottom plating and2006/12/13
longitudinal stiffeners attached to them, are to be complied with Ch.6, Sec.3“Buckling & Ultimate Strength of ordinary Stiffeners and Stiffened Panels”, it is
not necessary to apply this rule to them. We would like to ask you to revise therule taking into account the above.

Such longitudinal PMA having wide width should comply with the requirementof [2.3], where it is applicable considering the configuration of the stiffener. In
case the stiffener should not comply with the requirement of [2.3] or [2.3]should not be applicable to the stiffener, such longitudinal should be modeledby shell elements in FEA and its yielding strength and buckling strength
should be verified as a primary supporting member.

BWE

The net required section modulus [3.2.3] of side frames in holds intended tocarry ballast water is excessive than our experience and approximately twice
the value required by [3.3.1].The cause of the above is the difference inposition to be assessed.In [3.3.1], the position to be assessed is the mid spanof side frame. And the position to be assessed in [3.2.3] is the fixed
ends.According to [3.3.3], the required section modulus at ends of side frame
is to be twice of the required section modulus at mid span.Therefore we would
like to ask you to revise the rule as follows:Case A - [3.2.3] "m=20 for side
frames of single side bulk carrier"orCase B - [3.3.1]To add the following:"...thenet section modulus at lower and upper bracket"

We conclude that there is no need to change the rule formula according to thefollowing reason. With our calculations, we have not seen this ratio of 2
between the application of [3.2.3] for side frames in holds intended to carryballast water and [3.3.1].It would be interesting to have more detailed
information on the comparative calculation to check that all parameters arecorrectly taken into account, and in particular the span, which is not the same
in both requirements. In [3.2.3], the span is defined in Ch 3, Sec 6, [4.2], i.e.
by considering reduction of span due to brackets; and, In [3.3.1], the span isdefined in Ch 3, Sec 6, Fig 19, i.e. by considering no reduction of span due tobrackets.Therefore, the text is kept as it is.

2006/12/8

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6/2.3.4.1

6/2.3.4.2

7/4.3.2.1

7/4.3.3

Topic

Date
completedpressure
formulaThe required scantlings by this rule is excessive than our experience. In theformula, counter pressures acting on side longitudinals, hopper / top side
longitudinals and backing brackets are ignored. Thus the rule brings heavy
2006/11/22
scantlings. We would like to ask you to revise the formula in which counterpressures are taken into account. If it is difficult, an alternative analysis suchas direct calculation should be permitted.

Question

directcalculation

From our experience, we have not seen excessive scantlings. We would likeThe required scantling and the material by this requirement are excessive than to have more information on this "excessive" values. In addition, to accept that
2006/11/23 our experience.An alternative analysis such as direct calculation should bealternative analysis such as direct calculation are permitted is a generalpermitted.
question for the totality of CSR (oil or bulk). This should be discussed as a
general matter.

Question

hot spotstress range

The procedure of obtaining hot spot stress brings very pessimistic results anddiffers from that of JTP.We would like to ask you to reconsider and revise the
2006/11/28
procedure as soon as possible.In conjunction with the above, 3.3.2 should bealso reconsidered.

The existing procedure is not modified. However, possible changes will be
subject to the future harmonisation work between CSR for oil tankers and
CSR for bulk carriers.

connection

Please develop and introduce a simplified method for the connection of lower
stool of transverse BHD with inner bottom as soon as possible.

The simplified method is applicable to the intersection of inner bottom plateand sloping plate of lower stool as well as the intersection of inner bottom
plate and hopper slant plate. That’s was the original intention of therequirement.

Type

Question

Question

2006/11/8

Question/CI

Attachment

Answer

The pressures to be considered in this formula are the pressures at mid-spanof the side frame. In addition, the differential pressures, if any, are to beconsidered.
Also included in Corrigenda 5

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8/1.1.3.1

8/2.2.3.1

8/2.2.3.2

8/5.3.1.1

Datecompleted

Type

Topic

Questionfatiguestrengthassessment

The number of members and locations to be assessed is many.We would like
2006/11/22 to ask you to reduce the number of locations taking into account damage
experience and your calculation results.

fillet weld

There is no category for welded joint of sloped plate and horizontal plate suchas hopper knuckle and lower stool in Table 1.Our understanding is as follows,
because Frank angle of the weld joint is lesser than fillet weld:"Kf=1.25 forwelded joint of sloped plate and horizontal plate"Please confirm the above assoon as possible.

Question

Question

Questionfatiguedamagenominalstress range

2006/11/8

Question/CI

Attachment

Answer
The members and locations subjected to fatigue strength assessment
described in Table 1 of Ch 8 Sec 1 are of the members and locations which
the fatigue damage are occurred in the past, even though the number ofdamages are neglected. Therefore, the fatigue strength assessment should
be carried out for the structural details specified in Table 1.
The fatigue notch factor Kf of 1.25 for welded joints of sloped plate andhorizontal plate such as hopper knuckle and lower stool can be applied
because their welded joints are classified with the load carrying full penetration
weld joints as well as butt welded joint. For the non-load carrying full
penetration welded joints between plate, the fatigue notch factor Kf may be
reduced.

The correction factor for mean stress is very complicated and sensitive to
2006/11/28 fatigue damage. Please reconsider and revise the factor to meet ourengineering sense as soon as possible.

According to the fatigue damage experiences, mean stress effect is the mostdominant factor to explain their fatigue damage. Then, the precise procedure
to consider the mean stress effect is mentioned in the text. However, tosimplify the procedure for the mean stress effect without losing the accuracy ofthe present fatigue assessment needs much time, careful discusstion andappropriate ramification study. Therefore, for the time being, the text is kept as
it is.

We understand that the nominal stress range obtained from this formula isbending stress of the cross deck.Thus the stress occurs in athwartshipdirection.In general, the major axis is arranged in longitudinal direction to
reduce the stress concentration due to hull girder bending moment.Therefore
2006/12/22
the explanation of ra and rb is not adequate to use the formula properly.For
example, ra and rb are inner radius and outer radius, respectively.This rulebrings very pessimistic results.In conjunction with the above comment, therules should be revised to obtain reliable results as soon as possible

The requirement on hatch corner fatigue check will be revised as soon as
possible, including a technical background.

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Attachment

Answer224

9/2.3.1.2

Question

stiffeners

This requirement is excessive than our experience. In structural design,
2006/11/22 stiffeners are suitably arranged on floors to prevent excessive vibration ofthem. And scantlings are determined taking account of vibration.

The CSR doesn't take into account the vibration effects for the scantlings, as itis outside the scope of classification.The floor webs are to be stiffened enoughto withstand the forces induced by rudder post, propeller post and rudder
horn.As a direct calculation of floors and their stiffening arrangement isgenerally never carried out in this area, it is preferable to indicate a value forthe maximum spacing of web stiffeners.

225

9/3.3.1.3

Question

frame
spacing

This requirement is excessive than our experience. This requirement should
2006/11/29 be reconsidered taking account of present designs.Please revise the rule asfollows, or delete the rule:"not greater than 5 frame spacing

According to the last sentence of [3.1.3], wider spaces may be accepted
based on the discretion of the Society. This sentence has been added torespond the comments from Industry. Therefore, the text is kept as it is.

When checking the condition under the ballast water exchange operation bymeans of the flow through method, static pressure for direct strength analysis
is specified in Ch 4, Sec 6, 2.1.2, but there is no description of dynamic
pressure. 1. Should the loading cases and wave conditions under
2006/12/14 consideration comply with the requirements of Ch 4, App 2? 2. The inertialpressure due to ballast is not to be considered according to the requirement in
Ch 4, Sec 6, 2.2.1. Does this mean that only static pressure due to ballast
defined in Ch 4, Sec 6, 2.1.2 and external pressure defined in Ch 4, Sec 5 areto be considered for direct strength analysis?

1. There is no need to comply with the requirements of Ch4App2. In theloading case specified in the loading manual with regard to ballast exchange,
the static load is considered for direct strength analysis.
2. Yes, the dynamic external pressure should be considered for direct strength
analysis.Where the ballast water exchange is carried out on the flow throughmethod, the direct strength analysis will be separately required on the ballast
water exchange condition in additional sea going ballast loading condition,
taking into account all EDWs.

226

4/6.2.1.2

QuestionBWE

227

9/4.5.3.1

Questionshear area

2006/11/22 It seems that the equation of Ash is missing. Please confirm.

The formula is not missing, but the words "and the shear area Ash, in cm2,"
should be deleted.

substantial
corrosion

The definition of “substantial corrosion” for vessels built under the IACS
Common Structural Rules for Bulk Carriers has described in the latest version
2006/11/29 of IACS UR Z10.2 and Z10.5. The description of substantial corrosion in CSR
for Bulk Carriers is not in line with that of IACS URs. To avoid confusion, thisparagraph is to be deleted.

In Chapter 13, Section 1, [1.2.2] of the Common Structural Rules for Bulk
Carriers, the current text is to be replaced by the following one: 1.2.2
Substantial corrosion Substantial corrosion is an extent of corrosion such thatthe assessment of the corrosion pattern indicates a gauged (or measured)
thickness between t renewal and t renewal+ t reserve.

228

13/1.1.2.2

Question

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QuestionCorrosion
additiondetermination2006/11/22

Corrosion addition determinationFor ships equal to and larger than 150m in
length, corrosion addition for lower stool of 5.2m is very large compared withthat for sloped plating of hopper tank of 3.7m. Corrosion addition for lower
stool should be the same as that for sloped plating of hopper tank.

The corrosion additions are set according to the results estimated byprobabilistic carrion model which are calibrated by huge amount of thickness
measurement data. Therefore, the value specified in Table 1 of Chapter 3 isconsidered appropriate.

Framing system; For ships larger than 120m in length, longitudinal framing
system is required for bottom, double bottom and sloped bulkheads of hopper
longi framing
Question
2006/11/22 tanks in cargo hold. For fore and aft parts of cargo hold, however, it may besystemdifficult to apply this system because of abrupt change of hull form there. So
please add 'in general' to allow transverse system for these parts.

The word “in general” has been deleted from the text as far as practicable inorder to eliminate the vague expression. Furthermore, from structuralcontinuity point of view, the same framing system is desirable to adopt inwhole length of cargo hold region. However, as you pointed out, we canunderstand that it may be difficult to apply the longitudinal framing system tofore part and aft parts of cargo hold because of abrupt change of hullform.Where it is difficult for the longitudinal system to apply to fore and aftparts of cargo hold region due to its hull form, the Society may accept on acase by case basis the changing the framing system. for such parts subject toprovide an appropriate bracket or other arrangements to provide structuralcontinuity in way of changes in the framing system.

244

245

3/6.6.1.2

3/6.9.5.2

Editiorial

hatch end
beams

Attachment

SOLAS XII Regulation 6.5.2 says, “effective continuity between the side shellstructure and the rest of the hull structure shall be assured,” Although theapplication of this regulation is limited to bulk carriers of 150m in length andupwards carrying solid bulk cargoes having density of 1,000 kg/m3 and above,it is considered that the intention of this regulation is applicable to all ships.
From the structural continuity point of view, the second paragraph of Ch 3 Sec
6 [9.2.4] (topside tank structure) of CSR for Bulk Carriers says “Where adouble side primary supporting member is fitted outside of plane of the topsidetank web frame, a large bracket is to be fitted in line with.”
Hatch supporting structureHatch end beams are required to be aligned with
In addition to the side structure, to alter the large bracket in order to ensuretransverse web frames in topside tanks. Partial transverse web or large
2006/11/30
bracket that is sufficient to transfer load should be considered as an alternative the structural continuity between the hatch end beams and topside tank web
to transverse web. They are normal structural arrangement of existing vessels. frame seems to overdo.

However, in oder to clarify whether the partial transverse web or large bracket
provided in the top side tank in line with hatch end beam is acceptable insteadof providing the ordinary transverse web, for clarification, we will consider arule correction with addition of the following text:"Alternatively, the appropriate supporting structures shall be provided in top
side tanks in line with the hatch end beam."

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3/6.9.5.3

Editiorial

hatch
supporting
structure

2006/11/28

Hatch supporting structureThe face plate of hatch coamings and longitudinaldeck girders are required to be effectively connected. On the other hand, theface plate of hatch end beam is normally tapered at end. Please explain
concrete requirements of 9.5.3.

UR S18Lower and upper stools of corrugated bulkheadsLower and upper stools are
required for corrugated watertight bulkheads of ships equal to and larger than
150m in length. According to UR s18, stools are not required for ships less
2006/11/10 than 190m in length. In view of the fact that many existing ships having
corrugated watertight bulkheads without stools less than 190m in length havebeen operated with successful results, we request this requirement be
modified so as to be the same as UR S18.

The issue is under consideration by IACS.

FE modelExtent of model; The extent of FE model is required to be three cargo holds
and mid one is the target assessment. In handy bulk carriers, loaded
2006/11/30
holds(Nos.1 and 5 holds) are not included in the mid part model(Nos.2-4
holds). Please clarify the FE model for handy bulk carriers with 5 cargo holds.

The FEA assessment of cargo holds is restricted to the midship area by the
CSR.However, assessment of holds of both ends is left to the responsibility ofeach Society – this may be an extrapolation schema, a specific FE analysis, a
FEA provided by the ship designer,…Furthermore, it should be noticed that
this problem is also relevant in the CSR for Oil Tankers.

247

248

249
attc

3/6.10.4.1

Question

7/2.2.1.1

Question

9/2.5.1.3

Connectionof aft peak
Question
structure withrudder horn

2006/12/1

Attachment

AnswerIn order to clarify this requirement, we will consider a rule correction as
follows: At hatchway corners, the face plate of hatch deck girders or theirextension parts and the face plates of hatch end beams on both ends are tobe effectively connected so as to maintain the continuity in strength.

The vertical extension of the hull structure is required not to be less than thehorn height. This requirement is considered primitive without detailed strength
basis. Normally, the vertical extension is between outer shell and steering gear
The feedback is noted and we will consider a rule change proposal.
flat and there may be many designs that could not comply with thisrequirement. Please delete this requirement or amend it considering strength
basis.

Y

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8/2.2.3.2

Type

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Question/CI

Equivalent hot spot stress range (Corrigenda 1) This item seems to be rulechange. We would like to know the impact of this rule change.

Attachment

AnswerThis revision includes the correction of the factor in the conditional equations
and the alternation of the expression. The correction of the factor in theconditional equations is made for the simple error in writing of the factor in thecondition that the shakedown in compression stress side is occurred. Thiscondition correspond the case that the large mean stress in compression side
is occurred. The effect of this correction on the scantlings of the structuralmember is very small since the fatigue damage in such case is negligible
small. The alternation of the expression is made to clarify the meaning of theconditional equations without changing the conditions.

hot spotstress range

2006/11/10

The bending moments induced on the FE model by local loads are explicitly
taken into account when using superimposition method for yielding andbuckling criteria (Cf Ch 7, Sec 2, [2.5.7]), and it seems necessary to proceed
in the same way for fatigue. Note: Ch 8, Sec 2, [2.2.2] should make reference
to Ch 7, Sec 2, [2.5.7].

251

8/3.2.2.2

Question

FE modelIn Chapter 8 Section 3 / 2.2.2, the calculation of hull girder stresses for thecomputation of fatigue life by direct strength analysis using superimposition
2006/11/10 method does not take into account the hull girder bending moments that exist
in the FE model due to the local loads. Consequently, some of the hull girder
bending stress is considered twice.

253

Fig 8.5.2

Question

Sectionmodulus

When calculating section modulus of the cross deck Wq and moment of
2006/12/20 inertia of the cross deck Iq, how to determine the neutral axis? Is it axis z ?
Please clarify it.

IQ and WQ are to be determined about z-axis. In order to clarify the difinitionof WQ and IQ, the editorial change will be issued as Corrigenda.

watertight

In Chapter 8 Section 4, Table 1, some details, in the "watertight" cases seems
to be similar (two by two): "3" and "10"; "7" and "12" or "8" and "14". But the
2006/12/11 values of the stress concentration factors differs from a detail to another. An
harmonization of the SCF between these details is needed, in order to apply
the right ones.

It is right that the details 3 and 10 (7/12 and 8/14) are very similar for the case"watertight". An harmonization should be very helpful. More generally, eachdetail should appear only once in the Table with SCF for the two assessed
points, and for both cases "watertight" and "non-watertight". It should beconsidered as a Rule Changewatertight

In Chapter 8 Section 4, Table 1, the meaning of "watertight" and "nonwatertight" in the column "collar plate" is not clear: does it mean that a collar
2006/11/23
plate is required in any case? Or does it mean that "watertight" is equivalent toa full collar plate and "non-watertight" is equivalent to a partial collar plate?|

A collar plate is not required in all cases."Watertight" means that a full collar
plate is fitted, and "non -watertight" means other cases: no collar plate is fitted
or a partial collar plate is fitted.It should be better to replace "watertight" by"full collar plate" and "non-watertight" by "other cases".

255

Table
8.4.1

256

Table
8.4.1

Question

Question

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257

Table
8.4.1

Questionwatertight

In Chapter 8 Section 4, Table 1, for details 1 to 8, stress concentration factors
are indicated for both cases 'watertight' and 'weathertight' for one of the
2006/11/18 assessed point and for case 'watertight' only for the other assessed point.
What are the values to consider the stress concentration factors in case 'nonwatertight' for this later point?

258

Table
8.4.1

Questionwatertight

In Chapter 8 Section 4, Table 1, a detail is missing: the one corresponding
2006/12/13 with detail 1, but without vertical stiffener. What are the values to consider forthe stress concentration factors for such a detail?

For a detail corresponding to detail 1, but without vertical stiffener nor bracket,
SCFs should be developed.

259

Table
8.4.1

Aft & Fore

|In Chapter 8 Section 4, Table 1, the meaning of "Aft" and "Fore" is not clear:
2006/11/23 does it mean aft and fore ends of the ship, or aft and fore ends of the stiffenerconsidered, or is it only a way to identify both sides of the detail?

"Aft" and "Fore" does not mean aft anf fore part of the ship. They are to beunderstood as being one side and the other side of the considered detail. It
should be better to give a name to the two assessed points, i.e. "Point A" and"Point B", and to modify the schemes accordingly ("A" and "B" instead of "a"anf "f", and delete "Aft" and "Fore".

268

6/3.3.1.2

Question

Question

FEM
buckling

The author requests changes and defines e3 & ky as equal to 1. As far as weconcern both kx (for longitudinally loaded plating) and ky (for transversely
2006/11/30 loaded plating) is defined in Tables 2 & 3(for curved plating) and e3 is welldefined in Table 4. IACS's proposed additional definition confuses the issue.
Propose to leave text as it was prior to errata

In the case 'non-watertight', the missing stress concentration factors for one of
the two points leads to less severe results in fatigue. That is the reason why
the values of the SCF are not indiciated. However, our point of view is to add
these values in the Table in order to be coherent.

Reference is made to: Additional information according to "Corrigenda 1, May
2006", Ch 6, Sec 3, [3.1.2]:
The following three lines are the original text: Each term of the above
conditions must be less than 1.0. The reduction factors kx and ky are given in
Tab 2 and/or Tab 3. The coefficients e1, e2 and e3 are defined in Tab 4. This
was the Add. inf.: For the determination of e3, ky is to be taken equal to 1 incase of longitudinally framed plating and kx is to be taken equal to 1 in case oftransversely framed plating. We added this additional information due toseveral requests from other classification societies, how to calculate e3,
because in the buckling assessment of a plate field in a transverse section
analsys only hull girder bending and shear stress have to be taken into
account (Ch6, Sec3, 3.1.2). Therefore the kappa parameter of a load normal
to the hull girder bending stress has to be set to "1" to calculate e3 according
Table 4.
In case of a pressure loaded bilge plate, the pressure induced circumferential
stress has to be neglected for a transverse section analysis. In a FEM based
buckling analysis this stress has to be taken into consideration and thecomplete interaction formula of 3.2.4 has to be used. The additional
information, given in "Corrigenda 1, May 2006", is kept because this isuniversally valid for the transverse section analysis. complete interaction
formula of 3.2.4 has to be used. The additional information, given in"Corrigenda 1, May 2006", is kept because this is universally valid for thetransverse section analysis.

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Table
9.1.2

Table
9.2.2

9/5.2.4.3

Fig.
10.1.20

Type

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Question

Question

Question

Topic

Date
completed

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Attachment

Answer

Min plate
thickness

We can not see the reason for IACS to change the coefficient from 0.7 to 0.9
on the denominator of the second term in the equation. The proposal will
reduce the required plate thickness at intact condition and bow flare area. We
2006/11/23
would like to stress that plating cannot be treated in the same way as a IACS
stiffener where the corresponding coefficient is 90% (i.e. 0.9) of the yielding.
Propose to remain as it is.

The reason of changing the coefficient from 0,7 to 0,9 is a matter of editorial
correction, which was forgotten at the time of publication.This coefficient if
normally equal to 0,9 as defined in Table 6 in Chapter 6, Section 1 for platings
not contributing to the hull girder longitudinal strength.

Min plate
thickness

We can not see the reason for IACS to change the coefficient from 0.7 to 0.9
on the denominator of the second term in the equation. The proposal will
reduce the required plate thickness at intact condition and bow flare area. We
2006/11/23
would like to stress that plating cannot be treated in the same way as a IACS
stiffener where the corresponding coefficient is 90% (i.e. 0.9) of the yielding.
Propose to remain as it is.

The reason of changing the coefficient from 0,7 to 0,9 is a matter of editorial
correction, which was forgotten at the time of publication.This coefficient if
normally equal to 0,9 as defined in Table 6 in Chapter 6, Section 1 for platings
not contributing to the hull girder longitudinal strength.

IACS's proposal to change the word "watertight" into "weathertight" is not
acceptable unless there is a Load line coaming. Propose to retain watertight.

The change from watertight to weathertight is correct. LL Regulation requests
a coaming heigth of 600mm for Pos.1 and 450mm for Pos.2. Subject to thisthe access hatches need to be weathertght only. In the CSR text in para. 2.4.1
we refer to the required coaming height. Consequently the access hatches asmentionend under para. 2.4.3 have to fulfill the requirement 'weathertight'. We
assume the questioner has mixed this with flushdeck hatches. They have to
be watertight.

watertight2006/11/23

plate
thickness

IACS propose to replace the definition of "t = plate thickness in accordancewith section 14, E.3.1. (mm)" with "t = thickness of rudder plating, in mm". It is
obvious that the reference is missing from the CSR Rules and by IACS'
2006/11/23 proposal to omit it instead of to complete the Rules means that the rudderplate thickness under the thick flange will be severely undermined. Propose tocomplete the reference as necessary for the sake of safety of the rudder at the
supporting level.

The previous reference in the legend to Fig. 20 of Ch.10 Sec.1 came from theoriginal source of the illustration (different rules as CSR). In the source theRules were splitted into seperate sections for 'Welded Joints' and 'Rudder andManoeuvering Arrangements'. The reference lead to the section describing
the plate thickness of the rudder. In the CSR both subjects are united under
one section. Consequently the reference is obsolete.

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Answer273

3/6.10.4.1

Question

corrugated
BHD

Lower stool with bottom width not less than 2.5 times mean depth ofcorrugation is required for L>=150m bulkers instead of L>=190m as defined in
IACS UR S18.We think this contradiction to be corrected as editorial error in
the corrigendum. If it is difficult to add new item in the corrigendum, IACS
should take it in the next earliest chance. As you know, most of Handy classbulkers and also significant number of Handy max. bulkers with length
between 150m < L 190m have corrugated bulkheads without lower stool
2006/11/23
and/or with rectangular lower stool which bottom width is same as corrugation
depth. If the defined lower stools are installed for those vessels, necessary
hold clear length about 27m for these class bulkers to load 2 rows of 40 feetlength product such as pipes, etc. can not obtained. The economical loss tothe shipping industry by the lower stool requirement is seemed tremendously
big. Huge number of safely operating bulkers without required lower stools
prove the safeness and propriety of this proposal.

274

3/6.10.4.8

Question

Upper stool

2006/11/22

Corrugated
BHD

Lower and upper stools are required for corrugated watertight bulkheads ofships equal to and larger than 150m in length. According to UR S18, stools are The corrected text in the next Corrigenda should be: "For ships of 190 m of
not required for ships less that 190m in length. Since there are many existing length and above, the transverse vertically corrugated watertight bulkheads
2006/11/23 ships having corrugated watertight bulkheads without stools less thabn 190m are to be fitted with a lower stool, and generally with an upper stool isin length and they have successful experiences, please amend as shown
fittedbelow the deck.For ships less than 190 m in length, corrugations may
below:"In ships less than 190m in length, corrugations may extend from theextend from inner bottom to deck."
inner botton to the deck."275

3/6.10.4.1

Question

We think that "The stool top" is correct(This comment is not for your summary
but for original rule).

The corrected text in the next Corrigenda should be: "For ships of 190 m oflength and above, the transverse vertically corrugated watertight bulkheads
are to be fitted with a lower stool, and generally with an upper stool isfittedbelow the deck.For ships less than 190 m in length, corrugations may
extend from inner bottom to deck."

The right wording should be “stool top of non-rectangular stools”. Thisrequirement comes from UR S18 (18.4.1.(b)).

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6/2.3.3

Questionside frames

2006/11/22

From our experience, we have not seen excessive scantlings. We would likeThe requirement of this rule for side frame seems to be excessive. The section to have more information on this "excessive" values.It would be interesting tomodulus of side frame of CSR is about twice of URS25.
have more detailed information on the comparative calculation to check thatall parameters are correctly taken into account.

2006/11/23

This item seems to be rule change.We would like to know the impact due tothis change.

This revision includes the correction of the factor in the conditional equations
and the alternation of the expression. The correction of the factor in theconditional equations is made for the simple error in writing of the factor in thecondition that the shakedown in compression stress side is occurred. Thiscondition correspond the case that the large mean stress in compression side
is occurred. The effect of this correction on the scantlings of the structuralmember is very small since the fatigue damage in such case is negligible
small. The alternation of the expression is made to clarify the meaning of theconditional equations without changing the conditions.

My only comment is that the Amendment for Ch7, App 2, [2.2.3], Fig 2 is still
not clear to me.

The numbers 1 to 8 in Fig. 2 indicate the diplacement nodes number of theshell element of FE. The numbers 1 to 6 in bold style in Fig.2 indicate thestress calculation points number of panel which is obtained from the transform
matrix using the displacement of the node numbers 1 to 8.The figure may be
splited into two figures in a next revision of the CSR: one for the displacement
points and the other for the stress calculation points.

277

8/2.2.3.2

Questionconditional
equations278

7/App.2,Fi
g2

Question

FE

279
attc

1/1.1.1

Question

application

2006/11/22

Question/CI

Attachment

AnswerIs CSR applicable for VLOO (Very Large Oil or Ore) carrier having
2006/11/13 configuration very similar to VLCC, but with hatch opening in center hold/tank? CSR Tanker or Bulker Rules are not applicable for Ore-Oil Carriers.
See attached sketch.

Y

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4/6.3.3.5

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283 & 5/1.4.2.1
Question
attc & 5/1.4.2.2& 5/1.4.2.4& 5/1.4.3.1

Topic

permeability

design stillwater
bending
momentDatecompleted2007/1/8

2007/1/16

Question/CI

Attachment

Answer

Minimum permeability of dry bulk cargoes:We will consider the following interpretation on "appropriate permeability" andAccording to CSR Ch.4 Sec.3 [2.4.2], it is stated that "appropriate permeability
the treatment in flooded condition.
should be used" while minimum permeability of 0.3 is also specified for iron
- Minimum permeabilty value for grain to be 0,3.
ore and cement. In addition, coal cargoes are mentioned in Ch.4 Sec.6 [3.3.5].
- Determination of still water bending moment in flooded condition is to be
For sake of order, minimum permeability should also be specified for grain andbased on actual loading conditions specified in the trim/stability booklet.
other mineral ore materials. Unless other data is justified, we propose to- Check of local strength check in flooded condition is to be based on cargodefine a minimum permeability of 0.5 for grain and 0.3 for other mineral ore
density as defined in Table 1 of Ch.4/Sec.6.
materials in addition to coal, cement and iron ore. The permeability in Ch.4
Sec.6 [3.3.5] should be replaced by reference to Ch.4 Sec.3 [2.4.2].

Design still water bending moments in CSR Bulk rules - 3 sub-questions withdiagrams (see attachment)

Question 1 . We assume the figure in attached file is related to the Fig 2 of Ch
4 Sec 3 [2.2.2] using the formulas of MSW,H & MSW,S and the extent within
0.4L amidships is shown by parallel line drawn in blue color in attached file. In
addition the values of the blue line at AE & FE should not be 0 but should becorrected as 0.2MSW in line with Fig 2 of Ch 4 Sec 3 [2.2.2]. At the end of thedesign process the still water bending moment used for scantling check and
FEA has to represent the individual envelope curve (CH4, Sec3, 2.1.1, first
sentence). This corresponds to the green line in the figures.
Question2 . Ch 4, Sec 3, [2.2.2] should be considered only as a preliminary
distribution of SWBM. It is not a minimum value of SWBM. Regarding thestrength point of view, the section modulus is to be checked according to its
minimum value (see Ch 5, Sec 1, [4.2.1] and [4.2.4]), and to its value basedon the permissible distribution of SWBM (see Ch 5, Sec 1, [4.2.2] and [4.3.1])
which may be the preliminary value of SWBM, if the permissible one comingfrom loading booklet is unknown.
Question 3. There is definition of a value of the SWBM in flooded condition. It
has to be calculated and included in the loading booklet and used for the
checking of hull girder strength according to Ch 5, Sec 1, [4.2.2] and [4.3.1], in
addition of the checks in intact condition.

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8.1.1

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Question
7.4.1

Topic

fatiguestrengthassessment

Datecompleted

Question/CI

List of locations subject to fatigue strength assessment: a) For ships having
length L of 150 m or above, are there any circumstances under which fatigue
assessment of the locations listed in the Table can be waived? b) Is each
2006/12/13 detail to be assessed for location in homogeneous hold, ore hold and ballast
hold? (This question is based on actual cases of different Class giving
different opinions of the locations requiring fatigue assessment based on
actual designs in progress.)colum plate
thickness

2006/12/18

Is the column plate thickness, t column, based on the gross inner bottom
plate?

288

7/4.3.3.3 &Table
Question
7.4.2

Radius Ra) The radius R is believed measured to the radius on upper surface of hopper
knuckle is that correct.
b) The thickness t is assumed to be the plate thickness in way of radiusknuckle. t is assumed gross thickness. Is that correct?
2006/12/20 c) K2 in Note 2 should read K3d) Note 2 only applies to radius knuckle, therefore the text “For bend typeknuckle ...” should be insertede) Does it mean that the insert plate in the floor web is to be the same
thickness as inner bottom plate?

289

7/4.3.3.3 &QuestionFig.7.4.7

longitudinalrib

2006/12/21

290

7/4.3.3.3
Fig 7.4.8

Question

longitudinalribs

2007/1/8

Attachment

Answera)No in general. The members and locations subjected to fatigue strength
assessment described in Table 1 of Ch 8 Sec 1 are of the members andlocations which the fatigue damage are occurred in the past, even though thenumber of damages are neglected. Therefore, the fatigue strength
assessment should be carried out for the structural details specified in Table
1.
b)If
the arrangement and scantling of the detailed to be assessed in holds aredifferent, each detail should be assessed.

The requirement of 1.4.1, Ch 7 Sec 1 mentions as follows. “Direct strength
analysis is to be based on the net scantling approach according to Ch 3 Sec
2.” According to this requirement, the thickness in Table 1 of Ch.7 Sec 4[3.3.3] is “Net thickness” in FEA. In order to clarify this, the text modification
will be proposed as "Corrigenda".
Also Included in Corrigenda 5a) Yes, it is correct.
b) No, it is not correct. The thickness t is always the “Net thickness” in FEA.
c) Yes. It is typo. The “Corrigenda” will be issued soon.
d) Noted. The text of Note (2) should be revised as follows. “In using thecorrection factor K3 for bend type knuckle, the members should be arranged
such that the bending deformation of the radius part is effectively suppressed.”This revise will be issued soon as “Corrigenda”e) Yes, it is recommended to be the same thickness as inner bottom plate
where the fatigue assessment is carried out by simplified method. However,where the fatigue assessment is carried out by very fine FEA, the thickness ofinsert plate is to be determined based on the results of fatigue assessment.

Is there a maximum distance for the position of the single longitudinal rib
required by Table 2 Note (2)?

No, there isn’t. This figure is just example. The distance for the position of
the single longitudinal rib is determined by case by case basis but the single
longitudinal rib is recommended to fit near of knuckle part as far aspracticable.

The figure shows two longitudinal ribs, and indicates a distance of 500mm
from the margin girder to the second rib. Is this correct?

Yes, it is correct that Figure 8 shows two longitudinal ribs, and indicates a
distance of 500mm from the margin girder to the second rib.
However, in order to clarify the arrangement of transverse rib, longitudinal rib
and extent of local reinforcement, we will consider the rule change proposal of
Figures 7 and 8 in future.

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292
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7/4.3.3.3
Table
7.4.2

7/4.3.2.2

Type

Question

QuestionTopicintersection

Radius R

Datecompleted

Question/CI

Answer

Attachment

2007/1/11

Regarding the simplified method, IACS Q&A (no 11) in the official
spreadsheet, indicates that simplified method is applicable to intersection of
inner bottom plate and sloping plate of lower stool as well.
For this connection with longitudinally framed inner bottom and verticallystiffened lower stool, K2 is understood = 0.9, and K4 =0.9. Is that correct?
It is assumed that Note 3 i.e. insert plate in web, is only applicable to hopper
knuckle connection.

In our point of view, if the simplified method is applicable to intersection of
inner bottom plate and sloping plate of transverse lower stool, the correction
coefficients K2 and K4 should be considered in the following way:
- K2 equal to 0,9 should be considered when there is a thickness increment of
longitudinal girder web, up to the thickness of the inner bottom plating,- K4 equal to 1.0 in general and equal to 0.9 when longitudinal ribs are fitted.

Y

2007/1/31

Please find the attached PDF describes our implementation for Lambda as
follows. Could you check it if our interpretation is correct?
(a) welded intersection between plane plates apply to;- Bilge Hopper plane part to Hopper Transring.
- Side Girder to Hopper Transring and Floor.
- Inner Bottom to Floor.
- Side Girder to Inner Bottom.
b) welded intersection between bent plate and plane plate apply to;- Bilge Hopper bent part (between R.ENDs) to Hopper Transring.

Your interpretation is correct, however, the parts indicated in the question are
not required to carry out the fatigue assessment. The fatigue assessment is
to be carried out for the members and locations described in Table 1 Ch 8 Sec
1.

Y

Surface stress is used for hot spot stress evaluation. Figure 3 shows thelocations of stress evaluation points to define the hot spot stress. In order toclarify used stresses, we will consider the editorial correction of the second
sentence of the first paragraph as follows. “The surface stress located at 0.5
times and 1.5 times the net plate thickness are to be linearly extrapolated at
the hot spot location, as described in Fig. 3 and Fig. 4.”

293

7/4.3.2.1

Questiongeometric
stress2007/1/23

The principal stress in the 4th line is a surface stress (at top or bottom of theelement? or a membrane stress (at neutral axis of the element? According to[3.1.1], the hot spot stress is defined as the structural geometric stress on thesurface at a hot spot. However, in figure 3, it seems a membrane stress.
Could you tell us which is correct?

294

7/4.3.3.2

Questionnominalstress range

2007/1/31

The second and third words "nominal stress" is not consistent with terminology The word “normal stress” instead of “nominal stress” is correct. This revisionused in 3.2.1 is "nominal stress" a principal stress? or normal stress?
will be issued as “Corrigenda”.

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301

9/5.1.5.1& Table9.5.2

Datecompleted

Attach
ment

Type

Topic

Question

Allowable
stresses ofexternal
Pressure

The external Pressure of 0.8 / 0.46 ReH allowable stresses in table 2 of Ch 9,
Sec 5, 1.5.1, it is subjected to Ch 4, sec 5, [2], we think that the correct one
2006/12/21 should be subject to Ch 4, sec 5, [2.2]; the other loads are water ballast load,cargo load and container load etc. If not, please inform us what other loads
are with the detail load.|

The Table 2 of Ch 9 Sec 5 is correct. The other loads specified in Table 2 areinterpreted as internal loads such as inertia pressure due to water ballast inballast hold.

Regarding to the load point, some classes require to use the hatch cover top,
but others are still on the top of hatch coaming yet. Which is correct one, on
top of hatch cover or top of coaming? If the load point is based on top of
coaming, the sea load can be reduced a hatch cover depth height (900-1200mm) from coaming to hatch cover top. We propose that load point on top ofcover is for the sea load, on top of coaming is for water ballast load.

The proposal is agreed, but should be more specific on the location of the load
point. Regarding the second and last points in Ch 9, Sec 5, [4.2.1], we willconsider the rule correction as follows: "- transversely, at hatchway side, vertically, at the top of the hatch cover for sea pressures, and at the top of thehatch coaming for internal pressures due to ballast water."

Question/CI

Answer304

9/5.4.2.1

Questionhatchcoaming305

9/5.7.5

Question

Cleat forwater ballast
load

Because the internal WB loads of CSR are very large on hatch cover bottom
2006/12/26 side, we advice that an allowable stress of cleat is needed, and propose it is0.9-1.0 ReH. As some class have an allowable and some have not it.

309
attc

Ch 9/ 5

Questionhatch cover

2006/12/21

Regarding to the triangular load like water ballast, both way of triangular load
and average uniformed load may be used based on class by class or local
office by office, but both calculation results is very different. What’s CSR
standard for folding and side rolling hatch cover from 1 to 5 (see attachment)?

The load cases are “H1” and “H2”, the internal pressure due to water ballast inballast hold is treated as uniform load. The load cases are “P1”, “P2”, “R1” and“R2”, the internal pressure due to water ballast in ballast hold is treated as
triangular load.

Y

311
attc

6/4.4.1.1

Questionve stress

How to determine the supporting area of the pressure to calculate the
2006/12/21 compressive stress? If the CSR Bulker Rules has not described, the proposal
in the attached file could be taken into consideration.

There may be various arrangement of pillars and other supporting structures.
Then supporting area should be determined on a case by case basis.

Y

2007/1/31

As [7.3] and [7.5] are coming from UR S21, the dimensioning of cleats iscovered under [7.3.5], whatever the loads are.

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Ref.

Type

9/1.4.4.4
Question& 9/2.4.3.4

Topic

FEA

Date
completed

Question/CI

Attachment

Answer

2007/1/31

For ships greater than 150 m in length, Ch 6, Sec 4 requires normally FEA
analysis. However, in the fore and aft parts, it seems that prescriptive
Which sub-section should be adopted to determine the scantlings of deck
formulae may be used instead of FEA. In such a case, the requirements in Ch
primary supporting members of the fore part and the aft part in accordance
6, Sec 4, [2.6] may also be considered as being applicable to primarywith Ch 6/Sec.4? For example, if the ship length L is 150m or above, the direct
supporting members in fore and aft parts for ships greater than 150m. We
strength analysis would be applied according to the provision specified in Ch
will consider the further rule development about the application of FEA to7(see Ch 6/Sec 4/[1.3.1]), but the procedure in Ch 7 is applied on the cargo
cargo areas outside midship region and determination of the scantling ofhold structures in midship area.
primary supporting members outside midship cargo regions for ships of 150m
in length and above.

313

12/1.2.3

Questiontransverse
lower stool

2006/12/21

Is the formula tGR to be applied to not only sloping side plating but verticalside plating of transverse lower stool?

It is expected that the grab operators often swing the grab in order to clear
cargo from sides and ends of a hold. Therefore even a vertical side plating oftransverse lower stool is likely to experience a great impact due to the grab hit.
As such the formula for tGR should be applied not only to sloping side plating
but vertical side plating of transverse lower stool.

314

2/ 1.2.1.2

Question

SOLAS II-1

2006/12/22

whichever gives the smallest measurement" should be added to be inaccordance with SOLAS Ch.II-1, Part B, Reg.11 and for clarification.

That is correct. The words "whichever gives the smallest measurement"
should be added at the end of the requirement to be in accordance withSOLAS Ch.II-1, Reg.11.

CI

Applicationof CSR vsIMO
PSCS(SOLAS II-1/3-2)

2006/12/7

For ships contracted for construction on or after the date of IMO adoption of
the amended SOLAS regulation II-1/3-2, by which an IMO “Performancestandard for protective coatings for ballast tanks and void spaces” will bemade mandatory, the coatings of internal spaces subject to the amended
SOLAS regulation are to satisfy the requirements of the IMO performancestandard.

Interpreation: This is the date of adoption by IMO MSC 82(Maritime Safety
Committee 82nd session) of the resolution amending the SOLAS regulation II1/3-2.
(Note: (1)The date of adoption is 8 December 2006;(2)IMO PSPC = IMO Resolution MSC.215(82);(3) SOLAS II-1, Part A-1, Reg.3-2 = IMO Resolution MSC.216(82))

316

317

3/5.1.2.2

Ch 4/ 6

Question sea pressure

2007/1/12

According to Ch4, Sec5, [1.1.1] external sea pressure is defined as summationof hydrostatic pressure and hydrodynamic pressure but should not be
Regarding the first item, the answer is, "Yes". Your interpretation is correct.
negative. However, Sec6 does not clearly specify whether negative pressures
The total pressure obtained by adding the static pressure to dynamic pressure
are allowed in case of dry cargo or liquid. We would like to confirm if theis not to be negative as specified in Ch 5 Sec 1 [1.1.1].
following interpretation is acceptable.
This is the basic principle.
- Internal pressure due to dry cargo or liquid is to be obtained as summation ofRegarding the second item, we assume that two kinds of internal pressurepressure in still water and inertial pressure but is not to be negative.
mean the example as shown in the question.
- In case where two kinds of internal pressures act on a considered location
The total internal pressure acting on one side of the boundary is not to beeach internal pressure is not to be negative.
negative and the total internal pressure acting on the opposite side of the
Example:boundary is also not to be negative, according to the basic principle as
In case of bulkhead plate between No.4 and 5 holds
mentioned above.
From No.4: Static=100, Inertial=-80, Sum=20
The grand total pressure acting on the boundary is obtained from the
From No.5: Static=60, Inertial=-80, Sum=0
difference between both internal pressure.
(Differential pressure=20)

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6/3.3.2.4

Type

Topic

Date
completed

Question/CI

In the first formula in Ch 6, Sec 3, 3.2.4, we are worried about the effect of thethird term with B factor which makes the buckling ratio higher in case when
Question buckling ratio 2006/12/21
one side is in tension than in case when both sides are in compression.Could
you confirm that the formula is correct?

Attachment

AnswerWe confirm that the formula is correct, with B factor defined in Table 4.

This requirement is coming from work of IACS WP/S at the time of fourth
revision of UR S12, in 2002/2003. A Technical Background explaining theformulae of Ch 6, Sec 2 , [3.4] of CSR for bulk carriers is herewith enclosed.
The calculation is on the conservative side (i.e. higher part of the end-fixing
moments is transferred by transverse supporting webs), but not unduly, andwe really don't think a change is technically justified.
The only interpretation that could safely be done looking at the derivation of
the formula in [3.4.2] is to replace the provided net section modulus wi by its
minimum required value to comply with [3.4.1].

YThis is "Typo". We will consider the editorial correction according to yourproposal.

Y

6/2.3.4.2

Question

brackets

2007/1/12

The value of the net connection area of upper and lower brackets to the ithlongitudinal stiffener supporting the bracket, obtained from Ch 6, Sec 2,[3.4.2]) may be 2 times the actual value.
Such a large increase may imply the following risks:- Uselessly reinforce bracket thickness.
- Uselessly ask for web stiffener connected to longitudinals.
- Uselessly extend brackets which could interfer with the PMA arrangement.
Please forward us the background of formula in [3.4.1] and [3.4.2].

321
10/3.2.1.2
attc

Question

Equipment
Number

2007/1/8

Query regarding the formula of EN (Equipment Number) - see attachment.

2007/1/4

The text reads: "Unless otherwise specified, the height of double bottom is not
to be less than B/20 or 2m whichever is the lesser." Does this require that the
double bottom height in way of cargo holds is not to be less than B/20 or 2m
Yes, this requirement is mandatory. The double bottom height in way of cargo
whichever is the lesser IN ANY CASE? For instance, even if the strength ofholds is not to be less than B/20 or 2m whichever is the lesser in any case.
double bottom structures is verified by FEA, is this requirement to be
maintained?

2007/1/12

The check of welding shear section attaching shell ordinary stiffeners toprimary member is effectively defined in Table 2 in Ch 11, Sec 2, considering
Hull area being "General", and connection of ordinary stiffener to cut-out in
way of primary supporting member, i.e. Category F2. Regarding the weldingof collar plates, it is covered by the same line of the Table. However, for abetter understanding, this line in the Table should be modified, replacing"ordinary stiffener" by "ordinary stiffener and collar plate, if any" and replacing"Cut-out web of primary supporting members" by "Web of primary members
and collar plates, if any".

319
attc

322

323

3/6.6.1.3

Table
11.2.2 &Text
11/2.2.6.1

Question

Question

FEA

fillet weld

The fillet welds to apply for the connection of collar plates with ordinary
stiffener and with web of primary members is not defined clearly in Table 2 ofChapter 11, Section 2. Please clarify this matter?

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11.2.2 &Text
11/2.2.6.1

327

328

6/2.4.1.3

3/6.5.2.1

Type

CI

CI

QuestionTopicside frames

inertialpressure

brackets

Datecompleted

Question/CI

Answer

2007/1/8

Two different requirements for welding thicknesses of side web frame in single
side bulk carrier are indicated in CSR: - Ch3, Sec6, 8.3 Side frames fig 19.
(URS12) - Ch11, Sec2 Welding Table 2 with Hull area side frame of single
side structure. Our understanding is that the maximum of both is to beconsidered. Please confirm?

The welding throats as defined on Fig 19 of Ch 3, Sec 6 are only to be
applied. Consequently, Tab 2 in Ch 11, Sec 2 should be modified, for the hullarea "Side frame of single side structure", connection of "side frame and end
bracket" to "side shell plate" by repacing "F1" by "See Ch 3, Sec 2, Fig 19".
We will consider the editorial correction.

2007/1/22

Regarding the internal inertial pressure p due to liquid to be applied, ourundestanding is that such pressure are those of:- Double Bottom pressure alone acting on bottom longitudinal. Pleaseconfirm?
- Topside tank ballast pressure alone acting on side and deck longitudinal.
Please confirm?
- Balance of Double Bottom pressure and Deep Tank ballast pressure actingon Inner Bottom longitudinal of Deep tank. Please confirm?
- Balance of Top side tank ballast pressure and Deep Tank ballast pressure
acting on top side sloping plate longitudinal. Please confirm?
In addition, in no case pressure p acting on watertight floors of double is not tobe considered, neither should it be considered for watertight part of bulkheads
belonging to wing tanks. Please confirm?

2007/3/23

The net thickness of web stiffeners and brackets are not to be less than theminimum net thickness of primary members on which they are fitted.
The situation is the following one: for capesize with usual length of 275m, tmin
net is 10mm. Thus tgross is ranging from 13 to 14mm due to tc of about 3 to
4mm.
For primary members of wider height such as Top side frames and hoppertank frames, web stiffening are made of angles instead of flat bars. Usual
angles or T shape sections have web thickness not exceeding 12mm and thecurrent requirement can't be complied with.
Additionally, there are two requirements which are applicable at C6.S2. 4.1.1
and 4.1.2.
Our request:
Alter the formula in C3.S6 5.2.1 to limit the tgross thickness to 12mm or
restreint its field of application to only flat bars or disregard C3S6 5.2.1 should
C6.S2. 4.1.1 and/ or 4.1.2. been satisfied.?

Attachment

Our interpretation is that the pressure to be considered should be only internal
inertial pressure acting on the longitudinal.
For better understanding, we will consider the editorial correction of thedefinition of p in [4.1.3].
Also Included in Corrigenda 5

We agree with you that the requirement asking that "the net thickness of web
stiffeners and brackets are not to be less than the minimum net thickness ofprimary members on which they are fitted" seems quite severe.
Our interpretation is that "the net thickness of web stiffeners and brackets are
not to be less than the minimum net thickness defined in Ch 6, Sec 2, [2.2.1]",
i.e. the minimum thickness of ordinary stiffeners (3 + 0.015 L2).
We will consider the Rule Change according to our interpretation

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331

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3/6.6.4.2

Type

Question

Question6/1.2.7.4 &Question6/2.2.5.4

Topiccargo holdUR S18

uniformloads

Datecompleted

Question/CI

2007/1/12

Corrosion deduction on cross deck beams between hatches:
As per corrosion deduction table – Dry bulk cargo hold area with othermembers in upper part - the corrosion margin is 1.8mm on each side, i.e. 4.5mm in total. Such corrosion margin for deck beams seems too severe.
Is use of this corrosion margin mandatory or may an alternative be used?

CSR doesn't allow to use an alternative for corrosion addition table. The
corrosion additions are to be considered as being mandatory.

2007/1/12

The net thickness and material properties of the supporting floors and pipetunnel beams are to be not less than those required for the bulkhead platingor, when a stool is fitted, of the stool side plating.
This requirement is similar to that of UR18 in case where there is no lower
stool. CSR extends it to the case where a lower stool is arranged. Thisextension could lead to up to +4mm for floors underneath deep tank stools on
capesize bulkers whereas all assessments show that it is not necessary.
Is this requirement possible to excuse when FEM calculation is satisfied? Itshould be cancelled, at least for L>150m for which FE is mandatory.

In general CSR doesn't allow alternative analysis. Alternative analysis such as
direct calculation could be allowed in some cases for ships greater than 150 m
in length. However, it is a general question for the totality of CSR (oil or bulk)
and it should be discussed as a general matter.

2007/1/12

In [2.7.4] of Ch 6, Sec 1 for plating and in [2.5.4] of Ch 6, Sec 2 for ordinary
stiffeners, for steel coil load with dunnage more than 5, it is stated that the
inner bottom may be considered as loaded by a uniform distributed load.
But CSR has no definition for uniform loads.
So such definition of uniform loads should be introduced CSR.

A definition of uniform loads on inner bottom will be included in CSR for bulk
carriers.

Attachment

AnswerPage 26 of 181

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completed(1) Primary supporting member are defined as: members of the beam, girderof stringer type which ensure the overall structural integrity of the hullenvelope and tank boundaries, e.g double bottom floors and girders,
Web stiffeners of primary supporting members:
transverse side structures, web frames/diaphragms in hopper side tanks,(1) Because there is no definition for “primary supporting member”, themeaning of “web stiffener of primary supporting member” itself is unidentified. topside tanks, lower stools and upper stools, side stringers, horizontal
girders/transverse web frames, hatch side/end coaming.
Please clarify the definition of “primary supporting members”.
(2) The requirements in Ch 6, Sec2, [2.2] adn [2.3] are not applicable to web(2) Please see the attached summary table about rule applications for web
stiffeners but to ordinary stiffeners, The only requirements applicatle to web
stiffeners of primary supporting members based on our understanding. It
stiffeners in CSR for bulk carriers are the following ones:- Ch 3, Sec6 [5.2.1]
shows that which requirements should be applied to web stiffeners. Please
for the net thickness of such stiffeners, which refers to the minimum net
confirm.
2006/12/18
thickness of the primary members on which they are fitted, i.e. to Ch 6, Sec 4,(3) We also would like to confirm that whether the web stiffeners fitted onwatertight girders, e.g. watertight centre girder and floors, should be applied to [1.5.1], and - Ch 6, Sec 2 [4] for the net scantlings of web stiffeners of primary
supporting members.
the both requirements for primary supporting members of Chapter6/Section4(3) The same requirements as stated in (2) above apply to web stiffeners fitted
and for ordinary stiffeners of Chapter6/Section2 or not.
on(4) If there is any needs to satisfy both requirements for primary supportingwatertight side girders, centre girders and floors, i.e. Ch 3, Sec 6, [5.2.1]for themembers and for members subject to lateral pressure, I would like to know
net thickness of such stiffeners ( and so Ch 6, Sec 4, [1.5.1] and Ch 6, Sec 2,
whether the web stiffeners fitted on the watertight bulkheads in the topside[4].
tanks and bilge hopper tanks are treated the same or not.
(4) See our comment in (1) as we consider that stiffeners on these bulkheads
are considered as ordinary stiffeners and not as web stiffeners.

333
attc

3/6.5.2
6/2.2.2
6/2.2.3
6/4.1.5

QuestionWeb
Stiffener334

7/2.3.4

Question

Measuremen
ts

336
attc

9/5.5.5

Question

Sectionmodulus

Question/CI

Attachment

Answer

2007/3/9

Would you please confirm which direction is the maxium relative deflectiondelta_ max between the double bottom and the afterward (forward) transvers
bulk head? Z or the reluctant?

The maximum relative deflection has to be measured normal to a line, whichconnects the adjacent bulkheads at Bottom / CL.

2007/2/8

We would like to confirm a way to apply the requirement of this sub-paragraphto a structural member shown in the attachment.
(1) Which position, A, B or C, shown in Figure, is to be selected to calculate
w0 and I0? We consider that position B is suitable for this requirement. Pleaseconfirm.
(2) Which position, A, B, C or else, is to be considered when the requirementof net section modulus of ordinary stiffeners, w, is applied? We consider that
position A is appropriate for this requirement. Please confirm.

According Fig. 1 a symmetrical beam with l_1 < 0.5 l_0 is the basis for thissimplification. The example in the attachment is not covered by theassumptions of the requirement, i.e., a symmetrical beam. For an
unsymmetrical beam as shown the attached document, the calculation should
be carried out by direct calculations or beam analysis as stated in [5.4.1].

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Question11/2.2.4.3

Ch11/27/2.3.2.3

Question

Question

Topic

S18

allowable
stressesvalue of leg
lengthStressLevelsDatecompleted

Question/CI

Attachment

Answer

2007/2/22

For the weld of corrugations and stool side plating to the stool top plate, only
full penetration is accepted in the requirement of Ch 3, Sec 6, 10.4.7. On theother hand, not only full penetration but deep penetration is accepted in therequirement of Ch 11, Sec 2, 2.4.3. It is considered that this requirement is
We will consider the editorial correction according to UR S18.
based on IACS UR 18.4.1(a), as follows:
Also Included in Corrigenda 5
The stool side plating is to be connected to the stool top plate and the inner
bottom plating by either full penetration or deep penetration welds. Therefore,
the requirement of Ch 3, Sec 6, 10.4.7 should be changed to be consistent
with Ch 13, Sec 2, 2.4.3 and IACS UR. Please confirm.

2007/7/16

The sizes of leg are determined based on the as-built thicknesses as perwhat is the design criteria (allowable stress value) when a leg length should be
Table.1 but the net thicknesses are not the basis. In case the requirements in
calculated according loads? which corrosion deduction gas to be used for
Chapter 11 should not be applicable the leg sizes should be subject to thesuch calculations?
Societies approval

2007/7/2

1. Your understanding that is the local plate bending is neglected is correct.
2. In principle stress levels of all elements should be within the allowable
According to Ch.7 Sec.2 [3.2.3] “The reference stresses in FE model that does
criteria. However, the averaged stress among smaller elements (e.g., quarter
not include orthotropic elements, as specified in [2.2.4] are not to exceed
size or smaller) can be used when deemed reasonable by the Society.
235/k N/mm2 (..)” We have 3 multiple questions. See the attached.
3. All elements over the height of the girder should be within the allowable
criteria when the difference of size of all elements in girder is relative small.

Y

1a. Your understanding is correct.
1b. Your understanding is correct.

341
attc

7/2.3.2.3

QuestionStressAssessment

2007/7/2

Section 3 Detailed stress assessment.
Item [2.1.1] “Where the global cargo hold analysis of Sec.2 is carried out usinga model complying with the modelling criteria of [2.2.4], the areas listed in Tab
1 are to be refined at the locations whose calculated stresses exceed 95% of
the allowable stress as specified in Sec 2,[3.2.3]. Please review following
related questions (see the attached).

2. According to 2.1.1 of Ch 7 Sec 3, as the refined areas are limited to thelocations listed in Table 1 of Ch 7, Sec 3 and the stresses thereof obtained bycoarse mesh FEA in Ch 7 Sec 2 exceed 95% of the allowable stress, theenlarged area to create the refine mesh is not required to the locations where
the stresses obtained by coarse mesh FEA is below 95% of allowable stress.
Therefore, The example given in "b" of your questionary document as
attached is correct.
3. The example given in "a" of your questionary document as attached iscorrect.

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Attach
ment

Y

Y

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8/4.2.3.6

QuestionTransverse
BHD

2007/5/22

Relative displacement of transverse BHD.
See the attached question.

The relative deflection for double bottom is defined as follows.
(1) On the bottom
The base line is defined as the line between connecting points of the floors tobottom in way of fore and aft of lower stools. The relative deflection is definedas the deflection of the connecting points of the adjacent floors to bottom
measured from the base line.
(2) On side shell
The case 2 as shown in your attached document is correct.

343
attc

7/2.2.3.1

Boundary
Question conditions for
FE analysis

2009/9/4

FE analysis of cargo hold structures - boundary conditions
See the attached question

Your comments have been noted and we can advise that the boundary
conditions have been changed accordingly in RCN No.1-5 to the July 2008
Rules.

2007/5/14

The current requirement is only considering the buckling strength from thelocal bending stress as it is only taken the maximum vertical stress without
shear component. Therefore, the panel size is only taken as b times b for faceplate and 2b times b for web plate. However it should be noted that thebuckling strength should be considered not only from the local bending stress If a FE analysis derives signifcant shear stress in face plates of corrugated
but from the global bending and shear stress. It is expected that the higher
bulkheads you may take this stress into consideration according case b),
shear stress would be induced at the connection of corrugated bulkhead todescribed in 1.3.4.
side shell, hence the shear buckling should also be taken into account. To
assess the shear buckling, the panel size should be taken separately fromabove, i.e. full length panel from top of lower stool to bottom of upper stool
and the shear stress to be taken as mean shear stress of the large panel.

Ch.6,
Appendix
1/1.3.4

Question

Corrugated
BHD

QuestionThe
Maximum
Verticalstress2007/7/2

The current requirement states that “the maximum vertical stress in the
Assuming a b x b or 2b x b buckling field (depending on the considered area)
elementary plate panel is to be considered in applying the criteria”. This results
you may derive the vertical stress as an average value of elements inside thisthe severe requirement when the quality of the mesh was poor at the edge ofarea. Lower part of the web plates prone to include bad shaped elements or
corrugation where the connection of other structures to corrugation is relatively
triangular elements may be neglected. Each area with a different thickness iscomplex. To apply the maximum vertical stress to the “elementary plate panel”
to be considered and checked separately.
is considered unrealistic. This should be enhanced to be more practical.

Chp 6/
346 Appendix1 Question/1.3.4The Edge
constraint
factor

2007/3/9

The current requirement, the edge constraint factor, F1 = 1.1. This should be
1.0.

344

Text
345 6/Appendi
x 1/1.3.4

As the correction factor F1 is not used for the buckling load cases 1 and 5, thelines "F1=1.1 is to be used" in (a) and (b) of 1.3.4 are not necessary. We willconsider the editorial correction.

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348 5/App1.2.2Typequestion

Topic

Hull girder
ultimate
strengthDatecompleted

Question/CI

Answer

2009/9/4

1) In Ch 5, App 1, there are editorial errors in the formulae for critical stresses
in the following requirements:[2.2.4] - Beam column buckling[2.2.5] - Torsional buckling of stiffeners[2.2.7] - Web local buckling of flat bar stiffeners
The correction should be to delete the coefficient in the brackets in formulae
giving critical stresses.Please confirm?
2) In Ch 5, App1, [2.2.8] - Buckling of transversely stiffened plate panels, thecoefficient is missing in the second line of the formula giving the critical sress,
between ReH and the first bracket. Please confirm?

Your observations were correct and the equations were amended in RCN No.
1 (Nov 2007), with further amendments in RCN No.1-1 to the July 2008 Rules.

Attachment

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351

Ref.

Ch 2/Sec
3

Type

Question

Topic

PMA

Date
completed2007/2/22

Question/CI

Attachment

Answer

PMA is in principle a SOLAS matter. The cause of the probable argument isdue to the following:1. The necessity of safe access is set out in CSR Ch1, S3, 2.5.1, however, it is
not clear whether the requirements are relevant to SOLAS PMA or not. In thisAs suggested, the requirements for PMA arrangements and ship structure
respect, the applicability of PMA appears more explicit in CSR-DHOT, S5, 5.1.
access manual should follow SOLAS II-1/3-6 and need not be applied to bulk
2. CSR is required for ships having L of 90 m or more, while PMA as part ofcarriers not more than 20,000 gross tonnage. As for Ch.2/Sec.3.1 and 3.2, all
SOLAS is required for ships having GT of 20,000 or more.
paragraphs are extracted from the corresponding section of Resolution
3. There must be many ships of which the particulars lie between the 90 m in
MSC.158(78) in association with IACS UI SC191. Therefore, the stipulations inlength and 20,000 in gross ton, which is left unclear when interpreting for
Italic character mean to follow SOLAS requirements. Accordingly, the 2nd
SAFCON purposes.
and 3rd sentences of Ch.1/Sec.3/2.5.1 will be corrected and the clear
4. Taking this opportunity, it is worth consideration that reference to SOLAS,
application requirement will be added in the Ch 2 Sec 3.
not as classification matters, be harmonised between CSR-BC and CSRDHOT. The International Regulations are transcribed in CSR-BC, which isuser-friendly while on the other hand may cause a possibility of unnecessary
misinterpretations. CSR-DHOT appears simple and clear for that matter.

5. Could you please confirm if all the PMA matters are strictly SOLAS items,
not a class requirement? The requirements of means of access are set out in
Ch1, S3, 2.5 and Ch2, S3, however, it does not appear explicit that PMA is aclass requirement. Is it that the stipulations in Italic are not class requirements
but SOLAS or other international regulations? SOLAS Reg.II-1/3-6 requires
PMA for ships of which the gross ton is equal to or greater than 20,000, while
CSR is to apply to ships of which the length is equal to or greater than 90 m.
Such being the case, the following question could arise with respect to
SAFCON, which should cause a dispute.
1: Bulk Carriers >=90m but =<20,000GT --> Class item
2: Bulk Carriers >=90m and >=20,000GT --> Class & SAFCON item.

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356
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5/1.2.2.2

8/5.2.1.1

6/2.3.3.1

Type

Question

Question

Question

Topic

Hull Girder

Parameter
correction

ModulusDatecompleted

Question/CI

Attachment

AnswerQ1:(a) For the structures at forward and aft of transverse bulkhead the scantlings
should be determined based on (symbol: delta)QCF and (symbol: delta)QCA
respectively.
(b) Permissible limits should be also based on (symbol: delta)QCF and(symbol: delta)QCA respectively for structures at forward and aft of transverse
bulkhead.
Q2: (symbol: delta)QC should be calculated for each non-homogeneous
loading condition. Therefore the permissible shear force is different for each
non-homogeneous loading condition.
Q3: Shear force correction should be done at the bulkhead where adjacent
holds are in non-homogeneous loading condition. Therefore shear force
correction should not be done at other transverse bulkheads than those of
No.4 ballast hold.
Q4:(a) Total mass of cargo M may include deadweight such as water ballast andfuel oil tank in double bottom, bounded by side girders in way of hopper tankplating or longitudinal bulkhead, if this space is loaded for the nonhomogeneous loading condition considered.
(b) In [2.2.3] flooded water in the hold may be included into M. (c) Deadweightin double bottom which is as defined in (a) may be included into M.
Q5: Yes.

2007/4/2

Multiple Questions on Hull Girder Shear Force Correction. See attached2007/3/20

In Chapter 8 Section 5,[2.1.1], the following parameters needs to be more
specific:
1) "AQ" is the shear area of the cross deck: does it includes the shear area ofall plates and of all ordinary stiffenerd, as shown on Figure 2 ?
2)"bS" is the breadth of the remaining deck strip beside the hatch opening: is it
the total breadth on both sides or is it only on one side? If it is the latest case,it should be identical to "b" defined in [3.1.1].
3) "LC" is the length of the cargo area, it should be noted LC, with "C" as andindex.

1) The shear area "AQ" is the effective shear area of the whole section shownin figure 2 with respect to the ship's longitudinal direction. For the deterninationof the effective shear area the consideration of only the plate elements issufficient, and the stiffeners can be neglected.
2) "bs" is only the reamaining deck strip on one side, so it is identical to "b" in[3.1.1]
3) This is an editorial typo: "C" should be as an index in "LC".
Also Included in Corrigenda 5

Questions on the requirement for mid-span sectional modulus. See theattached.

(a) Yes, ps and pw in the formulas in Ch.6 Sec.2 [3.3] are pressures in intact
condition.
(b) Yes, Ch.6 Sec.2 [3.2.3] is to be applied to side frame only in way of ballast
hold in heavy ballast condition.
(c) Q1: The required section modulus by the formula in Ch.6 Sec.2 [3.2.3]
should be applied to whole span of side frame. Please note that while thespan l in Ch.6 Sec.2 [3.3.1] is to be determined without consideration to end
brackets according to Ch.3 Sec.6 Fig.19, the span l in Ch.6 Sec.2 [3.2.3] may
be with consideration to end brackets as specified in Ch.3 Sec.6 [4.2]. (d) Q2:
The required net section modulus at end brackets is to be not less than twice
the greater of the net section moduli required for the frame mid-span area
obtained from Ch.6 Sec.2 [3.3.1] and Ch 6 Sec.2 [3.2.3] for ballat hold.

2007/3/16

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Date
completed357

6/2.4.1.1

QuestionWeb
Stiffener

2007/5/14

Which value of k1 is to be used for a web stiffener on watertight primary
supporting member ?

For a web stiffener on watertight primary supporting member, i.e. with fullcollar plate, k1 is to be taken equal to 0.2.

2007/2/22

Ch4 Sec5 [4.2.1] specifies the design bottom slamming pressure. The
pressure is defined from almost 0.5L to fore end. Ch9 Sec1 [5] specifies therequired sturctural scantlings using the pressure. However the strengthening
required by Ch9 is forward of 0.2Vx(root L) from fore perpendicular end.Theremay be a zone between abt. 0.5L and 0.2Vx(root L) where there is norequirement to structural scantlings in Ch6 using the slamming pressure.
Please confirm that there is no scantling requirement in this zone using theslamming prressure.

Your undestanding is correct.

358

4/5.4.2.1

Questionbottomslamming

Question/CI

Attachment

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8/4.2.3.4,
359 8/4.2.3.5 & Question
4.3.3.4

Topic

FatigueCalculations

Datecompleted2007/7/2

Question/CI

Attachment

Answer

A1 The same loading condition should be applied to both direct strength
analysis and prescriptive requirement for fatigue check.
Please review the below questions related to Fatigue calculations.
(a) rho_c = MH/VH and filling to upper deck may be applied to.
Q1: Loading conditions and assumptions. Fatigue calculation is performed in(b) Fuel oil is always filled to half the height of FOT.
the following 4 load condition; Homogenous, Alternate, Ballast and Heavy
A2: Tanks other than Water Ballast Tanks are considered as being filled atballast. The design loading condition for FEM is listed in Ch. 4 App.3. Are
50%. All Water Ballast Tanks are considered either full or empty. Even thoughthese conditions also applicable for prescriptive calculation of stiffenersuch WBT are intended to be partially filled at the standard loading condition,connection according to Ch. 8 Sec. 4? Following differences are fond between the partial filling of such tanks is not considered for fatigue check.
Ch.8 Sec. 4 and Ch. 4 App. 3: a.Filling height and density for Homogenous
A3:
condition. According to Ch. 8 Sec. 4 [2.3.5] the definition of Ch.4 Sec. 6 [1.3](a) Yes, actual still water bending moment in the Loading Manual for theshould be applied. That is = max(MH/VH,1) and filling to main deck.
respective loading conditions may be used for fatigue strength assessment.
According to Ch.4App.3 the = MH/VH with filling height to main deck.
(b) The requirement of Chapter 4 Section 3, 2.2.1 mentions that “The designb.Heavy fuel oil tanks(HFO). According to Ch.8 Sec.4 [2.3.4] the filling height
still water bending moment, MSW,H and MSW, S, at any hull transverseof HFO tanks may be taken as “half height of the tank”. According to Ch.4
section are the maximum still water bending moment calculated, in hogging
App.3 the HFO tanks is full. Q2: Partially filled ballast tanks. Please advice if
and sagging condition, respectively, at that hull transverse section for the
all ballast tanks are 100% for the purpose of fatigue calculations?
loading conditions, as defined in 2.1.1.”.
Q3: Still water bending moment We assume the actual still water bending
Therefore, the loading condition is to be used which gives the maximum still
moment in the Loading Manual for the respective loading conditions may bewater bending moment among the considered loading conditions, i.e.,
used for the fatigue calculations. Please confirm. Please also clarify which
departure, arrival and intermediate conditions specified in Loading Manual.
conditions to use, departure, arrival or max./average? Q4: Partially filled Heavy A4:
fuel oil tanks. According to Ch. 8 Sec. 4 [2.3.4] the HFO tanks are indicated as (a) Yes, the equation in Ch.4 Sec.6 [2.2.1] may be used as is, provided; half full when calculating CNI factor. Please advise on the following related
Liquid surface level at mid-height of the tank may be assumed to remain
items: a.The dynamic pressure is calculated according to Ch.4 Sec.6 [2.2.1].
unchanged relative to tank geometry even when hull motion should occur, The equation is, as far as we can see, developed based on a full tank. How is Ztop may be taken as the Z-coordinate, in m, of the Liquid surface level atthis modified to account for filling height? Can this equation be used as is with mid-height of the tank, and - xB, yB and zB may be taken on the Liquid
respect to Ztop and reference point (xB,yB,zB). ? b.Mean stress and still water surface level at mid-height of the tank.
pressure according to Ch.8 Sec.4 [3.3.4]. The static pressure is calculated(b) Ztop may be taken as mentioned in (a).
according to Ch.4 Sec.6 [2.1]. This still water pressure is assuming PBS =(c) We confirm that ballast exchange operation is not applicable. Please note
Lg(zTOP-z+0.5dAP) or Lg(zTOP-z)+100PPV whichever is greatest.
that Min.25kN/m2 is not applicable to fatigue strength assessment.
Minimum 25kN/m2. How is this modified to treat partially filled tanks? c.We
assume ballast exchange operation is not applicable when
doing fatigue calculations? Please confirm.

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Table
6.3.2

Type

Topic

Question Rule Change

Datecompleted2007/7/1

Question/CI

Attachment

AnswerYour conclusions are right. We will prepare a rule change proposal as follows:
Definitions in Symbols
Ch6 Sec3 We get different results for LC5 in Table 2 depending on whether
we denote the longer side b and the shorter side alpha*b, or vice versa. This is a: Length in mm of the longer side of the partial plate field in
an unexpected result. We suspect this is caused by an inaccurate definition of general or length in mm of the side of the partial plate fieldb. The definition of b should be similar to the definition of la in CSR Tank. We according Table 2, BLC 3 - 10
b: Length in mm of the shorter side of the partial plate field inpropose the following definition, which is in line with CSR Tank:
general or length in mm of the side of the partial plate fieldb: length in mm, of the shorter side of the plate panel for Cases 1 and 2, or
according Table 2, BLC 3 - 10
length in mm, of the side of the plate panel as defined for Cases 3-10.
Further we suspect the formula for reference stress sigma_e in the List of
In accordance with these definitions of a and b the definition of the reference
Errata of April 2006 is incorrect. b, as defined above, should be used for the
stress S_e of the CSR for Bulk Carrier 2006 is correct. We will reject thecalculation, not b'. This means the formula as printed in the Rules of January
definition, given in the Corrigenda 1. "Note: IACS Council expediated the2006 is correct.
rrule change required as a result of this question and on 19 July 2007 agreed
By making the above described modifications we avoid the problem for LC5,
and we are also in line with CSR Tank. Please comment.
that the correction in the attached file should be made to Ch.6, Sec.3
Symbols."
Also Included in Corrigenda 5

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Answer

1.Your comments have been noted and we will clarify the application of theflooding requirement in a future revision of the rules.

361
attc

1/3.2.2.2

Question

Flooding
Scenario

2009/9/4

2.Regarding the summarized table as attached, the answer is as follows.
(1)Design still water bending moment and shear forces, your understanding iscorrect.
(2)Design wave bending moments and sheer forces, your understanding is
According to this functional requirement, we assume that flooding scenario
correct.
should be taken care of for all ships. It is unclear how this is taken care of for(3)Longitudinal strength (Yielding), your understanding is correct.
BC-C vessels and for small ships with length below 150 m. It should be(4)Longitudinal strength (Buckling), your under standing is correct.
explained and included in the rules or if applicable, the functional requirement
The answer to the question in the “Remark” box in the attached document isshould be modified for sake of clarity.
as follow.
Meantime, please confirm if our understanding of the current CSR is correct as
No, the axial buckling check according to UR S17 is not applied to. Hull girdersummarized in the table attached. In the following questions we also highlightultimate strength check should be carried out in stead of the axial buckling
our concerns.
check.
(5)Hull girder ultimate strength, your understanding is correct.
The answer to the question in the “Remark” box in the attached document is
as follow.
Yes, hull girder ultimate strength applies to BC-C ships.
(6)Design loads for corrugations of transverse bulkhead: your understanding iscorrect.

(7)Strength of corrugation of transverse watertight bulkhead: yourunderstanding is correct.
(8)Shear buckling strength of corrugation of transverse watertight bulkhead:
this is applied to all ships according to “Corrigenda 2 approved by IACS
Council on 27 January 2007.”.
(9)Flooding scenario for double bottom: your understanding is correct.
(10)Design load and strength of double bottom: your understanding is correct.
(11)Design load for boundaries of dry compartment: your understanding iscorrect.
The answer to the question in the “Remark” box in the attached document is
as follow.
Where sigma x is not defined for longitudinal members, sigma-x for intact
condition is used.
The MwH,f is not considered.
Combination factor for intact condition is used.
(12)Design load and strength of primary supporting members on theboundaries of dry compartment; your understanding is correct. There is norequirement in CSR.
(UPDATED OCT 2009)

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Answer362

3/4.2.4.1

Questionhull girder

2007/3/20“Longitudinal strength of hull girder in cargo hold flooded condition is to beassessed in accordance with Ch 5 Sec 2.” Reference to Sec 1 should also begiven for longitudinal strength in hold flooding, which is however limited to BC- Yes, your understanding is correct.
A and BC-B. Sec.2 is about ultimate strength of hull girder for ships with length
equal to 150 m in length L and above, i.e., including BC-C. Please confirm.

363

3/4.2.4.3

Questioncargo hold2007/2/22“Bulkhead structure in cargo hold flooded condition is to be assessed inaccordance with Ch 6 Sec 4.” Sec 4 does not give any requirement forbulkhead structure in flooding scenario. Is this a typo error of Sec 1 and Sec
2?

Yes, it is typo and the correct wordings are “Sec 1 and Sec 2” instead of“Sec.4”.

In flooding scenario, do we apply the vertical acceleration aZ for “intact”
condition as defined in Ch 4 Sec 2 [3.2.1]?

Yes. The draft and total weight of ships in intact condition is slightly different
from those in flooded condition. But the difference is very small and there is no
significant effect due to flooding for the acceleration or the motion of a ship.
Therefore, the vertical acceleration az for “intact condition” is applied to theformula in flooded condition specified in Ch 4 Sec 2 [3.2.1].
Yes, your assumption is right.
The current CSR requires to BC-A, BC-B and BC-C ships to check the hull
girder ultimate strength under not only intact condition but also flooded
condition but the yielding check of hull gider under flooded condition isrequired for BC-A and BC-B ships, and not required to BC-C ships.
In order to resolve this discrepancy, it is decided that the yield check of thehull girder is to be performed for BC-A, BC-B and BC-C ships.
This will be considered as a rule change.

364

4/6.3.2.1

Question

VerticalAcceleration

2007/3/20

365

Ch 5 Sec
1

Question

Strength of
Hull Girder

2007/5/11

Longitudinal strength of hull girder in flooded condition is given in Ch 5 Sec 1
for BC-A and BC-B only. We assume that this is not required for BC-C andships below 150 m in length. Please confirm.

366

Ch 5 Sec
2

Question

Hull girder

2007/3/20

Longitudinal strength in flooding condition is given in Sec 1 and is limited to
As mentioned in the requirement Ch 5 Sec 2 [1.1.1], the requirement on
BC-A and BC-B ships only. We assume that the same limitation applies to Sec
ultimate strength check of hull girder apply to ships equal to or greater than
2 for ultimate strength of hull girder in flooding condition. Please confirm. If so,
150m in length (L), i.e., BC-A, BC-B and BC-C ships.
please add the limitation in Sec 2 as well.

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Flooding
6/1.3.1.5 &Question Requirement
6/2.3.1.5sDatecompleted2009/9/4

Question/CI

Attachment

Answer1) When hold flooding is considered for local scantlings check of a plate or a
stiffener, MSW,F, MWV,F and MWH,F are to be used in lieu of MSW,MWV
and MWH respectively for calculating sigma_x by the formulas in Ch.6 Sec.1[3.1.5] and Ch.6Sec.2 [3.1.5], where MWH,F=0.8MWH. However in this casethe same load combination factors CSW, CWV and CWH as those for intact
condition are to be used.
The definition of sig-x is unclear for longitudinal members in flooding condition.
Notwithstanding the above, for a ship of length Ls <150m the sigma_x is to be
The MSW,F in Ch 4 Sec 3 [2.4] assumes flooding of individual cargo hold andcalculated by the same formula as that in Ch.6 Sec.1 [3.1.5] or Ch.6 Sec.2
is required only for BC-A and BC-B ships. Does the same MSW,F apply to any[3.1.5], as applicable."
dry compartment, for instance, inner side and duct keel in double bottom
space? How do we apply MWH,F and any of the load combination factors?
2) When flooding of the compartment other than a hold is considered,sigma_x is to be calculated by the same formula as that in Ch.6 Sec.1 [3.1.5]
or Ch.6 Sec.2 [3.1.5], i.e, only intact conditions should be used to determine
Sigma_x, as applicable.
This interpretation will be included in the Rules at a future revision.

Ch 6
Sec1.3.1.5
Question
368&
Sec2.3.1.5

369

Ch 6 Sec
1.3.2.2
and Sec
2.3.2.5

Question

Calculation

2007/3/20

In order to calculate sig-x for BC-C ships and ships with length less than 150
m, do we have to calculate MSW,F by flooding individual cargo holds which is
not required for longitudinal strength?

corrugatedBHD

2007/3/20

We assume that these requirements apply to stools of corrugated bulkheads
with the design load as given in Ch 4 Sec.6 [3.2.1]. Flooding load given in [3.3] Yes, your interpretation is correct.
does not apply to the bulkhead stools. Please confirm.

2009/9/4

The MSW,F is defined in Ch 4 Sec 3 [2.4] by flooding individual cargo holds. If
the same design moment is applied to any dry compartment such as ductkeel, the flooding requirements may, according to our calculation, give heavier
scantlings than the intact requirements. This means that the flooding
requirements may have to be applied to all structural boundaries as minimum.
Please explain.

When flooding of the compartment other than a hold is considered, sigma_x isto be calculated by the same formula as that in Ch.6 Sec.1 [3.1.5] or Ch.6
Sec.2 [3.1.5], i.e, only intact conditions should be used to determine Sigma_x,
as applicable.

2007/3/9

Shear buckling of vertical corrugated bulkhead is required for BC-A and BC-B
only. The same limitation is stated in [1.1.2 b)]. This is inconsistent to otherrequirements for corrugated bulkheads which apply to all ships. Does thisrequirement apply to all ships as well, same as Sec 1 [3.2.3] and Sec 2[3.2.6]? Please explain.

It is typo. The wordings "for BC-A and BC-B ships" are delted from the text in
Ch. 6 Sec 3 [1.1.2] and the title of [6]should be deleted. This editorial
corrrection is included in "Corrigenda 2".

Flooding
6/1.3.2.2 &370
Question Requirement
2.3.2.5
s

372

6/3.6

Question

corrugated
BHD

Sigma x for intact condition is used.

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AnswerYes, it is a typo error. The text of this requirement should be read as:

373

374

375

6/4.1.3.1

6/4.

8/App.1,
1.3.1

Question

directcalculation

Flooding
Question Requirements

Question

Calculation
ChangeFor primary supporting members for ships having a length of 150 m or more,
the direct strength analysis is to be carried out according to the provisions
specified in Ch 7, and the requirements in [4] are also to be complied with. In
addition, the primary supporting members for BC-A and BC-B ships are tocomply with the requirements in [3].
Also Included in Corrigenda 5

2007/3/5

In addition the primary supporting members for BC-A and BC-B ships are tocomply with the requirements in (3) and (4)" The Sub-Section (4) is aboutbuckling strength of pillars is this typo error?.

2009/9/4

This section applies to primary supporting members in intact condition only.
Do we not check primary supporting members on the boundaries of dryYour comments have been noted and further studies have been made tocompartments against flooding load, such as those on a plane bulkhead atconsider extending the requirements for flooding conditions, the outcome of
forward of foremost hold or aft bulkhead of aftermost hold? This is inconsistentwhich will be included in a future revision of the Rules.
to flooding requirements for local plates and stiffeners in Ch 6 Sec 1 and Sec 2
covering all ships. Please explain.

2007/3/9

1) That is right: the stiffeners are not to be considered in the calculation of theproperties of the cross section. Only the plates are to be considered as "partialarea" (defined in [1.1.1]).
2) The parameter "yS" which appears in the calculation of "Iz" for symmetriccross section should be considered equal to zero. By defining it in the same
way as for asymmetric cross section, it comes equal to zero, as "Sz" should be
In Chapter 8, Appendix 1, [1.3.1], the following items needs some clarification: equal to zero for such symmetric cross secton.
3) We agree that using twice the same symbol for different definitions is1) it is understood that the stiffeners are not considered in the calculation of
confusing, It should be corrected. However, your understanding is correct: thethe properties of the cross section. Please confirm?
2) In table 1.4, for symmetric cross section, the parameter "yS" appears in the parameter "Iwy" used in the definition of "Iw" is also the one defined in Table
1.4
calculation of "Iz", but is not defined. What is the definition of "yS" in such a4) That is right, this is a typo: in Table 1.4, for symmetric cross section, in thecase?
definition of " Iw", "zm" should be understood as "zM".
3) in table 1.4, for symmetric cross section, it is understood that theparameters "Iwy" and "Iz" which appears in the definition of "zM" are5) in the statement "S, Iw are to be computed with relation to shear centre M",
thoseparameters defined just above in the table, and not those defined in the "S" is to be understood as being "Sy", "Sz" and "Sw" in the list of formulae at
beginning of [1.3.1]. Please confirm? Using twice the same symbol forthe beginning of [1.3.1], and "Iw" is to be understood as being "Iw", "Iwy" anddifferent definitions is confusing. The same understanding is considered for
Iwz". It means that in such expressions the coordinates "yk", "yi", "zk" and "zi"the parameter "Iwy", used in the definition of "Iw".
are to be considered also in reltion with the shear centre M.
4) In Table 1.4, for symmetric cross secton, in the definitionof "Iw", it should be 6) We agree that the formula giving "Delta w" is not clear. The formula should"zM" instead of "zm".
be replaced by: "Delta wi = zM * yi". In order to clarify all symbols in Chapter
5) Below Table 1.4, it is stated that "S, Iw are to be computed with relation to
8 Appendix 1, we will consider the rule change proposal. the coordinates "yk",shear centre M". What are the meaning of "s" and "Iw" in this statement?
"yi", "zk" and "zi" are to be considered also in reltion with the shear centre M.
6) The formula giving "Deltaw" is not clear. Please explain?
6) We agree that the formula giving "Delta w" is not clear. The formula should
be replaced by: "Delta wi = zM * yi". In order to clarify all symbols in Chapter
8 Appendix 1, we will consider the rule change proposal.

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IACS Common Structural Rules Knowledge Centre

Datecompleted

Attach
ment

KCID
No.

Ref.

376

Table
9/3.7.2 &Table 2

Question net thickness

2007/1/24

Ch.9 Sec.3 [7.2] Table 2. We assume the bedplate net thickness is in mm, not
We agree with the comment and will consider a rule amemdment proposal.
m.

377

9/5.2.2

Question

2007/1/24

Ch.9 Sec.5 [5.2.2] The first formula is incorrect? Should read t=10s, not
t=0.01s

We agree with the comment and will consider a rule amemdment proposal.

With respect to the names given in 9/5.5.5.1, considering wCS=w0 gives asection modulus of wCS=w0 only if w1>=0.8*w0, i.e only if the stiffener/PSM's
cross section is not really varying. For 0=<w1=,0.8*w0, the section modulus tobe considered is given by the second formula and is greater than the midspansection modulus w0. In addition, we can consider that the midspan section
modulus w0 is not to be equal to the section modulus of an constant crosssection stiffener/PSM for this calculation; it has to be used for the 9/5.5.5.1. A
similar approach can be applied to inertias. Furthermore, these calculations
can be replaced by a direct approach as it is usually made.

Type

Topic

formulaQuestion/CI

Answer378

9/5.5.5.1

Question

formula2007/3/12

Our understanding of this item is that the section modulus for a stiffener/PSM
with variable cross section always is to be at least equal to the section
modulus of a stiffener/PSM with constant cross section ( w = wCS ). Thismeans there is nothing to gain by varying the cross section. Example: For asimply supported PSM with constant CS the section modulus at midspan, w0,
will be governing. Our understanding is that for a PSM with varying CS, theminimum section modulus is w0, independent of the position along the axis (w = wCS = w0 ). We have the same problem for moment of inertia. Pleaseclarify.

379

9/5.6.3.1

Question

formula2007/2/22

This formula comes from IACS UR S21, S21.4.2. The constant value 15.98
Ch.9 Sec.5 [6.3.1] What is the background for the factor 15.98 in this formula?
is obtaind from muttiplying 14.9 by squareroot of 1.15 (=Scoam specified in
Is it a misprint for 15.8?
UR S21.4.2). Therefore, the formula is correct.

380

6/1.2.7.3

Question

Holds loadedwith steel
coils

2009/10/6

The results currently obtained show an important increase of the grossthickness for plating of hopper and inner hull when applying the formulas of
Ch.6 Sec.1 [2.7.3] under steel coils loads. Should this calculation of hopper
sloping plate and inner hull plating for steel coils loads be performed?

382

6/2.3.1.5

Question

stiffeners

2007/3/9

Could you please confirm how to determine the reference point of Z cordinates The reference point for stresses and loads calculations is at the bottom andof stiffeners when calculating the normal stress sigma_x of stiffeners which
middle of its web, ie. where the stiffener joins the attached plating. This iscontribute to the hull girder longitudinal strength? Is it the same as JTP?
different to the CSR Oil choice which base the reference point at the top.

383

6/3.4.2.1

Question

The NormalStressSigma_n2007/10/24

Could you please confirm how to determine the normal stress sigma_n which
is based on the axial stress calculated at the attachment point of the stiffenerto the plate? Is it the same as JTP?

Your comment has been noted and this issue has been addressed in RCN
No.1-3 to the July 2008 Rules.

We confirm that:
1)the normal stress sigma_n is the axial stress of longitudinal stiffener which is
calculated at the attachment point of the stiffener to the plate,2)it is the same way as JTP.

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No.

385
attc

386
attc

388

389

Ref.

8/5/3.1.1

8/5.3.1.1

3/5.1.2.2

Table
6.3.2

Type

Question

Question

Question

Question

Topic

Elliptic
Corners

Formula
"Kgh"

PSPC

Shear
Buckling

Datecompleted

Question/CI

Attachment

Answer

2007/3/9

We have some doubts on the correction factor for elliptic corners whichappears in the formula of the stress concentration factor in Ch 8, Sec 5,[3.1.1]. We see on the knowledge centre under the answer to question 223
Having considered your attached document, it seems effectively that “ra” andthat "The requirement on hatch corner fatigue check will be revised as soon as“rb” are not defined correctly. We will consider it at the time of revision of thispossible, including a technical background". However, to help for this revision,requirement.
we would like to ask you to consider the attached document. It shows thatsome misunderstanding has occurred between "ra" and "rb". Please consider
this proposal?

Y

2007/4/25

It is right, there is a mistake in the formula of “Kgh”. See the technicalbackground attached, in which it is clearly shown on figure 1(b) that “b” should
It seems that there is a mistake in the definition of the term “b” in the formula
be twice the distance from the edges of hatch opening to the ship’s side. So,
defining “Kgh”. We think that “b” should be twice the distance from the edge ofthe definition of “b” may remains the same as it is, but the formula of “Kgh”
hatch opening to the ship’s side. Please confirm our interpretation?
should be modified accordingly by replacing the term “b” by “2b”.
Also Included in Corrigenda 5Y

2007/2/5

Since PSPC has been adopted by IACS as of Dec. 8, 2006, not by IMO, if the
Builder and Ship owner agreed not to apply PSPC, is it acceptable to theClass or not?

On 8 December 2006, IMO adopted amendments to SOLAS by resolution
MSC. 216(82) which mandate compliance with the new IMO "PerformanceStandard for Protective Coatings for dedicated seawater ballast tanks in all
types of ships and double-side skin spaces of bulk carriers", (IMO PSPC,
Resolution MSC. 215(82)). Compliance with the IMO PSPC is required by the
IACS Common Structural Rules for Bulk Carriers and for Oil Tankers for ships
subject to those Rules which are contracted for construction between shipbuilder and ship owner on or after 8 December 2006. The relevant Rulereferences are the following:- IACS CSR for Bulk Carriers Chapter 3, Section 5, 1.2.2;- IACS CSR for double hull oil tankers, Section 6, 2.1.1.2. Therefore, for suchships (i.e. ships subject to CSR) the answer is "PSPC is to be applied if they
are contracted for construction between ship builder and ship owner on orafter 8 December 2006". For other ships, the answer is that PSPC is to be
applied in accordance with IMO Resolution MSC 215(82) and IMO MSC
216(82).

2007/5/14

Case 6 of Table 2 for shear buckling is applicable only for da/a<=0.7 anddb/b<=0.7. Then, how to calculate shear buckling where da/a>0.7 ordb/b>0.7? Please advise particularly on the following points:
1) Presume that the formua of "r" yields conservative results. If so, is it
acceptable to use the formula of “r” also for the case of da/a>0.7 or db/b>0.7?
2) In case of the panel with large aspect ratio with opening of da/a>0.7 ordb/b>0.7, please advise any guidance/criteria of shear buckling calculation forthe panel with one edge free (similar to Case 3 and Case 4 for axial
compression).

If a cut out has a size beyond the limits of d_a/a<=0.7 or d_b/b<=0.7 only
small stripes are left beside the opening. The whole shear is transformed in a
S-shape deformation of the stripes. This behavior is not comparable to theassumption, that the elementary plate field acts as one buckling field. An
extrapolation of the formulae of BLC 6 is not designated. Up to now we are notable to provide user of the CSR for BC with such an additional buckling loadcase.

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No.

393

398
attc

400

Ref.

7/2.2.3.1

3/6.2.3.1

3/5.1

Type

Question

Question

CI

Topic

Longitudinal
Items

Structural
DesignBallast Hold

Date
completed

Question/CI

2007/6/11

1. Normally at neutral axis on centreline, there are no longitudinal items
present,so to which "independent point" are the nodes on longitudinal
members at both end sections to be linked ?
2. to which node is the total moment (still water & wave) to be applied ?
3. are boundary conditions to be applied only to the master node of coupling
equations & not at all end nodes of longitudinal items ?

2007/6/15

According to this requirement, structural members welded to the strength deckor bottom plating is to be made of the same higher tensile steel of strength
deck or bottom plating. The same requirement is applicable for non
continuous longitudinal stiffeners welded on the web of a primary member
contributing to the hull girder longitudinal strength. However, it is not clear
which member should be applied to this requirement. Please confirm if ourunderstanding of this requirement is correct as summarized in the attached
Table.

2007/3/16

1) In CSR for BC, Ch 3, Sec 5, [1.2], there are already mentioned areas which
are to comply with IMO PSPC. This means that IMO PSPC shall be applied to
all dedicated seawater ballast tanks and void double skin spaces in bulk
carriers. Therefore, we believe that the cating for the ballast hold spaces
described in [1.4.1] is not related to PSPC, we would like to request thebackground for the interpretation.
(2) Additionally, the ballast hold spaces are keeping in dry condition as otherholds in sea-going condition. also, after cargo unloading, the tank bottom will
be damaged due to unloading action. Therefore, we would like to recommendthat the coating for tank bottom of all cargo hold spaces sahll not be painted
as described in [1.3](3) Furthermore,please clarify whether the partially floodable hold spaces are
the ballast hold spaces or mornal cargo hold spaces in respect of coating
issues.

Attachment

AnswerIn general “independent point” does not locate in any members of the FEmodel but shall be produced additionally near the cross point of centerline andneutral axis. The nodes on the longitudinal members at the end shall be rigidly
linked to the “independent point”. It might be common way to use the bulk
data card “MPC” (Multi-Point-Constraint) in case of MSC/NASTRAN. The total
moments (enforced moment for BM/SF adjustment) and boundary conditions
are to be applied to the independent point only.

Ch 3, Sec 6, [2.3.1] could be considered as the requirements in general. If thestress level due to hull girder bending, in longitudinal member not contributing
to hull girder longitudinal strength, should be verified as to satisfy therequirement in Ch 5, Sec 1, [3.1.1], application of the requirements in Ch 3,
Sec 6, [2.3.1] might be mitigated.
As a matter of opening the door, the word "generally" should be added
between "The same requirement" and "is applicable...".

(1) Ballast hold used in heavy weather condition and partially floodable holds
used in harbour condition for loading/unloading operations are not considered
as dedicated sea water ballast tanks and need not comply with IMO PSPC.
(2) Regarding [1.4.1], an effective protective coating is not required to inner
bottom in ballast hold by the CSR/Bulker.
(3) The partially floodable holds used in harbour condition forloading/unloading operations are not to be considered as ballast hold spaces
in respect of coating issues.

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No.

401

Ref.

4/7.3.4,
4/2.2.1.1,
4/App.2.
Table 1

Type

Topic

Discription of
Symbols of
Question"Kr" and"GM"

Datecompleted

Question/CI

2007/7/1

According to CH 4, Sec 7, 3.4 Cargo holds have to be loaded with atheoretical cargo mass [t] of M_HD + 0.1 x M_H with rho = 3 t/m. This loading
condition has to be used for prescriptive requirements as defined in CH 6 andFEA. Such a concentrated load has a significant higher GM than inhomogeneous full load condition. Table 1 of Ch 4, Sec 2 takes the different
loading conditions (alternate / homogeneous) not into account.
(1)Is it correct, to consider the described loading condition for prescriptive
requirements?
(2)If yes, the main influence for the dynamic loads are neglected by using thesame GM and k_r values for homogeneous full loading condition and alternate
loading condition. Do we have to use the GM value for the alternate fullloading condition of the loading manual? (cargo masses are different!!!)(3)k_r values are not included in the loading manuals. Which formula can beused to derive k_r to the individual corresponding GM of the loading manual?

Attachment

AnswerAs specified in the description of symbols of “Kr” and “GM” in 2.1.1 of Ch 4
Sec 2, when the value of Kr and GM are not known, the values indicated inTable 1 may be assumed. This means that the actual values of Kr and GM in
the loading manual should be used in the calculations of the ships motions
and accelerations in Ch 4 Sec 2 as a principle.
The values of GM and Kr indicated in Table 1 have been proposed as the
typical and actual values for usual conditions such as the full alternate or
homogeneous load condition (even distribution of mass in transverse section)in order to provide these values when they are not known at the initial stage.

(4)In case of FEA, concentrated loading conditions have to be evaluatedaccording Ch 4, App. 2, Table 1 ff. In these cases the used GM values,
derived with Table 1 of Ch 4, Sec 2 are wrong. It should be recommended,that only GM values defined in the loading manual have to be used for theseanalyses.

402
attc

403

6/1.3.1.3,
6/1.3.2.2,
6/2.3.1.3,
6/2.3.2.5

3/6.10.4.2

CICI

Flooding
Requirements

Bending
Radius2007/7/12

3 Questions related to flooding requirements in Ch.6, Sec.1 1 and 2

Question Q1: Your understanding is correct: Ch 6, Sec 1, [3.1.3] and Sec 2,[3.1.3] will be revised, as editorial correction to “The lateral pressure in flooded
conditions pF is defined in Ch. 4 Sec. 6 [3.2.1]”.
Question Q2: Ch 6, Sec 1, [3.2.2] and Sec 2, [3.2.6] are requirements comingfrom UR S18. The reference to the design resultant pressure in Ch 4, Sec 6,[3.3.7] only is fully in line with UR S18. Consequently, there is no need to add
any reference to [3.3.6].
Question Q3: Your understanding of the summary of flooding requirements
should take into account the answer to question Q2 above.
Also Included
in Corrigenda 5

2007/4/10

According to CSR-Bulker Ch.3 Sec.6 [10.4.2], the bending radius R is not lessthan 3.0 t but using net plate thickness. If the intention is to control cold
forming, is it reasonable to use as-built thickness? For sake of clarity, thebending radius R should be defined as the "radius of inner plate surface" asillustrated in Figure 3.6.28.

The intention of this requirement is to control the cold forming. As described in
IACS Rec. No.47, the minimum bending radius is 3 x t, where t is the grossthickness. The definition of "R" is defined as he "radius of inner plate surface".
Threrefore, we will consider the editorial correction according to yoursuggestion.

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406

Ref.

4/6.3.3.2,
Symbol4.6, 4/6.1

Type

CI

Topic

Date
completed

Pressure

Questions related to interpretation of the pressure in Ch. 4 Sec.6 :Q1 Ch.4 Sec.6 [3.3.2]
Please advise how to check the load scenario as stated in the last sentence of A1 For bulkhead strength check under flooded condition, the cargo mass,
Ch.4 Sec.6 [3.3.2] which reads; "the maximum mass of cargo which may be
cargo density and cargo upper surface are as follows.
carried in the hold is also to be considered to fill that hold up to the upper deck (1)Homogeneous loading conditionlevel at centreline."(a)Cargo density is less than 1.78 t/m3
Cargo density is given in Ch.4 Sec.6 [Symbols] when the hold is filled up to the Cargo Mass: The maximum cargo mass in case where the cargo is loaded up
upper deck for BC-A and BC-B. This however assumes homogeneous loaded to the upper deck in homogeneous loading condition at maximum draught.
condition Mh at maximum draught.
Cargo density: According to loading manual
Upper surface of cargo: Upper deck level at center line of cargo hold.
2007/10/23
Q2 Ch.4 Sec.6 [Symbols]
However, for hold of cylindrical shape, the upper surface of cargo may be
Do we not check alternate full hold in BC-A vessel filled up to upper deck?
evaluated by the requirement of 1.1.1.
•As far as we understand, this is not in line with URS18 and Ch4 Sec.6 [3.3.2] (b)Cargo density is not less than 1.78 t/m3
•Regarding intact condition for BCA. Only rho = 3 is to be checked according
Cargo Mass: The maximum cargo mass in case where the cargo is not loaded
to Ch.4Sec.6 [Symbols] E.g. for ships are set up with cement loading in
up to the upper deck in alternate loading condition at maximum draught.
alternate condition, at least two conditions should be calculated as they are
Cargo density: According to the loading manual
decisive for different elements. Cond 1: M = MHD +10%MH with density, rho= Upper surface of cargo: The upper surface of cargo can be obtained by the3 ReposeAngle=35 deg. Cond 2: M = MHD +10%MH with density, rho= 1.25 formula specified in 1.1.2.
ReposeAngle=25 deg.
Please consider revising.

Question/CI

Attachment

Answer

Q3: Ch. 4 Sec.6 [1]Equivalent cargo filling height hc is calculated according to Ch.4 Sec.6 [1.1.1]
when the cargo hold is loaded "up to the top of hatch coaming". This does notcorrespond to the load scenario in [3.3.2] as mentioned above "to fill that hold"up to the upper deck level at centerline". The same applies for the fillingheight as defined in the last sentence in [1.1.2]. Please clarify.

(2)Alternate loading condition(a)Cargo density is less than 1.78 t/m3
Cargo Mass: The maximum cargo mass in case where the cargo is loaded up
to the upper deck in alternate loading condition at maximum draught.
Cargo density: According to loading manual
Upper surface of cargo: Upper deck level at center line of cargo hold.
Q4: Ch. 4 Sec.6 [1]However, for hold of cylindrical shape, the upper surface of cargo may be
According to Ch.4 Sec.6 [3.3.3], the load scenario with cargo density 1.78 t/m3
evaluated by the requirement of 1.1.1.
at flooding level of 0.9D1 can be a dimensioning load case for bending(b)Cargo density is not less than 1.78 t/m3
capacity of vertical corrugation in flooded condition. In this load scenario,
Cargo Mass: The maximum cargo mass in case where the cargo is not loadedcargo hold is normally not loaded up to the upper deck.
up to the upper deck in alternate loading condition at maximum draught.
How to calculate hc according to Ch.4 Sec.6 [1.1.2] when the cargo hold
Cargo density: According to the loading manual(alternate full hold in BC-A vessel) is not filled up to upper deck. Cargo surface
Upper surface of cargo: The upper surface of cargo can be obtained by theis close to upper deck touching the topside tank sloping bottom. This is notformula specified in 1.1.2.
assumed in the formula as illustrated in Figure 4.6.2. Please clarify.

A2 The 2nd sentence in Ch.4 Sec.6 [3.3.2] reads:"The most severe
combinations of cargo induced loads and flooding loads are to be used for the
check of the scantlings of each bulkhead .....". Accordingly if the cement
loading in alternate loading should be the severest, transverse verticallycorrugated watertight bulkheads needs to be checked in such condition.
Therefore there is no need to change the current rules.
(Continues to the next page)

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Ref.

4/6.3.3.2,
Symbol4.6, 4/6.1

Type

CI

Topic

Pressure

Datecompleted

Question/CI

2007/10/23 (Refer to the former page)Attachment

Answer(Continuation of the former page)A3 The filling height specified in the requirement of 1.1.1 of Ch 4 Sec 6 isbased on the experiments and their findings to evaluate the cargo load underintact condition. Hence, it is different from the load scenario for flooded
condition which the permeability should be considered in addition to the cargo
filling height. But in order to estimate the cargo filling height for non-cylindricalshape by ample and easy procedure, the last sentence of 1.1.2 can be accept
the same procedure on cargo filling height under flooded condition.
A4 When the cargo is not loaded up to the upper deck but close to upper decktouching the topside tank sloping plate, the cargo filling height can be obtainedby the requirement of 1.1.2 neglecting the topside tank.

408

6/1.2.2.1

Question

scantling
determination

2007/3/12

In the determination of the minimum net thickness of side shell plating inparagraph [2.2.1] of Chapter 6, Section 1, which draught is to be used in theformula ? The moulded draught or the scantling draught ?

Since the moulded draught can change during the ship's life, the draught to be
used in the formula is the scantling draught.

409

6/1.2.2.1

Question

formula2007/3/2

In the determination of the minimum net thickness of side shell plating inparagraph (2.2.1) of chapter 6, section 1, can you recdefine more clearly theextent of side shell where the formula is to be applied.

The formula is to be applied from the minimum design lowest ballast waterline
amidships to 0.25 Ts (minimum 2.2m) above Ts.

410
attc

1/1.1.2

Question

Lime Stone
Ship

2007/3/15

Is CSR/Bulker applied to the attached self-unloading lime stone ship ?

No, the CSR is not applicable to the concerned design of the self-unloading
lime stone ship.

2007/6/12

Handling of horizontal moment induced by P1-Loadcase: Loading conditions
with load case P1 create horizontal bending moments, which increases from
"0" at one model side to a maximum value at the other side. We adjust thesehorizontal bending moments with counter shear forces and bending moments
at the model ends analog to the horizontal bending moment in the R1 loadcase. The target value for the horizontal bending moment in P1 load case is"0" at mid of cargo hold model.Please confirm.

2007/10/8

Ch.9 Sec. 3 [7.2] Table 2
The requirement for net sectional area of bedplates is significantly exceeding
current designs, in some cases by more than 50%.
The requirement for a typical Handymax vessel with current design has
P=9500kW, nr = 130, LE=8.5m
The required bedplate net area is 640cm2. Current design is about 430cm2,
which is a nearly 50% increase.

411

413

7/2.2.5

Table
9.3.2 &
9/3.7.2

QuestionCI

Horizontal
Bending
MomentNet Sectional
area ofbedplates

We confirm that the target value for the horizontal bending moment in P1 loadcase is “0” at the mid of cargo hold model.

It was not intended to increase the scantlings compared to current design.
We noted your comment. The following interpretation are prepared and will be
submit it to the Hull Panel for review.
"The net scantlings of the structural elements in way of seatings are to be
determined by the engine manufactures. They are to be checked on the basisof calculation result supplied by the engine manufacturers. If thesecalculations are not supplied, the net scantlings of the structural elements in
way of the internal combustion engine seatings are to be obtained from theformulae in Table 2."

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414

415

Ref.

3/6.1

3/6.2.2.5

416
3/6.10.5.1
attc& 3/6.5.2.1

Type

CI

CI

CI

Topic

Cargo holdareas

Plating
Thickness

Depth ofStiffener

Datecompleted

Question/CI

2007/7/11

Ch.3Sec.6 [1]The requirements in section [6] are only applicable for the cargo hold area.
Our opinion is that the subsections dealing with general principles, plating,stiffeners and primary supporting members should also apply to otherstructures, as we can not find any corresponding requirements in Ch.9. Pleaseadvise.

2007/4/2

2007/5/14

A change in plating thickness is not to exceed 50% of thicker plate thickness
for load carrying direction.” Please specify whether the requirement is basedon gross or net thickness.

Ch.3Sec.6 [10.5.1] and Ch.3Sec.6 [5.2.1]. The requirement "Depth of stiffeneris to be more than 1/12 of stiffener length”. Case 1: Typical web spacing is(3x800mm) = 2.4meter. A flat bar on longitudinal girder is then required to be
200mm. With a ship length of 200meters, utilizing the interpretation KC#328 ina typical pipe duct (tc=2), the required thickness is (3+0.015x200+2=) 8mm.
That is minimum FB 200x8. Current comparable design is FB150x12. Case 2:
Wash bulkhead in way of ER with a height of 4.5 m. Minimum height ofsupporting stiffeners is 375mm. Current comparable design is HP200x9.

Attachment

Answer
The requirements in Ch.3 Sec.6 are applicable to not only cargo hold area but
also other areas, where the application is appropriate, including the areas
related to Ch.9 in general, as defined in Ch.1 Sec.1 Table.1. Actually somesubsections in Ch.3 Sec.6 specify the requirements to the structures outsideof cargo hold area.
However where the requirements in Ch.9 should contradict those in Ch.3
Sec.6 the former should govern.

In this case, Plating thickness means the as-built thickness of plating. We willconsider the Editorial Change.

A1. The requirement of 5.2.1 has been based on the modified one of thecurrent classification rules, taking into account the net scantling concept. Thisrequirement is provided to ensure the appropriate scantling and rigidity of web
stiffener for the purpose of avoiding the buckling of web plate of primary
supporting member based on the experiences.
Y

Please refer to the attached documents for the background of the requirement
Q1: Please explain background of these requirements.
of 5.2.1 of Ch 3 Sec 5.
Q2: With reference to Case1. The minimum required scantling is high andslender. Compared to current design the cross sectional area is smaller,
A2 and A3: Such stiffeners as described in the question are to be considered(200x8 = )16cm2 vs. (150x12=) 18cm2. The slender profile will be more prone
as ordinary stiffeners, with application of the full requirements of Ch 6, Sec 2.
to tripping . It is also outside the slenderness requirement for ordinary
stiffeners listed in Ch. 6 Sec. 2 [2.3.1]. We consider the original scantling to bea better choice. Please advise.

Q3: With reference to Case 2. The dimensions required for the wash bulkhead
stiffeners will be larger than for a comparable water tight bulkhead. This does
not seem reasonable.

417

Ch 3 Sec
6/ 10.5.1

CI

Bulkhead
Stiffener

2007/5/14

Yes, the same interpretation specified in KC 328 can be applied to [10.5.1].
This interpretation is the following one:
It is agreed that the requirement asking that "the net thickness of bulkhead
The requirement “The net thickness of bulkhead stiffener is not to be less thanstiffener is not to be less than the minimum net thickness required for thethe minimum thickness required for the considered bulkhead plate” . Withconsidered bulkhead plate" seems quite severe.
reference to KC #328 approved 22/01/07 regarding web stiffeners on primary
The interpretation is that "the net thickness of bulkhead stiffener is not to besupporting members. Can the same interpretation be applied to [10.5.1]?
less than the minimum net thickness defined in Ch 6, Sec 2, [2.2.1]", i.e. theminimum thickness of ordinary stiffeners (3 + 0.015 L2).
We will consider the Rule Change according to our interpretation.

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6/2.4.1.2

CI

Net Sectional
Modulus ofweb
Stiffeners

419

Ch.6
Sec.2

Question

Ordinary
Stiffiners422

3/5.1.2.2

CI

MeasurementsDatecompleted

Question/CI

Attachment

Answer

2007/1/14

Ch.6 Sec.2 [4.1.2] Net sectional modulus of web stiffeners of primary
supporting members.
Should the net sectional modulus be calculated with or without attachedplating? If the answer is "with the attached plate", then what is the effective
width to be considered?
Please consider clarifying the section.

The net section modulus of web stiffener of non-watertight primary supporting
member should be calculated without the attached plating.

2007/4/25

What is the definition of “ordinary stiffener”?
Are web stiffeners of primary supporting members to be considered “ordinary
stiffener”?

Web stiffeners of primary supporting members are not to be considered as"ordinary stiffeners".

2007/3/7

What is the interpretation of whether under CSR the ballast tanks and the
double side skin spaves of bulk carriers is for length of 150m and upwards.
CSR say".. For ships contracted the coating of internal spaces subject to theamended SOLAS regulations are to satisfy the requirements of the IMO
performance standard". this would indicate that this is applicable to 150 L for
both the ballast tanks and the double side skin spaces of bulk carrier; although
the CSR for bulk carriers si for 90m and upwards

IMO PSPC is applicable for all ballast tanks of new ships of 500gt above anddouble side skin spaces of new bulk carriers of 150m above. CSR BC makes
IMO PSPC effective for CSR bulk carriers contacted for construction on andafter 8 Dec 06. Therefore, under CSR BC, IMO PSPC is applicable for all
ballast tanks of bulk carriers of 90m above and double side skin space of bulk
carriers of 150m above. If double side skin space is of ballast tank, PSPC isapplicable for such space of bulk carriers of 90m above. If double side skinspace is of void space, PSPC is applicable to such space of bulk carriers of
150m above.

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No.

424

Ref.

3/6.10.4.2,
3/6.10.4.4&
3/6.10.4.8

Type

CI

Topic

definition ofcorrugation
span “l”:

Datecompleted2007/3/9

Question/CI

Attachment

Answer[Q1] “Note” in IACS UR S18 Figure 2b indicates the following restrictions forthe definition of corrugation span “l”:
“For the definition of l, the internal end of the upper stool is not to be taken
The intent of these requirement is the same as IACS UR S18. Namely,for the
more than a distance from the deck at the centre line equal to:definition of lc, the lower end of the upper stool is not to be taken more than a- 3 times the depth of corrugation, in general
distance from the deck at the center line equal to:- 2 times the depth of corrugation, for rectangular stool “- 3 times the depth of corrugation, for non-rectangular stool
Instead, neither CSR for BC Ch.3 Sec.6 /10.4.4 nor Figure 29 has such
- 2 times the depth of corrugation, for rectangular stool.
restrictions. If the intent of CSR is the same as IACS UR S18, such restrictions[A2]Same reply as in [A1].
should be clearly indicated in the Rules.
[A3] Option 1 should be used for calculation "lc".
[Q2] On the other hand, CSR for BC Ch.3 Sec.6 /10.4.4 indicates “For the[A4] "0.3lc" should be measured from the upper end of corrugation span "lc".
definition of lc, the height of the upper and lower stools may not be taken
Also Included in Corrigenda 5
smaller than the values specified in [10.4.7] and [10.4.8]”.
This is just the opposite from IACS UR S18. Presume that this sentence
should read “For the definition of lc, the height of the upper and lower stools
may not be taken GREATER than the values specified in [10.4.7] and[10.4.8]”. Please confirm.
[Q3] If the restrictions in [Q1] are applicable to CSR, please further advise on
the relation 'between the upper stool width at top and maximum 'effective
depth for the calculation of corrugation span “lc”.
CSR Ch.3 Sec.6/10.4.8 indicates “The stool top of non-rectangular stools is tohave a width not less than twice the depth of corrugations”. In this connection,in case of a non-rectangular upper stool has a width at top of 1.5d and heightof 3d, where d is the depth of corrugation, how to measure the corrugation
span? There may be two options as follows. Which option (or any other else)
is to be applied?
Option 1: Treat this as a rectangular stool since the width at top is less than2d, and take into account 2d for the calculation of “lc”.
Option 2: Calculate “lc” by linear interpolation between rectangular stool andnon-rectangular stool having a width at top of 2d. In case of this example, 2.5d
is used for the calculation of “lc”.
[Q4] CSR Ch.3 Sec.6 /10.4.2 indicates that the thickness of the middle part ofcorrugations is to be maintained for a distance from the deck (if no upper stool
is fitted) or the bottom of the upper stool not greater than 0.3lc. In case “lc” isadjusted by [Q1], is “0.3lc” to be measured from the upper end of corrugation
span “lc” or may be measured from the actual upper stool bottom? Pleaseadvise.

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KCID
No.

Ref.

Type

Topic

Date
completed

Question/CI

Attachment

AnswerPlease see enclosed document "Ch6. Sec. 1 [2.7.3] Steel coil loading on
hopper plate.doc" regarding steel coil loading on inner side/hopper plate.

425 6/1.2.7.3 &2.2.5.3
attc

CI

Steel coilloading

2009/10/6

Q1: Please comment on enclosed document regarding acceleration
formulation for steel coil on hopper sloping/inner side. Please note that thehopper normal acceleration calculated directly based on the fundamental
accelerations is smaller than the rule accelerations. Dependent on the termsin(alpha-theta2) , the roll acceleration will work towards the gravity
acceleration. Please note that the acceleration is sensitive to the definition of
COG. The procedure to define COG should be clearly defined in the rules.
With reference to IACS KC #380 please consider above acceleration
calculations.

Your comment has been noted and this issue has been addressed in RCN
No.1-3 to the July 2008 Rules.

Y

Q2: DNV have noted that the results of eq. [2.7.3] give very strict results forthe hopper sloping plate. The thickness of the hopper sloping plate is in manycases in excess of the requirement of the inner bottom. The force on thehopper is larger than the force for the inner bottom. This is caused by the Ck
factor which is 4 for 2 tiers stowage. Could you please give details regarding
the background of this term. According to our steel coil experts the stowage is,even though it is shored, quite flexible. Have there been attempted any test to
account for the amount of force taken by the hopper plating?

426

3/5.1.2.1

CI

428 5/App1.2.2
Question.8
attc

Double side
Skin Space

Formula2007/5/14

2007/4/19

Ref. Ch. 3 Sec. 5 [1.2.1]"All dedicated seawater ballast tanks and void double side skin spaces are tohave an efficient corrosion prevention system (..)" Please advice on below
related questions. Q1:Could you please clarify "double side skin spaces". Is
this only covering cargo hold area or entire ship?
Q2: If a ship is arranged with double side in machinery space enclosing void
spaces, should such spaces have corrosion prevention according to [1.2]? Q3:
If you have a top wing tank that is a fuel oil tank the new Marpol require thatyou add a cofferdam toward the side skin, will this then be considered as a
double side skin space in bulk carriers? Or when you have fuel oil tanks in theengine room that is, for the same reason fitted with a coffrdam towards theside, is this a double side space in bulk carriers?

A1. Chapter 1 Section 1 [1.1.1] of CSR for Bulk Carrier describe “With bulk
carrier ……..and with single or double side skin construction cargo length area…..”. Accordingly, the double side skin spaces specified in Ch 3 Sec 5 [1.2.1]
are covering the cargo hold length spaces.
A2. The double side spaces in machinery space is not necessary to apply tothe requirement of [1.2]A3. Yes, such spaces arranged in cargo length area are considered as a
double side skin spaces but such spaces arranged in spaces other than cargo
length area are not considered as a double side skin spaces.

In Ch 5, App 1, [2.2.8], it could be some interpretation on “l” in the formula
For a more clear application of the formulae of the requirement Ch 5,
giving “sigmaCR5”, and of “s” in the formula giving “betaE”.In order to apply
Appendix 1, [2.2.8], please refer to the file attachement "Draft Answer Ch 5,
such formulae in the right way, it could be useful to specific the exact definition
App 1, [2.2.8].doc". Also Included in Corrigenda 5of the parameters “l” and “s”.
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No.

429

Ref.

3

Type

Question

Topic

Port
ballasting

Datecompleted2009/10/6

Question/CI

Attachment

AnswerCurrently CSR Bulk has no requirement/mention of port use ballasting of
ordinary dry cargo holds which is a common practice of large bulk carriers
typically Capesize. In our opinion, the following items (may not be exhaustive)
should be clarified urgently:
1. In the past, acceptable filling height was determined for the given scantlings
and based on design formula and criteria for ballast tanks. The same
We note your comments and requirements for the treatment of port use
approach may be used in CSR for local plates and stiffeners, hold frames andballast hold will be included in the rules at a future revision.
all internal members, i.e., boundaries of topside and hopper tanks, inner
bottom and bulkhead stools.
2. In an extreme case, the hold in question may have to be filled up to thehatchtop, then we definitely should check the strength of various membersbounding the hold in question unless it is a dedicated heavy ballast hold.
3. How much dynamic load to be considered?

4. For corrugations and primary support members, scantlings have to beverified by a hold FEA with a separate “intact-harbour” load case because
there is no formula for corrugation in intact condition vaide for ships above 150
meters. (Ref. Ch. 6 Sec. 2 [3.2.4])
5. Any requirements against over filling, alarms, etc. if partial filling?
6. Should tank test be required?
7. What should be stated in the Loading Manual?
8. According to Chapter 3, Section 5 [1.4.1], all internal and external surace ofhatch coamings and hatch covers, and all internal surfaces of ballast holds areto have an effictive protective coating.
Is Chapter 3, Section 5 [1.4.1] applicable to port filled ballast holds?
436
attc

1/1.1.1.2

Question

Selfunloadingbulk carrier

2007/4/6

Is the self-unloading bulk carrier, showed in the attached file, NOT a CSR-bulk Your interpretation is right. This self-unloading bulk Carrier is not a CSR-bulk
carrier like the lime stone carrier of question #410?
carrier as defined in Ch 1, Sec 1, 1.1.2.

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No.

439

444

445

446

447

Ref.

Text
2/1.1.1.2

3/6.7.2.1

3/6.10.4.4

3/6.2.3.1

3/6.5.2.1

Type

Question

CI

RCP

Topic

Additional
Bulkheads

Structural
DesignSpan ofcorrugations

Question

Hull Girder
BendingCI

Depth ofStiffener

Datecompleted

Question/CI

2007/6/20

In Chapter 2, section 1.1.1.2 "Additional bulkheads" it is stated that "For ships
not required to comply with subdivision regulations, transverse bulkheads
adequately speced, and not less in number than indicated in Tab 1, are to be
fitted."Would you like to explain "subdivision regulations"?

The Subdivision regulations" is the damage stability required by SOLAS in
Chapter 11-1, Part B-1 and Chapter Xll, regulation 4.
All bulker with CSR notation are required to comply with subdivision
regulations. Consequently, the Table 1 will not enforce on the CSR bulkers.

2007/6/11

In Chapter 3, Section 6, [7.2.1] it is stated that "Where the double side spaceis void, the structural members bounding this space are to be structurally
designed as a water ballast tank according to Ch.6. In such case thecorresponding airpipe is considered as extending 0.76m above the freeboard
deck at side"
Does this requirement apply to both scontling and welding design?.

Yes, this requirement applies both to the scantling and welding designs.

2007/7/11

In Chapter 3, Section 6, [10.4.4]- Span of corrugations", it is stated that "The
span lc of the corrugations is to be taken as the distance shown in Fig 29. For
the definition of lc, the height of the upper and lower stools may not be taken
smaller that the values specified in [10.4.7] and [10.4.8]".
On the basis of UR S18-fig 2b and its note, it seems that the word "smaller"
could be replaced by "greater".

CI

Net
Thickness &Corrugation
Flange

The intent of these requirement is the same as IACS UR S18. Namely,for thedefinition of lc, the lower end of the upper stool is not to be taken more than adistance from the deck at the center line equal to:- 3 times the depth of corrugation, for non-rectangular stool- 2 times the depth of corrugation, for rectangular stool.
The draft Corrigenda for clarification of this requirement will be issued.
Also Included in Corrigenda 5

2007/6/11

According to the answer of question #208 of IACS CSR KC,is the material of
mild steel for the flat bar on the double bottom girders accepted?

It is accepted, provided that the stress level due to hull girder bending in suchflat bar complies with the requirements in Chapter 5, section 1, [3.1.1]

2007/7/11

The last sentence "Depth of stiffener is to be more than 1/12 of stiffenerlength".
What is the definition of "depth of stiffener"?
Does it mean the web height + flange thickness if any?

Answer:In order to be in line woth the Chapter 6,section 2, [2.3] the depth of stiffener
should be considered as only the height of its web.

Would you give me a clear interpretation for CSR BC Rule Ch.3 Sec. 6,
10.4.7.

450
3/6.10.4.7
attc

Attachment

Answer

2007/5/14

The quoted para. is as below. "The net thickness and material of the stool top
plate are to be not less than those required for the bulkhead plating above.
The thickness and material properties of the upper portion of vertical or
sloping stool side plating within the depth equal to the corrugation flange widthfrom the stool top are to be not less than the required flange plate thickness
and material to meet the bulkhead stiffness requirement at the lower end of
the corrugation." My interpretation is (t_S_TOP)net >= (t_BHD)net and(t_S_SIDE)gross >= (t_BHD)gross. (refer to the attached picture) It is because
lower stool side plate has lower corrosion addition that transverse BHD plate.
Do I interpret correctly?

First, all the requirement (coming from UR S18.4.1) should be given in net
thickness. Secondly, the word "flange" in the text means "flange of thecorrugation of the transverse bulkhead".
Consequently, the text should be modified as:"The net thickness and material of the stool top plate are to be not less thanthose required for the bulkhead plating above. The net thickness and material
properties of the upper portion of vertical or sloping stool side plating within
the depth equal to the corrugation flange width from the stool top are to be notless than the required corrugation flange net plate thickness and material tomeet the bulkhead stiffness requirement at the lower end of the corrugation."

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452

Ref.

Table
8.1.1 &
8/1.1.3.1

Type

RCP

Topic

fatiguestrengthassessment

Datecompleted2009/10/6

Question/CI

Attachment

Answer

It is requested from interpretation point of view that the members andlocations to be assessed for fatigue strength can be waived with a proviso. It isconsidered unnecessary to assess fatigue strength by FEM analysis for every
We noted your comment and this issue has been addressed in RCN No.3
location in Table 1 in particular any taken as less significant. Fatigue(issued September 2008).
assessment by FEM should be streamlined to be more practical to focus on
critical locations such as lower hopper corners and lower stool connections
with inner bottom considering selective cargo holds.

The matter leads to a rule change proposal. As a result of our detailed fatigue
strength calculation based on simplified method for lower hopper corners andlower stool connections with inner bottom of a panamax bulk carrier, it is foundthat the fatigue life of these locations is impractically too short. Moreover, it isfound that the fatigue life calculated for lower hopper corners in the empty holdis shorter than that in the ballast hold in both cases of bent and welded
corners, which is in serious contradiction of the ubiquitous fact of experience.
The least fatigue life calculated is only a few years at a lower stool connectionin the ore hold for which no way of designing to achieve the prescriptive
fatigue life of 25 years could be possible.

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453
attc

Ref.

Ch.5
Sec.1

Type

Question

Topic

Shearforce
correction

Datecompleted

Question/CI

Answer

2007/6/12

According to a draft reply to KC #353, hull girder shear force correction is only
considered at bulkheads where adjacent holds are in non-homogeneous
loading. In our opinion, this is valid when permissible limits Qp is establishedaccording to [5.1.3] considering shear force correction Delta-Qc. Q1: In our
opinion, such shear force correction should only be considered to thepermissible limit giving the same sign to actual shear force at that bulkhead
position and the permissible limit of opposite sign need not be corrected.
Please confirm. Q2: For the determination of the required scantlings according
to [2.2.2], however, shear force correction Delta-Qc should in principle beconsidered at every bulkhead for non-homogeneous loading conditions. As
explained last time, hull girder shear force will increase after shear force
correction, in case of heavy ballast conditions, at the aft bulkhead of the holdaft of the heavy ballast hold thereby requiring larger scantlings. See Point-A in
the attached figure. Same issue at the forward bulkhead of the hold forward of
the heavy ballast hold.

A1:The understanding is correct.
A2:Shear force correction is to be considered only at the bulkhead where
adjacent holds are in non-homogeneous loading condition. Therefore shear
force correction should not be done at other transverse bulkheads than thoseof No.4 ballast hold. In that case, shear force correction in point A is not
relevant.

Attachment

In our opinion, this reflects physics behind shear force correction. In case of alarge Capesize bulk carrier, this effect is not negligible giving impact on therequired scantligs. Please confirm.

454

Ch11/
Sec.2
Table 1CI

Adjustments
to the weld
length due tocorrosion

2007/5/1

As you mentioned, no adjustments to the weld length due to corrosion should
be made to plates with tc=4mm.
According to the proposed Background document for CSR Bulk, no
Until the rule change proposal is adopted by IACS, the interpretation of theadjustments to the weld length due to corrosion should be made to plates with note 2 in Table 1 is as follows.
tC = 4mm. This is not in line with note 2 in Table 1, which specifies that for+1.0mm for tc>5
tC=4 the leg length is to be increased by 0.5mm. Please explain.
+0.5mm for 5=>tc>4
0 for 4=>tc>3-0.5mm for 3=>tc

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456

Ref.

4/6.2.2.1

Type

CI

Topic

Ballast waterexchangeDatecompleted2007/7/13

Question/CI

It is considered literal that Ch.4, Sec.6-2.2.1 ruling out the inertial pressure isframed on the assumption that a ballast water exchange by means of flowthrough method is carried out in calm sea and dynamic pressure (inertialpressure) is ignored. In that case, the following interpretations to be clarified
arise when calculating lateral pressures due to liquid.
(1) External pressure
When considering external (sea) and internal (ballast water) pressuressimultaneously according to Ch.6, Sec.1-1.3.1, it should be possible that theexternal dynamic pressure (hydrodynamic pressure) is similarly ignored bothfor prescriptive Rule calculations and Direct Strength Assessment (DSA).
(2) Wave bending moment
It should be possible that vertical and horizontal bending moments are ignored
both for prescriptive Rule calculations (e.g. Ch.6, Sec.1-3.1.5) and DSA.
(3) Question ID:226
Should the above interpretations be the case, it is considered necessary that
the Q&A ID:226 about DSA as quoted below is reviewed.
*****QUOTE*****
Question ID: 226 Approved: 12/01/07
Rule Ref.: Text 4/6.2.1.2
Question:
When checking the condition under the ballast water exchange operation bymeans of the flow through method, static pressure for direct strength analysis
is specified in Ch 4, Sec 6, 2.1.2, but there is no description of dynamic
pressure.
1. Should the loading cases and wave conditions under consideration comply
with the requirements of Ch 4, App 2?
2. The inertial pressure due to ballast is not to be considered according to therequirement in Ch 4, Sec 6, 2.2.1. Does this mean that only static pressure
due to ballast defined in Ch 4, Sec 6, 2.1.2 and external pressure defined in
Ch 4, Sec 5 are to be considered for direct strength analysis?
Answer:1. There is no need to comply with the requirements of Ch4App2. In theloading case specified in the loading manual with regard to ballast exchange,
the static load is considered for direct strength analysis.
2. Yes, the dynamic external pressure should be considered for direct strength
analysis. Where the ballast water exchange is carried out on the flow throughmethod, the direct strength analysis will be separately required on the ballast
water exchange condition in additional sea going ballast loading condition,
taking into account all EDWs.
*****UNQUOTE*****

Attachment

AnswerUnless the external dynamic pressure and hull girder wave moment areconsidered for local scantling check and DSA as you mentioned, all scantlingsof hull structure are not determined in such load conditions. Then, we madethe answer specified in KC 226.
On the other hand, in tanker CSR, all dynamic loads are considered based on
the assumption that a ballast water exchange by means of flow-throughmethod is carried out in sea going condition.
We think this assumption should be harmonized between tanker CSR andbulker CSR.
Therefore, the interpretation is not necessary and the answer specified in KC
226 is kept as it is, till harmonization work will be done.

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457

Ref.

6/2.3.2.3

5/1.5.1.2,
459 5/1.5.1.3 ,attc 5/1.5.3.2,& 5/1.5.3.3

460

462

6/3, 5/2

Table
10.3.1 &10/3.2.1.1

Type

CI

CI

CI

RCP

Topic

FormulaShear
Stresses &Shear
ForcesOrdinary
Stiffeners &Stiffened
PanelsRule Change

Datecompleted

Question/CI

Attachment

Answer

2007/7/16

According #356 the span "l" in the formula of CH6, Sec3, 3.2.3 has to be
calculated taking the brackets into consideration according CH3, Sec6, 4.2.
In case of a ballast cargo hold frame of a SSS-BC the side frame brackets are For the application of Ch6, Sec2, 3.2.3 in case of a ballast cargo hold frame of
not comparable to the ones shown in Fig. 3 of CH3, Sec6, 4.2.1. The brackets a SSS-BC, the way to consider the brackets is clearly defined in the fourthof a side frame elongate the side frame more than that they shorten it.
sketch of Fig 2 of Ch3, Sec6, 4.2.1.
How should we take the brackets of a side frame in a ballast cargo hold into
consideration?

2007/7/2

Please see the attachment for question containing several figures.
Note that reference is made to KC #353 and to the supplementary questions
KC #453 submitted on 20 April 2007.

In CSR for bulk carriers, they are two different ways of assessing shear
stresses and shear forces:
1 - using direct calculation, as stated in 2.2.1, and in such a case thepermissible still water shear force is obtained through 5.1.2, OR
2 - using simplified calculation with correction of shear force as stated in 2.2.2,
and in such a case permissible still water shear force is obtained throgh 5.1.3.
Both approaches are not to be mixed, and generally the direct calculation
approach is used.

2007/7/13

Ch. 6 Sec. 3 Bucking & ultimate strength of ordinary stiffeners and stiffened
panels.
According to [1.1.2] buckling assessment of longitudinal material is not
required for flooding conditions.
According to URS 17 buckling check is required for flooding condition.
Quote: S17.5 - Strength criteria
The damaged structure is assumed to remain fully effective in resisting the1)Yes. Your assumption is correct.
applied loading.
2)Yes. Your assumption is correct.
Permissible stress and axial stress buckling strength are to be in accordancewith UR S11.Unqoute.
The Ch. 5 Sec. 2 HULS is calculating axial stress buckling of hull girder due toflooding bending moment.
Q1. We assume that CSR fulfils URS17.5 by HULS check of Ch. 5 Sec.2.
Please confirm
Q2. We assume that buckling according to Ch. 6 Sec. 3 need not becalculated in flooding condition as outlined in [1.1.2]. Please confirm.

2007/6/12

In Chapter 10, Section 3 of CSR for bulk carrier para 2.1.1 refers to ships withequipment number EN greater than 16000, however the data range in 'Table
1: Equipment' only covers EN up to a value of 4600. Requirements for vessels
with equipment numbers in the range 4600 to 16000 need to be added to the
The "Corrigenda" will be issued.
tabular information.
This appears to be an editorial omission in the CSR for bulk carriers. The datatables in the LR Rules for Ships, CSR for tankers and the IACS Mooring &Anchoring requirements (UR A) all cover the full data range up to 16000.

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465
attc

Ref.

4/7.2.2.1

Type

Question

Topic

BallastConditions

Datecompleted2007/7/12

Question/CI

Attachment

Answer

According to Background document for CSR BC, Page 26 – Ch 4: Design
Loads, it is said the regulation on ballast tank capacity and disposition is inaccordance with IACS UR S25. IACS URS25: 4.4.1(b) Heavy ballast condition:ii. at least one cargo hold adapted for carriage of water ballast at sea, whererequired or provided, is to be full.
CSR BC, Ch 4, Sec 7:Heavy ballast condition:
Heavy ballast condition is a ballast (no cargo) condition where: at least one
cargo hold adapted for carriage of water ballast at sea is to be full.
My understanding to UR S25 is that cargo hold for water ballast is just an
option or choice, not definitely/mandatorily required by UR S25. But if required In CSR for Bulker, a heavy ballast condition is considered as a ballast
or provided as necessary, then it is to be full in heavy ballast condition.
condition where at least one cargo hold adapted for carriage of water ballast
at sea is full.
If a ship does not have a cargo hold for carriage of water ballast, heavy ballast
condition does not exist in such a ship in CSR for Bulker.
While according to CSR BC, the condition clause "where required or provided"
in UR S25 was deleted in CSR BC, then at least one cargo hold for water
In addition, providing a cargo hold for carriage of water ballast to a ship is notballast should be arranged. Do you think this requirement in UR S25 ismandatory in CSR for Bulker.
consistent with that in CSR BC? As to BC of Double Side Skin Structure, if
ballast tank with enough capacity, should at least one cargo hold also used as Regarding the multi-purpose container vessel, CSR for Bulker does not apply
water ballast tank?
to such a kind of ship.
The attached is the typical section of a ship, normally considered as multipurpose container vessel. In my opinion/understanding, CSR BC does not
apply to such a kind of ship, but shipowner want to have the notation of BC
and CSR. If as required by CSR BC, at least one cargo hold should be as
water ballast. There are double rows of hatches in weather deck, then how to
calculate the internal pressure on weather deck and hatch cover? Can we
calculate the internal pressure on weather deck and hatch cover seperately foreach hatch assuming the central longitudinal box girder as longitudinalbulkhead? It's very difficult to arrange the locking device to resist the upward
force due to internal pressure.

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No.

Ref.

Type

Topic

Date
completed

Question/CI

Attachment

Answer

According to Ch 3 Sec 2 [2.1.1], the scantling of superstructure anddeckhouses specified in Ch 9 Sec 4 is based on the gross scantling concept.
Also, according to Ch 9 Sec 4, [1.2.1], all scantling and dimensions refered toin [4] and [5] are gross. In the requirement of [4.1.1], [4.2.1], [4.5.1] and[5.3.2], the thickness formulae are given as follows.

468

9/4.4.1.1,
4.2.1,
4.5.1 &
5.3.2

CI

Scantlings ofs/structures&
deckhouses

2009/10/6[4.1.1] t=1.21s*(k*pSI)^0.5+tc,[4.2.1] t=1.21s*(k*PD)^0.5+tc,[4.5.1] t=8s*(k)^0.5+tc,[5.3.2] t=0.9s*(kpA)^0.5+tc
Where, tc is defined as corrosion addition defined in Ch 3, Sec 3, specified in"Symbols". To refference to the corrosion addition defiend in Ch 3 Sec 3means that the scantling is based on the net scantling concept. This isinconsistet with the requirement in Ch 3 Sec 2 [2.1.1] and Ch 9 Sec 4 [1.2.1].
According to Technical Background, these formulae are based on the current
GL Rules. In the original formula, tk instead of tc is used and tk is taken equal
to 1.5mm. Please consider revising the text.

470
attc

6/3.3.2.4

QuestionCompression
Stress2008/7/2

What kind of compression stresses have to be used in the buckling check
formulae for the individual compression stresses in 3.2.4 of CH6, Sec3?

As you pointed out, the reference to the corrosion addition, tc, defined in Ch 3
Sec 3 in the formulae is inconsistent with the requirements in Ch 3 Sec 2[2.1.1] and Ch 9 Sec 4 [1.2.1]. These requirements have come from thecurrent GL Rules and there are no intention to modify the scantling approachconcept specified in Ch 9 Sec 4 [1.2.1]. Therefore, the value of tc used inthese formulae is taken equal to 1.5mm as an interpretation, according to thecurrent GL Rules. This has been reflected in RCN 1-7 to the July 2008 Rules.

We will consider the rule change proposal.

Y

Could you confirm that for CSR-BC internal pressure:
1. The total pressure (pcs+pcw) should not be negative471

4/6.1.1.1 &Question
4/6.1.1.2

CSR-BC
internalpressure

2007/7/11

2. For loading condition where the cargo hold is loaded to the upper deck
(Chapter 4, section 6, 1.1.1), for the point above the local height HC,(i) The static pressure PCs is zero(ii) The vertical dynamic pressure az KC aZ (hC + hDB − z) is zero(iii) Therefore PCW =ρC *0.25aY (y − yG )3. For loading condition where the cargo hold is not loaded to the upper deck
(Chapter 4, section 6, 1.1.2) for the point above the local height HC,(i) The static pressure PCS is zero(ii) The dynamic pressure PCW is zero.

A1. Your understanding is correct: the total pressure (pcs+pcw) should not be
negative.
A2. For loading condition where the cargo hold is loaded to the upper deck
(Ch 4, Sec 6, 1.1.1), for the point above the local height HC: the staticpressure and the inertial pressure pCW are equal to zero.
A3. For loading condition where the cargo hold is not loaded to the upper deck
(Ch 4, Sec 6, 1.1.2) for the point above the local height HC, the static pressure
and the inertial pressure pCW are equal to zero.

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473
attc

Ref.

1/1.1.1.2

Type

CI

Topic

Date
completed

Question/CI

Ch.1 Section.1 1.1.2:
Structural
Please see attachment for structural arrangement of bulk carrier in midshiparrangement
hold and hold adjacent to engine room. Please note:of bulk- Vessel has no hopper tank in parallel midship area
carrier in
2007/10/24 - Vessel has a sloped hopper-like shape in bilge area due to hull shape.
midship hold
Hopper shape is extending the entire cargo hold.
and hold
Please advice if the vessel falls within the category "hybrid bulk carrier" asadjacent tostated in 1.1.2. and whether or not CSR is mandatory for this design.
engine room.
Common guidelines urgently needed

Attachment

Answer

According to the clause in Ch.1, Sec.1 [1.1.2], the subject design needs tocomply with the CSR for Bulk Carrier.

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Ref.

Type

Topic

Date
completed

Question/CI

474

Ch.4
App.1

475

6/1.2.3.3

CICI

Determining
the holdmass curves

Net
Thickness of
the Bilge
plating2007/7/2

2007/7/27

Ch. 4 Appendix 1:
1) When determining the hold mass curves according to Appendix 1 weassume that weight of masses concealed in the double bottom in between
margin girders are to be considered both when generating the hold mass
curves and when utilizing them in operation phase. (E.g. Heavy fuel oil, waterballast) Please confirm.
2) Please advise how to handle ship trim both when generating the hold mass
curves and later when utilizing the curves. Please consider a rule clarification.

Ch. 6 Sec. 1 [2.3.3]:
This section requires that the “net thickness of the bilge plating is to be notless than the actual net thicknesses of the adjacent 2 m width bottom or side
plating(..)”
Is this requirement referring to:
1. As built thickness;
2. Thickness required by Ch. 6;
3. All thickness requirements in CSR. (Ch. 7 FEM requiremtns, 9 sec. 1
Strengtheing of bottom forward etc).
Please advise.

Attachment

AnswerA1) CSR regulates to determine the maximum allowable mass and theminimum required mass of the hold mass curve on basis of strength
estimation in Ch4 Sec7, App1 and App2. The maximum allowable mass refers
to the loading mass at the strength estimation in full load condition. Filling ratein the double bottom in full load condition tanks is regulated as follows;a. FOT: Full
b. WBT: Empty
a. Carriage in DBFOT in full loading condition in the strength estimation isassumed full as the most severe situation. The mass in DBFOT is notnecessary to be considered when generating and utilizing the hold mass
curve.
b. Carriage in DBWBT in full loading condition in the strength estimation isassumed empty as the standard loading pattern. If water ballast is carried in
DBT in full loading condition, the strength estimation including such loading
condition should be carried out also. Namely full loading condition with full
DBWBT, should be considered in the strength estimation as the most severe
condition. In such case, the mass in DBWBT is not necessary to beconsidered when generating and utilizing the hold mass curve.
A2)Trim should be taken into account as follows as similar to UR S1A.2.1
requirements:(i)Maximum allowable and minimum required mass of cargo and double
bottom contents of each hold to be as a function of the draught at mid-holdpoistion(ii)Maximum allowable and minimum required mass of cargo and double
bottom contents of any two adjacent holds to be as a function of the mean
draught in way of these holds. This mean draught may be calculated byaveraging the draught of the two mid-hold positions.

This requirement is referring to the net thickness offered of the adjacentbottom and side plating.

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No.

476
attc

Ref.

9/5.1.5.1

Type

CI

Topic

Allowable
stress on
hatch covers

477

9/5.5.2.3

Question

Criticalbuckling
stress478

4/5.3.4.1

CI

Minimum
Lateralpressure479

4/5.3.4.1

CI

Definition of
"n"

Date
completed

Question/CI

Answer

Attachment

2007/8/23

Ch. 9 Sec. 5 1.5.1. Allowable stress on hatch covers:
Reference in the rule text is made to ILLC Reg.15(6) and 16(5).
Regulation 15(6) is relevant for “Hatchways closed by portable covers andsecured weathertight by tarpaulins and battening devices”. The allowablestress for pontoon hatch covers given as Sigma_A = 0.68ReH is originatingfrom Reg. 15(6).
Regulation 16(5) is relevant for “Hatchways closed by weathertight covers ofsteel or other equivalent materials. The allowable stress for “weathertighthatch cover” Sigma_A = 0.8 ReH is originating from Reg. 16(5).
It is our interpretation that 15(6) is not relevant for modern bulk carriers. UR
S21 and UI LL70 are both covering Reg. 16 and relevant for pontoon hatch
covers. We assume that Pontoon hatch covers in modern bulk carriers shouldbe treated as “weathertight hatch covers” with allowable stress Sigma_A =0.8ReH. This is not clear as Table 2 is written in the current rules.

The Common Interpretation is as follows:- If hatch covers are considered weathertight by construction, and without
the need of tarpaulins and battening devices, the allowable stresses to be
used are those corresponding to the line "Weathertight hatch cover" in the
Tab 2, i.e. 0.8ReH for sigma. This is in line with ILLC Reg.16(5).
- If hatch covers are considered weathertight by using tarpaulins and battening
devices, the allowable stresses to be used are those corresponding to the line
"Pontoon hatch cover" in the Tab 2, i.e. 0.68ReH for sigma. This is in line withILLC Reg.15(6).

Y

2007/10/4

Ch. 9 Sec. 5 5.2.3 Critical buckling stress check. Last sentence of therequirement states: “In addition, the bi-axial compression stress in the hatch
cover plating, when calculated by means of finite element analysis, is tocomply with the requirements in Ch.6 Sec.3” We assume the sentence
originates from UR S21 3.6. In case of FEM analysis, please advise if biaxial
buckling in accordance with requirement of Ch. 6 Sec. 3 is additional orinstead of the uniaxial buckling requirement in 5.2.3.

The Common Interpretation is as follows:- If no finite element analysis is performed for the buckling of the hatch coverplating, only the criteria for buckling for uniaxial compression is to be checked.
- If a finite element analysis is performed for the buckling of the hatch coverplating, criteria for buckling for bi-axial compression are to be checked.

2007/8/3

In Table 9, Minimum lateral pressure, P_Amin, is defined for the 4th tier with
P_Amin=2.5kN/m. In the GL-Rules this minimum pressure has a value of
12.5kN/m. Is this a typo?

This is a typo. The correct minimum pressure for the 4th tier and above is
12.5kN/m2.
Also Included in Corrigenda 5

Please explain in the definition of "n", what is the actual distance?

This is a typo. The complete sentence reads as follows:"However, where the actual distance (D-T) exceeds the minimum noncorrected tabular freeboard according to ILLC as amended by at least one
standard superstructure height as defined in Ch 1, Sec 4, [3.18.1], this tiermay be defined as the 2nd tier and the tier above as the 3rd tier." Thisdefinition based on the definition, given in IACS UR S3.
Also Included in Corrigenda 5

2007/8/23

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483
attc

484

485
attc

486

Ref.

Table
6.3.3

7/2.3.3

Table
4.4.3

Ch 4 Sec
7

Type

Topic

RCP

Buckling andreduction
factors forcurved plate
panelsBuckling andUltimate
Questionstrengthassessment

CI

CI

Load
combination
factorLoading
conditions

Datecompleted

Question/CI

2007/8/28

Regarding the buckling and reduction factors for curved plate panels in Ch 6,
Sec 3, Table 3, there is a partition line in the first column between bucklingload cases 1a and 1b. However, in the original GL rules, there is no such line,
see attached. This partition line is likely to cause incorrect values of Sigma x,
hence should be deleted.

2007/7/2

Regarding buckling and ultimate strength assessment in a global strength
analysis, an increase in thickness of each panel satisfying requirements will beobtained by iteration. As there is no clear process in the current rules, it is
CSR only requires that the results of DSA are to comply with the strength
considered appropriate that the stress may be used as it is with no reductions
criteria in Chapter 7. There is no need to specify the iteration procedure toassociated with thickness ratios in each iteration step. Is this correct?
confirm the reinforcement of structure in CSR because it is considered that the
If not correct, some known approches are considered available, for example,
responsibility of reinforcement of structure which does not comply with the(i) all component stresses are reduced with thickness ratios,
strength criteria is up to designers not classification societies. Classification(ii) the same as (i) but stresses in the global X direction are not reduced,
society only confirms that the results of DSA carried out for the given(iii) only the stress due to local loads is reduced with thickness ratios and thescantlings of structure comply with the strength criteria specified in the Rules.
stress due to hull girder loads is not reduced.
Please advise a common process to apply proper stresses for required
thickness calclations.

2007/7/16“Load combination factors, LCF in Ch 4, Sec 4, Table 3, in the case that theencounter wave comes from the starboard side are left unspecified thus there
is a possibility of unnecessary confusion unless they are clarified, especiallyfor ships having unsymmetrical hull sections. Pease see the attachment andconfirm if the signs marked in red from what we understand are correct. If not,please supply correct signs together with technical backgrounds.”

2007/8/7

The loading conditions which are required by Ch.4 Sec 7 are only for checking
the longitudinal strength, direct strength analysis and for capacity anddisposition of ballast tanks and stability purposes as mentioned in 1.2.4.
Therefore, these loading conditions will not included the loading manual but
shall be just submitted for assessment of structure-wise.
Above conditions will not be applied to hold flooding calculation andintermediate condition calculation.
Our understanding is that the loading condition required Ch.4 Sec 7 and Sec 8
have different concept.
So when we check the hull structure strength, loading conditions required by
sec 7 should be necessary. And then the loading conditions should be
prepared in loading manual within permissible limit which is result of hullscantling

Attachment

AnswerYes. This is typo.
Y

We will issue the "corrigenda" soon.
Also Included in Corrigenda 5

When the starboard is the weather side, the reference hull girder loads andmotions of ship and load combination factor are shown in the attached file.

1 - The loading conditions which are required by Ch 4, Sec 7 are "artificial
loading conditions" considered for the check of strength.
2 - Regarding flooding conditions, our interpretation is that they should have to
be considered only for loading conditions defined in Ch 4, Sec 8, as they arereally navigation conditions.
3 - Regarding intermediate conditions required in Ch 4, Sec 3, [2.1.1], if
considered more severe, they are to be considered for loading conditions
defined in Ch 4, Sec 7 and Sec 8.
" This answer is superseded by the anwswer to KC ID 622. Please refer
to KC ID 622"

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Ref.

Type

Topic

Date
completed489

4/6.1.3.1,
4/6.2.2.1,
4/5

CIInertial
Pressures2007/8/2

490

Symbol
4.6

CI

DesignDensity forfuel oil2007/7/13

491

4/7.2.1.1

CI

Deterninationof themaximumcargo massin cargoholds

2007/7/2

Question/CI

Attachment

AnswerInertial pressures Chapter. 4 Section 6
Reference is made to Ch. 4Section. 6 [1.3.1] “Inertial pressure due to bulk
cargo” and [2.2.1] “Inertial pressure due to liquid”. Both items have astatement that the longitudinal term may be “freezed” in x direction at two
points in the tank. According to [1.3.1] “ (x-xg) is to be taken at 0.25lH in theload case H1 or -0.25lH in the load case H2..(..)” Pressures from these twopoints may be utilized for local scantling according to Ch.6 and Ch.8.
Q1: Please advise if this statement is valid also for scantling of transverse tankboundaries such as cargo hold bulkheads and plane bulkheads separating
A1: This requirement is also valid for scantling of tank boundaries.
BW tanks according to relevant requirements of Ch.6.
A2: According to the Rule, “a” is correct.
Q2: According to Ch. 6 Sec.1 [1.3.1] and Sec.2 [1.3.1] “(..) If the compartment
adjacent to the outer shell is intended to carry liquids, this still water and wave
internal pressures are to be reduced from the corresponding still water andwave external sea pressures.” When the internal pressure is constant in xdirection according to Ch. 4 Sec. 6 [2.2.1] what is the correct application of
Ch.6 Sec. 1 [1.3.1] and Sec.2 [1.3.1]? Note. Ch. 4 Sec. 5 “External pressures”
have no statement fixing the x location.

a.Combine the internal pressure according to Ch. 4 Sec. 6 [2.2.1] with the sea
pressure at the x location considered

CSR for bulk carrier does not specify the minimum design density for fuel oil.
The design density for fuel oil shall be determined by the designer or
shipbuilder with agreement of the owner.

b.Combine the internal pressure according to Ch. 4 Sec.6 [2.2.1] with the sea
pressures located at (x-xB) = 0.75 (H2) and -0.75 (H2) ?

According to the provision of [2.1.1] maximum cargo mass Mh or Mhd should
be obtained from loading conditions at full scantling draft and with 50%
consumables.
In general the maximum cargo mass (Mh) for an empty hold (Mh) corresponds
to the cargo mass in homogeneous full condition at scantling draft and with
50% consumables. Hence Mhd corresponds to the cargo mass in alternate
loading condition at scantling draft and with 50% consumables. Mfull is an
artificial cargo mass and the maximum permissible cargo mass for an empty
cargo hold in connection with the determination of hold mass curve.

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492

493
attc

Ref.

4/7.2.1.4

6/2.4.1.1

Type

Question

CI

Topic

Loading
conditions

Correct
application of
the formulawith respect
to pressure
on ordinary
stiffeners.

Datecompleted

Question/CI

Answer

2007/7/13

Ch. 4 Section 7 2.1.4 BC-A
Please consider following example.
1.BC-A vessel with minimum loading conditions as per Section Which comply
with both [2.1.1] and [2.1.4].
2.Additionally, vessel's loading manual has a short voyage alternate condition
with more severe filling than prescribed by minimum conditions as defined by
the item 1 above.
For strength verification of 2), should same rate of filling and cargo density as
per [2.1.4] be required for such short voyage condition?

Sea going condition and harbour condition are specified in CSR.
A short voyage condition is not specified in CSR but it is obvious that it is not a
harbour condition.
Therefore, where a short voyage alternate loading condition with more severe
filling than the minimum loading condition in [2.1.1] and [2.1.4] is specified in
the loading manual, strength check for such more severe loading condition
should be carried out in accordance with the CSR requirements.

2008/1/9

Attachment

A1. The requirement of Ch 6 Sec 4 [4.1.1] is provided for checking thescantling web stiffener and web connection with ordinary stiffener.
Therefore, the checking formula is provided as a function of the pressure
acting on the ordinary stiffener with coefficient depending on the web
connection with ordinary stiffener.
In case of web stiffener attached to floor in double bottom which is used forwater ballast, the pressure p is to be calculated as follows:
A: Web stiffener and the web connection with the bottom longitudinal:
The considered pressure is the greater of:Ref. Ch. 6 Sec. 2 [4.1.1](1) Pressure acting on bottom longitudinal due to external sea water in full
Q1: Please advice what is the correct application of the formula with respect to load condition, orpressure on ordinary stiffeners:(2) Pressures acting on bottom longitudinal due to internal pressure due toa.External and internal pressures are to be considered separately.
ballast water in double bottom tank and external sea water in ballast condition,b.Combined effect of pressures to be considered.
in line with Ch 6 Sec 2, 1.3.1
In case of b.) please advice how to combine pressures(see attached drawing)
B: Web stiffener and web connection with the inner bottom longitudinal:
Q2: We assume correct interpretation of “Web stiffener mid height” is “WebThe considered pressure is the greatest of:stiffener mid length” . Please advise..
(1) Pressures acting on inner bottom longitudinal due to bulk cargo in full loadcondition, or(2) Pressures acting on inner bottom longitudinal due to ballast water in ballast
condition, or(3) Pressure acting on inner bottom longitudinal due to ballast water in ballast
hold, if applicable, in heavy ballast condition.
The required net sectional areas of web stiffener are to be calculated
independently for the foregoing connections A & B.
The final required net sectional area of the web stiffener is the greater the
calculated areas for A & B.
A2: “Web stiffener mid height” means “Web stiffener mid length”.

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Type

Topic

Date
completed

Question/CI

Attachment

Answer

Ref. Ch. 9 Sec. 1 ”Fore Part” Table 9.1.1 and Ch. 9 Sec. 2 “ Aft Part” Table
9.2.1.
Q1: Tables 9.1.1 and 9.2.1 are referring to “Platform”. It is assumed that this isa non-watertight horizontal member. Please confirm.
494

495

497
attc

Table
9.1.1 &
Table
9.2.1

9/1.3 &
9/2.2

6/1.1.5

CI

Fore part &Aft part

CI

Fore part &Aft part load
model

Question

Pressure
point forscantlingcheck ofcorrugationweb

2007/9/13

2007/9/28

2007/10/9

A1:Platform referred in tables 9.1.1 and 9.2.1 are effectively non-watertighthorizontal member.
Q2: Tables 9.1.1 and 9.2.1 are extracts of Table 6.1.2. Tables 9.1.1 and 9.2.1
A2:Tables 9.1.1 and 9.2.1 are incomplete with respect to horizontal andare incomplete with respect to horizontal and vertical watertight boundaries.
vertical watertight boundaries, and relevant items of Table 6.1.2 may be used
Please advise if relevant items of Table 6.1.2 may be used for watertight items
for watertight items in fore/aft part.
in fore/aft part. Please consider completing the Tables 9.1.1 and 9.2.1 withwatertight divisions.

Ref. Ch. 9 Sec. 1 ”Fore Part – load model” [3] and Ch. 9 Sec. 2 [3] “Aft Part load model”
Following pressures are explicitly given for calculation:
1.External pressure according to Ch. 4 Sec.5
2.Internal lateral pressure in testing condition according to Ch.4 Sec. 6 [4]Internal pressures due to liquid ps+pw according to Ch. 4 Sec. 6 [2] is not
specified for Fore/Aft regions.
Please advise if Ch. 4 Sec. 6 [2] pressures need to be considered for fore andaft regions or if only testing pressures should be applied.

Where is the pressure point in the attachment to be used for scantling checkof corrugation web ?
Please note that option 1 is inside the gusset/shedder. Therefore, eventually
there is no pressure.

it is quite clear that internal pressures defined in Ch 4, Sec 6, [2] need also to
be considered for fore and aft regions in addition of testing pressures.
Also Included in Corrigenda 5

For the determination of the net thickness of the web plate according to Ch 6,
Sec 1, [3.2.1], the load point for the pressure is taken at the bottom ofcorrugation (e.g., Option 1 in the attached sketch).
The reason is that the effect of shedder and gusset plates is not considered toinsure that the calculation is conservative.

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No.

498
attc

Ref.

3/6.5.7.4

Tanker App
A/2.2.2.3
499& 2.2.2.4;
attc& Bulker- Ch.5, App
1. 2.2.2

9/1.5.4.1 &500
9/1.5.4.2

Type

Question

CI

CI

Topic

Primary
SupportMembers

Hard corners
in the Hull
GirderUltimate
Strength

Loaded area
between the
supports ofthe structure
consideredDatecompleted

Question/CI

Answer

Attachment

2007/8/2[A] Where opening is provided, as per the attachment, in primary supporting
members such as double bottom girders, etc., should Ch.3, Sec.6, [5.7.4] beinterpreted as follows regarding distances between the opening and slot
openings for longitudinals ?
1) at the mid-part within 0.5 times of the span of the primary supporting
members: l <= d1, d2, d3 and d4,2) at the ends of the span, l<=0.25x(d1, d2, d3 and d4).
[B] If Ch.3, Sec.6, [5.7.4] should not be applicable to the distances between
the opening in primary supporting members and the slot openings, isn't there
any restrictions to the distances ?

A) Your understanding is correct. You may see Fig.15 of Ch 3 Sec 6 that theexample without collar plate in cut-outs is shown.
B) According to the 1st sentence of 5.7.5, the reinforcement of such openings
is required.

Y

2007/10/9

The CSR for Oil Tankers and for Bulk Carriers need to have the samedefinition of hard corners in the Hull Girder Ultimate Strength.
The attachment is a proposal for a common interpretation in this respect.
The differences between the Rules in force are:
The hard corners in the hull girder ultimate strength is defined as shown in the
CSR for Oil Tanker:The area on which the value of the buckling stress offigure of the attached file “Fig._KC499.pdf”.
transversely stiffened panels applies is to be taken as the breadth between thehard corners, i.e. excluding the end of the hard corner if any. Refer to KC
CSR for Bulk Carriers: The definition is too vague and needs improvement
through this CI.

Y

In 5.4.1,Girders
A is given by the following formula.
A=S*l
Where,
S: Spacing of center or side girders under consideration, in m.
l: Span of floors under consideration, in m.

2007/9/28

In Ch 9, Sec 1, (5.4.1] and [5.4.2], a parameter A defined as "Loaded area
between the supports of the structure considered" is used in the determinationof the net thickness of girders and floors in flat bottom forward area. The
In 5.4.2, Floors
definition of this parameter is not clear enough and needs interpretation, orA is given by the following formula.
formula to calculate it.
A=S*l
Where,
S: Spacing of floors under consideration, in m.
l: Span of center or side girders under consideration, in m.
Also Included in Corrigenda 5

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501

Ref.

Type

4/7.1.2.4,
4/7.1.2.2, Question& 4/7.2.3.1

Topic

Loading
conditions

Datecompleted2007/8/2

Question/CI

Attachment

Answer

Q1: In Ch.4 Sec.7 [1.2.4], it is stated that "the loading conditions listed in [2]are to be applied for the check of longitudinal strength ----, for capacity anddisposition of ballast tanks and stability purposes". Are these loading
conditions, which satisfy the departure and arrival conditions as stated in
1 - The loading conditions which are required by Ch 4, Sec 7 are "artificial”[2.3.1], intended to fulfil the requirements as stated in Sec.8 [2.2.2] and shallloading conditions" considered for the check of strength.
be included in the vessel's Loading Manual?
Q2: In Ch.4 Sec.7 [1.2.2], it is stated that "these requirements are not intended 2 - Regarding flooding conditions, our interpretation is that they should have toto prevent any other loading conditions to be included in the loading manual --- be considered only for loading conditions defined in Ch 4, Sec 8, as they arereally navigation conditions.
." Does this mean that loading conditions required in Sec.8 [2.2.2] can be
3 - Regarding intermediate conditions required in Ch 4, Sec 3, [2.1.1], ifdifferent from those stated in Sec.7 [2]?
considered more severe, they are to be considered for loading conditions
Q3: According to SOLAS Reg.V/22, navigation bridge visibility is required
defined in Ch 4, Sec 7 and Sec 8.
minimum "two ship lengths or 500 m, whichever is less". Is it required for the
A3: It is not necessary.
design loading conditions as stated in Ch.4 Sec.7 [2], which satisfy thedeparture and arrival conditions as stated in [2.3.1], to fulfil the bridge visibility A4: This requirement is the same of IACS UR S25 [4.5]requirements? We assume that any other loading conditions as stated in Ch.4
Sec.7 [1.2.2] shall satisfy the visibility requirements.
Q4: In connection with the above, please also clarify what is meant by "Unlessother wise specified" as stated in Ch.4 Sec.7 [2.3.1]. Who specifies what andwhere?

502

507

Table
3.1.4

11/2.2.6.1

Steel gradeof lowerbracket, of
Question hold frames,of single side
BCA/BCBbulk carriers

Question

The leglength of thefillet weldThis requirement is applied to web plate of lower bracket only.
2007/8/2

2007/9/28

Steel grade of lower bracket of hold frames of single side BCA/BCB bulk
carriers. Reference is made to Chapter 3 Section 1 Table 4. The requirement
is originating from SOLAS XII/6.5.3. Please advice if the requirement should
be applied to lower bracket web and flange or web plate only.

The leg length of the fillet weld is regulated in Ch11 Sec2, 2.6.1 and thissection stipulates to refer to Table 1.
Bulker CSR has no indication whether rounding treatment is to be applied ornot, even though Tanker CSR has rounding treatment in Sec6/5.7.1.1 of
Tanker CSR.
Please confirm which of the following leg length is to be applied:a. leg length as specified in Table 1;b. rounded leg length as specified in Table 1, nearest half millimetre.

It is considered that this answer is an interpretation but there is no change oftechnical background and no scantling impact.
Therefore, in order to clarify this matter, the corrigenda will be issued.
Also Included in Corrigenda 5

We noted your comments.The draft interpritation will be submitted to Hulll
Panel for their view.
Also Included in Corrigenda 5

For example, if the leg length according to Table 1 is 7.2mm, then the required
leg length would be:- 7.2 mm for a;- 7.0mm for b.

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11/2.2.6.2

RCP

Continuous
fillet welds

510
attc

3/6.7.2.1

Question

Upper andDouble side
Void Space

Question

Midship
section &Sections incargo holds

CI

Definition of
Ship's speed
V

RCP

The correct
formula todeal withdifferent
cargo massin each hold

511
attc

514

1/1.1.1.2

1/4.2.1.1

515
4/A1.3.1.2
attc

516

6/3.1.1.3

Question

elementary
plate panels

Datecompleted

Question/CI

2007/10/9

The CSR of Ch.11,sec.2,2.6.2 is unreasonable considering other category.
Therefore the 2.6.2 might be reconsidered as below:"Where double continuous fillet welds in lieu of intermittent welds are applied,leg length of fillet weld is to be of Category F3."

We noted your comment. We will consider the edditorial correction.
Also Included in Corrigenda 5

2007/8/3

In the attached document is a cross section of a DSS-BC shown, which has avoid space in the area of the top wing tank to separate a FOT from the side
shell. Is this upper part of the void spaces a double side void space according
CH3, Sec6, 7.2.1, which has to be treated like a water ballast tank?

the area dashed in red in the attached document should be designed as awater ballast tank, as specified in the text of Ch 3 Sec 6 7.2.1.

Y

2007/9/25

The midship section and sections in cargo holds other than NO.1(Foremost)cargo holds are as per No.1) Midship in the attached sketches. There are 5
kinds of designs of NO.1 cargo hold as shown in No.2) through No.6) in theattached sketches. Please advise whether the respective designs No.2)
through No.6) need to comply with the CSR requirements.

In case of designs as per the sketches No.3) thru 6) for No.1 cargo holdsection CSR needs not be applied. However CSR needs to be applied for thecase of sketches No.2.

Y

2007/8/28

Ship’s speed, V, is defined in Ch1 Sec4, 2.1.1 as Maximum ahead service
speed, in knots. My understanding is that the definition of V in CSR is same as Yes, your understanding is correct.
the one in 2.1.1 of UR S10, namely maximum service speed (knots) with the
Also Included in Corrigenda 5
ship on summer load waterline. Is my understanding correct?

Attachment

AnswerThe correct formula is as follows.

2007/10/22 Please see the attached file.

Wmax(Ti) = MHD,fore + 0.1*MH,fore + MHD,aft + 0.1*MH,aft
Wmax(Ti) = MFull,fore + MFull,aftYwhichever is the greater, for Ts ≥ Ti ≥ 0.67*Ts in order to deal with possibly
different cargo mass in each hold.

2007/7/26

Regarding to Ch 6 Sec 3/1.1.3, "The boundary condition for elementary plate
panels". We normally consider that cases 3, 4 and 7 to 10 of Table 2 areapplicable where one or two plate edges are supported by solid floors, bottom
girders, non-tight/tight bulkhead plates (bottom/inner bottom plate), side web
frames, side stringers, deck plates, non-tight/tight bulkhead plates (side shell)
and Transv. webs, deck girders, non-tight/tight bulkhead plates (deck plate).
Please advise an example of structures for the application of case 3.4., and 7
to 10 of tables 2 for clarity of the requirement in 1.1.3

BLC3 and BLC 4: These BLCs can be applied for a typical plate field, where
the plate is not continuous at one side. This side may be stiffened with aprofile without flange (e.g. Flat bar) or not stiffened. Structural examples areplate fields located at manholes or plate fields of the hopper transverse web
frame.
BLC7: The edge of an elementary plate panel can only be treated as aclamped edge, when the rotation about its axis is prohibited. Therefore, thisBLC can be applied for in a web buckling check of stiffeners without flanges
which are attached to a very thick plate, e.g. a Flat Bar 400*20 mm attached
to a 50mm thick plate.
BLC8 to BLC 10: These BLCs are mostly theoretical cases included for thesake of completeness of the Table. There is no case to be applicable for an
actual structure.

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Ref.

Type

Topic

Date
completed517

2/1.1.1.2

CI

Number ofwatertightbulkheads

2007/8/20

Question/CI
Number of watertight bulkheads
Minimum number of bulkheads is indicated in Ch2, Sec1, Table 1. Does it
include bulkheads required in 1.1.1 such as collision bulkhead, after peakbulkhead and E/R bulkhead(s)?

Answer

Attachment

Yes, it includes bulkheads required in 1.1.1.

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No.

518

Ref.

6/1.2.5.3

519 Ch5 App1
2.2
attc

Type

Topic

CI

Definition of
the length of"longsuperstructures"CI

Ultimate
Strength by
Incremental iterative

Datecompleted

Question/CI

Answer

2007/8/30

Please advise the definition of the length of "long superstructures" specified in
Ch6 Sec1, 2.5.3 .

Long superstructures are effective superstructures as defined in Ch.9 Sec.4[1.1.5], i.e. located within 0.4L amidships and having a length greater or equal
than 0.15L or 12 m.
Also Included in Corrigenda 5

2008/2/7

Attachment(A1) Where materials of plate and stiffener are different, two calculations arecarried out:
1) for the stiffener: by adding to the stiffener an attached plating of the samematerial as the one of the stiffener, then determine the shortening curve andthe stress σ to be applied to the stiffener.
2) for the attached plating: by adding a stiffener made of the same material as
the one of the attached plating, then determine the shortening curve and thestress σ to be applied to the attached plating.

With regard to calculation procedure for ultimate strength by incrementaliterative approach, please be clarified three questions as follows.
Q1. Shortening curve for a stiffened plate element where material of plate andstiffener are different.
Q2. Shortening curve for an element where thickness of plate are different.
The element can be stiffener or plate.
Q3. Shortening curve for an element where material and thickness of attachedplate are different.
(A2):An average thickness by the area of each considered plate is used for the(Attachment included)
considered element.

Y(A3): An average thickness and yield strength by the area of each considered
plate is used for the considered element.

520 Ch5 App1/
2.1.1.,
attc

521
attc

522

BulkerCh5
App1/2.2

6/2.1.4.2

CI

PlatesStiffener

For plates stiffened by not longitudinally continued stiffeners such as girders in
If the stiffener is not continuous it does not participate to the hull girder
double bottom, how to divide the plate to calculation elements. Should theultimate strength and thus it is not to be taken into account.
2007/10/23 stiffeners be neglected and considered as plate elements?
But it divides the plate into elementary plate panels which are calculated(Attachment included)
independently.

YCI

Length of
Stiffeners

For stiffeners where one side of web are supported by bracket which spaceless than the space of primary supporting members, which is length of this
2007/10/23
element, space of brackets or supporting members?
(Attachment included)

YCI

Pressurecalculation
positions

2007/8/28

The pressure calculation positions would be clearly defined for vertical
stiffeners where spans are corrected according to Ch3 Sec6 4.2.1. Positions
for pU and pL need not to be considered the corrected upper and lower pointsof the span. Or positions for pU and pL should be also corrected 4.2.1.
According to Sec3 5.2.2.3 of Tanker CSR, corrected span need not to beconsidered.

The length of the stiffener is taken as the space of primary supporting
members as it cannot be considered that a bracket on one side of thestiffener’s web is enough to reduce this length.

The pressures pU and pL are to be calculated at the ends of the vertical
stiffener - i.e. without considering any correction of span - as it is stated in thedefinition of pU and pL in Ch 6 Sec 2 [1.4.2] and in accordance with thepractice.

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No.

524

525

Ref.

Ch.9,
Sec.1 & 2

6/4.1.1.1

Type

RCP

RCP

Topic

Scantlings ofFore Part
and Aft Part
structures

Primary
SupportMembers

Datecompleted

Question/CI

2007/9/28

1) The question relates to scantlings of Fore Part and Aft Part structures inflooding condition(Ch.9, S.2, 1.1.2).
It being noted that there is no specific paragraph in Fore Part referring to needof scantling assessments in case the fore part is arranged with floodable
spaces other than the fore peak tank, it is requested that the requirement in
Ch.9, S.2,1.1.2 be incorporated in Fore Part, as well.
2) In Ch.9, S.1 and S.2, there is no requirement of net minimum thickness ofplating for watertight bulkhead, while CSR Tanker Rules specify. It isrequested that net minimum thickness of plating for watertight bulkhead in
Fore Part and Aft Part be specified.

2007/10/2

Regarding Ch.6, Sec.4-1.1.1 (Primary supporting members - Application), theconjunction 'and' in the passage quoted below is equivocal hence it isrequested to change it to 'and/or' to be such that transverse members to bealso applied are cleary referred to.
Quote;'subjected to lateral pressure and hull girder normal stresses’
Unquote;Without the proposed change, there would be a risk of being read that therequirement can be applied only to longitudinal primary supporting members(PSM) such as bottom girders. The requirement, in particular minimum net
thickness of webs of primary supporting members (Ch.6, Sec.4-1.5.1), should
be applied to transverse PSM as well such as transverse web in hopper tank.

Attachment

Answer1) We noticed your advice and will prepare a rule change accordingly.
2) Tables 9.1.1 and 9.2.1 are incomplete with respect to horizontal and verticalwatertight boundaries, and relevant items of Table 6.1.2 may be used forwatertight items in fore/aft part.

The requirements of this Section apply to the strength check of pillars
and primary supporting members,subjected to lateral pressure and/or hull
girder normal stresses for such members contributing to the hull girderlongitudinal strength.
Also Included In Corrigenda 5

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Ref.

529 6/3.4.2.2 &attc 6/3.5.1.1

Type

RCP

Topic

Buckling
requirementforlongitudinalandtransverse
stiffeners

Datecompleted

Question/CI

2008/6/19

Regarding the buckling requirement for longitudinal and transverse stiffeners(6/3.4.2.2, 6/3.5.1.1), it is requested that the Rule sub-paragraphs below are
given editorial review in respect of the comments/questions attached thereto.
If these be found justifiable, a corrigendum would be considered necessary.
1. Nominal lateral load (Pzy) for transverse stiffeners (6/3.4.2.2):
In the equation, sigma_xl should be changed to sigma_x , since the sigma_x
in this case is not axial stress of the transverse stiffeners and hence theattached area will not be necessary.
2. Elastic support provided by the stiffener (cf) for transverse stiffeners:(6/3.4.2.2):
Cs depends upon a degree of fixity at the ends of the stiffener sustaining
lateral pressure and is independent of any elastic support due to in-planestresses working in the attached plate. The Cs should therefore be deleted in
the relevant equation.

Attachment

Answer

A1 - It is agreed that in the equation giving the nominal lateral load (Pzy) for
transverse stiffeners (6/3.4.2.2), sigma_xl should be changed to sigma_x.
A2 The parameter c_s defines the degree of fixation for the transverse
stiffener. In case of a structure as defined in Fig. 1 the transverse stiffener will
collapse between the longitudinal girder and not between the longitudinal
stiffeners. In this case c_s reduces the buckling length of the stiffeneraccording the Euler buckling case (partially restrained).
If it can be assumed that the transverse stiffener will collapse between theordinary longitudinal stiffener c_s =1.
Therefore no modifications of the formulas are necessary.

Y

A3 The effective breadth has to be calculated under the assumption that theneighbouring elementary plate field is buckled under loads, acting parallel tothe stiffener. Therefore the effective plate breadth has to be reduced to the
3. Effective width of attached plating for transverse stiffeners (6/3.5.1.1): The
effective width. The formulae in 4.2.2 are connected to the co-ordinate
effective width of the attached plate is considered part of the stiffener spacesystem, defined in Figure 1. In this figure a transverse ordinary stiffener (n=1)
and depends upon working stress along the stiffener. In this connection,is located on the shorter edge of the elementary plate panel. In case of an
kappa_y in the formula should read kappa_y' which is calculated in Ch. 6, Sec.
ordinary stiffener, located normal to the ship's x-axis, but at the longer side of3, Table 2 as kappa_x in Buckling Load Case 1 with a in place of b. It should
the attached elementary plate field, this stiffener is a LONGITUDINAL stiffener
be noted that kappa_y itself in Buckling Load Case 2 depends upon the stressin terms of buckling! Therefore the formula for p_zx has to be used with theworking normal in the case of application to transversely stiffened stiffeners.
effective with a_m and S_x= transverse stress is ship co-ordinate system. But
this translation has not to be done in the rules text.
Therefore no modifications of the formulas are necessary.

533

534
attc

4/5.4.1.1

3/6.6.1.3

RCP

CI

With regard to the flare angle α, "α" is not defined in this paragraph.
So, please explain how to determine the "α" and add the definition of it.

Flare angle"a"2007/9/19

Position of
the mainpropulsion
machinery

The position where the main propulsion machinery is seated is normallyrecessed from the main double bottom structure in engine room. And thebaseline of this seating can be located at which the height from the baseline isless than required. Please refer to the sketch as an example (Moulded of thisship is 45m).
2007/10/23 In this circumstance, we would like to have your confirmation whether theabove arrangement is acceptable or not for the SOLAS and CSR points ofview.
In addition, we would like to have your general interpretation on the above
regulations such as the extent of exemption, necessity of bottom damage
calculation, etc.

The flare angle alpha at the load calculation point is to be measured in planeof the frame between a vertical line and the tangent to the side shell plating.
Also Included in Corrigenda 5

The minimum height for the double bottom is defined in CH9, Sec3, 2.1.2.
The proposed arrangement with a reduced double bottom height in way of themain engine is acceptable provided the lateral extent is limited to the M/E
breadth and by lateral tight girders for the CSR for bulk carriers view point andprovided the Administration agrees for SOLAS view point.
The rigidity of the engine seating and the surrounding bottom structure must
be adequate to keep the deformations of the system due to the loads
within the permissible limits, given by the engine manufactures. In special
cases, proof of deformations and stresses may be required.

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Ref.

9/5.5.3.2 &9/5.5.4.2

Type

Topic

RCP

Minimum
thickness of
web ofprimary
supporting
member andordinary
stiffeners

Question/CI
1. Ch 9 Sec 5 [5.3.2] and [5.4.2]
We think it is wrong in Ch 9 Sec 5 [5.3.2] and [5.4.2] to link both minimum
thickness of web of primary supporting member and ordinary stiffeners withtnet = 6 mm & tnet = 10s of hatch cover top plate on Ch 9 Sec 5 [5.2.2] in thefollowing reasons.
(1) The minimum net thickness specified in Ch 9 Sec 5 [5.2.2] is required forsteel plating forming the tops of hatch covers by ILLC Reg.16 (5) (c) which isonly applied to the top plate, not to the web of primary supporting members
and ordinary stiffeners.

2007/10/26 (2) If the current ordinary stiffener size L 125*75*7 or stiffener with a U-profile
are satisfied with the strength requirement specified in IACS UR S21, thestiffener spacing is required to be reduced to 450 to 500 from 600 or 700 mm
so that it complies with the minimum net thickness [tnet = 10s] specified in
Ch9 Sec5 [5.2.2]. In addition, the web thickness of such stiffeners is increasedby 1 to 2mm due to the minimum net thickness of 6mm. The stiffener weightof the hatch cover will be increased about 40% compared to the current one
which satisfies the requirements of IACS UR S21. Therefore, we propose torevise the requirement for minimum net thickness requirement for webs ofprimary supporting members and ordinary stiffeners specified in Ch 9 Sec 5[5.3.2] and [5.4.2], respectively.

535

536

Date
completed

9/5.1.4.1

Question

Stiffeners
with a Uprofile

Ch 9 Sec 5 1.4.1 Corrosion additions(1) Box type stiffeners such as stiffeners with a U-profile are used in many
hatch covers. The internal environment in a stiffener with a U-profile is similar
to the one for internal structures of double skin hatch covers.
Therefore, we consider that the total corrosion addition for such stiffeners
should be 1.5mm for single skin hatch covers.
2007/10/26 Please clarify the requirement on the corrosion addition of such stiffeners.
(2) In applying a finite element analysis in order to evaluate the stresses in the
primary supporting members of hatch covers, are FE models considered a full
corrosion addition or a half corrosion addition?
(3) In calculating the net moment of inertia of a primary supporting member,does a full corrosion addition subtract from the gross offered thickness of a
primary supporting member?

Attachment

AnswerIn Ch 9, Sec 5, [5.3.2],the web minimum net thickness of the ordinary
stiffener, in mm, is to be not less than 4 mm.
In Ch 9, Sec 5, [5.4.2],the web minimum net thickness of the primary
supporting member, in mm, is to be not less than 6 mm.

1) As pointed out by the questioner, the corrosion environment inside of a boxtype stiffener may be the same of the inside of double skin hatch cover, but
the corrosion environment outside of a box type stiffener is the same of the
cargo side of a hatch cover. Therefore a corrosion addition of 2mm has to be
applied.
2) We think that full corrosion addition has to be considered, because incomparison of the hatch cover to the bulk carrier hull it can be assumed, thatthe whole hatch cover structure may corrode simultaneously, because theenvironmental conditions are not so different.
3) When calculating the net moment of inertia of a primary supporting
member, full corrosion addition has to be considered to be in line with S21.3.5
and the design approach in Ch6.

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537

538

540

Ref.

Table
9.5.2

9/5.5.2.3

3/6.6.5.2

Type

Question

Topic

Weathertighthatch covers
and pontoon
hatch covers

Datecompleted

Question/CI

Attachment

Answer

3．Ch 9 Sec 5 Table 2(1) The allowable stress for weathertight hatch covers and pontoon hatch
covers subjected to external pressure are 0.80 ReH and 0.68 ReH,
respectively, in accordance with Reg.15 and Reg.16 of ILLC, but the allowablestress for both weathertight hatch covers and pontoon hatch covers subjected
to other loads is the same.
Why does the same allowable stress apply to the different types of hatch
cover?
A1: For loads which are different from ILLC sea loads, the practice of somePlease clarify.
classification Societies, since many years, is to consider an allowable stressdifferent from the one indicated by ILLC and applicable for all types of hatch
covers.
2007/10/19 (2) According to ILLC, external pressure is only external wave pressure acting
A2: This is related to question 527 and your interpretation is correct:
on the hatch cover. As CSR considers 4 load cases, i.e., H, F, R and P, the- external pressures are sea pressuresexternal pressure for R1, R2, P1 and P2 at any point of an exposed deck is- other loads are those defined in Ch9 Sec5 [4.1.3] to [4.1.6].
considered, in addition to the external pressure for load cases H1, H2, F1 andF2, that is the same as IACS UR S21. Therefore, we understand that “Externalpressure, as defined in Ch 5 Sec 5, 2” means the external pressure specified
in Ch 4 Sec 5 [2.2] and [2.3] and does not include “Load carried on exposed
deck” specified in Ch 4 Sec 5 [2.4].
We also understand that other loads in Table 2 mean “load carried on
exposed deck” and internal pressure due to liquid in ballast hold specified in
Ch 4 Sec 6 [2]Please confirm.

A1 The Common Interpretation is as follows:- If no finite element analysis is performed for the buckling of the hatch coverplating, only the criteria for buckling for uniaxial compression is to be checked.
- If a finite element analysis is performed for the buckling of the hatch coverplating, criteria for buckling for bi-axial compression are to be checked.

4.Ch 9 Sec 5 [5.2.3](1) Where the stresses in the primary supporting member are evaluated by
FEA, the uni-axial buckling check can be omitted since the buckling strength
check using the bi-axial compression stress in the hatch cover plating iscarried out in accordance with the requirements of Ch 6 Sec 3.
A2
Please confirm.
According to the stuffiness of the stiffener with U-profile, we think the(2) As there is no stiffener buckling factor "c" or F1 in Table 1 of Ch 6 Sec 3 for coefficient factor F1 is acceptable to the same value for girders specified in
special shape stiffeners such as a stiffener with a U-profile, please make an
Table 1 of Ch 6 Sec 3, i.e., F1 = 1.30.
interpretation for the buckling factor of a stiffener with a U-profile.
However a higher F1 value than 1.30 may be accepted provided the bucklingstrength of panel stiffened by U-beams is verified by non-linear buckling
analysis using FEA.

CI

Stresses in
the primary
supporting
member

2008/4/11

Question

The bilge
keel length

The last sentence in the 1st paragraph of Ch.3 Sec.6 [6.5.2] reads:" The bilge
keel with a length greater than 0.15L is to be made with the same grade of
2007/10/19 steel as the one of bilge strake." In this connection please confirm that theintermediate flat is not required to be made with the same grade of steel as
the one of bilge strake regardless of the length of the intermediate flat.

The intermediate flat is also to be of the same steel grade as the bilge strake
and the bilge keel in case of a bilge keel length > 0.15L.

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542

Ref.

7/2.3.3

Ch.9
Sec.1,
543
Sec.2 and
Sec.3

Type

Topic

Date
completed

Question/CI

Attachment

Answer

RCP

Whilst an answer has been given in IACS KC484 to the question on thickness
iteration procedure for buckling strength assessment, it is still requested that acommon iteration procedure or a Rule stipulation be specified.
Question: Regarding buckling and ultimate strength assessment in a global
strength analysis, an increase in thickness of each panel satisfying
requirements will be obtained by iteration. As there is no clear process in thecurrent rules, it is considered appropriate that the stress may be used as it iswith no reductions associated with thickness ratios in each iteration step. Is
this correct? If not correct, some known approaches are considered available,
for example, (i) all component stresses are reduced with thickness ratios, (ii)the same as (i) but stresses in the global X direction are not reduced, (iii) only
Thicknessthe stress due to local loads is reduced with thickness ratios and the stressiteration
due to hull girder loads is not reduced. Please advise a common process toprocedure for
The report of the FE analysis has to demonstrate that the ship structure has
2007/10/24 apply proper stresses for required thickness calculations.
buckling
been designed according CSR-BC.
Answer: CSR only requires that the results of DSA are to comply with thestrength
strength criteria in Chapter 7. There is no need to specify the iterationassessment
procedure to confirm the reinforcement of structure in CSR because it isconsidered that the responsibility of reinforcement of structure which does notcomply with the strength criteria is up to designers not classification societies.
Classification society only confirms that the results of DSA carried out for the
given scantlings of structure comply with the strength criteria specified in the(m) proposed amendments to structure where necessary, including revised
assessment of stresses, buckling and fatigue properties showing compliancewith design criteria", it is considered necessary for CSR-BC to implement a
harmonised iteration process for determining amended scantlings by thickness
iteration.

CI

Although scantling of PSMs in Fore part, Aft part and E/R are regulated in Ch9Sec1 through Sec3 in CSR, scantling requirement for not all the PSMs are
regulated in Ch9.
Scantlings ofScantling requirements of some of the PSMs, such on decks or deep tank
PSMs inbulkheads, refer to Ch6 Sec4. In Ch6 Sec4, scantling formulas are regulated
2007/10/23
Fore Part, Aft
for ships having ship’s length L less than 150m, and direct strength analysis isPart & E/R
required for ships having L=150m or more according to provisions in Ch7.
However, Ch7 regulates direct strength analysis of cargo hold structures only.
Please advise how to determine scantling of PSMs in Fore part, Aft part andE/R for ships having L=150m or more.

According to the agreed answer of question #312, PSM in the fore and aft partof the vessel may be designed according Ch6, Sec4, 2.6.
We will consider the further rule development about the determination of thescantling of primary supporting members outside midship cargo regions forships of 150m in length and above.

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544
attc

546

Ref.

12/ 1.2.1

6/1.2.7.4 &
6/2.2.5.4

Type

CI

CI

Topic

Inner bottom
plating

Weight of theSteel Coil

Datecompleted

Question/CI

Answer

2008/4/25

Our interpretation of 2.1.1 to 2.1.3 of CH12, Sec1 is the following:a) the whole inner bottom plating has to be dimensioned according 2.1.2b) the sloped hopper tank plating and the sloped or non-sloped lower stool
plating have to be dimensioned according 2.1.3 up to a height of 3m above
the inner bottom (vertically measued)c) in case of a hybrid-bulker the inner longitudinal wall, welded directly on the
inner bottom wihout a hopper plate, has to be dimensioned according 2.1.3 up
to a height of 3m above the inner bottomd) The coaming, deck girders below coaming, top wing sloping plate andupper stool plating have not be increased due to the GRAB-notation
Please confirm these interpretations.

A1) Yes the whole inner bottom plating has to be dimensioned according toCh.12 Sec.1 [2.1.2].
A2) The interpretation of Ch.12 Sec.1 [2] is as follow:
Ch.12 Sec.1 [2.1.1] is applicable to plating of inner bottom, hopper, lower stoolside plating and inner hull up to a height of 3m above inner bottom.
Ch.12 Sec.1 [2.1.2] is applicable to the plating of inner bottom.
Ch.12 Sec.1 [2.1.3] is applicable to plating of hopper, lower stool side plating,inner hull up to a height of 3m above inner bottom.
A3) Yes, inner longitudinal walls of an hybrid bulker have to be dimensioned
with respect to Ch.12 Sec.1 [2.1.3].
A4)No, coaming, deck girders below coaming, to wing sloping plates andupper stool plating are not concerned by Ch.12 Sec.1.

2008/2/7

JBP rules Chapter 6,Section 1.2.7.4 and Chapter 6,Section 2.2.5.4 (steel coil).
In this requirement it is stated that where the number of load points perelement plate panel n2 is greater than 10 and/or the number of dunnages n3
is greater than 5, the inner bottom may be considered as loaded by a uniform
distributed load.
The question is how to calculate the above uniform distributed load. Is it theweight of the steel coil divided by the diameter and length of the steel coil as
the uniform load, or the weight of the steel coil divided by the length of thesteel coil only?

Attachment

A similar question was asked under KC ID #331. The approved answer (on12/01/2007) was "A definition of uniform loads on inner bottom will be includedin CSR for bulk carriers.
Considering your specific proposals, the interpretation is that the uniform load
is the weight of the steel coil divided by the diameter and length of the steel .
We will consider the rule change proposal based on the output of the Hull
Panel.

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Ref.

Type

Topic

Date
completed

Question/CI

Attachment

Answer

The sequence of the buckling checks follows the arrangement of Chapter 6,
Section 3.
In case of the buckling check for a typical ship structure (e.g. longitudinal
stiffened bottom) the elementary plate panel has to be dimensioned firstaccording the plate buckling criteria.

547

6/3.1

CI

The
Sequence of
Buckling
Assessment

2008/1/9

What is the right sequence of performing the buckling assessment according
CH6, Sec3?

In the following lateral buckling check of the stiffeners the net moments ofinertia is derived including the effective width of the attached plating. Thiseffective width depends on the thickness of the plate field. If this thickness is
not sufficient for plate buckling, the effective width and also the moment ofinertia of the stiffener is too small. As a result a larger stiffener would be
required to pass the lateral buckling check. And this larger stiffener gives nobonus for the plate buckling check.
Therefore it is important to make the plate buckling check before performing
the lateral buckling check.

548

1/1.1.1.2

Ship notQuestion being HybridBC

If a ship is not an hybrid-BC according to CSR definition in Chapter 1, 1.1.2(i.e. for the considered ship no one hold has hopper tank and topside tank), it
is not required to apply the CSR.
In case an owner intends to build a ship longer than 90 m having all cargoholds of box type and expected to carry cargo in bulk for a number of travels ayear, i.e. a bulk carrier according to SOLAS chapter XII, the following
questions are to be answered:
1.if the Shipyard or Ship-owner asks - for any commercial reason - to classify
the ship (which is not hybrid because all the holds are without hopper andlower tanks) as Bulk Carrier, can each Society decide to classify the ship as
Bulk Carrier without applying the CSR? Applicable Rules would be eachSociety’s Rules for BC and the URs to Bulk Carriers.
The questions are considered to be outside of PT1's scope of work.
It is requested to Hull Panel to provide answer to your questions.

2007/10/9
2.if the Shipyard or Shipowner asks to classify the ship (which is not hybrid
because all the holds are without hopper and lower tanks) as Bulk Carrier withscantlings according to CSR, can each Society decide to classify the ship as
Bulk Carrier applying the CSR even if Chapter 1, 1.1.2 does not require it?
The CSR can be applied, because in 1.1.2 is stated that “The structural
strength of members in holds constructed without hopper tank and/or topsidetank is to comply with the strength criteria defined in the Rules.“, meaning
therefore that the CSR scantling can be applied to such holds.
It is to be noted that in no case ESP will apply as this is not required under
SOLAS XI-1 Reg.2.

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No.

549

551

557
attc

Ref.

Type

Topic

Table
4.6.2

Testing Load
Questionheight of aballast holdSymbol6.1

Countermea
sure forpanel
buckling

Question6/1.2.3.2,
6/1.3.2.1, Question& 6/1.3.2.4

Datecompleted2007/10/9

Question/CI

In table 2 of CH4, Sec6 the following formula is given for the testing loadheight of a ballast hold:z_st = z_h + 0,9
In the GL-Rules the same formula is the constant 2,5 instead of 0,9. What isthe basis of the additional height of 0,9m?
Mean height of a hatch cover, experimental results, sloshing effects?

As a countermeasure for panel buckling, a carling with snipped ends is fitted
on a slender panel so as to reduce the aspect ratio of the panel.
2007/10/24 Can the reduced aspect ratio of the panel which is calculated by (s/l) be usedin determining the thickness of such panel according to Ch 6 Sec 1?
Where s and l are defined in "Symbols" in Ch 6 Sec 1.

Regarding bilge plate thickness,
Q1: Is always C6/S1/[2.3.2] to be applied regardless of the spacing (sb) of
floors or transverse bilge bracket vs chord length (l)?
Q2: Is C6/S1/[3.2.1] to be applied regardless of the spacing (sb)of floors ortransverse bilge bracket vs chord length (l)?
Bilge Plate
Thickness

2008/1/28

Q3: Is C6/S1/[3.2.4] to be applied regardless of the spacing (sb)of floors ortransverse bilge bracket vs chord length (l)?
Q4: If C6/S1/[3.2.4]is to be applied,is cr to be calculated as follows;(a) when sb < l: cr=1-0.5sb/R=1.0 assuming that R=infinitive,(b) when sb>=l: cr=1-0.5l/R?

Attachment

Answer

0.9m head is based on the item number 4 of Table 1 in IACS UR S14.

Yes, the reduced aspect ratio of the panel which is calculated by (s/l) may be
used in determining the thickness of such panel according to Ch 6 Sec 1.

A1: The requirement of Ch6 Sec 1 2.3.2 applies only to bilge plating which aretransversally framed.
A2: The requirement of Ch 6 Sec 1 3.2.1 is applied to bilge plating regardlessof the framing system.
A3: The requirement of Ch 6 Sec 1 3.2.4 is applied to bilge plating regardlessof the framing system.
A4: The additional stiffness of a panel due to curvature is given by theparameters radius and chord length. If sb>=chord_length, the elemenatry
plate panel is longitudinal stiffened, hence cr=1-0.5*s/r. If sb<chord length, theelementary plate panel is transversally stiffened, Cr is taken equal to 1.

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558

Ref.

10/1.3.3.2

Type

RCP

Topic

Unit
displacement
due totorsionDatecompleted2007/10/9

Question/CI

With reference to the technical background document, the requirement Ch10,
Sec1, 3.3.2 is according to C.3.2, Sec. 14, Chapter 1, Part 1 of the GL Rules,
and based on IACS UR S10, however coefficient of ft, unit displacement due
to torsion, differs as follows;
GL & UR: 3.14
CSR: 3.17

Attachment

AnswerYour comment is noted.
We will consider the edditorial correction.
Also Included in Corrigenda 5

We think that the value in CSR is not correct. Therefore, we propose the value
should be changed to the one in IACS UR S10.

559

560

Text 9/3

3/6.5.7.2

CI

RCP

Longitudinalstrength andlocal strengthof plates andstiffeners inmachinery
space

Lightenign
holes inprimary
supporting
members

2008/4/10

2008/4/11

Regarding the requirements of longitudinal strength and local strength ofplates and stiffeners in machinery space, our interpretations are as follows;
1. Longitudinal strength
1-a. Longitudinal bending and shear strength are checked according to Ch5,Sec1.
1-b. Hull girder ultimate strength is checked according to Ch5, Sec2.
2. Local strength of plate and stiffener
2-a. Flooding requirements in Ch6, Sec1, 3.2.2 and Ch6, Sec2, 3.2.5 areapplied with considering longitudinal stress sigma_x as similar to cargo area
2-b. Buckling requirements in Ch6, Sec3 3.1.2 and 4 are applied withconsidering longitudinal stress sigma_x and tau as similar to cargo area
Please clarify above interpretations.

The first sentence of Ch 3, Sec 6, 5.7.2 states:"Where openings such as lightening holes are cut in primary supporting
members, they are to be equidistant from the face plate and corners of cutouts."
Even though the above, the distance from the opening to the face plate of the
primary supporting member is larger than the ones to the corners of the cutsout as "a" indicated in Fig 15.
At the same time, the location of the opening is restricted by the note,"h<=d/2", as indicated in Fig 15.
We consider that this requirement is obviously impractical.
Therefore, the word "the face plate and" should be deleted from the 1st
sentence of 5.7.2.
Furthermore, we would like to confirm the following:(a) this requirement is not applicable to the access hole;(b) "phi" in the figure means the width of the lightening hole, not the height of
the hole;(c) even if the arrangement of holes in primary supporting member does notmeet Ch 3, Sec 6, 5.7.2, it can be accepted based on the results of DSA.

1. Longitudinal strength in machinery space
1-a. Longitudinal bending and shear strength are checked according to Ch5,
Sec1, provided flooding in machinery space needs not be considered .
1-b. Hull girder ultimate strength is checked according to Ch5, Sec2, provided
flooding in machinery space needs not be considered .
2. Local strength of plate and stiffener in machinery space
2-a. Requirements in Ch6, Sec1, 3.2.2 and Ch6, Sec2, 3.2.5 are applied withconsidering longitudinal stress sigma_x in intact condition.
2-b. Buckling requirements in Ch6, Sec3 3.1.2 and 4 are applied withconsidering longitudinal stress sigma_x and tau as similar to cargo area.

We will consider a rule change with considering your comment.
The answers to the items (a) to (c) in the question are as follows.
(a) This requirement is not applicable to the access hole.
(b) “phi” is the diameter of lightening hole, neither height nor width of
openings.
(c) As there are too many locations to be assessed, it is considered
impracticable to determine the arrangement by FEA. Therefore, thearrangement of holes in primary supporting member meets this requirement
as a principle. However, since it might be possible to determine thearrangement of hole in primary supporting member based on the results of
FEA, it could be accepted based on the FEA at the discretion of theClassification Society.

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3.6.19,563
6/2.3.3.3 & Question
attc
6/2.3.3.4

564

565

3/6.8.3.1

4/6.3.3.6 &4/6.3.3.7

Question

CI

Topic

Modulus of
the Lower or
upper
BracketSide Frames- GeneralNet
thinkness ofcorrugations

Datecompleted

Question/CI

Attachment

Answer

According to Ch.6 Sec.2 [3.3.3] and [3.3.4], section modulus of side
frame+bracket is required at the level of lower or upper bracket as shown in
Ch.3 Sec.6 Fig.19. According to the Fig.19, it is unclear how to measure theheight of the bracket for the purpose of section modulus calculation. For the
purpose of hLB/tLB ratio the height of the bracket is defined in Ch. 3 Sec. 6
figure 22, which is also unclear.
2008/2/7

2007/11/2

2008/4/24

In Ch 6, Sec 3, [3.3.3] and [3.3.4], for the purpose of calculating the actual
section modulus of the lower (respectively upper) bracket, the web height is tobe measured at section noted "lOWER BRACKET" (respectively "UPPER
BRACKET") on Fig 19 of Ch 3, Sec 6.
In Ch 6, Sec 3, [3.3.3], for the purpose of hLB/tLB ratio the height hLB of the
We assume hLB for section modulus and hLB for hLB/tLB ratio is calculated in bracket is measured according to the definition in [3.3.3] and so according to
the same way. Please confirm.
Ch 3, Sec 6, Fig 22. It is corresponding to the Figure B of your attached
Attached please find two alternative approaches for calculation of hLB.
document.
A. hLB is measured perpendicular to bracket flange.
B. hLB is measured perpendicular to the projection of the lower bracket slope.
Please confirm correct approach for measuring bracket height hLB.

Reference is made to Ch. 3 Sec. 6 [8.3.1] Side frames – general
This requirement is originating from UR S12.5.
In CSR the formula states r= 0.3 x (..) wihile in UR S12.5 r = 0.4 x (..).
Is this a typo? If not, what is the reason for the formula change.

Reference is made to KC#402 Q2. Quote:
Q2:Ref. Ch. 6 Sec. 1 [3.2.3] and Sec. 2 [3.2.6]
The item Ch. 6 Sec. 1 [3.2.2] is giving “Net thickness of corrugations (..) for
flooded conditions” and Sec. 2 [3.2.6] is giving “Bending capacity and shear
capacity (..) for flooded conditions.” Both items refer to the design resultant
pressure and resultant force as defined in Ch. 4 Sec. 6 [3.3.7].
Ch. 4 Sec. 6 [3.3.7] is defining the resultant pressure in combined bulk cargowater flooding. [3.3.6] is defining the pure water flooding pressures on
corrugations. This pressure seem to be overlooked in Ch.6. We assume thatthe reference to [3.3.6] is missing in Ch. 6.
Please consider revising the definition of p in Ch. 6 Sec. 1 [3.2.3] and Sec. 2[3.2.6] to "(..)either [3.3.6] or [3.3.7] whichever greater".
Q2 Answer: Ch 6, Sec 1, [3.2.2] and Sec 2, [3.2.6] are requirements comingfrom UR S18. The reference to the design resultant pressure in Ch 4, Sec 6,[3.3.7] only is fully in line with UR S18. Consequently, there is no need to add
any reference to [3.3.6].
Unquote.

We will consider the rule change in order to be in line with IACS UR S12.
Also Included In Corrigenda 5

We agree that the pressures and forces on a corrugation on flooded empty
hold specified in Ch 4, Sec 6, [3.3.6] should be considered for scantling checkof corrugation in Ch 6, Sec 1, [3.2.3] and Ch 6, Sec 2, [3.2.6].
We will consider the rule change proposal in order to be in line with the 2nd
sentence of Ch 4, Sec 6, [3.3.2].

Please advise how Ch. 4 Sec. 6 [3.3.6] is accounted for when calculating theresultant pressure in [3.3.7]" or any other scantlings requirements. According
to Ch. 4 Sec. 6 [3.3.2], the 2nd sentence reads; "In any case, the pressure dueto the flooding water alone is to be considered" and the 4th line from thebottom reads; "For the purpose of this item, holds carrying packed cargoes areto be considered as empty." We understand that the pf and Ff of [3.3.6] deal
with such cases but we can not find if they are referred to anywhere in CSRB.
Please advise.
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No.

566

Ref.

Ch.4/3.2.4,
Ch.4/7 &Ch.4/8

Type

CI

Topic

Single Hold
Flooding

Datecompleted2008/4/11

Question/CI
Reference is made to IACS KC #501 (CSR Bulk Ch. 4 Sec. 3 [2.4], Sec.7 andSec.8)
Regarding the single hold flooding as required by CSR Ch4 Sec.3 [2.4] andURS17.
According to current URs:
•URS25.2.2 “The loading conditions listed under Section 4 are to be used forthe checking of rules criteria regarding longitudinal strength(2), local strength,
capacity and disposition of ballast tanks and stability.(..)”•Note 2: “As required by URs S7, S11 and S17”
According to current CSR:
•URS25 Conditions are enclosed in Ch. 4 Sec. 7•URS1 Loading manual conditions are enclosed in Ch. 4 Sec. 8•SW bending loads in general is given in Ch. 4 Sec. 3 [2.1.1] “(..) The
shipbuilder has to submit for each of the loading conditions defined in Ch. 4
Sec. 7 a longitudinal strength calculation”•SW flooding bending moments are given in Ch. 4 Sec. 3 [2.4] In [2.4.3] “(..)
The loading conditions on which the design of the ship has been based are to
be considered..”Attachment

Answer

A1. The loading conditions specified in Ch. 4 Sec. 3 [2.4.3] are the conditions
listed in Ch. 4 Sec. 7. That is the same as stated in URS25.
A2. According to the first bullet of Ch 4 Sec 8 [2.1.2], the loading condition isthe condition specified in Ch 5 Sec 1, which refers to Ch 4 Sec 3, and theloading conditions specified in Ch 4 Sec 3 are the conditions listed in Ch 4 Sec
7.
Therefore, the answer in KC 501 is kept as it is.
However, to avoid the confusion, we may chenge the link in "CH4, Sec8,
2.1.2" from "Ch5, Sec1" to "Ch4 Sec3".

Q1: We assume that the conditions referred to in Ch. 4 Sec. 3 [2.4.3] are theconditions listed in Ch. 4 Sec. 7. That is, the same loading conditions as
stated in URS25.
Please confirm.
Q2: The answer given to IACS KC #501 is indicating that only Ch. 4 Sec. 8
conditions have to be considered for flooding purposes. In our opinion, also
Ch. 4 Sec. 7 should be considered for flooding purposes. Please consider
changing the wording in KC #501 in order to avoid confusion.

Reference is made to IACS KC#475.
Quote
This thickness requirement is referring to the net thickness offered of theadjacent bottom and side plating.
Unquote567
attc

6/1.2.3.3

Net
thicknessoffered of the
Please advise how to define the bilge plating for fwd and aft parts of the cargo
Question
2007/10/26
adjacent
hold region.
bottom andE.g.
side plating- attached sketch is showing a cross section in the fore part of a bulk carrier.
- Bottom is strengthened for bow impact- bilge plating is to comply with KC#475.
Please advise bilge extent.

Within 0,4L amidship the definition of bilge plate is the same as defined inTable 4.1.1 of Section 4, CSR for DH oil tanker. That is:“The area of curved plating between the bottom shell and side shell. To betaken as follows:
From the start of the curvature at the lower turn of bilge on the bottom to thelesser of, the end of curvature at the upper turn of the bilge on the side shell or
0.2 D above the baseline/local centerline elevation.”
Outside of 0.4L amidships the bilge plate scantlings and arrangement are tocomply with the requirements of ordinary side or bottom shell plating in thesame region. Consideration is to be given where there is increased loading in
the forward region.

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568

569

571
attc

579

Ref.

10/1.5.1.4

10/1.5.2.1

Ch4 App3
and Ch7
sec 4

6/3.2.1.3

Type

Topic

Date
completed

Question

bending
stressReference is made to Ch. 10 Sec. 1 [5.1.4] Strength of rudder body. We
2008/10/27 assume ths stresses is originating from UR S10.5.1b) Please advice technicalbacground for the increase of bending stress form 75 to 90N/mm2.

RCP

Question

QuestionThickness of
Rudderplating

fatiguestrengthassessment

Shear force
for buckling

Question/CI

Attachment

Answer

The technical background for the increase of bending stress form 75 to
90N/mm2 is to consider the bending stress and shear stress due to torsion.
However, as the data to verify this increment can not be available. Therefore,
we would like to consider the RCP to be in line with the requirements of UR
S10, in order to avoid the confusion.

2007/10/2

Reference is made to Ch. 10 Sec. 1 [5.2.1] Plating thickness of Rudder
plating.
“The influence of the aspect ratio of the plate panels may be taken into
account according to Ch.3.”
The reference to Ch. 3 is wrong. Please advice if Ca according to Ch. 6 Sec. 1 Thank you for your note. We will consider the editorial change in order to be in
Symbols may be utilised for this purpose.
line with IACS UR S10.5.2. Also Included In Corrigenda 5
The requirement of Ch. 10 Sec. 1 [5.2.1] is originating from URS10.5.2.
Please note that the aspect ration formulation of UR S10.5.2 is different fromthat of Ch.6 Sec. 1 Symbols.
Please updated the rule formulation and references of Ch. 10 Sec. 1 [5.2.1].

2008/8/9

Please answer to the attached question for fatigue of Bulker CSR.

A1. For fatigue strength assessment, the cargo density used is to be as much“realistic” as possible. Therefore, the cargo density according to Ch 4 App.3
should be used for fatigue strength assessment not only by direct analysis
specified in Ch 8 Sec 3 but also simplified method specified in Ch 8 Sec 4.
We will consider the rule change proposal accordingly
A2. We think that Ch 7 Sec 4 3.3.2 referred in the question is Ch 7 Sec 4 3.2.2
correctly. The the definition of lamda for "welded intersection between plane
plates" is applicable for intersection of two plates and intersection of plating
and bracket.
A3 The correction factor of Ch 7 Sec 4 [3.2.2] is applicable to the case where
the stress at the 0.5 t from the hot spot is slightly greater than the stress at the
1.5 t from the hot spot.

2008/5/30

Total shear force for buckling check is to be obtained by following formula
Q = Q_SW + C_QW x Q_WV.
Then the distribution of total shear force is discontinuing at midship since thesign of C_QW is to be change at midship according to the foot note of Table 3
in Ch4 Sec 4. This discontinuity will cause scantling change between midship,especially for H1, H2, F1 and F2 load cases. Is it correct and expected?

Yes, it is correct but the scantling discontinuity is not expected.
We will consider the rule change proposal in order to eliminate or minimize thescantling discontinuity, considering the answer in KC 685.

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580
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Ref.

6/2.3.2.4

Type

CI

Topic

Date
completed

Question/CI

The line
In Ch 6, Sec 2, [3.2.4], it seems that in Table 4 (case with lower stool), the line
Supported by“Supported by girders or welded directly to decks or inner bottoms” should notgirders or
be mentioned in the table since this case is a case without any lower stool.
weldedPlease confirm our interpretation.
2007/10/26
directly to
Furthermore, both Table 4 and Table 5 should not mention the column
decks or“Supported by girders” since it is not applicable to bulk carriers.
inner
bottoms

Attachment

Answer
We agree with your interpretation: in Table 4, the only case to be taken into
account is the “Welded to stool efficiently supported by ship structure” one.
Also, the “supported by girder ends” do not correspond to bulk carriers but
other type of ships.
Consequently, the column “Supported by girders” should be deleted in Table 4
and 5.
Corrected table 4 and 5 are given in attached file.

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582
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583

Ref.

6/2.3.2.4

9/3.2.1.9

Ch.9
Sec.3/4 &
5

Type

Topic

Date
completed

Question/CI

Attachment

AnswerSpan "I" toIn Ch 6, Sec 2, [3.2.4], what is the span "l" to be considered for the calculation The span “l” to be considered for the calculation of pressures (p_mid-span,beof pressures (p_mid-span, p_u , P_L)?
considered
p_u, p_L) is the span as defined in figure 6.
Question
2007/10/25
Is it the span defined in figure 6 or the span between upper level of lower stool
for theand lower level of upper stool?
calculation ofpressures

CI

ManholeDimensions

RCP

scantlings
for platform
structuresand pillars

2008/2/7

Chapter 9, Section 3. [2.1.9]:
1) The 2nd paragraph has the general requirements for the manhole size infloors. We note that many ships are designed with two separate tanks
vertically in way of main engine bed. The access manholes exceeding theabove size limit due to lower floor height in way are designed in each upperand lower tanks as shown in the attachment. We understand that sucharrangement may be acceptable provided the shear area of the floor is notless than that with the hole of 40% of floor local depth based on minimum
required thickness in way and the local strength is satisfied. Please confirm orotherwise advise.
2) We understand that the requirements in paragraph 2 of 9-3/2.1.9 is notapplicable to girders. Please confirm.

A1 - Where access manholes dimensions exceed the size limit in Ch 9, Sec 3,[2.1.9] due to lower floor height in way, such arrangement may be acceptableprovided that the shear area of the floor is not less than that with the hole of
40% of floor local depth based on minimum required thickness in way and thatthe local strength is satisfied.
A2 - The requirements in paragraph 2 of 9-3/2.1.9 are also applicable togirders.

2007/3/23

9-3/4 and 9-3/5: The platforms and pillars will support the loads of machinery,
independent tanks etc.. However there is no loads specified in CSR for
determining the scantlings for platform structures and pillars. It is also
impracticable to obtain the dynamic loads for each machinery weight due tolack of information. Therefore, based on current CSR , it is impracticable todetermine the scantlings of platforms and pillars in engine room except theminimum plate thickness specified in CSR. As an alternative, we think thateach Class Society Rules may be used for determining the scantlings ofplatforms and pillars in addition to the minimum plate thickness requirements
specified in CSR. Please confirm. Also suggest CSR to specify the loads forplatforms in engine room and pillars.

1) There are no specific loads in CSR BC for determining the scantlings ofplatforms in machinery spaces. There is only a minimum plate thickness
requirement.
2) For determining the scantlings of platforms and pillars in addition to theminimum plate thickness requirements specified in CSR for BC, a Rule
Change will be considered in future.

584

6/4.4.1.1

CI

We understand that the compressive stress of pillars mentioned in 6-4/4.1.1 isthe stress by the static loads and the dynamic loads. However, there is noCompressive
Yes, the stress to be checked is the one induced by the static and dynamic
clear statement in CSR how to calculate the loads on pillars. The clear
stress of
2007/10/23
loads that are acting onto the decks above the considered pillar.
interpretation on this is to be developed. As an alternative, we think that thepillars
These loads are to be calculated accordingly to chapter 4.
current Class Society Rules may be used for determine the pillar scantlings.
Please confirm.

586
attc

1/1.1.1.2

CI

Longitudinal
Bulkhead

2008/4/24

In case we have an inclined longitudinal bulkhead, is it possible to consider
there is no hopper tank and therefore not to apply CSR Rules?
If this inclined longitudinal bulkhead is made with small change with two
slopes, is it possible to consider there is no hopper tank?

A few similar questions have already raised to IACS KC. IACS works on an
entire answer for the application of the CSR-BC for different ship designs,
considering a clear definition of the hopper tank.

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587
attc

589

590
attc

594

Ref.

1/1.1.1.2

Table
10.1.1

3/6.5.4.1

6/1.2.3.3

Datecompleted

Attach
ment

Type

Topic

CI

Structure ofbulk carrierin midship,
aft and fore
body hold

Please see attachment for structure of bulk carrier in midship hold and aft andA few similar questions have already raised to IACS KC. IACS works on anfore body hold.
2007/10/24
entire answer for the application of the CSR-BC for different ship designs,
In this case, whether or not is CSR mandatory?
considering a clear definition of the hopper tank.

RCP

The
definition for
Coefficient
Kappa_2 foreach rudder
profile2007/10/28

Coefficient kappa_2 for each rudder profiles is defined in Ch10, Sec1, Table1.
However, the definition of each rudder profiles is not cleary mentioned.
Therefore, it is requested that rudder profiles indiated in Table1 be defined
clearly such with figures of Table1 in UR S10.

2008/5/28

The main concern is on the definition of ATTACHED PLATINGS of primary
members (girders/ webs etc). I have been using a LOGICAL spreadsheet to
calculate the Effective width of attached plating for Primary members (as forsecondary members the effective width is the normal frame spacing and iswell defined).The spreadsheet I have been using for the same is attached foryour reference.
Based on the Latest ABS CSR 2006 requirement the definition says…”
effective breadth of attached plating of primary supporting member to beconsidered in the actual net section modulus for the yielding check is to betaken as the mean spacing between adjacent primary members.”
This would mean that the primary would be stronger if the spacing of the
primary is higher (in some cases). I have attached a case study on the
Effective Width of plating considered based on IACS requirement and earlier
Ship Rules. The summary is also attached in the same.
I would request if you could arrange to clarify my little query on the same.

Question

Question

Definition of
Attached
platins ofprimary
members

The
Thickness of
the Bilge
Strake2008/2/7

Question/CI

AnswerYYour comment is noted. We will consider the editorial correction.

The definition of the effective breadth in CH3, Sec6, 5.4.1 is an antagonism tothe definition, given in CH6, Sec4 Symbols. In this paragraph it is clearlystated that the effective breadth b_p is defined according CH3, Sec6, 4.3,
which is b_p = min(s, 0.2l).
The definition given in CH3, Sec6, 5.4.1 will be corrected accordingly.

In order to have no large discrepancies in thicknesses for welding, it is anormal building practice to provide a continuity of thicknesses between
The thickness of the bilge strake is determined according CH6, Sec1. The
bottom, bilge and side shell.
scantling check includes also a buckling check of the longitudinal or transverse
That is the reason of the requirement that the thickness of the bilge strake isframed curved plating. Nevertheless it is required, that the thickness of the
not less than the greater thickness of the bottom and the side shell.
bilge strake is not less than the greater thickness of the bottom and the side
shell plating. What is the reason, that the thickness of the bilge strake has to
However, provided all the design criteria have been fullfilled:
be increased, if the bilge strake with a thickness smaller than the bottom and- minimum thickness,the side shell passes all design checks (Yield, Buckling, FE-Analyses).
- yield,
The GL-Rules (I-Part 1, Sec6, 4.1) allows a smaller thickness, if the shear- buckling,strength is sufficient and if the bilge plate panels passes the buckling check- FE analyses,
including buckling of curved panels.
a smaller thickness of the bilge strake may be accepted.

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YIACS Common Structural Rules Knowledge Centre

KCID
No.

598

Ref.

3/6.6.3.3

Type

Question

Topic

Ordinary
stiffener
spacingDatecompleted

Question/CI

2008/1/10

According to CH3, Sec6, 6.3.3 a spacing of MIN (4.5m; 5x ordinary stiffenerspacing) is required DB side girders in case of longitudinal framed double
bottom.
According to the GL rules and our experience, a spacing of maximum 2x
ordinary stiffener spacing is appropriate in the strengthening forward area of avessel.
According CH9, Sec1, 5.4.1. the spacing "S" is not limited. is this limitation
missing for the strengthening forward part?

Attachment

AnswerIn CSR of BC, the scantlings of girders and floors in the strengthened bottom
forward are determined by the scantling formulae which in turn define thespans and spacing of the floors and girders. Therefore, by using the scantling
formulae, there is no need to separately define the spacing of the girders andfloors in the strengthened bottom forward.

Page 85 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

601

Ref.

1/1.1.1.2

Type

Question

Topic

Application
to convert
ships

Date
completed2008/3/14

Question/CI

Attachment

AnswerCSR Application to converted ship;
In response to the recent demands of the bulker market, there are many
conversion plan of the existing tanker into bulk carrier. The most of such plans
indicate that hull envelope (i.e., bottom, side and portions of deck structures)of the existing ship is retained as original and inner bottom structures and
TST/hopper tank shaped structures (void) are newly installed for satisfactorily
comply with the grain stability. Such conversion is considered as a "major
conversion" under the statutory requirements. However, it is not clear inapplication of CSR for bulk carrier. Please advise of your views for thefollowing inquiries:
Q1: In line with the definition of "alterations and modifications" of the statutory
requirements, such as SOLAS II-2Reg. 1.2.3.2.(FP), is CSR for bulk carriers
required to be applied to the converted bulk carrier? Please advise your views. The issue is being discussed at Hull Panel for Council decision on the IACS
procedures to be followed.
Q2: There is no clear statement in the current text on applicability of CSR for
bulk carriers which undergo alterations and modifications or conversion fromother type of ship into bulk carrier. We would think such statement should beindicated in the text.
Q3: Is such applicability related to the extent of conversion ? If yes, we would
think that definition of "(Minor) Conversion" or "Major Conversion" should be
defined in the application of CSR for bulk carrier with the clear extent of
conversion, e.g., new cargo hold structures replace the existing cargo area
construction for XX% of the entire hull structures

603
attc

8/4.2.3.6

CI

Displacemen
t oftransverse
bulkhead.

2008/4/18

JBP rules Chapter 8,Section 4.2.3.6 Stress due to relative displacement oftransverse bulkhead. There are 3 questions:
Q1. Is the relative displacement an absolute value or with a sign?
Q2. If it is not absolute value, how to decide the sign of them?
Q3. We understand that this additional stress is only applied at thetransververse bulkhead. This additional stress is not required for the rings
adjacent to the transverse bulkhead.

Regarding the requirement in Ch 8, Sec 4, [2.3.6], please find our answers.
A1: The relative displacements are not absolute value. They should be
calculated with signs (+ or -);A2: The signs of the displacements are decided as per the rules in theattachment;
A3: Your understanding is correct and comfirmed.

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KCID
No.

604

Ref.

Type

1/4.2.1.1 &Question
4/3.2.4

609 6/1.2.7.1&
attc 6/2.2.5.4

RCP

Topic

LongitudinalStrength
Calculation

Steel Coil
LoadingDatecompleted

Question/CI

Attachment

Answer

2008/5/6

It is mandatory to make Longitudinal Strength Calculation for one flooded holdfor Bulk Carriers having length of 150 m or above; according to SOLAS Ch. XII
Reg. 5. For that calculation the length of the ship is to be taken as Loadline
Length according to SOLAS Ch. XII Reg. 1
SOLAS Rule Reference: SOLAS Ch. XII Reg. 1 (for length definition) &SOLAS Ch. XII Reg. 5 (for Strength Calculation).
The rule length as defined in Ch 1, Sec 4, [3.1.1] should be used for the
According to CSR for Bulk Carriers the same calculation for flooded holddetermination of still water bending moment and still water shear force inshould be carried out but in CSR it is stated that the length of the ship is to be
flooded condition according to Ch 4, Sec 3, [2.4].
taken as the Rule Length.
CSR Rule Reference: CSR Ch.1 Sec. 4 2.1.1 (for length definition) & CSR
Ch.4 Sec. 3 2.4 (for Strength Calculation)
In our project, the Rule Length < 150 m while the Loadline Length > 150 m.
Would you please advise what kind of application should be followed? Should
the strength calculation be made in this particular case? Which length should
be taken into consideration?"

2008/2/7

Reference is made to Ch. 6 Sec. 1 [2.7.1] and Sec. 2 [2.5.4] Steel coil loading
and related KC# 331 and 546.
Ch. 6 Sec. 1 [2.7.1] and Sec. 2 [2.5.4]
Quote“Where the number of load points per elementary plate panel n2 is greaterthan 10/or the number of dunnages n3 is greater then 5, the inner bottom may
be considered as loaded by a uniform distributed load. In such a case, thescantling of the inner bottom ordinary stiffeners is to be obtained according to This question is identical to KC ID#546, and the answer is that the uniform
load of due to steel coil is the weight of the steel coil divided by the diameter[3.2.3]”and length of the steel .
UnquoteA rule change proposal will be considered based on the output of the Hull
Panel.
We understand that “distributed load” is sometimes interpreted as P =WCoil/(lcoil x dcoil) where lcoil and dcoil is the length and diameter of coilrespectively. DNV have investigated the effect of such interpretation with thestiffener scantling as example. Our conclusion is that such a interpretation isunsafe and should be changed to distributed load over one elementary plate
panel as described below.
Please find enclosed DNV report and rule change proposal enclosed for yourconsideration.

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KCID
No.

Ref.

Type

Topic

Date
completed

Question/CI

Attachment

Answer

1. Lateral buckling assessment of stiffened panel including side frame istreated as longitudinally stiffened panel which has a stiffener arranged on the
direction of the longer side of the panel. Please confirm it.

610

Ch.6,
Sec.3 4.2.

RCP

Buckling
Assessmentof stiffended
panel

2008/5/30

2. In case that shear stress on side shell as attached plate of side frame islarge, shear stress is the dominant load of lateral buckling of side frame. It is
not understandable for us. Please show the technical background in thisregard.
Even though the thickness of side shell plates comply with Ch5 Sec1, 2.2 &Ch6 Sec3, 2.1.3, the side shell plate thickness should be increased due to theresult of lateral buckling assessment of side frame.
It is necessary to reconsider the above requirements which require increase of
scantling of hull girder members due to the result of local strength check.

A1) Confirmed.
Comment on 2) and 3)
It is obvious, that for transverse members the axial stress component is zeroin the formula for the criteria and the equation for p_z (nominal lateral load).
The remaining stress component is the hull girder bending stress with its zerocrossing and shear. And so shear becomes dominant.
We support to reconsider the requirements for lateral buckling.

3. We request to reconsider the requirement of lateral buckling assessment forside frame in connection with above 1. and 2.

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IACS Common Structural Rules Knowledge Centre

KCID
No.

Ref.

Type

3/6.9.6.3 &612
FigureQuestion
3.6.25Topic

Extremecorners ofendhatchways

Datecompleted2008/5/30

Question/CI

Attachment

Answer[Q1] C3S6[9.6.3] reads in its 3rd last paragraph: "For the extreme corners ofend hatchways,…"
Please clarify the location of "the extreme corners of end hatchways".

[A1] The extreme corners of end hatchways are:a) the fore end hatch corners of foremost hatch, andb) the aft end hatch corners of aftmost hatch.

[Q2] According to C3S6[9.6.3], for the extreme corners of end hatchways, thethickness of insert plates is to be 60% greater than the actual thickness of theadjacent deck plating. Is this requirement also applicable to hatch corners withthe elliptical or parabolic profile?

[A2] Please refer to 4th paragraph in Ch.3 Sec.6 [9.6.3] which reads:"Forhatchways...insert plates are, in general, not required .....where the plating cutout has an elliptical or parabolic profile and the half .... ● twice the transverse
dimension, in the fore and aft direction."
According to this paragraph "60% greater" requirement needs not be applied
if the afore-quoted condition of 4th paragraph is satisfied.
In case the condition is not satisfied a strake or an insert plate containing thehatch corner needs to comply with the requirements of thickness in [9.6.3]
including "60% greater" requirement.

[Q3] For the dimension requirements of hatch corner inserts as specified in
Fig.25 of C3S6[9.6.3], is this requirement also applicable to the corner insertswith the elliptical or parabolic profile? If yes, how to determine the value of "R"
as indicated in Fig.25 for the elliptical or parabolic profile?

[Q4] With regard to the question [Q3], since the required material class ofhatch corner plating is Class III and that for adjacent deck plating is Class II,
the insert plate may be required in some cases even if the corner profile is anelliptical or parabolic profile. In this case, are there any dimension
requirements for such inserts? Are the requirements in Fig.25 of C3S6[9.6.3]
applicable and if yes, how is the value of "R" shown in fig. 25 determined?

[A3] Dimension requirements of Fig.25 needs not be applied to the elliptical orparabolic profile which complies with the half axes and half lengths
requirements of 4th paragraph of C3S6[9.6.3]. In case the foregoing 4th
paragraph requirements are not satisfied a strake or an insert plate containing
the hatch corner needs to comply with the dimension requirements of Fig.25.
In such a case the starting points of d2 and d3 are to be taken from the radii's
ends of the elliptical or parabolic profile.

[A4] Please consider separately the steel grade from insert plate. In case astrake or an insert plate within 0.4L amidship includes the hatch corner, grade
III or grade E/EH is to be applied. In case a strake or an insert plate does notcontain the hatch corner and is not the stringer plate, grade II is to be applied.
Dimension requirements for insert plate need not be applied to an elliptical orparabolic profile which complies with half axes and half length requirements of
4th paragraph of C3S6[9.6.3]. Fig.25 needs to be applied only when insert
plate is required by [9.6.3].If elliptical or parabolic profile does not satisfy therequirements of half axes and half length requirements, a strake or an insert
plate containing the hatch corner needs to comply with the dimension
requirement of Fig.25. Then the steel grade of the strake or the insert plate
within 0.4L amidship to be III or grade E/EH.

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IACS Common Structural Rules Knowledge Centre

KCID
No.

613

Ref.

Symbol
9.5 & 9
Sec.5

Type

CI

Topic

Hatch Coverof ballast
hold

Date
completed

Question/CI

2008/4/24

Reference is made to Ch.9 Sec. 5
Q1 Requirement for hatch cover of ballast hold
In Chapter 9 Sec.5 Symbols, it is stated that "FS = 0 and FW = 0.9 for hatch
covers of the cargo ballast hold". It is our understanding, these coefficients areapplicable to ballast pressure only and not sea pressure or cargo pressure. If
so, please consider rephrasing the paragraph to"FS = 0 and FW = 0.9 for ballast pressure of hatch covers on the cargo ballast
hold".
Q2 Ballast pressure calculation
When calculating ballast pressure according to Ch.4 Sec.6 [2.2] we assume
that the fixed value of (x-xB) may be utilized. (0.75lh or -0.75lh)
Please confirm and if relevant, update rules accordingly.

Attachment

AnswerA1. Your understanding that the coefficient FS = 0 and FW = 0.9 areapplicable to ballast pressure only is right.
A2: This fixed value has to be used in prescriptive assessment of structure.
A3:Formulae as per Chapter 9, Sec.5 should be used.

Q3 Structural calculationa. When ballast pressure or dry cargo pressure is considered for the hatch
cover, please advise the formula to use in order to calculate the required plate
thickness, section modulus and shear area of stiffeners? Can the formula inCh.6 Sec.1 [3.2.1] and Ch.6 Sec.2 [3.2.3] or the formula in Ch.9 Sec.5 5.3.3
be used?
b. In Ch.9 Sec. 5 bending stresses of primary supporting members areaccounted for when calculating scantlings of local structures such as plate andstiffeners. If we use the formulas of Ch. 6 Sec. [3.2.1] and Ch. 6 Sec.2 [3.2.3],
shall primary bending stress be accounted for? (Ref. lambdaP and lambdaS
factors)
Please clarify the rules.

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KCID
No.

614
attc

Ref.

3/5.1.2.1

Type

Topic

Coatingrequirementsof doubleQuestionside skinspaces ofbulk carriers

Datecompleted2008/5/6

Question/CI
Comment to the answer, A3 of KC#426
Since coating requirements of double-side skin spaces of bulk carriers in
regulation 3/5.1.2.1 of CSR for Bulk Carriers are developed based on theformer SOLAS regulation XII/6.3, definition of “double-side skin” should be inaccordance with SOLAS regulation XII/1.4.
***quote***Former SOLAS Regulation XII/6.3 (Resolution MSC.170(79))
Double-side skin spaces and dedicated seawater ballast tanks arranged inbulk carriers of 150 m in length and upwards constructed on or after 1 July
2006 shall be coated in accordance with the requirements of regulation II-1/32 and also based on the Performance standards for coatings* to be adopted
by the Organization.
SOLAS Regulation XII/1.4 (Resolution MSC.170(79))
Double-side skin means a configuration where each ship side is constructedby the side shell and a longitudinal bulkhead connecting the double bottom
and the deck. Hopper side tanks and top-side tanks may, where fitted, be
integral parts of the double-side skin configuration.

Answer

Attachment

We agree to your interpretation.

Y***unquote***Accordingly, the said regulation 3/5.1.2.1 is only applicable to void spaces
when located within cargo length area in bulk carriers of double-side skinconstruction.
Therefore, the asked void spaces arranged as a part of top-side tank, whenprovided in bulk carriers of single-side skin construction, need not to beconsidered as a double-side skin space.
The attached interpretation would be effective to the amended SOLAS
regulation II-1/3-2 (resolution MSC.216(82)).
Please clarify the above again.

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IACS Common Structural Rules Knowledge Centre

KCID
No.

615

616

617

618

620

Ref.

10/1.5.1.4

10/1.5.3.4&
10/1.5.3.5

3/1.2.3.9

10/1.5.5.1

9/5.5.4.6

Type

Topic

The effective
cross
Questionsectional
area underconsideration

CI

CI

RCP

QuestionThickness ofthehorizontal
web plates

Datecompleted

Question/CI

2008/3/5

In the definition of e: lever for torsional moment in Ch10 Sec1 [5.1.4], a-a: isdefined as the centre line of the effective cross sectional area underconsideration.
Please clarify the definition of “the effective cross sectional area underconsideration”.

2008/6/19

1. Ch10 Sec1, 5.3.4 regulates the thickness of the horizontal web plates in thevicinity of the solid parts.
Please clarify the definition of "the vicinity of the solid parts".
2. Ch 10 Sec 1, 5.3.5 regulates the thickness of verical web plates welded tothe solid part.
(1) Please clarify the extent of the vertical web plates to be applied to thisrequirement.
(2) Can different thickness be accepted when justified on the basis of direct
calculation as specified in [5.3.4]?

2008/5/30

Ch3, Sec1, 2.3.9 states as below;"Rolled products used for welded attachments on hull plating, such as gutter
bars, are to be of the same grade asthat used for the hull plating in way."
Is it applicable to small members, such as coaming plates fitted aroundmooring winch on upper deck?
Please clarify the applicability of this requirement.

Maximum
pintlediameter

2008/5/13(1) Ch10 Sec1, 5.5.1 refers to 4.4 and 4.6, however, the references to Ch10
Sec1, 4.4 and 4.6 are not appropriate. It seems that the correct references are
to Ch10 Sec1, 5.4.4 and 5.4.6.
Please clarify the above.
(2) According to IACS UR S10, the length of the pintle housing in the gudgeon
is not to be less than the maximum pintle diameter. However, such arequirement is not mentioned in CSR. Please add a requirement regarding thelength of the pintle housing to [5.5] of CSR for Bulker.

Error in theformulagiving kt

2008/5/12

Weldedattachments
on hullplating

In Ch 9, Sec 5, [5.4.6], it seems that there is an error in the formula giving kt,
which is not in accordance with UR S21. Please confirm?

Attachment

AnswerThis requirement is refered to the centre of the horizontal cross section where
the stress levels are evaluated. Hence, the structural weakest horizontal
section of the rudder-blade considered i.w.o. the cutout for the rudder-horn.

A0: For the horizontal webplates; "in the vicinity" should be interpreted as toextend to the next vertical web from the solid piece. The goal is to assure
proper integration of the solid-piece, hence torsional forces are to be properly
distributed by means of shear to the next structural members in the rudderblade.
A1: The vertical extend should be interpreted as to extend to the next
horizontal web from the solid piece.
A2: A thickness reduction due to direct analyses is not allowed.

This requirement applies to the longitudinal members attached to hull plating
except internal members and which are considered in the longitudinal strength
calculation such as gutter bars.

A1: Your understanding is right. We will make an editorial correction. The
references will be changed from [4.4] to [5.4.4] and from [4.6] to [5.4.6].
A2: This requirement is given in CH10, Sec1, 5.4.6. which combines
URS10.7.1 and URS10.8.2.

It is right. The formula of kt should be modified from kt=5.35+4*(a/d)^2 to
kt=5.35+4/(a/d)^2, to be in accordance with UR S21.3.6.3.
This editorial correction will be issued as a Corrigenda.

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IACS Common Structural Rules Knowledge Centre

KCID
No.

621

622

Ref.

6/3-4.2
and 5.1

Ch.4,
Sec.7

Type

Topic

CI

Ultimate
Strength inlateralbuckling
mode of side
framesQuestion

Loading
conditions

Datecompleted

Question/CI

2008/4/11

Regarding ultimate strength in lateral buckling mode of side frames of single
side bulk carriers in Ch.6, Sec.3-4, our interpretation is that 'transversely
arranged' side frames should be treated as ‘longitudinal stiffeners’ in Ch.6,
Sec.3-4.2 and -5.1 since the ends of side frames can be considered as fixedends taking account of the requirements of upper and lower connections ofside frames as stipulated in Ch.6, Sec.2-3.4.
Confirmation is requested as to whether the above interpretation is correct ornot.

2008/4/11

Attachment

AnswerYes, side frames of single side bulk carriers are longitudinal frames in context
of CH6, Sec3. The definition "longitudinal" is given in CH6, Sec3, Symbols andFig. 1. This is independent from the fixation of the ends of the frames.

As you pointed out, CSR requirements for flooding conditions are the same as
those requirements of IACS UR S25 and S17.
The loading conditions defined in CSR Ch 4 Sec.7 [2], which come from IACS
UR S25.4, are to satisfy the requirement of the longitudinal strength in flooded
condition.
With regard to loading conditions used for flooding, KC ID. 486 says
‘Regarding flooding conditions, our interpretation is that they should have to be The loading conditions for local strength defined in CSR Ch 4 Sec.7 [3], whichcome from IACS UR S25.5 need not satisfy the requirement of the longitudinal
considered only for loading conditions defined in Ch 4, Sec 8, as they arereally navigation conditions.’ This reply seems to mean that loading conditions strength in flooded condition.
define in Ch 4, Sec 7, which comes from UR S25, does not need to be applied Accordingly, the answer in KC ID #486 has now been modified as follows.
1. The loading conditions which are required by Ch 4, Sec 7 [3] are “artificial
to flooding.
loading condition” considered for the check of local strength only and need not
However, UR S25-2.2 and Note (2) clearly says that the loading conditions
satisfy longitudinal strength.
listed in UR S25-4 are to be used for the checking of rules criteria regarding
1bis. The loading conditions specified in Ch 4, Sec 7 [2] are required to checklongitudinal strength required by UR S17. It is our understanding that thethe longitudinal strength and are to be described in the loading manual
requirements of the CSR BC Rules have to be the same as those of UR S25
specified in Ch 4 Sec 8.
since both are IACS requirements.
2.Regarding flooding condition, the loading conditions in Ch 4 Sec 7 [2] areHence it is requested to clarify the discrepancy above.
required to check the longitudinal strength.
3.Regarding intermediate conditions required in Ch 4, Sec 3, [2.1.1], if
considered more severe, they are to be considered for loading conditions
defined in Ch 4, Sec 7 and included in the loading manual specified in Ch 4,
Sec 8.

623
6/A1.1.3.2
attc

RCP

Buckling
Panel
idealization
for d)
GeneralTriangle

2008/4/24

Regarding the buckling panel idealization for d) General triangle in Ch 6,
Appendix 1, 1.3.2, it is mentioned that general triangle is treated according toa) "Quadrilateral panels" above. However, in the case of a triangle with allacute angles, a rectangle with the smallest area cannot be specified as thethree rectangles that completely surround the general triangle have the same
area, see attached. Just the original paragraph cannot result into a final
rectangular panel with the smallest area represented by the dimensions, a, b
and panel angle Theta. As such, an alternative stipulation covering both
obtuse triangles and acute triangles is requested.

Neither the DIN18800 nor the GL-buckling rules, which are the basis for CH6
Sec3 of the CSR-BC, consider triangular elementary plate panels as describedabove. The appendix of CH6 describes general approaches for an engineer toevaluate non standard geometry. Remeining items are up to engineering
judgement.

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YIACS Common Structural Rules Knowledge Centre

KCID
No.

624
attc

Ref.

Symbol6.3 &
6/3.1.1.2

Type

CI

Topic

Applicationof buckling
requirements

Datecompleted2008/5/12

Question/CI

Attachment

AnswerThis question relates to application of buckling requirement (Ch.6, Sec.3) and
SOLAS XII/6.5.3.
(A) According to IACS Unified Interpretation of SOLAS XII/6.5.3 (SC209, June
2006), safety factor of 1.15 for buckling requirement should be applied tolongitudinal and transverse ordinary stiffeners for the following areas: hatchway coaming, - inner bottom, - sloped panel of topside tanks and hoppertanks (if any), - inner side (if any), - top stool and bottom stool of transverse
bulkhead (if any), - stiffened trasnverse bulkhead (if any), and - side shell (ifdirectly bounding the cargo hold).
(B) According to Symbols in Ch.6, Sec.3 of CSR-BC Rule, safety factor (S) forbuckling requirement refers to the same members as stated in above (A)except stiffened transverse bulkhead, e.g. collision bulkhead and aft bulkead
in an aftermost cargo hold.
Your interpreation (A) to (C) is correct.
(C) According to Ch.6 Sec.3-1.1.2 (a) of CSR-BC Rule, the application of thebuckling requriement is to 'ordinary stiffeners in a hull transverse section
We will consider the Rule Change proposal or Edditorial correction foranalysis'. We think the interpretation of 'hull transverse section analysis' isclarification of the application.
'longitudinal members and hold frames'.

If the interpretation is correct, locations to be checked are the same as statedin above (A) except stiffened transverse bulkhead and top/bottom stools.
Considering the above situation, it is considered necessary that the following
elements be inserted:in Safety factor (S) in Symbols in Ch.6, Sec.3, 'stiffened transverse bulkhead,
if any',in Ch.6, Sec.3-1.1.2(a), 'ordinary stiffeners on stiffened transverse bulkhead
and on top and bottom stools, if any'.

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No.

625

626

Ref.

Ch.4,
Sec.5

4/5.1.3.1

Type

Topic

CI

Ambiguity
found indeterminingx/LCI

pHF When
the relevant
hull section
is totally
above thewaterline

Datecompleted2008/4/11

2008/2/21

Question/CI

This question relates to the ambiguity found in determining x/L in the following
cases as x is on the global co-ordinate system whereas L is Rule length.
(i) In Ch.4, Sec.5, 1.3.1, clarification is requested in case x/L lies at a position
less than 0 or more than 1.0 in calculating kl.
(ii) In Ch.4, Sec.5, 1.3.1, clarification is requested in case |x-0.5L| lies at a
position less than 0 or more than 1.0 in calculating kp.
(iii) In Ch.4, Sec.5, 2.2.1, Table 4, clarification is requested in case x/LLL lies
at a position less than 0 or more than 1.0 in calculating pw.

This question relates to pHF(Ch4. Sec.5, 1.3.1) when the relevant hull section
is totally above the waterline.
It is noted that there are some totally above the waterline in the aft and fore
parts of ships in normal or heavy ballst condition. Bi at the location in theabove condition is regarded as 0.
When considering external pressure under H1, H2, F1 and F2, clarification on
how to calculate pHF is requested when Bi=0. Is |2y|/Bi=1 applicable?

Attachment

Answer

A-1 If x/L is less than 0 or greater than 1.0, x/L is taken equal to 0 or 1.0,
respectively.
A-2 If x is less than 0 or greater than L, x is taken equal to 0 or x=L,
respectively.
A-3 If x/LLL is less than 0 or greater than 1.0, x/LLL is taken equal to 0 or 1.0
respectively.

When the considered location is above the waterline, Bi is regarded as 0.
In this case, the pHF at the considered waterline is calculated assuming|2y|/Bi=1 and then the pressure at the considered location is correctedaccording to 1.6.1 of Ch 4 Se 5.

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No.

627
attc

Ref.

4/6.3.3

Type

CI

Topic

Floodedconditions forTransverse
verticallycorrugatedwatertightbulkheads

Datecompleted

Question/CI

Attachment

AnswerRegarding lateral pressures and forces in flooded conditions for Transverse
vertically corrugated watertight bulkheads (Ch.4, Sec.6-3.3) originated fromIACS UR S18, it should be that the density of dry bulk cargo (ρc) and cargo
filling level (hc) in Ch.4, Sec.6-3.3 are the same as for those in UR S18.
In calculating scantling of corrugated transverse bulkheads in flooded
conditions for BC-A ships, it is interpreted that the Rules are requiring
scantlings using the ρc defined in Table 1 of Ch.4, Sec.6 (probably, 1.0 for
homogeneous load condition and 3.0 for alternate load condition) and an
imaginary hc defined in Ch.4, Sec.6-1.1.
2008/2/21

If this is the case, the likelihood is that a required net scantling determined by We will consider the rule change proposal regarding flooding condition.
bending capacity is less than that required by UR S18 as in our experienced
cases where it is shown that a density such as 1.5 resulting from M_HD/V_H
with the cargo filling to deck at centre has frequently been critical. As shown in
our calculation attached, the required net bending capacity by the CSR BC
Rules is less than that by UR S18 by around 10 %.

Such being the case, it is considered neccessary to avoid a case where
scantlings less than those determined by applying UR S18 is accepted. To thisend, any density of dry bulk cargoes (ρc) and cargo filling to deck at centre
should be considered for flooded conditions.
With respect to external pressures on exposed forecastle deck and a hatch
cover if arranged thereon, it is requested that the following are clarified.

Externalpressures on
4/5.2.2.1 &Question
exposed628
4/5.5.2.1
forecastle
deck

1. External pressures on freeboard deck and forecastle deck are explicit as set
out in Ch.4, S.5, 2.2.1. Tables 4 and 5, would lead you to believe that thepressure Pw on forecastle will be linearly increased to a maximum at the fore
perpendicular.
2008/5/28

2. It is our understanding that this is not the case as the linear increase inpressures is only applicable to exposed freeboard decks iaw Reg 16.2 of the1988 Protocol to the ILLC 1966 (Loadline Convention)

The assumption made by LR is right and we will consider the Rule change
proposal to clarify this issue.

3. If the coefficients in Tables 4 and 5 were applied the pressures on theforecastle would grow to such a disproportionate extent such as 90 kN/m2 ascompared to the constant pressure of 34.3 kN/m2 on a hatch cover applicableas set out in Ch.4, S.5, 5.2.1 and Regulation 16 (2) (d) in the 1988 Protocol to
the ILLC 1966 (LL Convention) defining Positions for hatchways.)

4.It is assumed that the conceptual background of the Rule is that pressureson exposed decks in Load Cases H1, H2, F1 and F2, are the same as thoseon hatchways in the LL Convention and the rules should be amended toreflect this more explicitly.
5. CSRPT1 should be requested to confirm our assumption and propose anamendment to the rules to clarify this issue.

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KCID
No.

629

Ref.

6/1.2.5.1

Type

CI

Topic

Net
thinkness ofa welded
sheerstrake

Datecompleted2008/5/9

Attachment

Question/CI

AnswerRegarding the requirement of welded sheerstrake (Ch.6, Sec.1-2.5.1, ‘The net
thickness of a welded sheerstrake is to be not less than the actual net
thickness of the adjacent 2 m width side plating, taking into account higher
strength steel corrections if needed’), it is noted that there is the relevant Q&A(KC ID No.212). However, the answer does not seem clear hence it would beappreciated if the following proposal be considered.
The answer of KC ID No.212 says, ‘Generally, when the side shell plating
adjacent to sheerstrake includes single side part and is increased due to thebuckling and hull girder shear strength, it is also the case for the sheerstrake,
which is located above. Consequently, we see no reason to modify thisrequirement’. This will be the case when the sheerstrake covers part of single
side skin (SSS) area. However the fact is that almost all sheerstrakes do notcover the part of single side skin area, i.e. they are located within top side tank(TST).

We agree to the interpretation that the net thickness of a welded sheerstrake
is to be not less than the net required thickness of the adjacent 2 m width side
plating, which is calculated according to the relevant requirements in Ch.6,
Sec.1

Generally speaking, hull girder shear strength is occasionally critical to thescantling of single side skin, while it is not to the scantling of sheerstrake
within TST area since the relevant shear flow calculation shows that the shear
stress in SSS is considerably bigger than that in TST area.
Such being the case, the requirement should be interpreted as follows: ‘The
net thickness of a welded sheerstrake is to be not less than the net required
thickness of the adjacent 2 m width side plating, which is calculated according
to the relevant requirements in Ch.6, Sec.1'.

Regarding Ch.3, Sec.6-9.2.3, the following question and suggestion are
offered for reply.

630

3/6.9.2.3

CI

Cross deckbeams

2008/6/19

1. The passage says, ‘…, beams are to be adequately supported by girders
and extended up to the second longitudinal from the hatch side girders
towards the bulwark’. Clarification of the beams is requested as to whether itmeans hatch end beam only or ordinary cross deck beams inclusive. A
bulwark is not always arranged hence rewording such as 'deck side' issuggested.
2. In case that ordinary cross deck beams are inclusive, the paragraph does
not seem to reflect practical design. It is therefore proposed that the extensionof beams up to the second longitudinals…can be waived provided a direct
strength analysis in compliance with the requirements in Ch.7 be foundsatisfactory.

A1: The continuity of structures and integration is the purpose of this section.
Base on the original intention, it is considered that the beams means not only
hatch end beams but also cross deck beams.
We agree to editorial correction that bulwark is changed to deck side.
A2: As mentioned by the questioner, this requirement does not seem to matchthe recent practice of design.
We will consider the rule change proposal in order to match the practicaldesign.

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Question/CI

Attachment

AnswerRegarding Ch.6, Sec.1-2.7 and Sec.2-2.5 about steel coils, it would beappreciated for KC to reply to the following comments.
1. The requirement for plates and ordinary stiffeners on hopper sloping andinner hull plating (Ch.6, Sec.1-2.7.3 and Sec.2-2.5.3) seems to requireconsiderably severe scantlings as compared to that in pre-CSR BC. In thisconnection, it is requested that a background document be supplied to users.
631
attc

6/1-2.7,
6/2-2.5

CI

Steel coils

2008/4/11

A1: A Rule Change Proposal with associated Technical Background is
2. It is understood that the requirements of Ch.6, Sec.1-2.7.3 and Sec.2-2.5.3
presently under preparation.
are based on the assumption that the steel coils are in uniform contact on theA2 and A3: Please, refer to the answer of KC ID#546 and 609.
hopper sloping or inner hull plating. In aft and forward cargo holds, however,there are some cases where the steel coils do not uniformly touch on them.
Attached is the example. Hence it is necessary that a procedure of how to deal
with it in that case be provided.

Y

3. Regarding Ch.6, Sec.1-2.7.4, it is noted that an answer of KC ID.331 saysthat a definition of uniform load will be included in CSR BC Rules. In themeantime, it is requested beforehand to be confirmed that the 'uniform load' is
not uniform load over the inner bottom plate but uniform line loads.

633
attc

Ch.4,
Appendix
1

RCP

Hold Mass
Curves2008/7/2

A change of the Rules regarding hold mass curves set out in Ch.4, Appendix 1
is proposed as described in the attachment.
Hold mass curves are to be based on design loading conditions for local
strength as defined and specified in Ch. 4, Sec. 7, Para. 3 of the Rules.
However, it has been found that hold mass curves to be drawn up in a
The content of the proposal will be studied and - if needed - the impact onpractical manner do not completely reflect the design loading conditions
scantling will be quantified. This may lead to a Rule Change Proposal.
defined in Ch.4, Sec.7, Para.3.

Y

It is proposed that the Rules are part changed as drafted therein for review
and consideration, where the wordings underlined by red and the figuresrounded by red line denote the proposed changes.

634
attc

Ch.5,
Appendix
1

RCP

Load end
shortening
Curves2008/3/26

A change of the Rules regarding load end shortening curves set out in Ch.5,
App.1 is proposed.
In case that stiffeners and attached plates are of different materials in someareas of hull girder transverse sections, it is proposed that the stipulations
relating to the load-end shortening curves defined in Ch. 5, App.1 areexpanded as underlined in red in the attachment to meet such case for userfriendliness purposes.

Please refer to the answer in KC ID 519.
Y

We will consider the rule change proposal in order to clarify this.

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635
attc

636

Ref.

Table
8.4.1

7/2.2.3.1

Type

CI

RCP

Topic

Stressconcentration factors

High Stressof Cross
Deck

Datecompleted2008/3/26

2008/3/26

Question/CI

Attachment

AnswerRegarding the stress concentration factors given in the Rules Chapter 8,
Section 4, Table 1, it is understood that where values are given only forYour understanding is correct.
connections with watertight collar plates fitted, these are also applicable forconnections with non-watertight collar plate or no collar plate fitted. NK Bulletin We will consider the rule change proposal in order clarify this.
No.276, 2006 refers. (in Japanese)
Please confirm.

Y

Regarding the draft answer for "PH7101_: High Stress of Cross Deck obtainedby DSA (KC ID No.343)", we would like to offer following suggestions to havea feasible conclusion for this issue before the wording of the draft answer issettled.
1. It is noted that the problem has happened in the DSA using a FE cargo holdmodel under the load cases of R1, R2, P1 and P1, where dynamic pressures 1.We will consider the rule change proposal regarding the boundary condition
induced will be unsymmetrical to the ship centre line. As described in Table 2 on rotational restriction about x-axis in order to avoid the unreasonableof Ch. 7, Sec. 2, Para. 2.3.1 of the CSR for BC, the cargo hold model is simply stresses due to unexpected and unreasonable warping of FE model.
supported at both ends through the independent point for vertical bending and 2. The examination regarding the stress assessment of hatch corner has beenhorizontal bending whilst relevant bending moments are applied at both ends carried out by IACS another PT separately.
to achieve the target values, however, the rotation around x axis at the fore
end is constrained in addition to the warping, i.e., fully fixed at the fore end for
torsion, whilst those are free at the aft end. Under such boundary conditions, if
there is any local pressure in it unsymmetrical to the centre line, the cargo holdmodel is naturally twisted without any control.

Relevant boundary conditions may need to be added to the aft end and willprobably be well modified the wave-induced torsional moment and warping.
2. It is understood that the load cases of R1, R2, P1 and P2 correspond to
beam sea since hydrodynamic pressures are independent of x coordinate as
shown in Ch. 4, Sec. 5, Paras. 1.4 and 1.5. Wave-induced torsional momentsin the load cases may, therefore, be relatively small as compared with thoseinduced in oblique sea which may be given in Ch. 4, Sec. 3, Para. 3.4,
however, the torsional moments are not available in any part of the Rules.
(Continues to the next page)

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Answer

Attachment(Continuation of the former page)636

7/2.2.3.1

RCPHigh Stressof Cross
Deck

2008/3/26

3. Warping may be calculated at any position using the formula in Ch. 8, Sec.
5 if relevant wave induced torsional moment is available, whilst the formula isinsufficient from the following points of view;
3.1. The rate of twisting is calculated by pure torsion, i.e., St. Venant's torsion
only. The secondary torque induced as a result of the constraint of warping is
ignored. (Note: Warping is proportional to the rate of twisting.) 3.2. The hull
section is treated as closed section and hatch openings is taken into accountby introduction of deck opening coefficient without any theoretical background.
The hull section is to be an open section and the cross deck is to be treated as(Refer to the former page)a spring resisting the torsion.

4. The control of the boundary conditions is quite complicated and difficult for
torsion, then, the rotation is to be constrained even at the aft end under theload cases of R1, R2, P1 and P2, i.e., Rx is to be fixed at the aft end. This may
give a reasonable solution for the cargo hold model apart from the torsion.
5. The cross deck bending due to torsion is to be examined in oblique sea
separately, if necessary.

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637
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Ref.

7/2.2.1.1

Type

RCP

Topic

The extent of
FE ModelDatecompleted

Question/CI

2008/5/12

Whilst an answer has been given in IACS KC248 to the question forassessment of holds of both ends, the procedure is not clarified but left to the
responsibility of each Society.
Question ID: 248 Approved: 30/11/06
Rule Ref.: Text 7/2.2.1.1 (bulker)
Question: Extent of model The extent of FE model is required to be threecargo holds and mid one is the target assessment. In handy bulk carriers,
loaded holds(Nos.1 and 5 holds) are not included in the mid part model(Nos.24 holds). Please clarify the FE model for handy bulk carriers with 5 cargoholds.
Answer: The FEA assessment of cargo holds is restricted to the midship areaby the CSR. However, assessment of holds of both ends is left to the
responsibility of each Society – this may be an extrapolation schema, aspecific FE analysis, a FEA provided by the ship designer,… Furthermore, it
should be noticed that this problem is also relevant in the CSR for Oil Tankers.

Attachment

Answer

We appreciate the questioner's effort to provide the disccusion material on thismatter.
We will ask the Hull Panel to resolve this matter and we will submit this
proposal tp the Hull Panel as a support material for discussion.

However, it is considered necessary to provide a common procedure to decidescantlings subject to Common Structural Rules. Furthermore, the local
strength and hull shear strength in way of the foremost and aftermost cargoholds should be assessed by the direct strength analysis using the FE cargohold models to confirm the structural adequacy and suitability in way.
1) Local strength aspect
Due to the hull form change, the double bottom shape will become slender
toward the fore end of the foremost cargo hold and the aft end of the aftermost
cargo hold respectively. Consequently bottom girder/floor arrangements inway will differ from those amidships and transmission of loads on the double
bottom to the girders and floors will differ from that amidships. Furthermore,
the sectional shape of the hopper tank will become crescent toward the fore
and aft ends whilst it is triangular amidships. Application of the outcome of thedirect strength analysis for the cargo holds amidships is very difficult for suchdifferent structural configuration and not relevant. The direct strength analysis
should be carried out for the foremost and aftermost cargo holds to assess theload supporting capability of the bottom girders/floors and the transverse websin the hopper tank.
(Continues to the next page)

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Answer(Continuation of the former page)

637
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7/2.2.1.1

RCP

The extent of
FE Model2008/5/12

2) Hull shear strength aspect
Under alternate loading conditions, very high hull girder shear forces will be
induced at the aft transverse bulkhead of the foremost cargo hold and at thefore transverse bulkhead of the aftermost cargo hold and those will becorrected by a factor which is derived taking into account load transmission to
the transverse bulkhead through the bottom girders on the assumption thatthe double bottom shape is rectangular whilst it is not rectangular in way. The
hull shear strength is critical at both transverse bulkheads, however, it deeply
depends upon accuracy of the factor. To avoid uncertainties in derivation of
the factor, the hull shear strength should be assessed by the direct strength
analysis.

(Refer to the former page)Y

The procedure of the direct strength analysis is proposed for the foremost andaftermost cargo holds as shown in the attachment which is basically in linewith those for the cargo holds amidships.
Please specify the procedure for assessment of holds of both ends on therules and provide the procedure of the direct strength analysis for the foremostand aftermost cargo holds.

638
attc

3/3.1.2.1 &
Table
3.3.1

CI

Corrosion
addition forballast watertanks

2008/4/22

Regarding corrosion addition for ballast water tank within 3 m below the top oftank in Table 1 in Ch.3, Sec.3 of CSR BC Rule, our interpretation is that itshould be applicable only to ballast tanks with weather deck as the tank top.
This interpretation is in line with Table 3 of Technical Background on
Corrosion addition and Note 1. of Table 6.3.1 of CSR for Double Hull Oil
Tanker Rule. Please confirm if our interpretation is correct.
According to Table 3 of the attached Technical Background, the corrosion
value of 1.7 is shown for topside tank in WBT when the tank is subject to hightemperature. The high temperature is expected for the members in ballast
water tank with weather deck as the tank top.
Therefore, a tank top of WBT which is not weather deck, e.g. the tank top of
WBT(APT) below steering gear room, should be treated not as ‘within 3 m
below the top of tank’ but as ‘elsewhere’ in Table 1 in Ch.3, Sec.3 of CSR BC
Rule.
In addition, if this interpretation is acceptable, an answer of KC ID 206(corrosion addition of hopper side tank not connected to top side WBT) should
be re-considered.

We examined the thickness measurement data regarding the position of
structural members in bilge hopper within 3m below from the tank top. As theresult, the corrosion diminution of structural members within 3m below fromthe tank top was not different from other than those.
Therefore, we will consider the rule change proposal based on the results ofthe examination.
Accordingly, we will modify the answer in KC ID 206

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639

Ref.

6/4.2.2
and 4.2.4

Type

Question

Topic

Net Webthicknessrequirements

Datecompleted2008/7/16

Question/CI

Attachment

AnswerWith respect to Net Web Thickness requirements for centre girders, side
1.1 When the water ballast tank of the double bottom is filled up to the tankgirders, floors, stringer of double side structure and transverse web in double
top, the static and dynamic pressures due to dry cargoes or heavy ballast areside structure for ships of less than 150m in length, it is requested to confirm
to be reduced from the corresponding ballast pressure of the water ballast
whether our interpretation below is correct or not.
tank.
1. Ch6/4.2.2.1,
1.2 When the water ballast tank of the double bottom is filled up to the top, the
1.1 pS,IB and pW,IB are Cargo pressures from Cargo Hold or Ballast
external still water and hydrodynamic pressures are to be reduced from thepressures from Ballast Hold. These still water and wave internal pressures arecorresponding ballast pressure of the water ballast tank.
to be reduced from the corresponding Ballast pressures from Water Ballast
2.1 When the water ballast tank of the double side is filled up to the top, theTank.
external still water and hydrodynamic pressures are to be reduced from the
1.2 pS,BM and pW,BM are External sea pressures. These still water and wave
corresponding ballast pressure from water ballast tank.
internal pressures are to be reduced from the corresponding Ballast pressures
2.2 When the water ballast tank of the double side is filled up to the top, thefrom Water Ballast Tank.
static and dynamic pressures due to dry cargoes or heavy ballast are to be
2. Ch6/4.2.4.1,
reduced from the corresponding ballast pressure from water ballast tank.
2.1 pS,SS and pW,SS are External sea pressures. These still water and wave
It should be noticed that the static and dynamic pressure combination of eachinternal pressures are to be reduced from the corresponding Ballast pressuresload is not to be negative (see CH4, Sec5, 1.1.1)
from Water Ballast Tank.

2.2 pS,LB and pW,LB are Cargo pressures from Cargo Hold or Ballastpressures from Ballast Hold. These still water and wave internal pressures areto be reduced from the corresponding Ballast pressures from Water Ballast
Tank. In this requirement, Cargo pressure from Cargo Hold is to be ignored.

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646

Ref.

Figure
3.6.2

Type

RCP

Topic

Span length
definition forordinary
stiffeners

Datecompleted2008/5/28

Question/CI

Attachment

Answer

Reference is made to Chapter 3 Section 6 Figure 2 “Span length definition forordinary stiffeners.”
The span l of ordinary stiffeners is to be measured as shown in Figure 2, Ch.3
Sec.3 4.2.1. The fourth sketch of Figure 2 indicates that the span length on
one side is to be related to the end bracket fitted on that side and on the otherside related to the depth of the web stiffener fitted on the other side. There is
We will review your question and proposal in the course of harmonizationno indication in the figure that the span reduction should be symmetrical,
process with CSR for Tanker.
which implies that an unbalance moment will be set up at the support. Thereis, however, not found any requirement in the rules that may ascertain that theunbalance moment can be supported by the web stiffener or the girder. Thereis also not found any requirement formulation that ensures that the rotational
stiffness of such a support is such that the unbalance moment will be
generated.
Proposal:
Sketch 4 of Figure 2 in Ch.3 Sec.6 4.2.1 is amended to show that the span
reduction on either side is not to be taken larger than the smaller of the span
reduction by the bracket and the depth of the web stiffener. Refer also to CSR
Tank Figure 4.2.2 b)

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647
attc

Ref.

3/6.5.2.1

Type

RCP

Topic

Web
Stiffeners on
primary
supporting
members

Datecompleted2008/5/13

Question/CI

Attachment

Answer

Applicable requirements to Web stiffeners on primary supporting members.
Reference is made to KC 204/328/333/416/419 which all considers therequirements to web stiffeners on primary supporting members.
We have looked into the above 5 KC items in order to gain a complete
overview. To us it seem like the some of the KC is out of date and some arecontradictory. Summary of our findings is enclosed in Excel spreadsheet.
Based on the summary findings, we would like KC to clarify and update therules on the following items:
1.Update if Ch.3Sec.6 with clear definition of web stiffeners with clear
sketches showing the arrangement and table referring to applicablerequirements. (KC also refer to buckling stiffeners.)
2.Update of Ch.3Sec.6 with clear definition of ordinary stiffeners with sketches
and table referring to applicable requirements.
3.Ref. KC id416 where PT advice that Ch3Sec.6 5.2.1 is ..”to ensure theappropriate scantling and rigidity of web stiffeners for the purpose of avoiding
the buckling of web plate(..)”.

The answers given to all KC items relevant to this subject (scantlings of web
stiffeners - KC 204/328/333/416/419) are considered are being selfexplanatory.
However, the following is reminded:
1 - It is clearly mentioned in Ch 3, Sec 6, [5.2.1] that this requirement applies
to stiffening arrangement of primary supporting members. No additionalsketch or definition is needed.
2 - In addition, the answer to KC#419 states clearly that web stiffeners ofprimary supporting members are not to be considered as “ordinary stiffeners”.
3 - Then both the answers (b) in KC#204 and (2) in KC#333 states that only
the following requirements are applicable to web stiffeners:- Ch 3, Sec 6, [5.2.1] for the net thickness of such stiffeners, which refers to
the minimum net thickness of the primary members on which they are fitted,
i.e. to Ch 6, Sec 4, [1.5.1],and- Ch 6, Sec 2, [4] for the net scantlings of web stiffeners of primary supporting
members.
If the buckling stiffeners are calculated for buckling according to Ch.6 Sec.3
and minimum scantlings according to Ch.6 Sec.2, can the requirement of Ch.3 In conclusion, we agree that all the KC items on this matter should be
consolidated in a future corrigenda.
Sec. 6 5.2.1 be waived? If so, this should be clearly written in the rules.
4.Please delete/consolidate above 5 KC items in order to avoid future
confusion.

648

4/5.4.2.1 &4/5.4.2.2

CI

Designbottomslammingpressure

2008/7/2

Reference is made to Ch.4Sec.5 [4.2.1]/[4.2.2] Design bottom slammingpressure[4.2.1] TBFP “Smallest design ballast draught, in m, defined at forward
perpendicular for normal ballast conditions. Where the sequential method forballast water exchange is intended to be applied, TBFP is to be considered forthe sequence of exchange.”[4.2.2] “It is the master`s responsibility to observe, among other, the weather
conditions and the draught at forward perpendicular during water ballast
exchange operations, in particular when the forward draught during these
operations is less than TBFP. The above requirement and the draught TBFP
is to be clearly indicated in the operating manuals.”Technical background for CSR Bulk:
4.2.2.a To limit the slamming loads at acceptable level, the smallest design
ballast draught at forward perpendicular should only be undercut in cases
where bottom slamming is not expected.
Please comment our understanding

Answer 1-3: Yes with no need for further clarifications of rule text changes.
Answer 4:The minimum draught forward in case of heavy weather is indicatedon the shell-expansion and should be mentioned in the loading manual.
Draughts that undercut the "minimum draught forward in case of heavy
weather" are to be used at the masters descretion as per Ch4, Sec 5, [4.2.2].

(Continues to the next page)

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Attachment(Continuation of the former page)648

4/5.4.2.1 &4/5.4.2.2

CI

Designbottomslammingpressure

2008/7/2

Q1. We assume the “smallest design ballast draught(..) for normal ballast
conditions” is referring to the ballast condition of Sec.7 [2.2.2]. Please confirm.
If yes, please add the reference in the rules for sake of clarity.
Q2. Regarding sequential ballast operation.
According to [4.2.1] “Where the sequential method for ballast water exchange(Refer to the former page)(..) is applied, TBFP is to be considered for the sequence of exchange”. Ch.4
Sec. 8 [2.2.2] require that “typical sequences for change at sea, whereapplicable” are included in the lading manual.
In order to evaluate [4.2.1] we understand that the loading sequence forballast exchange is required in the loaing manual in case of sequential ballast
operation.
Please confirm. If yes, please clarify rules.
Q3. Regarding sequential ballast operation.
We assume design draft for slamming, TBFP, is minimum among TBFP,
according to Sec7 [2.2.2] And TBFP, Ballast exchange in LM Sec8 [2.2.2]
Please advice. Please amend rules for clarity.
Q4. Masters responsibility.
According to [4.2.2] and CSR TB we understand that TBFP may be undercut if
weather permits.
If the loading manual includes more than one ballast exchange condition e.g:
WB Seagoing (Sec.7 [2.2.2]) TBFP = 7m
WB Exchange cond. 1 TBFP = 6 m
WB Exchange cond. 2 TBFP = 6.5 m
if no explicit request exist from designers, we assume TBFP for bottom
forward scantling may be chosen to be TBFP=6.5 m.
The limitation to TBFP will be stated in the vessel operating manual.
It is then the masters responsibility to utilize WB Exchange cond. 1 only when
weather permits according to [4.2.2]
Please advise.

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Question/CI

Attachment

Answer

Reference is made to Ch. 4 Sec. 7 [2.1.1] and KC Id. 491. In KC #491 we
asked the basis for MHD/MH according to [2.1.1] Quote Question: Ch. 4 Sec.
7 [2.1.1] “For determination of the maximum cargo mass in cargo holds, thecondition corresponding to the ship being loaded at maximum draught with
50% of consumables is to be considered.” [2.1.1] is stating that a typical shortvoyage condition should be the basis for strength verification. Please advise
correct interpretation of this paragraph for a typical BC-A vessel.

649

4/7.2.1.1

Question

Maximum
Cargo Mass

“Empty holds”: Maximum cargo mass from loading manual is normally themass MH from homogenous condition. This mass is normally smaller than the
Mfull mass according to [3.2.1]. Maximum cargo mass in cargo hold istherefore Mfull. It is therefore assumed that [2.1.1] is automatically fulfilled for
empty holds. Please confirm. “Ore loaded holds”: Maximum cargo mass MHD
from the loading manual is normally the maximum cargo mass in cargo holds.
2008/10/10 MHD + 10% MH is, according to [4.4.1], used for strength assessment.
Please advise if the mass MHD according to [2.1.4]/[3.2.1] should beestablished based on a short voyage condition with 50% consumables witheven filling at scantling draft.

[2.1.1] is applicable only to [2.1.2] thru [2.1.4]. The latter paragraphs requiresame filling ratio in all loaded cargo holds.

According to the provision of [2.1.1] maximum cargo mass Mh or Mhd should
be obtained from loading conditions at full scantling draft and with 50%
consumables. In general the maximum cargo mass (Mh) for an empty hold(Mh) corresponds to the cargo mass in homogeneous full condition at
scantling draft and with 50% consumables. Hence Mhd corresponds to thecargo mass in alternate loading condition at scantling draft and with 50%
consumables. Mfull is an artificial cargo mass and the maximum permissible
cargo mass for an empty cargo hold in connection with the determination ofhold mass curve. Unqoute We can not see that PT answered whether or notthese conditions should be based on “even filling at scantling draft.” Pleaseadvise.

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Answer

Reference is made to Chapter 7 Section 2 3.2.1

650
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7/2.3.2.1

RCP

FE Model2008/5/28

Quote
Where the effects of openings are not considered in the FE model, thereference stresses in way of the openings are to be properly modified withadjusting shear stresses in proportion to the ration of web height and opening
height.
UnqouteWe will consider the Rule change considering the proposal.

Y

There is no clear definition in the rule on how to make this correction. We
know this is done differently between different customers. Definitions known to
DNV are the “Vertical” and “CSR Tank” procedure as illustrated in attachment.
Please conclude on a procedure to be used for CSR Bulk and include in Ch. 7
Sec. 2 or in Appendix to Ch. 7 as found appropriate.

651

Table
11.2.2CI

Girder/Primary supporting
members

2008/5/28

Reference is made to Ch. 11 Sec. 2 Table 2.
Please find enclosed an extract of all girder/primary supporting entries of Table
2.
"Primary supporting member" in "Hull area" of Table 2 means the primary
1.General requirements to welding of primary supporting members is given in supporting member arranged in the structure other than double bottom and"Primary supporting members" => “Web plate and girder plate” to “Shell
double side structure, i.e., the primary supporting member with one plate
plating, deck plating, inner bottom plating(..) => F1 for "at end (15% of span)flange.
and F2 for "Elsewhere"
Therefore,the primary supporting members with two plate flanges such as
2.If we refer to “Bottom and double bottom” => “Side girder (..)” to “Bottom and girders or floors in double bottom, horizontal girder or transverses laying frominner bottom plating” => F3. This is in contradiction to item 1 above where the side to side in double side are not applicable to "Primary supporting
same structural elements are specified. There is no special consideration atmembers".
15% of span at ends. (Towards bulkheads)
3.If we refer to “Side and inner side in double side structure” => “Web ofIn order to clarify this matter, the words "and girder plate" in "Of" column forprimary supporting members” to “Side plating, inner side plating and web of
the Hull Area "Primary supporting members" should be deleted.
primary supporting members” => F2. Which is in line with item 1, except thatno increase is specified towards span ends.
We will issue the editorial corrections as a "Corrigenda" for clarification of thisQ1: Please comment on above understanding.
table.
Q2: We assume that girder web to shell plating to inner bottom/side should be
minimum F2 as given in “Primary supporting members”. Please advise.

In Ch 4, Sec 5, [4.1.1], the definition of pS and pW is not clear, there are twodifferent interpretations:653

4/5.4.1.1

CI

pS and pW

2009/3/3

1. the pS & pW is calculated at position TB at side shell, whatever is the valueof z
2. the pS & pW is calculated at the exact value of z of the loading point where
the bow pressure P_FB is to be estimatedInterpretation 2 is correct.
In order to clarify the requirement together with the clarification of thecalculation point, we will consider the rule change proposal.

What is the correct interpretation?

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Ref.

Type

Topic

Date
completed

Question/CI

Attachment

Answer654

9/1.4

Question

collision
bulkhead

2008/9/10

The scantling of collision bulkhead is enhanced to the other bulkheads,
according to Ch 6 Sec 1, [3.2.2] for bulkhead plating and Ch 6 Sec 2, [3.2.5]
How is the additional safety taken into account for the collision bulkhead,for ordinary stiffeners. Where the collision bulkhead is a boundary of voidwhen not subjected to lateral loads from tanks, hence fore peak is void space? space, the scantling may be derived by considering the void space as flooded,using the requirements mentioned above. We will consider a rule change forprimary supporting members under flooded condition.

655

10/1.5.3.2

Question

Diameter of
rudder stock

2008/4/22

Please amend the diameter of rudder stock in the formula of ws to D1 from d1

This is a typo. We will consider an editorial correction

2008/5/13

When a vessel is sailing on a light ballast condition, rudder force may not act
on the upper part of the rudder above the ballast draft. This gives
unfavorable(increased) support force for the neck bearing or upper pintle
bearing in case of semi-spade rudder. This should be taken into account as
minimum support force like DNV Rules.

We think that a partly submerged semi spade rudder generates less bending
moment in the neck bearing than in fully submerged operation. A minimum
value for the support force is not to be defined.

2008/4/22

The unit of shear stress should be N/mm^2.

This is a typo. We will consider an editorial correction.

2008/4/22

Wrong formula for equivalent stressThis is a typo. We will consider an editorial correction

2008/7/2

Application of the requirement "t>b/100"
The formula does not seem applicable to bilge strake or other curved panels

This is right. This requirement is only applicable to planar plate panels. A rulechange will be considered.

2008/5/9

Ch3, Sect6,6.5.2 of the subject rules states "The net thickness of theintermediate flat is to be equal to that of the bilge strake. However, thickness
may generally not be greater that 15mm."
It is understood that the 15mm maximum should be the 'as-built' thickness, in
keeping with previous rule sets.
We propose the following corrigenda to clarify this:"The net thickness of the intermediate flat is to be equal to that of the bilge
strake. However, the gross thickness need not be greater than 15mm."656

10/1.3.3.3

QuestionLight ballast
Conditions657

10/1.5.1.3

Question

Unit of shear
stress658

10/1.5.1.3

Question659

6/3.3.1.1

Question661

3/6.6.5.2

RCP

Formula forequivalentstressBilge strakeor othercurvedpanelsNet
Thickness oftheintermediate
flat

Yes, the 15mm maxumum should be the "as-built' thickness.
We will consider the editorial correction in order to clarify this.

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KCID
No.

662

Ref.

4/6.2.2.1

Type

CI

Topic

Inertialpressure due
to liquid

Datecompleted2008/5/28

Question/CI

Answer

Attachment

CSR_JBP_Chapter4_Section6_[2.2.1] Inertial pressure due to liquid[Quote]When checking ballast water exchange operations by means of the flow
through method, the inertial pressure due to ballast water is not to beconsidered for local strength assessments and direct strength analysis.
[End quote]
Please consider the answer to question in KC ID 226.
Please be kindly requested to clarify that when the ship’s ballast water change
method is designed as flow through method, only hydrostatic water ballastpressure, regardless of inertial pressure, would be considered for local
strength check as per Chapter 6 and to carry out the direct strength analysis
as per Chapter 4_Appendix 2 (e.g. analysis of the transverse bulkhead underheavy ballast load condition).

Page 110 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

663

Ref.

9/3.7.2.1

Type

RCP

Topic

minimum
Scantlings ofthe structuralelements

Datecompleted2008/5/13

Question/CI
1.In the course of applying CSR for Bulkers, CCS has found some problems
existing with the CSR requirements relating to minimum scantlings of thestructural elements in way of machinery seatings, as specified in CSR BC,
Chapter 9 - Other Structures, Section 3, 7.2 Minimum scantlings, which isquoted below for easy reference:"7.2.1 The net scantlings of the structural elements in way of the internal
combustion engine seatings are to be obtained from the formulae in Tab 2."
2. This requirement is found to be irrational since the calculation results
proved to be unnecessarily large.
2.1 CCS is of the opinion that the internal combustion engine manufacturers
are the ones who should be responsible for the design of the engine seatings
since they have the richest experience of application and the authority, andaccordingly the design of the seatings should follow thesuggestions/instructions provided by the manufactures.

Attachment

AnswerAs the same question is uploaded on KC ID 413, please refer to the answer in
KC ID 413.

3. Therefore, CCS proposes to substitute the above mentioned paragraph andtab.2 by the new "7.2.1 The net scantlings of the structural elements in way of
the internal combustion engine seatings are to be in accordance with thescantlings provided by the manufactures."

664

665

6/1.3.2.3

9/3.4.1.2

Question

RCP

thickness forcorrugatedbulkheadplate

Transverse
spacing

Required thickness for corrugated bulkhead plate Ref. CSR for Bulk Carriers
Ch6 Sec.1 2.1.1, 3.2.1 and 3.2.3 When calculating the required thickness forbuild-up corrugation bulkheads in intact condition by 3.2.1 of Ch.6 Sec.1,
should s of the formula be taken greater width of flange or web according to
2008/10/10
2.1.1? We understand that the requirements of 2.1.1 are come from UR S18
and only applicable to the requirement of flooding condition. Please clarify.
According to UR S18.4.7, s of the formula for obtaining tN is taken narrower
plate width. Can we use narrower width for tN in CSR? Please clarify.

2008/4/24

1. Ch 6 Sec 1 [3.2.1] and [3.2.4] “s” is to be taken equal to the value defined in[2.1.1]. For built up corrugation, when the different thickness of flange andweb are designed, “s” is to be taken equal to the flange and web ofcorrugation respectively.
2. Ch 6 Sec 1 [3.2.3]
1) “s” and “p” of the 1st formula should be selected respectively for web andflange in general, (e.g., applied to also for cold forming corrugated bulkhead),2) “s” and “p” of the 2nd formula should be selected for narrower plating,3) “s” and “p” of the 3rd to 5th formulas should be selected for wider plating.
In order to clarify these requirements, we will conisder the RCP. Regarding
the answer of KC 553 The answer seems to be vague but not to be incorrect
because it is obviously that the elementary plate panel for built-up corrugatedbulkhead is divided into the flange and web of corrugation.

Transverse spacing in machinery space
In Ch9, Sec3, 3.1.3, the side transverse spacing is restricted upto 4/5 frame
spacings.
On the other hand, greater spacing is also permitted at the last sentence
The primary support i.w.o. the platform is to be integrated with the primarystated below;
members in the side. Hence where larger spacings are allowed in the side it"Side transverse spacing greater than that above may be accepted provided
will result in an equally larger spacing in the platform.
that the scantlings of ordinary frames
are increased, according to the Society’s requirements to be defined on a caseby case basis."
In Ch9, Sec3, 4.1.2, the platform transverse spacing is restricted upto 4 frame
spacings.
Can greater spacing be permitted as similar to the above?

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666

669
attc

671

Ref.

Type

9/1.4.4.4 &Question
9/2.4.3.4

Table
11.2.1

4/5.2.2.1 &
Table
4.5.4

RCP

RCP

Date
completed

Question/CI

Answerdeck primary
supporting
members

2008/9/10

According to the answer in KC 312, the requirement of Ch6 Sec4, 2.6 isapplicable to deck primary supporting members in Fore and Aft. In calculating
the scantling of the members in Fore and Aft according to the formulaspecified in Ch 6 Sec 4, 2.6.3, we understand that the applicable allowable
shear stress and lamda_s are R_y/square root (3) and 0.9 instead of 0.4 R_y
and 0.8, respectively, because the lamda_p is 0.9 in the formula for plating of
aft part specified in Ch 9 Sec 2. Please confirm the above.

Your interpretation is not right. If the scantling formulae for primary supporting
members are used in the fore and aft part, lambda-s and the allowable shear
stress, given in CH6, Sec4, are to be used (i.e. lambda-s equal to 0.8 andallowable shear stress tau-a equal to 0.4Ry). However we will consider arule change in Ch.9 Sec.1 [4.4.4] and Ch.9 Sec.2 [4.3.4] so that therequirements to primary supporting members are coherent within Ch.9 Sec.1
and Ch.9 Sec.2 respectively.

Thickness ofabutting
plate

Reference is made to Chapter 11 Section 2 Table 1. Thickness of abutting
plate. Ref note (1) “t is as-built thickness of the thinner of two connected
members” However, in Chapter 11 Section 2 Figure 1, t refers to “as-built
2008/10/10
thickness of abutting plate”. Assuming that t1>t2 in attached figure. From astrength continuity point of view we assume t1 should be applied whenevaluating the criteria. Please confirm Please update Table 1 accordingly.

Topic

Externalpressures on
exposeddecks

2008/7/16

AttachmentYour interpretation is right. We will consider the Rule Change proposal.

Y

A separate definition of x (load point in the reference co-ordinate systemdefined in Ch.1, Sec.4) appropriate for pressures defined in Ch.4, Sec.5, Table
4 is necessary.
External pressures on exposed decks (on hatch covers in Ch.9, Sec.5 as well)for load case H1, H2, F1 and F2 are calculated based on x/LLL where LLL is afreeboard length as defined in Ch.1, Sec.4, 3.2, while x is the X co-ordinate of
the load calculation point from the aft end of the scantling length L. The aftend (AE) in Ch.1, Sec.4, Figure 4 is relevant to the scantling length L only
We will consider the rule change proposal in order to be in line with IACS UR
despite the fact that positions of the aft end and fore end in L are not the same
S21.
as those in LLL.
It is therefore proposed that x in Table 4 is to read 'xLL' measured from the aftend of freeboard length LLL to be aligned with the text in the amended ILLC or
IACS UR S21, the origin of the requirement.
A background of this proposal is a sample calculation below indicating aconsiderable difference in pressures between CSR-BC and IACS UR S21.
For exposed deck in way of No.1 cargo hold of a capesize bulk carrier where
LLL=279.622 m, a=0.356.

1) x(from aft end of L)=250.787 m, pw=80.564 kN/m2 according to the current
CSR-BC Ch.4, Sec.5, 2.2.1.
2) x(from fore end of LLL=24.872 m, pw=85.028 kN/m2 according to IACS UR
S21,2. In this case x(from aft end of LLL)=254.750 m.
The difference in pressure exceeding 5% should not be ignored.

672
Table 11.2 Question
attc

fillet weld

2009/3/3

Ch11 Sec2, Table2 regulates the fillet welding as follows;- The ends of stiffeners : F0.
- The brackets at the ends of stiffeners : F1
In case of stiffeners which are fitted with brackets at the ends, we think it
acceptable to apply F1 welding to the ends of the stiffeners. (Please refer tothe attachment.) Please confirm the above.

Where a bracket is provided at the end of a PSM or an ordinary stiffener,stresses in a PSM or an ordinary stiffener may be reduced at its end.
Therefore, the fillet weld size F0 may be reduced to F1 which is the same asintended for brackets.
Table 2 will be updated accordingly.

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KCID
No.

Ref.

673 4/3.2.2.2,
attc & 4/3.3.1.1

Type

CI

Topic

Still Water
bending
moments

Datecompleted2008/4/18

Question/CI

Please see attached Question

Answer

Attachment

The assumed still water bending moments specified in Ch 4 Sec 3, 2.2.2 areused for strength check other than fatigue strength when the design still water
bending moments are not defined at the preliminary design stage. In this case,the coefficient fp should be taken as 1.0.
The assumed still water bending moments may be used for fatigue checkwhen the design still water bending moments are not defined at the
preliminary design stage.
In this case, the coefficient fp should be taken as 1.0 too, because the staticload components are independent of the probability of occurrence.
Therefore, our interpretation is given as follows.
In applying the requirement 2.2.2 of Ch 4 Sec 3, MWV,H and MWV,S arecalculated by 3.1.1 with fp=1.0.

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674

Ref.

3/6.7.2.1

675

7/2.3.2.3

676

Table
11.1.1680

1/1.1.1.2

Type

CI

Topic

DSS BC

Question

doublebottomgirders

RCP

IACS
recommenda
tion No.47

Question

Bilge hoppertank and
VOID

Datecompleted

Question/CI

Attachment

Answer

2008/4/24

In case of a DSS BC which hopper and double side space forming a single
sea water ballast tank, whereas the topside tank is a dry compartment, we
Answer or Interpretation:
have the following question:
A1- The topside tank in this case (dry compartment from the water ballast tank
1 - In relation to KC#510, should this topside tank be considered as a waterin double side space) should be considered as a dry compartment since it isballast compartment for the purpose of net scantling and fatigue assessment? physicaly separated from the double side space.
In case of yes:
A2- Not relevant
2 - Should this topside tank be considered as a separated water ballast tank or A3- It is considered as a dry compartment for corrosion addition tc as similar
continuous with the double side tank?
to the design principle specified in Ch 3 Sec 6 7.2.1.
3 - Since it is for the purpose of NET scantling, does that mean that corrosion
thickness tc should be considered as that of the actual dry compartment
instead of the virtual water ballast compartment?

2009/5/27

1) Is it suitable to evaluate the equivalent stress of the coarse mesh of adouble bottom longitudinal girder (3 elements over the height and loaded withbending), if the element size of the upper and lower element is 1.2 x frame
spacing? What is the maximum allowable element size and/or number in
relation to the girder height in order to consider the bending stress in theequivalent stress criteria?
2) Please confirm that is not necessary to model a dummy truss element at
the connection of the double bottom girder to adjacent plating in order toevaluate the bending stress of the girder!
3) If a girder is built with a flange instead of connecting two PSM, the axial
stress of the flange is to be evaluated and has to be within the design limits(S_axial<=235/R_eH)?

2008/5/6

As stated in Ch11 Sec1, 1.3.1, Table1 is based on IACS recommendation
No.47.
However, it does not match the latest one, Revision 3 of IACS
recommendation No.47 issued in November 2006.
We request to update Ch11 Sec1, Table1 as the latest one.

We will consider the rule change proposal.

2008/6/19

This bulk carrier is arranged with bilge hopper tank and VOID or TRUNK
space at deck as attached.
Please confirm whether CSR should be applied to the bulk carrier or not.

As stated in Ch1 Sec1, 1.1.2, CSR should be applied to a bulk carrier withtopside tanks. The questioned bulk carrier also has the configuration of
topside tanks, where VOID or TRUNK space is arranged in your sketch. The
usage of the space does not affect the application of CSR.
Accordingly, the ship should be applied with CSR.

1. The girders such as the 1/3 of its height are 1.2 time of longitudinal frame
spacing should be divided into 4 or more elements height-wise. In general,mesh height of girder is expected less than spacing of longitudinal stiffeners
according to Ch.7 Sec.2 2.2.4.
2.Such dummy element is not required from CSR requirements.
3. The axial stress of the flange should be less than the design limit (235/k).
This is the same as the axial stress of flange of trans. rings in bilge hoppertanks and top side tanks should be less than design limit according to Ch.7
Sec.2 3.2.1.

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No.

Ref.

Type

Topic

681
attc

6/2.3.3.3

RCP

Gross
Thicknessand NetThickness
Scantling682

6/3.4.2 &6/3.4.3

Question

stiffeners

Datecompleted

Question/CI

Answer

Attachment

Y

2008/4/11

It is proposed that the paragraph in CSR-BC, Ch.6, Sec.2, 3.3.3 be changedin part to eliminate the equivocality as shown in the separate attachment.

IACS UR S12 Rev. 4 is based on the gross thickness.
CSR is based on the net thickness scantling.
According to Ch 3 Sec 3, the total corrosion addition for webs and flanges oflower brackets of side frame is 5.0mm, and the total corrosion addition of side
frame other than lowe brackets and upper brackets is 4.5mm.
According to the current requirement of 3.3.3, the gross thickness of lower
bracket is greater than 2.0mm of the thickenss of web of side frame.
Therefore, as the current rule of Ch 6 Sec 2 3.3.3 is in line with IACS UR S12,
the text is kept as it is2009/3/3

Are Ch.6, Sec.3, [4.2] and [4.3] applicable to stiffeners on watertighttransverse bulkheads in lower/upper wing tanks and double side and on
watertight floors ?

Ch.6, Sec.3, [4.2] and [4.3] are applicable to the stiffeners on watertighttransverse bulkheads in lower/upper wing tanks and double side and on
watertight floors. In case of hull transverse section analysis, the axial stress forstiffener and shear stress in attached plate are not to be considered.

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No.

Ref.

Symbol9.5,
684 9/5.5.3.2,
9/5.5.4.2 &9/5.5.4.6

Type

RCP

Topic

minimum net
thickness of
web plate ofordinary
stiffeners
and primary
supportmembers

Datecompleted

Question/CI

Attachment

Answer

According to Ch.9, Sec.5, Symbols:s is defined as length, in m, of the shorter side of the elementary plate panel.
My understanding to the minimum net thickness of web plate of ordinary
stiffeners and primary supporting members is as follows:
According to Ch.9, Sec.5, [5.3.2], The minimum net thickness of web plate ofordinary stiffeners should be (tnet)min=min(10s,6), while in the calculation, theparameter s should be of web plate panel of ordinary stiffeners (normally web
height) and should have no relation to the top plate panels of hatch cover.
This understanding can also apply to determine the minimum net thickness of
web plate of primary supporting members.
Regarding the minimum net thickness of web of ordinary stiffeners andprimary supporting members, please refer to the answer in KC ID 535.
In addition, the correct formula for kt is kt=5.35+4.0/(a/d)^2 as specified in
IACS UR S21.3.6.3.

2008/5/13

According to Ch.9 Sec.5, [5.4.2],The minimum net thickness of web plate ofprimary supporting members should be (tnet)min=min(10s,6) the parameter s We will consider the Rule Change proposal or edditorial correction on thismatter.
should be of web plate panel of primary supporting members (normally web
height) and also have no relation to the top plate panels of hatch cover.
If the above understanding is correct, then there will be no limit to use thecurrent widely used ordinary stiffenr L125x75x7 in hatch covers of vessels with
CSR BC notation.

We propose to revise the text for minimum net thickness of web plate ofordinary stiffeners and primary supporting members in Ch.9 Sec.5 [5.3.2] and[5.4.2], respectively.
The formula kt in Ch.9, Sec.5 [5.4.6] should be corrected as
kt=5.35+4.0/(a/d)^2 or kt=5.35+4.0(d/a)^2.

685

686

6/3.2.1.3 &Question
5/1.2.2.1

Shear force
for bucklingassessment

9/5.5.2.1

Water
BallastPressureCI

2008/5/30

Ch.6,Sec.3,[2.1.3] defines the shear force for buckling assessment as follows:
Q=Q_SW + C_QW x Q_WV.
There seems to be no limitation to the signs of Q_SW and Q_WV for their
combinations. On the other hand Ch.5, Sec.1, [2.2.1] reads: "When they are
combined, vertical shear forces Q_SW and Q_WV in intact condition are to betaken with the same sign."
Which way should be taken when calculating Q in Ch.6, Sec.3, [2.1.3]:a) Q to be calculated only for the combinations where Q_SW and Q_WV areof same sign, orb) Q to be calculated for all combinations where Q_SW and Q_WV are ofeither same sign or opposite signs ?

Hull girder shear stress check should be performed at the maximum absoluteshear force. Such case occurs at the combination of either(1) Q_SW_pos +(C_QW_pos x Q_WV), or(2) Q_SW_neg +(C_QW_neg x Q_WV), where,
C_QW_pos , C_QW_neg : positive and negative load combination factors
according to load cases as defined in Ch.4, sec.4,Table 3.
The sentence in Ch.5, Sec.1, [2.2.1], which is quoted in the question, reflects
this interpretation.
Therefore we will consolidate the paragraphs referring to shear force
combination into CH5, Sec1 [2.2.1] and replace CH6, Sec3, [2.1.3] with a notereferring to CH5, Sec1.

2008/4/10

FEM’s Fs and Fw for water ballast pressure on Ch 9 Sec 5
The water ballast pressure will be calculated by using Fw (=0.9) for net
thickness (Ch9, Sec 5. 5.2.1) and isolated beam models.
We think it can be applied for FEM too, is it correct?

We think that the combination of the static load and dynamic load for hatch
cover in way of ballast hold is introduced as a special case.
Therefore, the factor FW=0.9 is also applicable for FEA.

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No.

688

Ref.

8/4.2.3.3

Type

Question

Topic

Fatigure of
stiffener end
connection

Datecompleted2008/5/28

Question/CI

Attachment

Answer

Reference is made to Ch.8 Sec.4 [2.3.3] – Fatigue of stiffener end connection– Stress due to wave pressure
Design pressure in the formula is CNE x pw.
The statement of Ch 4 Sec 5, [1.1.1] is not valid when calculating sea
pw should be calculated according to Ch. 4 Sec. 5 [1.3], [1.4], [1.5]
pressure according to Ch 8 Sec 4, [2.3.3]. Becasue Ch 8 Sec 4, [2.3.3] is
Ch. 4 Sec.5 [1.1.1] is generally valid for Section 5. Quote “The total pressure p concerned only the hydrodynamic pressure, not the static pressure.
at any point of the hull, in kN/m2, to be obtained from the following formula is
The statement of Ch4 Sec5[1.1.1] is only applicable to the one wave state.
not to be negative: p=pS+pw.” Unquote
When a wave, which has a certain wave height, is acting on the ship's side,
It is unclear whether or not [1.1.1] is valid for pressure calculation for Ch.8
wave pressure has to be corrected so as not to generate negative pressure.
Sec.4 [2.3.3].
Therefore the degree of correction is different by the wave height although the
Please note that if no correction to the dynamic pressure is made, the total
correction procedure is the same.
dynamic pressure for side longitudinals right below the water line is larger than The statement of Ch8 Sec4[2.3.3] is introduced to obtain the expected wave
the static pressure at the same location, that is Ps+(CNE x pw) < 0. This is in condition considering the stochastic nature of wave height so as to evaluate
contraddiction to the general statement in Ch.4 Sec.5 [1.1.1]
stress range for fatigue assessment.
Q1: Is the statement of Ch.4 Sec. 5 [1.1.1] valid when calculating sea pressure
for Ch.8 Sec.4 [2.3.3]?
Q2: If yes, it is assumed that Ch.4 Sec.5 [1.6.2] should be used for correcting
the dynamic sea pressure. Please advice how to apply [1.6.2]:
a.No correction according to [1.6.2] is made for pw when calculating CNE?
b.Correction of dynamic pressure according to [1.6.2] for the total dynamic
pressure
pw = CNE x pw(uncorrected)?

689

3/6.7.2.1

CI

Where thedouble side
space is void

2008/5/28

Chapter 3 Section 6 Par 7.2.1 states as follows:"Where the double side space is void, the structural members bounding thisspace are to be structurally designed
as a water ballast tank according to Ch 6. In such case the corresponding air
pipe is considered as extending 0.76
m above the freeboard deck at side."
Is therefore to be interpreted that in fatigue calculations, performed according
to Chapter 8, these spaces are to be considered void? This is reasonablebecause such spaces are actually void in operating conditions. If confirmed, it
could be useful to give explicit mention of this in Ch 3 Sec 6 Par 7.2.1.

Where the double side space is void, the requirement in Ch 3, Sec 6, [7.2.1] isclear enough as it requires only the application of Ch 6 as water ballast tankand doesn't require anything for fatigue. It is confirmed that these spaces areto be considered as void for the fatigue assessment.

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No.

690

692

693

694
attc

696

Ref.

12/1.2.1.3

1/1.1.1.2

9/4.3.2.1

Type

Topic

QuestionGrabrequirement
(tGR)

CI

Question

combination
carrier

Lateralpressure fordeck

4/5.4.1.1

Bow flare
Question reinforcement10/1.5.2.1

Influence of
the aspectratio of plate
panelsQuestion

Datecompleted

Question/CI

Answer

2008/3/13

Is the Grab requirement (tGR) specified in Ch.12 Sec.1 [2.1.3] applicable toplating of Collision and Engine Room Bulkhead within 3.0m from inner
bottom? Or is there any other paragraph requiring reinforcement against grab
handling to these bulkhead plates?

Swinging of the grab by the operator may provoke great impacts on thebottom of any side of a hold. The requirements of Ch.12 Sec.1 [2.1.3]areapplicable regardless of the design and the function of a cargo hold bulkhead.

2008/9/10

Reference is made to Ch.1 Sec. 1 [1.1.2] . Vessel in question is a 7 hold
Bulk carrier where 3 holds are arranged for carriage of Caustic Soda. Vessel
has traditional bulk carrier cross section with top wing and hopper tank in
As the ship is 7 hold Bulk carrier having cross section with top wing andcargo area . According to [1.1.2] CSR is not applicable for combination
hopper tank in cargo area, even if some holds are arranged for carriage ofcarriers. However, combination carrier according to SOLAS definition is a
Caustic Soda, it should be considered as a CSR bulk carrier, if intended
vessel that can carry both dry bulk and oil. As Caustic soda is characterized as primarily to carry dry cargoes in bulk, which seems to be the case. An
a chemical and not oil we are of the opinion that above vessel can not be
additional consideration to necessary equipment and hydrodynamic load due
considered a combination carrier. Following this, we consider that this vessel
to loading of caustic soda solution, if applicable, should be made , whichshall comply with CSR in addition to be designed to carry Caustic soda in the should be subject to the review and approval of the class.
specified cargo holds. Design loads from the liquid cargo will be used andbased on the principles as given in CSR. Please advice.

2008/5/1

Ch9 Sec4, 3.2.1 regulates the lateral pressure for deck to be p_D in Ch4
Sec5, 2.1.
However p_D in Ch4 Sec5, 2 is the external pressure on the exposed deck.
No clear indications are found in CSR for the lateral pressure on theunexposed deck, such as the deck inside of accommodation.
Please clarify the above.

2008/4/24

The bow flare reinforcement should be considered above the normal ballast
waterline in the fore part, with reference to the bow flare area pressure
Reinforcements due to large dynamic pressures, caused by bow flare, areregulated in Ch4 Sec5, 4.1.1
only necessary, when the flare angle is positive. Large "flare loads" on the top
Just above the normal ballast waterline, the flare angle, alpha, may be inclinedof the bulbous bow are not physical possible.
inside as the attached sketch.
Please show how to treat the flare angle, alpha, in the case as above.

2008/5/28

In Ch.10, Sec.1, [5.2.1] the following sentence is read:"The influence of the
aspect ratio of the plate panels may be taken into account according to Ch 3."
Q1: Which paragraph in Ch.3 is referred to ?
Q2: Isn't it the intention to apply c_a factor as used in the formula in Ch.6
Sec.1, [3.2.1] ?

Attachment

A lateral load for unexposed decks will be defined. We will initiate a rulechange proposal.

The wrong reference to chapter 3 is a direct copy of the underlying rules. The
formula for the consideration of small aspect ratios for rudder plating iscurrently not given in the CSR-BC. Without the influence of the aspect ratio
the necessary plate thickness is slightly conservative.
We will make a rule change proposal to fix this problem.
The usage of c_a according to CH6, Sec1 is not applicable for thedimensioning of rudder plating

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6/2.1.4.2

9/3.2.1.8

Type

Question

QuestionTopic

The pressureP

wef stiffenerDatecompleted2008/7/16

2008/9/10

Question/CI

Answer

Attachment

The attachment contains four pressure distibutions, where the pressure p can
not be derived according to the formulae in Ch.6 Sec.2 1.4.2 How to calculate
the pressure p, used in Ch.6 Sec.2 3.2.3 for examples(1)The pressure distributions shown in cases (c) to (f) may effectively occur
when differential pressures are to be considered, i.e. only for vertical stiffenersof the outer shell. However, the scantling of such stiffeners is quite always
governed by the case "still water and wave external pressures" to be applied
independently of the differential pressures (see Ch 6, Sec 2, [1.3.1]).
(2)In addition, such distribution of presssure may be approached by one of thetwo "standard cases" defined in [1.4.2]. This gives wrong results, but
regarding the comment in (1), it doesn't affect the scantling.
(3)Of course, some definition of "p" for these distributions may be developped,
but no effect on scantlings will occur (see comment in (1)above).

Y

With regard to a requirement of web stiffener on non-watertight double bottom
floor in Engine Room, it is requested to provide the detailed technicalbackground while it is understood to have been based on the protection of
web plate buckling, and it is also requested to modify it considering current
designs with almost no damage record.

The formula in Ch 6 Sec 2 [4.1.2) is the based on the following assumption.
(See attached file)(a) web stiffener is flat bar type.
(b) thickness of web of web stiffener is equal to that of web of PSM.
(c) the height of web stiffener is approximately equal to (stiffener length/12) as
specified in Ch 3 Sec 6 [5.1.2](d) the effect of the attached plate is considered as a function of spacing of
web stiffener

Re. the technical background, it is noted that the equation in 6/2.4.1.2 is notdimensionally balanced, i.e., left side = cm3, right side = m5. In addition,
9/3.2.1.8 requires the section modulus as 1.2 times of that required by
6/2.4.1.2. The reason of this 1.2 times should be also clarified.

This requirement is provided to ensure the minimum stiffeness of web
stiffener, hence this requirement is applicable to all types of stiffener (flat bar,angle, T-section). The meaning of 1.2 times of that required by Ch 6 Sec 2[4.1.2] seams to the safety margin based on experiences.

Re. the section modulus requirement compared with the current design of
non-CSR, it is noted that CSR BC Rule requires much severe web stiffener
scantling than that of non-CSR. Our example calculations show:(A)Capesize – 300*90*13/17 (CSR),à200*90*8/14 (as built)(B)Panamax – 150*16 FB (as 200*20 FB (CSR),àbuilt)
250*90*9/15à
(C)Handymax – 200*90*9/14 (as built) (CSR)
Hence the requirement should be modified considering current designs withalmost no damage record..

When the effect of the attached plate is considered, the mentioned example isprobably satisfied with the requirement in Ch 9 Sec 3 [2.1.8]. However, we
will consider the RCP in order to elminate the dimentional unbalance between
left side and right side in the formula of Ch 6 Sec 2 [4.1.2] together with thecarifiction of the application. Furthermore, according to this TB, the answer in
KC ID 418 should be modified as follows: The net sction modulus of web
stiffener of non-watertight primary supporting member should be calculatedwith the attached plating, according to Ch 3 Sec 6 [4.3.1].

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No.

700

701

702
attc

Ref.

9/3.3.1.2

Table
3.3.1

3/6.4.5.2

Type

Topic

Question

Longitudinal
Structure

QuestionCorrosion
addition on
one side ofstructuralmembers

Question

Ordinary
stiffeners

Datecompleted

Question/CI

2008/7/16

Ch9 Sec3, 3.1.2 regulates that the longitudinal structure should be maintained
for at least 0.3 times the length of the machinery space.
We have an opinion that the above requirement is not applicable to thefollowing members.
-Longitudinal bulkheads-Topside slant plates-Bilge hopper slant plates
Because the longitudinal continuity of the above members can be ensured by
the appropriate fitting of girders/large brackets on the back side of E/R
bulkhead.
Please confirm the above.

2008/5/28

2008/5/30

Ch3 Sec3, Table 1 regulates the corrosion addition on one side of structuralmembers.
Please advise which corrosiion addition in Table 1 should be applied to theinner side of hollow pillar.

Attachment

AnswerWe confirm your interpretation.
The extension concerns only the longitudinal structure attached to the side
shell and doesn't apply to the plantings and attached ordinary stiffeners ofstringers of DSS, topside tank and bilge hopper tank. In addition, thecontinuity of strength is to be ensured in the machinery space in way ofstringers of DSS and strake of topside tank / bilge hopper tank directly
attached to the side shell.

A hollow pillar or the space behind a shedder or gusset plate is airtight closed.
This means that oxygen will be dissipated in the first corrosion process andwill be not replaced by new one. This is different from void spaces, where
irregular inspections are carried out through man holes.
Therefore, the corrosion addition for the inside of a hollow pillar and gusset or
shedder plate is to be taken equal to 0.5mm as a void space.

Ch3 Sec6, 4.5.2 regulates as follows;
Where ordinary stiffeners are cut at primary supporting members, brackets areto be fitted to ensure structural continuity. In this case, the net section modulus
and net sectional area of the brackets are to be not less than those of theordinary stiffener.
Please confirm the definition of “the net section modulus and net sectional
area of the brackets” as follows.
1. The section of the bracket and the stiffener;
When web and/or flange of stiffener is welded to primary supporting member
1-a. at the end of the stiffener.
(1-a) may be taken. For other cases (2-b) should be taken.
1-b. at the mid-point of the free edge of the bracket.
In case 1, is the snipped flange of the stiffener included in the calculations?
2. The section of the bracket;
2-a. normal to the free edge of the bracket.
2-b. at the end of the stiffener.
2-c. attached to the stiffener.
2-d. smaller of 2-b and 2-c.
(Refer to the attached sketch)

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709

711

716

Ref.

6/2.4.1.3 &Figure6.2.9

9/6.3.3.4

3/1.2.3.3

Table
4/A.2.1

Type

Topic

CI

Web
stiffeners ofprimary
supporting
members

Question

Required
thickness ofthoughened
glasses inside scuttles

CI

CI

Steel gradeof bedplates

DSA

Date
completed

Question/CI

Answer

Attachment

2008/5/28

Ch.6, Sec.2, [4.1.3] says that this requirement is applicable to the web
stiffeners of primary supporting members in water ballast tanks when no
bracket is fitted.
On the other hand Fig.9 shows, at its left end, the stiffener with integrated
bracket at toe to which the subject requirement is applicable.
What is meant by "when no bracket is fitted". Please advise if theinterpretation on applicability of the requirement is as per the attached casesof stiffener.

It is obviously that Case 1 and Case 3 is applicable to this requirement
because the bracket is not fitted as shown in the attached file.
For Case 4 to Case 6, as the bracket is fitted to the web stiffener and thevalue “h’” becomes large, the stress range delta-sigma is small, then suchcases are always complied with this requirement.
Therefore, although Case 4 to Case 6 shown in the attached file is applicableto the requirement, it is not considered that the check according to thisrequirement is necessary for such cases.
For Case 2 shown in the attached file, although the bracket is fitted, thesmallest breadth of such case depends on the bracket size and shape and issimilar to that of Case 3. Therefore, this case should be applied to therequirement of Ch 6 Sec 2 [4.1.3] as mentioned in the attached file.
As a conclusion, the interpretation specified in the attached file is correct.
In order to clarify this interpretation, the editorial correction will be considered
as "Corrigenda".

Y

2008/5/28

Ch.9, Sec.6, [3.3.4] specifies the required thickness of toughened glasses inside scuttles.
Is the calculated thickness to be rounded up or round off or others?
For instance, in case the calculated values are 12.24mm, 12.27mm,
12.40mm, 12.52mm, 12.85mm, what are the required actual thicknesses
respectively?

The glass thickness to be fitted is the thickness available from the glasses
manufacturers and above the calculated value.

2008/5/28

Technical Background document says that Ch.3, Sec.1-2.3.3 is derived from
BV Rule Part B, Ch.4, Sec.1, Note 2 of Table 3. The requirement of Ch.3,
Sec.1-2.3.3 is, however, different from the latest BV Rule, saying:‘The steel grade of bedplates of seats for propulsion and auxiliary engines
inserted in the inner bottom is not to be less than A/AH for plate thickness
lower than 40 mm. For plate thickness greater than 40 mm, different grades
may be required by the Society on a case by case basis’.
Hence the requirement of CSR BC Rule should be interpreted as same as thelatest BV Rule. Please confirm...

The requirement in CSR is correct. Referring to Class I (Tab3),it means that
A/AH is required for thicknesses up to 30 mm, then B/AH up to 40 mm andD/DH up to 50 mm.
In BV Rules it was required A/AH up to 40 mm and requirement "on a case bycase basis" above 40 mm.
We think that the requirement in CSR-BC is more clear and more easily
applicable.

2008/10/3

CSR_JBP_Chapter4_Appendix 2 Standard loading condition(e.g table1 No.5
load pattern) for DSA.
With respect to the ballast water load pattern ofthe deepest ballast condition, current rule gives one standard loading
pattern(e.g. load pattern No.5 in table 1), in which the upper wing tanker in
way of the middle cargo hold is fully filled but hopper tank and double bottomtank in way of the middle cargo hold are empty. However, in many actual
design practice, the wing ballast tank is normally connected to the hopper
ballast tank. In addition, the ballast tank is sometimes designed to cover two
cargo hold region. Therefore, there would be three loading pattern options for
DSA, as illustrated in attached document. Please kindly clarify or provide
common interpretation that, Which load pattern exactly is to be used for DSA?

The loading pattern 5 in Table 1 of Ch 4 Appendix 1 corresponds to therequirement of Ch 4 Sec 7 [3.2.3]. Where the topside water ballast tank isconnected to bilge hopper or double bottom water ballast tank or where theballast tanks are designed to cover two cargo hold region, the topside waterballast tank or the ballast tanks extended over two cargo hold region shouldbe empty in order to be empty with all double bottom tanks in way of cargohold being empty. In this case, the deepest ballast tank specified in theloading manual should be used.

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718

719

Ref.

6/3.3.2.4

7/2.3.3

7/A2

Type

CI

CI

CI

Topic

buckling
check

Change ofelement
thickness &material in
EPP buckling
check

Displacemen
t bucklingcheck basedon DSA

Date
completed

Question/CI

Answer

Attachment

2008/9/10

Chapter6_Sec3_[3.2.4] Does tensile stress need to be considered for bucklingcheck? Regarding the tensile stress , there is still different view point onwhether it need to be considered for buckling check or not. There would be asolution that, 1) For check the resultant buckling utilization factor, combinedby sigma_x, sigma_y and tao, the tensile stress need to be considered as theactual values but with negative sign. 2) For check the individual buckling
utilization facor, the factor would be taken as 0. Please be kindly request to
provide clarification or confirmation.

1) Even if the estimated stress is negative (tensile stress), the buckling checkshould be carried out according to the first formula specified in Ch 6 Sec 3[3.2.4] using the actual values. 2) No individual buckling checks have to be
performed for tensile stresses. It is clearly stated, "In addition, each
COMPRESSIVE STRESS ... are comply with the following formulae."Y

2008/7/31

Chapter7_Sec2_[3.3] Change of element thickness & material in EPP buckling
check
Regarding the EPP, which consist of elements with different thickness and/or
material yielding strength, it would better provide a practicable approach forbuckling check based on DSA reults. Currently, there would be three options ,1) The weighted average thickness, along with the minimum material yieldstrength will be used
2) The weighted average thickness, along with the weighted average material
yield strength will be used
This issue is still under investigation. An interpretation will be prepared.
3.1) When the plate thickness changes within the field breadth b, bucklingstrength may be checked for an equivalent plate field axb' by using the smaller
thickness t1, whereb' = b1 + b2 * ( t1 / t2) ** 1.5.
In this case b1 is the breadth with the smaller thickness t1 and b2 is thebreadth with the larger thickness t2 within the total breadth b..
3.2) When the plate thickness of an elementary panel varies over the length""a"", the minimum plate thickness will be used.
3.3) Anyway, for elements with different material yield strengths, the minimum
material yield strength is generally to be used.
Please be kindly request to provide clarification or confirmation.
Chapter7_Appendix2 Displacement buckling check based on DSA
JBP rule provides a displacement method to obtain the reference stress forbuckling check of EPP. However, following issues would still need to beclarified,

2008/7/31

1)The conditions, under which the displacements method is to be used
compulsively.

A1 The displacement method for evaluating the stresses of panel is notcompulsively.
A2 Yes, the displacement method is optional.

2)Does the displacement method is just optional ? Therefore, we could use
stress method only for any EPP buckling check.

720

3/1.2.3.9

Question

Grades ofsteel

2009/6/2

What kind of plate member shall be considered here ? Is it also applied tosmall plate members such as oil spill coaming at mooring winches?

This requirement applies to the longitudinal members attached to the outside
plating of the hull and which have lengths greater than 0.15L such as gutter
bars. For example, an isolated oil spill coaming at mooring winches is not in
the range of the application.

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Type

Topic

Date
completed

Question/CI

Answer721

Chapter 4

Questiondesign loads

2009/6/2

Rules for protected/non-watertight decks cannot be found. Please clarify thedesign load for protected decks; platform decks in engine room or upper deck
under superstructure.

Presently, design loads for protected/non-watertight decks, including platformdecks in engine room and upper deck under superstructure, are based on
individual society Rules.

722

6/4.4.1.1

Question

Pillars

2009/6/2

Please clarify the design load for pillar scantling calculation.

The design loads acting on the pillar are the static and dynamic loads that are
acting onto the decks above the pillar under consideration. These loads are to
be determined according to Chapter 4 considering the relevant loads on thedecks above.

Attachment

723

9/2.4.1.1 &Question
Table 1

Net minimum
thickness ofplating

2009/6/2

To which dose the tank top plate of steering gear flat correspond in Table 1,[Inner bottom] or [Platform and wash bulkhead] ?

Platform and wash bulkheads in Table 1 Ch 9 Sec 2 are non-watertight plating
members. As the tank top plate of steering gear flat is a watertight plating
member and not inner bottom, the net minimum thickness for the tank top
plate of steering gear flat is not specified in Table 1. As an interpretation, thenet minimum thickness for the tank top plate of steering gear flat is the sameas that for watertight bulkhead specified in Ch 6 Sec 1, Table 2, i.e.
0.6xL^(0.5) mm.

724

9/2.5.2.1

sidetransverse

2009/6/2

Is there any exceptional easing steps concerning spacing of a ship's sidetransverse spacing?

The required side transverse spacing is based on design experience andservice history. It has proven to be satisfactory and cannot be relaxed.

2009/6/2

Refer to KC ID 543 which states: PSM in the fore and aft part of the vessel
may be designed according Ch6, Sec4, 2.6. We will consider the further rule
development about the determination of the scantling of primary supporting
Please explain a specific procedure of the direct strength calculation in engine
members outside midship cargo regions for ships of 150m in length androom construction.
above. For the time being, the direct strength calculation should be submitted
to the Society for examination on a case by case basis, as specified in Ch 9
Sec 3, [1.2.3].

725

9/3.1.2.3

Question

Question

Primary
SupportMembers

2009/6/2

The width of aft peak tank is generally narrow at the double bottom level ofengine room when the engine room is located immediately forward of aft peaktank. Considering the aspect ratio (l/b) of double bottom in such an engine
Please explain the reason that the double bottom is to be transversely framed.
room becomes very large, where l is the length of engine room and b is themean breadth of engine room, it would be natural to provide main supporting
members transversely. This requirement stands on this background.

2009/6/2

We would like to have your confirmation whether the arrangement ofoverlapping tank top is acceptable as continuous structure.
Please see attachment below.

726

9/3.2.1.1

Question

doublebottomgeneral727
attc

9/3.2.1.2

Question

doublebottomheight

CSR-BC allows only a sloped transition, when the inner bottom of the cargoarea is on another level than that of the machinery space.

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No.

Ref.

Date
completed

Attach
ment

Type

Topic

2009/6/2

The extension described in [3.1.2] concerns only the longitudinal structureattached to the side shell and doesn't apply to the platings and attachedIs the extension of longitudinal structure applied to the platings of topside tank ordinary stiffeners of side stringers, topside tank and bilge hopper tank.
and bilge hopper tank?
However, in the light of Ch 9, Sec 3, [1.3.2], the continuity of strength is to beensured in the machinery space in way of side stringers and strake of topsidetank / bilge hopper.

Question/CI

Answer728

9/3.3.1.2

Question

longitudinal
structure
within themachinery
space

729

9/3.4.1.2

Question

platformtransverse

2009/6/2

Is it possible to arrange platform transverses 5 frame spacings as well as
3.1.3 Side transverses? Usually , the platform transverses are connecting toside ransverses continuously.

According to the last sentence of [3.1.3], wider spaces may be accepted
based on the discretion of the Society.

730

9/3.6.1.1

Question

Ordinary
stiffener
spacing

2009/6/2

Is there any exceptional easing steps to the regulation about 750 mm
spacing? Usually, the vertical stiffeners are connecting to the deck
longitudinals continuously.

No, there is not. The required value of about 750mm for spacing, which wasdeveloped based on many years of experience, is applied and considered tobe satisfactory. However, the vertical stiffeners are to be connected to thedeck longitudinals continuously.

2008/9/10

Chapter4_Sec2_[2.1.1] - GM & Kr value for others load conditions . The valueof GM and Kr will affect the roll motion and consequently affect the inertia
loads. Current CSR Bulk carrier rule only specify GM & Kr for three standard
load conditions (i.e. full load condition, normal ballast and heavy ballast).
However, regarding some load condition used for DSA (e.g.multiport loadcondition), there is no any specification in the rules on how to decide GM andKr for such conditions. It is found that CSR Tanker rules provide theinstruction for those non-standard load conditions as follows, "For optionalloading conditions with a mean draught other than the values defined, GM isto be obtained by linear interpolation based on values for 0.6Tsc and
0.9Tsc."[JTP section 7/3.1.3.2] Please kindly advise how to calculate the kr &GM for those load conditions, which is not specified in the table 1 of
CH4_SEC2_[2.1.1], particularly for the multiport load condition.

The GM and k_R values as given in Table 1 are only preliminary values. The
scantlings and the approval have to be based on the actual values. For the
purpose to make an initial design, the designer has to choose preliminary
values from his/her experience or from the mentioned table. In case of a multi
port loading condition you may use the GM and k_R values for full loadcondition.

2008/7/2

In Ch 7, Sec 1, relevant to direct strength assessment of the primary
In this context, a "recognized" program is a FEA program well known andsupporting members, the requirement [1.2.1] states that: "Computer programs
widely used in the shipbuilding industry, which has been proven its reliability.
for FE analysis are to be suitable for the intended analysis. Reliability of"Recognized " program in this context doesn't mean that such program shoud
unrecognized programs is to be demonstrated to the satisfaction of the Society
be recognized by a specific procedure from Class Society or IACS.
prior to the commencement of the analysis."
The meaning of "unrecognized" programs needs to be clarified.

736

738

4/2.2.1.1

7/1.1.2.1

CI

load
conditions

Question

Strength
Assessmentof theprimary
supporting
members

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739

741

Ref.

9/2.3.1.2

4/6.1.1.2

Type

RCP

CI

Topic

frame
spacingcargoparameters

Datecompleted

Answer

2008/9/10

The requirement in Ch 9, Sec 2, [3.1.2] requiring that "Solid floors are to be
fitted at every frame spacing" seems very severe and is not in line with someactual design of ships.We would like to ask IACS to review this requirement
and to introduce a Rule Change Proposal.

It is not required to built solid floors at every frame spacing in the whole aftpeak area. Solid frames up to the tank top are only required in way and nearof rudder post, propeller post and rudder horn. The transverse extension
depends on the arrangements proposed. It might be neccessary to built solid
floors below tank top over the whole breadth, e.g. if no longitudinal walls arearranged. In case, where floors are not extended over the full breadth,paragraph [3.1.3] covers the design of the transverse primary supporting
members. We will consider a rule change to clarify this requirement

2009/5/25

The last sentence in Ch.4, Sec.6,[1.1.2] reads:"For holds of non-cylindricalshape, and in case of prescriptive rule requirements, the upper surface of thebulk cargo may be taken at the upper deck level with a density of dry bulk
cargo equal to M/V_H.". Please clarify how to determine the parameters,h_HPU, B_H, h_0 when the cargo is loaded to the top of hatch coaming ,since those parameters are variable within the non-cylindrical holds.

For holds of non-cylindrical shape, only the last sentence in Ch.4 Sec.6 [1.1.2]
is applicable. In this case, cargo height (hc) is measured from the inner bottom
to upper deck level at the centerline of the mid hold and the density of the dry
bulk cargo is taken equal to max (1.0, M/VH), where M and VH are defined in“Symbol” in Ch 4 Sec 6. There is no need to define the parameters h_HPU,
B_H and h_0 since [1.1.1] is not applicable such holds.

A-1 Structural members can be evaluated by the simplified method according
to the specification in Ch 7 Sec 4 [3.3] if applicable, except for the following
members: hold frames of single side bulk carriers, connections between
corrugations and stools and ordinary stiffeners in double side space at theconnection of transverse stiffeners with stringer or similar. Where the fatigue
assessment is carried out by the very fine mesh FEA, all cargo holds shouldbe evaluated. If the structural details in cargo holds other than heavy ballast
hold are the same as those in heavy ballast hold and the evaluated results of
those in heavy ballast hold are satisfactory, the very fine FEA for cargo holds
other than heavy ballast hold can be omitted.
A-2 The transverse BHD connection with vertical lower stool and upper stool
as well as sloping ones should be checked.
A-3. Only representative locations should be checked.

742
attc

Table
8.1.1

Question

FEA

2008/10/10

See the attached Question. It has multiple questions, however, for the sake ofeasy reference, they are grouped as one Question.

743

Figure8.5.2

Question

Co-ordinate"Y"

2008/7/2

Ch 8 Sec 5 Figure 2 indicates coordinates. Is the co-ordinate "Y" typo? Should
Yes, it is typo. We will consider a rule change.
it be "X" ? .

747

4/5.2

Question

DSA

Attachment

Question/CI

2008/9/10

Regarding Direct Strength Assessment (DSA) for cross deck, while loads oncross deck and hatch cover are stipulated in Ch.4, Sec.5-2, it is not clear how
to consider the load on cross deck from hatch cover through hatch end
coaming or stay. Hence it would be appreciated to clarify how to assess the
cross deck by DSA, considering load from hatch cover.

Normally, the strength of hatch cover and hatch coaming is evaluated by theprescriptive requirement and FEA using the loads thereon separately from thehold structures. Hence, the cargo hold FEA is carried out using the cargohold FE model excluding the hatch cover. This seems a practical way.
Therefore, in principle the wave loads on hatch cover need not be considered
for the cargo hold FEA. In addition, the cross deck structure is normallyassessed by the cargo hold FEA under the loading conditions specified in Ch
4 Appendix 2. However in case special cargoes are loaded on hatch coversuch as timber, etc., the strength of supporting deck structures in such aloading condition should be assessed appropriately

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Ref.

748 6/A.1.1.2.2

Type

CI

Topic

elementary
plate panels

Datecompleted

Question/CI

Answer

2008/9/10

It seems that the 2nd & 3rd sentences in Ch 6, appendix 1, [1.2.2] such as"The effective width ... in accordance with Ch6, Sec 3 [5]. A constant stress...
adjacent elementary plate panels." could be interpreted as follows:
1) When a width of the attached plate is calculated a constant compressive
stress to be assumed, accordingly always psi=1.0 both for longitudinal andtransverse stiffeners.
2) Sigma_a in Ch 6, Sec 3 [4.2.1]
and sigma_x in [4.3.1] for longitudinal stiffener are to be taken as the greaterof the following hull girder bending stresses:(a) stress at
half length of the stiffener, and(b) 0.5 of the maximum compressive stress of the adjacent elementary plate
panels. Please advise if the above interpretation is correct.

1) Your interpretation is right. Regardless of the actual stress distribution of theadjecent plates, psi equal to 1 is assumed for the calculation of the effective
width according to CH6, Sec.3, 5.
2)sigma_a is theaxial stress of the stiffener. In the transverse section analysis this stress is aconstant value, which is equal to sigma_n for a stiffener in ship length
direction. sigma_x, sigma_y (in EPP co-ordinate system) and tau are stresses
in the adjacent plates, acting at the position of the stiffener, which causes
additonal vertical forces on the stiffener. In case of the transverse section
analysis normal stresses in other directions than in ships longitudinal direction
may be set to zero.
We willconsider the RCP in order to clarify these interpretation.

Attachment

749

10/1.5.5.1

Question

Diameter ofPintles

2008/5/30

In CSR for BC, the diameter of pintles is equal to: da = 0.35 (B1 kr)^(1/2), withkr equal to (235/ReH)^e.
The formula in CSR BC is correct.
However, in the UR S10, it is written that the diameter of pintles is equal to: dp= 0.35 (B kp)^(1/2), with kp equal to (SigmaF/235)^e.
This two text give two different values: which one is correct?

750

10/1.3.1.1

Question

Diameter ofthe rudder
stock

2008/6/6

The diameter of the rudder stock is supposed to be calculated in m. However,this seems incorrect: the unit should be changed to mm.

Your comment is correct. This correction has been made by "Corrigenda 5"
approved by the Council on 15 May.

QuestionTheequivalentstress ofbending andtorsion2008/6/6

In CSR for BC, the equivalent stress of bending and torsion for the increased
rudder stock diameter is not to exceed 118/kr, with kr equal to (235/ReH)^e.
However, in the UR S10, it is written that the equivalent stress of bending andtorsion for the increased rudder stock diameter is not to exceed 118/K, with K
equal to (SigmaF/235)^e.
This two text give two opposite values: which one is correct?

The formula in CSR BC is correct.

2008/6/6

1/ In CSR for BC, the diameter of coupling bolts is equal to: db = 0.62 [ (D^3kb) / (kr n e) ]^(1/2), with kb and kr equal to (235/ReH)^e.
However, in the UR S10, it is written that the diameter of coupling bolts isequal to: db = 0.62 [ (d^3 Kb) / (Kr n em) ]^(1/2), with Kb and Kr equal to(SigmaF/235)^e.
This two text give two different values: which one is correct?
The formula in CSR BC is correct.
2/ In CSR for BC, the thickness of coupling bolts is equal to: tf = 0.62 [ (D^3 kf)/ (kr n e) ]^(1/2), with kf and kr equal to (235/ReH)^e.
However, in the UR S10, it is written that the thickness of coupling bolts isequal to: tf = 0.62 [ (d^3 Kf) / (Kr n em) ]^(1/2), with Kf and Kr equal to(SigmaF/235)^e.
This two text give two different values: which one is correct?

751

752

10/1.3.2.1

10/1.4.2.1&
10/1.4.2.2

Question

The
Diameter ofcoupling
bolts

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753

756

757

758
attc

759

Ref.

10/1.4.3.1

3/6.5.2.4

11/1.1.2.1

3/6.6.1.3

9/1.2.3.2

Datecompleted

Question/CI

2008/6/6

In CSR for BC, the diameter of coupling bolts is equal to: db = 0.81 D/n^(1/2)(kb/kr)^(1/2), with kb and kr equal to (235/ReH)^e.
However, in the UR S10, it is written that the diameter of coupling bolts isequal to: db = 0.81 d/n^(1/2) (Kb/Kr)^(1/2), with Kb and Kr equal to(SigmaF/235)^e.
This two text give two different values: which one is correct?

2008/5/30

A symbol, b, is missing in the 2nd formula in Ch3 Sec6, 5.2.4.
Ch3 Sec6, 5.2.4. requires the arm length of tripping brackets, where originates
This is a typo. we will consider the editorial correction.
in 4.7.6, Section 3, Chapter, 4, Part B of the BV Rules.
Please correct it.

2008/9/10

The minimum bending radius for cold forming is required to be at least 3 times
the plate thickness in Ch11 Sec1, 1.2.1 of CSR for Bulkers. With reference tothe relevant Technical Background (TB), this requirement originated from thestandard radius when bending corrugated bulkhead in IACS Rec. No. 47. On
the other hand, CSR for Tankers regulates the minimum bending radius for
We will condier the rule change proposal in order to be in line with IACS Rec.
cold forming is required to be at least twice the plate thickness in Sec6,
No. 47.
4.2.3.1. We are of the opinion that the minimum bending radius, 3 times theplate thickness, should be kept only when bending corrugated bulkhead. It isrequested that the minimum bending radius for cold forming in Ch11 Sec1,
1.2.1 of CSR for Bulkers be changed to twice the plate thickness.

Minimumheight of
doublebottom2008/7/16

1st sentence of Ch 3 Sec 6 [6.1.3] requires the minimum height of double
bottom.
There are attached designs where the double bottom height varies according
to the transverse locations. This is due to that bottom shell is not kept flat overthe extent of inner bottom width.
The double bottom height h, measured vertically from the plane parallel withkeel line to inner bottom, is not to be less than B/20 or 2 m whichever is the
Please advise whether the foregoing requirement means:lesser. However, in no case is the value of h to be less than 760 mm.
a) only double bottom height at centerline (h_CL) is to be kept to be not lessthan B/20 or 2m whichever is lesser, orb) B/20 or 2m whichever is the lesser is to be kept over the extent of inner
bottom width including h_s.

Spacing ofsolid floors

The requirement in Ch 9, Sec 1, [2.3.2] says that the spacing of solid floors
should be Min.[3.5m, 4 frame spaces] in case of the longitudinal stiffened
system. We understand the philosophy that the spacing must not be too big,
however, for example, when the design in fore part has a spacing of 3.75m (52008/10/27 frame spaces), the actual difference of spacing is just 0.25m from therequirement. Is it possible to allow a greater value of spacing after
confirmination that the strength or scantlings are enough, on the basis of FE
analysis, for exemple? We would like to ask IACS to review this requirement
and to introduce a Rule Change Proposal.

Type

Topic

Question

The
Diameter ofcoupling
bolts

RCP

Symbolmissing inthe 2nd
Formula

RCP

CI

RCP

Bending
RadiusAttachment

Answer

The formula in CSR BC is correct.

Such larger distances may be used, when the structure is verified by means of
FEA deemed appropriately by the Society, using direct, calculated, slammingloads

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Type

Topic

Date
completed

Question/CI

Attachment

Answer

Applicability of minimum thickness requirement to web stiffeners: Regarding
applicability of minimum thickness requirement to web stiffeners, the type of
web stiffeners is referred at the end in the question in KC328, however, theanswers in KC328 and KC647, relevant to KC328, are not clear to web
stiffener type.

760

3/6.5.2.1

CI

web stiffners

2009/3/3

The requirements of minimum thickness of web stiffener are as follows;-Ch3 Sec6, 5.2.1 : minimum net thickness of primary support members,
referred to Ch6 Sec4, 1.5.1.
-Ch6 Sec2, 2.2.1 : minimum net thickness of web of ordinary stiffeners
The types of web stiffeners are as follows;- Flat bar type- Angle or T type

Ch 3 Sec 6 [5.2.1] is only applicable to web stiffener with flat bar type.
The minimum net web thickness for web stiffener with angle or T type is to be
not less that that for ordinary stiffener specified in Ch 6 Sec 2 [2.2.1].

Please clarify the applicability of the above two requirements to the two types
of web stiffeners.

761

3/6.5.6.2

CI

end bracket
hight ofprimary
supportmembers

2009/6/26

Ch3 Sec6,5.6.2 requires that the end bracket height of primary support
The mandatory requirements for the scantlings of the end connection is given
members should be not less than that of the primary supporting member. With
with the sentence "The scantlings of end brackets are to be such that thereference to the interpretation of KC414, the requirements in Ch3 Sec6 aresection modulus of the PSM with end brackets is not less than that of the PSM
applicable not only cargo hold area but a ｌso other areas, where the application
at mid-span". An editorial change will be made by introducing the word
is appropriate. Please confirm whether the above requirement in Ch3"generally" in the sentence in Ch3 Sec6,5.6.2, stating that "the height of end
Sec6,5.6.2 is applicable to side transverse web in steering gear room. If
bracket is generally to be not less than that of the primary supporting
applicable, providing large bracket according to the above requirement
member".
interrupts the arrangement of fittings in steering gear room.
The above requirement originates in BV Rule, Part B, Ch4 Sec3,4.4 as
indicated in the technical background. BV Rules also require the end bracket
height of primary support members on ship side in Part B, Ch4, Sec3. 3.2 asfollows: The height of end brackets is to be not less than half the height of the
primary supporting member.
We are of the opinion that the above criterion of end bracket height in BV
Rules is applicable to primary support members on ship side. Please confirm
this interpretation.

762

3/6.6.3.1

CI

centre girder

2009/3/3

Ch3 Sec6, 6.3.1 requires tightness of center girders as follows: Where double
bottom compartments are used for the carriage of fuel oil, fresh water orballast water, the centre girder is to be watertight, except for the case such as
The word "etc." means the case of small watertight compartments that freenarrow tanks at the end parts or when other watertight girders are provided
surface effects thereof are considered very small, compared with thewithin 0.25B from the centreline, etc.
arrangement specified in this requirement.
With reference to “etc” at the end, it seems that the CSR permit non-tightcenter girders under specific conditions. Please indicate the conditions inwhich non-tight center girders are permitted.

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763

Ref.

Table
9.3.2

Type

QuestionTopic

net crosssectional
area ruleDatecompleted2009/3/3

Question/CI

Attachment

AnswerWe have noted your answer concerning our complaints on requirements for
Net Cross Sectional Area on tank top bedplates (KC ID #611). Your answer
does not lead to a better understanding of the problem since we have alreadybeen informed about the answer on the approved question KC ID#413. We do
not understand the reason for the requirement and would like you to explainYour comment has been reflected to the Rule Change Proposal 4 which has
the meaning of this formulae. As an example the width of each tank top
been reviewed according to PR 32.
bedplate for our engine S70MC-C is 1365 mm. When fulfilling the IACS rules
the thickness is required to be 69 mm and the cross sectional area will be1826 cm^2. Accordingly a width of 2640 mm of each tank top bedplate isrequired. This will in some cases mean that the tank top plate penetrates thehull at the aft part of the engine.
Alternatively the thickness of the bedplate must be twice the normal size, 134
mm which is obviously a meaningless size. So we are of the opinion that the
IACS rule on net cross sectional area should refer to “bedplates in total” andnot to “each bedplate” as we proposed in our letter to IACS. Several shipyards
are asking us for calculations on this matter, referring to the question KC
ID#413, but it is not possible for us to make such calculations.

764

765

6/2.4.1.3

Text 3/6

RCP

QuestionCorrosion
Formulacontinuity ofstrengthWith reference to the Technical Background, Ch6 Sec2, 4.1.3 is based on NK
Rules. The coefficient, 1.1, of the stress formula in Ch6 Sec2, 4.1.3 is also
shown in NK Rules as “correction coefficient for corrosion”. However, CSR
2008/10/27 adopts a net scantling approach and the scantling considered in thecalculation formula is the net scantling, excluding corrosion additions.
Accordingly, the formula in Ch6 Sec2, 4.1.3 incorrectly counts corrosion twice.
Please reconsider the way to consider corrosion in this formula.

2009/3/3

Please confirm that the requirements in Ch3 Sec6 are not required to be
applied to areas other than cargo hold area, provided there is no crossreference to Ch3 Sec6 in the requirements to those areas specified in therelevant chapters, such as Ch9, etc

Considering the original rules and the background, it is not considered that theconstant value 1.1 used in the formula of CSR based on the net scantling
approach is necessary. We will consider the RCP because the correction of
the formula will give the scantling impact.

According to Ch 3 Sec 6 [1], the requirements of this section apply to thecargo hold area. For other areas, the requirements of Ch 9 Sec 1 to Ch 9 Sec
4 are to be applied.
In fact some requirements are applicable in the whole ship, e.g. CH3, Sec6,
5.1.1 "Continuity of strength". We will make a rule change proposal in order toclarify the applicability of this chapter.

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766

767

768
attc

Ref.

9/3.2.1.8

6/3.1.1.2

6/3.4.2.2

Type

Question

Question

RCP

Topic

web
stiffeners

Buckling
Assessment

stiffeners

Datecompleted

Question/CI

Attachment

Answer

2009/3/3

Please confirm that the following our interpretation, on the web stiffeners on
the double bottom floors and side transverse web frames in machinery space,is correct.
1) In Ch 9 Sec 3 [2.1.8], Ch 3 Sec 6 is referred to in the first sentence, as "inaddition to the requirements in Ch 3 Sec 6". It means the stiffeners provided tothe double bottom floors in Machinery space shall comply with Ch.3 Sec 6 andIt is agreed that some requirements of Ch 3 Sec 6 are applicable to theCh 9 Sec 3 [2.1.8].
structural arrangement of the entire hull structure. In this regard, modifications
The depth of the stiffeners provided to the floors in Machinery space is to be
in CSR will be prepared for clarification.
more than 1/12 stiffener length and the section modulus is to be not less than
1.2 times that required in Ch 6 Sec 2 [4.1.2].
2) There is no cross reference to Ch.3 Sec 6 in the side transverse
requirements in [3.1.3] of Ch 9 Sec 3 "Machinery space". Accordingly it is not
required to apply the requirements of C3 Sec 6 to the web stiffeners on theside transverses in machinery space.

2009/3/3

1. It has come to our notice that there is an inconsistency between the CSR
BC and IACS UR S17 about assessment of the buckling capability of the hull
structure in flooded condition.
2. S17.5 requires buckling assessment for elementary plate panels andordinary stiffeners in a hull transverse section stating that “Permissible stress With the additional ultimate strength check according to CH5, Sec2 for flooded
and axial stress buckling strength are to be in accordance with UR S11”.
condition, the requirements of UR S17 and UR S11 for the buckling
3. However, Paragraph 1.1.2 of Chapter 6, Section 3 of the CSR BC requires assessment in flooded conditions are fulfilled.
buckling assessment only for transverse vertically corrugated watertightbulkheads in flooded condition.
4. Both are IACS documents and are to be consistent for buckling assessment
for the elementary plate panels and ordinary stiffeners.

2009/11/3

For continuous stiffeners, the bending moment due to the deformation of
stiffener (M0) always takes the same sign as the bending moment due to thelateral load (M1), i.e. since Mo can act in any direction. However, for a sniped
stiffener, the eccentricity of the compressive load and the neutral axis of theplate-stiffener combination means that M0 can only act in one direction (i.e.
plate in compression). Accordingly, Mo and M1 should have the same signwhen the lateral pressure is acting on the plate side, but different signs when
the lateral pressure is acting on the stiffener side.

Please see the Rule Change Proposal in the attached file.

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No.

769

Ref.

Table
3.1.4

Type

RCP

Topic

Applicationof material
classes andgradesDatecompleted

Question/CI

Attachment

AnswerWith respect to CSR-BC, Ch.3, Sec.1, Table 4: Application of material classes
and grades, it is proposed that the following parts in Special structural member
category be editorially corrected.
1. We agree to your proposal.
2. Our understanding is that the bottom column of table 4 is applicable to bulk
1. The terms, 'ore carriers' and 'combination carriers' are inapproriate in view
carrier having the longitudinal hatch coamings of length greater than 0.15L.
2008/10/15of the application set out in Ch.1, Sec.1, 1.1.2 where these ships are cleary
This is in line with the third column from the bottom of the table. In order toruled out. The text being a transcription from C5 in Table 1 as available inclarify these items and to cover the revision of IACS UR S6 Rev. 5, we will
IACS URS6, Rev.5, this column should be more appropriated to CSR bulk
consider the RCP.
carriers hence can only be changed to 'Strength deck plating at corners ofcargo hatch openings (2)'.
2. The bottom of the category specifying 'End brackets and deck housetransition of longitudinal cargo hatch coamings (5)' is most likely to be proper
to container ships and not to bulk carriers. Should this be the case, pleasedelete this column. If this should not be the case and applicable to CSR bulk
carriers, clarification is requested as to whether the column refers to end
brackets of discontinuous hatch side coamings having the length less than
0.15L. Otherwise, grade D/DH would be irrationally mandatory even for smallbulk carriers.

770

9/6.6.3.1

771

Ch. 6,
Sec. 1772

773

3/6.8.6.1

Table
3.3.1

RCP

coamingheight ofenergency
generatorroom

2008/9/10

Coaming height of emergency generator room. Ch9 Sec6, 6.3.1 states thecoaming height of emergency generator room with reference to 8.1.3.
This is typo. We will conisider an editorial correction.
However 8.1.3. requires closing appliance and it seems that the reference is tobe corrected to 8.1.2. Please confirm it.

2009/5/27

It seems that the answer in KC551 is applicable when fitted with carling
effective enough to prevent buckling. Please show the conditions such as
minimum scantlings of the carling which are effective enough to prevent
buckling.

We will make a rule change proposal to establish minimum scantling
requirements for such carlings.

CIcarlings

Question

brackets
supporting
longitudinal
stiffeners

According to Ch3 Sec6, 8.6.1 of Bulker CSR, brackets above the side framesin every frame space are fitted to ensure structural continuity. Consequently atleast one side of the lowest longitudinal stiffeners on topside slant plates are
2008/10/15
normally supported by the brackets in every frame space. Please clarify how
to take into account the effect of such brackets supporting longitudinal
stiffeners with a view to determining the longiudinal stiffener span.

Span,"l", is the spacing of bracket or the distance between the transverse web
in bilge hopper tank or topside tank, as applicable, and the adjacent bracket,
when applying the formulas in Ch.6, Sec.2,[3.2.3], [3.2.5] or [3.2.7]. Please
note that spacing, s, is to be a half longitudinal spacing between the adjacentlongitudinal plus the half distance between the longitudinal and the connectionof topside tank/bilge hopper tank sloping plate and side shell.

Corrosion
addition in
way of a
WBTThis issue relates to the application of Table.1 in Ch3 Sec3 with respect to the
corrosion addition in way of a WBT (particulary, Top Side Tank) within 3m of
the tank top. If only the part of face plate of an ordinary stiffener is locatedwithin 3m of the tank top while the web plate of the ordinary stiffener is located2008/10/10 outside 3m from the tank top, which corrosion addition applies to such a
stiffener?
(1) Corrosion addition in way of a WBT within 3m of the tank top, or(2) Corrosion addition in way of a WBT oustside 3m from the tank top. Pleaseclarify it.

According to the 2nd sentence from the bottom of Ch 3 Sec 3 [1.2.1], where a
streuctural member are affected by more than one value of the corrosion
addition, the scantling criteria are generally to be applied considering theseverest value of corrosion addition applicable to the member. This is a
general principle. Normally, the location of stiffener is judged from thecoordinate at the conection of the attached plate. Therefore, for the case inquestion, corrosion addition in way of a WBT oustside 3m below the tank top.
In order to clarify this, we will consider the RCP.

RCP

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776
10/1.5.1.4
attc

Type

Topic

RCP

semi-blade
rudderDatecompleted

Question/CI

Answer

Attachment

2008/9/10

Reference is made to an equation in Para. 5.1.4 of Ch. 10, Sec. 1 of the CSR
BC about a bending moment MR working on a semi-blade rudder at the cutout. 2. It has come to our notice that unfortunately the force B1 came into
equation by a typographical error and it should be replaced by the force Q1.
Please see a supporting document as attached.

Reference is made to the file attachment. This is not an error and need not tobe modified.

Y

777

Tanker
12/1.1.3 &Bulker3/2.3.3

CI

as-built
thickness

2009/5/19

The plans to be supplied onboard the ship are to include both the as-built andthe renewal thickness. Does this mean all thicknesses on all drawings shall
include as-built and renewal thickess ? Is it sufficient that renewal thickness
are shown on main drawing or in a separate document?

The submitted structural drawings (Section 3, 2.2.2.1, (a) & (c) in CSRTankers and Ch 3 Sec 2, 3.3 in CSR-BC) is to show renewal thickness andas-built thickness. Any owner's extra thickness is also to be clearly indicated.
For the plans to be supplied on board the ship, see Section 3/2.2.3 in CSRTankers. Alternatively, it is acceptable to present renewal thickness in a
separate plan ("Renewal thickness plan") in which the as-built thickness may
not be presented, and any owner's extra thickness is also to be clearly
indicated. This plan is to be approved and supplied on board the ship.

780

3/6.8.2.1

Question

air pipes

2009/3/3

The 2nd sentence in Ch.3 Sec.6 [8.2.1] reads: " If air pipes are passing
through the cargo hold, they are to be protected by appropriate measures toavoid a mechanical damage."
Please advise what the appropriate
measures are.

Appropriate measures to avoid mechanical damages to air pipes passing
through the cargo hold should be subjected to the Class Society.

2009/3/3

KC ID# 596 allows one side continuous fillet welding for stiffeners in deckhouse of CSR/Tanker except areas otherwise specified or those where suchwelding is not suitable. Is one side continuous fillet welding also allowed toapply to deck house of CSR/Bulker?

One side continuous fillet welding could be applied to stiffeners in a deckhouse subject to the following;
1. This welding method is not allowed for the area where is affected by theconcentrated loads and excessive vibration such as under winches, cranes,
davits and machineries and exposed to weather, and for wet spaces andtanks.
2. Welding size is to be of the fillet required by Ch.11, Sec.2, Table 1 forintermittent weld.
3. Welding at ends of the stiffeners is to be F0 according to the row "General,
unless otherwise specified in the table" in Ch.11, Sec.2, Table 2.
4. The fabrication process has to assure that the deviation from the given
angle of the profile to the plate is within the permissible values of thefabrication standard e.g. IACS REC47.

2009/3/3

The lateral pressure for decks of superstructures and deckhouses is defined in
Ch9, Sec4, [3.2.1].
This requirement refers to the external pressure pD defined in Ch4, Sec5,[2.1], which is a pressure for EXPOSED deck.
In case of non-exposed decks of superstructure and deckhouses, as nointernal pressure is defined for such decks in Ch4, Sec6, we would like toknow what is the pressure to be used?

Effectively, no internal pressure is defined in CSR-BC for non-exposed decks
of superstructures and deckhouses. Such internal pressure will be added in
CSR-BC, and we suggest to use a value of 5 kN/m2 including dynamic load
effect.

781

785

Table
11.2.2

9/4.3.2.1

Question

CI

Continuous
fillet welds

Lateralpressure fordeck

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Type

Topic

Date
completed

Question/CI

Answer786

3/6.4.1.1

Questionbulb profile

2008/9/10

In CSR-BC, Ch 3 Sec 6, [4.1.1], the thickness tw of the web of the built-up
section equivalent to a bulb profile is not defined. We assume that the
thickness of the web is taken equal to the thickness t'w of the web of the bulb
profile. Please confirm our interpretion.

Your interpretation is correct: in CSR-BC, Ch 3, Sec 6, [4.1.1] the thickness twof the web of the built-up section equivalent to a bulb profile is to be taken
equal to the original thickness t'w of the web of the bulb profile.

787

3/1.2.3

Question

UR S6

2008/9/10

Considering Rev.5 (Sept 2007) of IACS UR S6, it seems necessary to update
CSR-BC Ch 3, Sec 1, [2.3] to be in accordance with this revision.

We agree with your comment. The requirements in CSR-BC Ch 3, Sec 1, [2.3]will be updated to be in line with Rev.5 (sept2007) of IACS UR S6.

Attachment1)The designer should define the design still water shear force QSW in linewith Ch.4, Sec.3 [2.3] in the first place.

788
attc

789

793

5/1.5.2.2

9/5.5.4.5

2/2.2.1.3

RCP

CI

Question

Permissible
still water
shear force

deflection
limit

fire
protection

Ch4 Sec8 requires that the permissible value of still water shear forces be
described in loading manuals. “Permissible still water shear force” is defined in2) Then using QSW the following strength is assessed
Ch5 Sec1 [5] based on the calculated shear stresses of hull girder strength(a) hull girder shear strength according to Ch.5 Sec.1 [5].
members. Further, other strength assessments, such as global strength
2008/10/27(b) buckling strength according to Ch.6 Sec.3
analysis in Ch7 Sec2 and buckling strength assessment in Ch6 Sec3, also(c) global strength according to Ch.7 Sec.2.
refer to hull girder shear force. However, the relationship of shear force values
is not clear in CSR. (See attached) Please consider a rule change to clarify the3) As a conclusion, the design still water shear forces can be taken as theabove.
allowable ones and described in the loading manual. We will consider the
RCP in order to clarify this understanding.

2008/9/10

We would like to confirm the interpretation of "Common Structural Rules for
Bulk Carriers" Part CSR-B Ch.9 Sec.5 5.4.5 : Deflection Limit of Primary
supporting members for Hatch Covers.
We interpret this Ch.9 Sec.5 5.4.5 as follows:
As clearly described as "when loaded by sea pressure" in Ch.9 Sec.5 5.4.5,
The "Sea pressure" means the pressure defined in [4.1.2] of Ch 9 Sec 5.
necessary considering load to keep deflection within the limit ( = ulmax ) is
Even when the requirement of [5.4.5] applies to the hatch cover of ballast
only the "Sea pressures" defined in Ch.9 Sec.5 4.1.2 and does not include the hold, sea pressure defined in [4.1.2] of Ch 9 Sec 5 is only considered.
"Internal pressures due to ballast water" defined in Ch,9 Sec.5 4.1.3, even incase of Ballast hold Hatch Covers.
We are looking
forward to receiving your reply with your confirmation to above ourinterpretation.

2009/1/29

In SOLAS II-I/Reg.10.6.3, paint locker is considered as a spacing containing
flammable liquids. If this is the case also in CSR BC Rule, the paint locker
inside a deckhouse is required to have a cofferdam, which seems to beFirstly, this requirement is not a SOLAS requirement. Secondly, the current
beyond SOLAS requirement and require current ordinal design of ships to be
SOLAS requirements regarding the fire protection are considered sufficient aschanged. In addition, it is considered that the current SOLAS requirement is
you mentioned. Therefore, we will delete the requirement Ch 2 Sec2 [2.1.3]
sufficient, considering the past experiences. Hence, it would be appreciated towith a rule change proposal.
inform us of a definition and an example of ‘spaces intended for the carriage offlammable liquids.’ If the definition is same as that of SOLAS, then it would berequested to modify the requirement to be line with SOLAS requirement.

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KCID
No.

794

798

799

Ref.

3/1.2.3.3

2/1.3.1.1

Table
9.2.5

Type

CI

Topic

top plate ofengine seats- material
grade

Question

Bulkhead

Question

castpropeller
post

Date
completed

Question/CI

Attachment

Answer

2009/4/1

1.Reference is made to IACS KC ID: 711 regarding the material grade of the
top plate of main engine seats inserted into inner bottom.
2.It is understood that a thicker top plate of main engine seats is required tosuit securing the engine bolts on installation of a main engine, then, it isconsidered to be a very local strength item.
3.Consequently it is also understood that Grade A/AH is acceptable for the top
plate of the engine seats located outside 0.6L amidships of any plate
This question will be addressed within the harmonisation process of both CSR
thickness and the requirement of Ch. 3, Sec.1, Para. 2.3.3 of the CSR BC is
BC and CSR OT.
applicable to the top plate of the engine seats located inside 0.6L amidships.
4.For information, LR Rules accept A/AH for the top plate of the engine seatsoutside 0.6L amidships and few damage has been reported for it so far. Mostof the classification societies’ Rules are understood to be in line with thisrequirement.
5.A prompt confirmation on Para. 3 as above would be very muchappreciated.

2009/3/3

SOLAS Ch II-1, Part B, Reg. 11, Para 8 states “Bulkheads shall be fitted
separating the machinery space from cargo and passenger spaces forward
and aft and made watertight up to the freeboard deck”. LR’s Rules allow theafter peak bulkhead to terminate at the first watertight deck above the loadwaterline in the aft peak, recognizing that the after peak bulkhead isn’t
This paragraph will be modified in order to comply with applicable SOLAS
separating the machinery space from a cargo or passenger space aft.
Regulations.
However, CSR BC Rules, Ch 2, Sect 1, 3.1.1, whilst referring to SOLAS Ch IIThe corrigenda will be issued.
1, Pt B, Reg 11, states that the after peak bulkhead is to be watertight to thefreeboard deck.
Can we have clarified the reason for this higher standard of subdivision thanrequired by SOLAS and LR’s Rules, or does this require a corrigendum?
It is also noted that the CSR OT Rules are in line with SOLAS and LR’s Rules

2009/3/3

In Chapter 9, Section 2, Table 5 the following change is proposed:
Column: "Cast propeller post", Row "R" the formula should be changed from:50 L^1/2 to: 50 mm.
Reason: typo found in the formula coming from RINA Rules and corrected in
RINA Rules 2008.

Your comment is noted and we will consider a rule change proposal changing
to 50 mm from 50L^1/2.

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IACS Common Structural Rules Knowledge Centre

KCID
No.

800

Ref.

6.3.4.2

Type

RCP

Topic

lateralbuckling of
longitudinal
stiffeners

Datecompleted2009/3/3

Question/CI

We have checked both criteria given in Ch 6, Sec 3 for lateral buckling of
longitudinal stiffeners not subjected to lateral pressure: criteria in [4.2.1] and[4.2.2] on one side and criteria in [4.2.3] on the other side.
These criteria were checked in case of longitudinal stiffeners (flat bars) of nonwatertight girders.
The conclusions are:(1) - When considering ends of stiffener not sniped: both criteria areequivalent.
(2) - When considering ends of stiffener sniped: both criteria seems
equivalent, but it is noticed that there is no convergence when increasing thescantling of the flat bar. The same problem occurs if bulb or T-bar are
considered. instead of a flat bar. Consequently, there are some doubts on theapplication of the formulae for sniped stiffeners and in particular on the default
value taken for the assumed imperfection w0.

Attachment

AnswerIn case of longitudinal stiffeners sniped at ends and located on non watertightgirders, when applying the criteria for lateral buckling given in Ch 6, Sec 3[4.2.1] and [4.2.2] on one side and [4.2.3] on the other side, it is right that
there is no convergence when increasing the scantling of the stiffener.
The requirement Ch 6, Sec 3, [4.2.3] is only applicable for non-sniped
ordinary stiffeners.
We will make a rule change proposal to clarify this matter.

Requirement should be re-considered in case of sniped stiffeners and atechnical background should be provided.

801

802

Text
4/6.2.2.1

9/5.7.3.5

Question

Question

inertialpressure

securing
arrangements

2009/6/19

Ch4 Sec6, 2.2.1 requires that the inertial pressure due to ballast water is not tobe considered, when checking ballast water exchange operations by means of
the flow through method. With regard to the treatment of hydrodynamic
external pressure under such conditions, KC226 has interpreted thathydrodynamic external pressure should be considered. On assuming ballast
The approach described in KC 226 is still valid. Dynamic internal pressure is
exchange operations are normally carried out under calm sea condition, thenot explicitly defined but the internal static pressure pBS defined in Ch.4 Sec.6
inertial pressure due to ballast water is considered negligible, and then the[2.1.2] contains an overhead of 25 kN/m2 which covers the dynamic internalrequirement in Ch 4 Sec 6 [2.2.1] seems to be reasonable and practicable.
pressure of BWE operations by means of the flow through method. However,
However, the interpretation, which requires to consider hydrodynamic external this matter is relevant to harmonisation with CSR OT and will be submitted topressure corresponding to the probability level of 10^-8, seems to be
the harmonisation team.
excessive and inconsistent with the treatment of hydrodynamic internalpressure. Please reconsider the treatment of hydrodynamic external pressure
under ballast water exchange operations by means of the flow throughmethod.

2009/3/3

In the first part of [7.3.5], the general formula for determining the gross crossarea A of each securing device is given.
Then, in the second part of [7.3.5], some special cases (packing linepressures exceeding 5 N/mm or securing arrangements which are particularly
stressed due to the unusual width of the hatchway) are specified and thecorresponding net cross area A.
Why the general formula is given for the gross cross area A when the crossarea for particular cases is the net one?

[7.3.5] is the copy of a part of UR S21.5.1 which specifies A as net sectional
area. In the light of S21.5.1 "gross cross area" is a typo which should becorrected. However the "gross cross area" of the current CSR is intended tomean the area measured at the root of threads of securing device which issame as the "net sectional area" of S21.5.1. Accordingly the foregoingcorrection of the current rule text from "gross cross area" to "net cross area"
will be considered as Corrigenda.

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No.

Ref.

Type

Topic

Date
completed

Question/CI

Attachment

Answer(1) and (2) Table 2 in Ch 11, Sec 2 is not applied to welding of hatch coverdirectly but the basic concept of Table 2 is applicable.

803

Table
11.2.2

Question

Welding
Sizes of
Hatch Cover2009/3/3

1] Please advise whether Table 2 in Ch.11, Sec.2 should be applied to
welding of hatch cover.
2] In case Table 2 in Ch.11, Sec.2 is not applicable to hatch cover pleaseconfirm that welding sizes should be subject to the Rules of the class.
3] In case Table 2 in Ch.11, Sec.2 should be applied to hatch cover,a) Please advise the rows and categories of welding in the table which to be
applied to the following connections:(1) Stiffener web to top plate/bottom plate(2) End of stiffener web to web of primary supporting member (PSM)(3) End of stiffener face to PSM web(4) PSM web to top plate/bottom plate(5) PSM web to PSM web at outermost end connections(6) PSM web to PSM web at intermediate connections(7) Web to face plate of PSM(8) PSM web to web of horizontal/vertical stiffener which is fitted on the PSMb) Please advise for which extent of categories (F0, F1, F2 or F3) theintermittent welding category “F4” can be used alternatively.
4] Please advise if the footnote (2) in Table 1 in Ch.11, Sec.2 is to be applied
to welding of hatch cover as it is.

(3) When the basic concept of Table 2 applies to welding of hatch cover, thecategory of the fillet weld of the following connection are as follows.
[3]a) (1) Stiffener web to top plate/bottom plate: F3 or F4*(2) End of stiffener web to web of primary supporting member (PSM):i) For bracket connection: F2ii) For no bracket connection: F1(3) End of stiffener face to PSM web:i) For bracket connection: F2ii) For no bracket connection: F1(4) PSM web to top plate/bottom plate: F2 at end (15% of span) and F3 or F4*
for the rest
(5) PSM web to PSM web at outermost end connections:i) For bracket connection: F2ii) For no bracket connection: F1(6) PSM web to PSM web at intermediate connections: F2(7) Web to face plate of PSM: F2 at ends (15% of span) and Fe3 or F4* for therest(8) PSM web to web of horizontal/vertical stiffener which is fitted on the PSM:
F4
Please note that F4 weld is not used for welding in way of intersection withPSM.
b) F3 weld instead of F4 can be used.

5] Please advise whether or not the intermittent welds, which have different[4] The footnote 2 of Table 1 is applicable
Length-Pitch other than “75-300” indicated in Table1 in Ch.11, Sec.2, can be
accepted. If accepted, please advise how to calculate the required Leg length.
[5] If the length of filet welds is greater than 75mm and pitch is less than
300mm, such intermittent welds are acceptable.
In order to this interpretation, we will consider a RCP.

804

Text
4/6.2.2

Question

inertialpressure

2009/6/23

In Ch 4, Sec 6, [2.2], the parameter (x-xB) in the definition of the inertialpressure pBW for load case H is taken equal to a default value for "local
strength by Ch 6" and for "fatigue check for longitudinal stiffeners by Ch 8".
Could you specify what is the meaning of "local strength by Ch 6" and "fatigue
check for longitudinal stiffeners by Ch 8"?
Could you also specify what value of the parameter should be used for "direct
calculation (i.e. FEM)"?

A1: Local strength by Ch 6: checking of plating and ordinary stiffeners,
including buckling check, by using the prescriptive formulae defined in Ch 6,
all sections included.
fatigue check for longitudinal stiffeners by Ch 8: checking of fatigue at ends oflongitudinal stiffeners by using the simplified procedure defined in Ch 8, Sec 4.
A2: For direct calculations, including buckling and fatigue, xB should be usedas defined in Ch 4, Sec 6, [2.2] (i.e. X co-ordinate of the aft end ..., or of thefore end...) where the reference point B is defined in the same requirement by
the angle "phi" for load cases H1 and H2.

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805

808

812

Ref.

4/6.3.3 &7.3.4

3/6.6.4.2

8/4.2.3.2

Type

Question

RCP

QuestionTopichigh density
cargoalignment

Stressconcentration factors

Datecompleted

Question/CI

Answer

2009/1/24

Regarding the mass of high density cargo used for strength check oftransversely corrugated watertight bulkheads in flooded condition, pleaseadvise on the following questions:
1) Ch.4 Sec.6 [3.3.4] & [3.3.5] refer hc. We understand hc should be
calculated according to either Ch.4 Sec.6 [1.1.1] or [1.1.2]. In case of nonhomogeneous loading conditions which should be the mass MHD or
MHD+0.1MH for BC-A ships?
2) In case of homogeneous loading conditions (e,g, homogeneous ore loading
conditions, etc.) which should be the mass MHD or MHD+0.1MH for BC-A
ships?
3) We understand for BC-B ships the mass should be MHD, of which pleaseconfirm.

The cargo mass to consider for flooding assessment of a BC-A in alternate is
MHD. The value of hc is then to be calculated with respect to the used cargodensity.
A2 : The cargo mass to consider for flooding assessment of a BC-A in
homogeneous is MH. The value of hc is then to be calculated with respect tothe used cargo density.
A3 : The cargo mass to consider for flooding assessment of a BC-B in
homogeneous is MH. The value of hc is then to be calculated with respect tothe used cargo density. As a "background", it is stated in S18 and now in CSR
BC Ch.4 Sec.6 [3.3.2] that the loading conditions to consider for flooding
assessment are those of the loading manual, i.e. "real conditions". The use of
MHD + 0.1 MH for a BC-A in alternate comes from UR S25 - now CSR BC
Ch.4 Sec.7 [3.4] and is only intended for design checks.

2009/3/3

Ch3 Sec6, 6.4.2 requires that the net thickness and material of floors in way oflower stools should not be less than those of lower stool side plating. The
requirement originates from the requirement of UR S18.4.1 (c)-"Alignment",
which requires the net thickness and material of floors in way of corrugate
bulkheads not to be less than those of corrugation flanges, in cases without
lower stools. In cases without lower stools, the floor supports bulkhead
corrugation and the necessities of equal net thickness and material of the floor This issues are included in RCP4 (Rule Change Notice 1, 2009) which has
are understandable from a structural viewpoint.
been reviewed according to PR32.
In cases with lower stools, however, bulkhead corrugation is supported bysuch lower stools and the floor supports the stool side plating. Accordingly,
any connections between lower stool side plating and floors are considered tobe continuous enough by assuring equal thickness. Therefore, we would liketo request a rule change stating that the material of floors will not be requiredin Ch3 Sec6, 6.4.2 in cases with lower stools.

2009/3/3

Geometrical stress concentration factor for stress due to lateral pressure, K_gl,
is permitted to be evaluated directly by FEM according to Ch8 Sec4, 2.3.3.
However, no indications of direct evaluation by FEM are found in the definition The geometrical stress concentration factor for stress due to hull girderof geometrical stress concentration factor for stress due to hull girder
moments, K_gh is also be able to evaluated directly by FEM. This is included
moments, K_gh, in Ch8 Sec4, 2.3.2.
in RCP 4 which has been reviewed according to PR 32.
Please confirm whether geometrical stress concentration factor for stress due
to hull girder moments, K_gh, can be evaluated directly by FEM.

Attachment

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IACS Common Structural Rules Knowledge Centre

KCID
No.

816

Ref.

9/5.5.2.1 &Question
9/5.5.3.3

817

3/6.5.2.2

818

Text
4/6.1.1.1

819

820

Type

4/7.3.4.2

6/2.2.3.2

Topic

hatch cover
top plating

Questiontripping
brackets

Question

noncylindrical
hold

CI

Loading
conditions high density
cargo

Question

Gross
Thicknessand NetThickness
ScantlingDatecompleted

Question/CI

Attachment

Answer

2009/3/3

CSR for bulker specifies the prescriptive rule requirements to the thickness ofhatch cover top plating in Ch.9 Sec. 5 [5.2.1] and the section modulus andshear area of ordinary stiffener in Ch.9 Sec. 5 [5.3.3].
1) Is it acceptable to apply FEA for the to evaluation of those scantlings in lieu
of the prescriptive rule requirements in Ch.9 Sec. 5 [5.2.1] and [5.3.3]
The formula for t_net, given in CH9, Sec5, 5.2.1, is equivalent to S21.3.3.
provided:This requirement is a minimum requirement, which can not be superseded by(i) all other relevant rules (e.g. minimum thickness, buckling etc.) are to be fully a direct calculation.
complied with, and(ii) the allowable stresses, specified in Table 2 of Ch.9 Sec.5 [1.5] are to be
used in FEA for the scantling evaluation of top plating and ordinary stiffeners?
2) If FEA is acceptable please advise the criteria on the modeling.?

2009/3/10

Ch3 Sec6, 5.2.2 generally requires tripping brackets welded to the face plates.
In addition, the last sentence in Ch3 Sec6, 5.2.2 also requires that the faceplates of the primary supporting members, which exceed 180 mm on either
Ch.3 Sec.6 [5.2.2] means that the side of the flange should be supportedside, should be supported by tripping brackets. We are of the opinion that the when the size of the side exceeds 180mm.
tripping brackets shoud only support the face plate of PSM in case where such
face plates exceed either side of the web. Please confirm the above.

2009/6/23

In Ch 4, Sec 6, [1.1.1], the distance hc is defined for cylindrical hold. The
determination of hc is not provided for hold completely filled when the cargohold is of non-cylindrical shape as it is provided for the requirement [1.1.2] atthe last paragraph.

2009/9/8

The requirements 4/7.3.4.2 has the purpose to cover the most severe casewith high density cargo. In a case we faced the max cargo density was 3. The
compliance for this requirement was checked with density equal to 3. Howevera worst case appeared for the upper part of the transverse Bhd with a smaller
This question and the draft answer you submitted will be considered in KC
density (1.3) filling the cargo hold for the considered MHD+0.1 MH. In
872 which has a larger scope.
conclusion the proposed interpretation should be considered for being surethat all the most severest cases are covered by consideration of 2 extreme
cases: one with the highest density and the 2nd with the smallest density
corresponding to the filling of the cargo hold.

2009/3/3

Regarding the application of Ch6 Sec2 2.3, should hw and bf of the formulae
be measured as gross scantling or net scantling?
In Tanker CSR Table 10.2.1, it is clearly defined that the breadth and depth ofstiffeners are based on gross scantling.
But, in Bulker CSR, there is no clear definition for the calculation of the net
dimensions of ordinary stiffeners given in Ch6 Sec2 2.3. Please clarify.

For the determination of hc in Ch 4, Sec 6, [1.1.1] for holds of non-cylindricalshape and in case of prescriptive rule requirements, the upper surface of thebulk cargo may be taken at the upper deck level. We will consider acorrigenda to clarify this.

It is clearly mentioned in the text of [2.3] that all scantling is the net
dimensions.

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No.

822

823

825

826

Ref.

7/3.2.1.1

Type

Question

9/5.1.4.2 &Question
Table 3/3

9/1.2.3

9/5.6.2.4

Question

QuestionTopicares to berefinedcorrosion
addition

collision
bulkheadhatchcoamingDatecompleted

Question/CI

Attachment

Answer

2009/3/3

Ch.7 Sec.3 2.1 Areas to be refined : For the end brackets of hatch side
coaming and hatch end beam, they are not listed in the Table 1. Thus, could
we understand these areas are not required to be refined even if theYes, the structural members not listed in Table 1 of Ch 7 Sec 3 are notcalculated stresses exceed 95% of the allowable stress as specified in Sec
required to be refined even if the stresses calculated by coarse mesh analysis
2,[3.2.3]? We suspect that there should be some technical background forexceed 95% of the allowable stress.
such brackets since the deck plating in way of the most stressed hatch corners
is listed in the Table 1. In general, the high stressed elements may be found at
the end bracket of hatch side coaming.

2009/3/3

The 2nd sentence in Ch.9, Sec.5, [1.4.1] reads: "The corrosion addition for
hatch coamings and coaming stays is defined according to Ch 3, Sec 3."
The 1st sentence in UR S21.6.2 reads: "For the structures of hatch coamings
and coaming stays, the corrosion addition t_s is to be 1.5mm."We
believe that the following corrosion additions for L>=150m are to be appliedreferring to Ch.3 Sec.3 Table 1;(a) Hatch coaming web: Roundup0.5[(1.8+1.0)]+0.5=3.5mm(b) Web of horizontal stiffener on coamings: Roundup0.5[(2x1.7)]+0.5=4.0mm(c) Flange of horizontal stiffener on coamings:
Rounduo0.5[(2x1.0)]+0.5=2.5mm(d) Coaming stays: Roundup0.5[(2x1.0)]+0.5=2.5mm.
Please confirm the above corrosion additions.

Your understanding is correct.

2009/3/10

Ch.9 Sec.1 is applicable to the structure in the area located forward of thecollision bulkhead, the bow flare area and the flat bottom forward area,according to Ch9 Sec1, 1.1.1. Each requirement has individual applicableareas, such as the bow flare area in 4.1.1 and the bottom forward area in
5.1.1. We are of the opinion that the requirements in 2.3 are applicable to thearea located forward of the collision bulkhead only. In other words, therequirements in 2.3 are not applicable to the area located aft of the collisionbulkhead. Please confirm the above.

Your understanding is right.

2009/3/10

Hatch coaming stiffeners are required to be estimated with considering thewave lateral pressure as stated in Ch9 Sec5, 6.2.1. In addition, hatch coaming
stiffeners in way of ballast hold are also required to be estimated withconsidering the ballast pressure in Ch4 Sec6 as stated in 6.2.4. In this context,
to consider the ballast pressure in Ch4 Sec6, the hatch coaming stiffeners
need to be applied with the applicable requirements in Ch6 Sec2. Morespecifically, we are of the opinion that following applications of the
The hatch coaming is a part of the central part as defined in Ch1 Sec1 [2.1.3],
requirements in Ch6 Sec2 should be considered;hence all the relevant requirements in Ch6 shall be complied with, in addition
1) Hatch coaming stiffeners in way of ballast holds;
to the relevant requirements in Ch9 Sec5.
Applicable : Section modulus and shear area in 3.2
Applicable : Dimensions in 2.3
2) The other hatch coaming stiffeners
NA : Section modulus and shear area in 3.2
NA : Dimensions in 2.3
Please confirm the above applications

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No.

827
attc

Ref.

3/6.7.2.1

Type

CI

Topic

void spaceDatecompleted

Question/CI

Answer

Attachment

2009/3/3

Please refer to the attached sketch of a bulk carrier with double side skinconstruction. This bulk carrier has FOT and pipe trunk in the topside area. The
pipe trunk is considered as void space.
Ch3 Sec6, 7.2.1 requires as follows; Where the double side space is void,
the structural members bounding this space are to be structurally designed asa water ballast tank according to Ch 6.
In the bulk carrier, FOTs are arranged with cargo hold length and the pipe
trunk is running through whole the cargo area length. According to our
calculation based on the above, the dynamic pressure in the long pipe trunk isestimated about twice the large pressure in FOTs and excessive scantlings
are required by the calculation based on the pipe trunk pressure. However,taking into account the technical background of Ch3 Sec6, 7.2.1 as quoted
below, requiring the above-mentioned excessive scantling is irrational;

It was not the intention of the CSR to derive irrational dimensions for void
bounding structures. We suggest to use the corresponding cargo hold length
for l_H in the formula for inertial water ballast pressure.
We will make a rule change proposal to eliminate this drawback.

Y

If the double side skin part is to be used as a void space, and cargo of highdensity is to be carried in the cargo holds, then local loads are not presumed
to act on the side structure of the cargo hold on the double skin side. Even insuch cases, appropriate thickness exceeding the minimum thickness is
considered necessary. As a conclusion, even if the double skin side part is avoid space, it is treated as a ballast tank and assessment of local strength isspecified.
In this bulk carrier, the longitudinal bulkhead can be considered appropriatelyby the estimation of the pressure in FOT.
Therefore, we are of the opinion that the longitudinal bulkhead between thepipe trunk and the FOT has an appropriate construction by calculating FOTinternal pressure, therefore, the bulk carrier is in compliance with Ch3 Sec6,
7.2.1, without calculation of the pipe trunk internal pressure.

830

831

4/5.3.4.1

6/1.2.4.1

QuestionCIvertical
stiffeners

FE and local
requirements

2009/3/10

Load calculation point for plating.
In case of vertical stiffeners, what is the load calculation point for plating? Is ita) the middle of the plate field, or b) the lower edge of the EPP or strake, as
described in Ch.6 Sec.1 [1.5.1]?

Load calculation point for plating in case of vertical stiffener is the lower edgeof the EPP or strake, as described in Ch 6 Sec 1 [1.5.1]. We will consider aRule Change Proposal.

2009/3/3

Please explain the technical background of this requirement.
Does this requirement refer toa) only the thickness required by local requirements?
b) both the thickness required by FE and local requirements?
Typically, we have pipe duct in way of the keel plating, and the length of theelementary plate panels are smaller than outside the pipe duct. The required
thickness obtained from the bi-axial FE buckling in way of the pipe duct may
then be smaller than outside the pipe duct. Can we accept this smaller
thickness?

This requirement refers to both the thickness required by FE and local
requirements, as it refers to "actual" thickness, for a matter of continuity ofstrength, and enough strength for docking.

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Ref.

832 6/2.4.1.3

833

834

835

6/4.3

9/1.2.2.1

9/2.5.2.1

Type

Topic

Question

Connection
ends of web
stiffeners differences
between NK
rules & CSR

Question

Primary
SupportMembers

Questiontripping
brackets

Questionsidetransverse
spacingDatecompleted

Question/CI

Attachment

Answer

2010/8/6

According to TB, the requirement originates from NK Rules. However, therequirement in CSR seems conservative on the following items:
1.The factor Cship in NK is depending on ship length. In CSR this dependence
is deleted. This means that we obtain stricter results for L<200m.
1. Design philosopy underlying CSR is based on the "North Atlantic
2.In NK, Klongi is 1.0 for bulbs. In CSR Klongi is 1.3. This seems conservative, Navigation" and service life of 25 years. This is different from NK rules.
because skew bending moment for bulbs is much less than for angle bars.
The factor "Cship" is intentionally deleted.
3.In NK, the pressure is clearly only considering vertical acceleration. Thismeans that the stress induced by the dynamic load is under the assumption
2. We agree with you. This is not intended. We will consider a corrigenda tothat the vessel is under maximum vertical hull girder bending moment. In
clarify this.
CSR, there is no specification about which wave the dynamic pressure isbased on. R and P waves will give high dynamic pressure in top wing tank.
3. We have noted your comment and we will send it to the Harmonization
However, R and P wave will not give highest vertical hull girder bendingTeam.
moment. CSR should clearly state the dynamic pressure is under H or F wave.
Are the above differences between NK and CSR Rules intended? If they are
not intended, please advise how they should be handled.

2009/3/10

Reference is made to Ch. 6 Sec. 4 [3] “Additional requirements for primary
supporting members of BC-A and BC-B ships.”
The full corrosion addition is to be considered when applying Ch.6 Sec.4 [3].
The section is referring to net dimensions. Please advice how to obtain the net
Ch.3 Sec.2 [2.1.1] and [3.2] define the cases where other corrosion values are
dimensions: a) deduct 0.5tc from gross scantling (In line PSM scantling
to be used for determining the net dimensions.
applied in FEM) b) deduct tc from gross scantling. (In line with scantling
applied in local checks) Please consider specifying this in Ch.3 Sec.2

2009/1/26

Ch.9 Sec.1 [2.2.1] Tripping brackets in fore part According to the technicalbackground this requirement is based on URS 12. URS 12 deals withasymmetrical sections, while no distinction is made between symmetrical andasymmetrical sections in Ch.9 Sec.1 [2.2.1]. Please clarify if this requirement
applies to symmetrical sections.

2009/2/11

Please explain why the required side transverse spacing is reduced to 2 frame
spacing in way of the rudder horn. This is not in line with common industry
practice. According to Chapter 9, Section 2 [3.1.2] solid floors are to be fitted
Referring to answer to question ID739 on 9/2.3.1.2, a rule change will be
at every frame spacing in way of the rudder horn and are to be extended up to
issued covering both requirements 9/2.3.1.2 and 9/2.5.2.1.
the peak tank top. In our opinion, this requirement should give proper support
for the rudder horn, and the requirement in Chapter 9, Section 2 [5.2.1] cantherefore be disregarded.

The reference, given in the technical background, is wrong. This paragraph isbased on GL-Rules I-Part 1, Section 9A 5.5. The requirements are valid forsymmetrical and asymmetrical side frames, because the loads (sea and tankpressures) act not parallel to the webs of the frames and cause obliquebending. We will adjust the technical background on this paragraph.

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No.

836

837

839
attc

842

843

Ref.

9/3.2.1.5

10/3.3.9.3

10/1.20 &
1.10

3/6.5

Text
3/6.2.2.5

Type

QuestionTopicmachinery
space

Question

chain cable

Questionhorizontal
ruddercouplingflangeQuestion

Questioncurved faceplatestapering

Datecompleted

Question/CI

Answer

2009/3/10"Forward of the machinery space forward bulkhead, the bottom girder are to
be tapered for at least three frame spaces and are to be effectively connectedto the hull structure." This implies that the additional bottom girder in way ofthe machinery seating has to be extended into the pipe duct in the aftmost
cargo hold. In our opinion, there is no room to extend this additional girder
inside the pipe duct. The requirement is not in accordance with common
industry practice and should be disregarded.

As the framing system and girder system changes at the engine room
bulkhead there is a change in hull girder stiffness and in local stiffness. The
extend of the foundation girders into the adjacent space (e.g. pipe duct ortank) reduces this abrupt change of stiffness. Structural continuity is to beensured in double bottom by bottom girders tapered and effectively connected
to hull structure forward of engine room. Specific designs are to be allowed ona case by case basis by each Society, provided the above provisions arerespected. A Rule Change proposal will be made.

2009/1/26

The last sentence in Ch10 Sec3, 3.9.3 requires about chain cable attachment
as follows; In an emergency, the attachments are to be easily released fromoutside the chain locker. Our customers, who are planning to adopt a fixed
type attachment without releaser, inquire the technical background of therequirement. Please indicate the technical background of the requirement.

In case of an emergency (Vessel is pressed onto the lee shore by offshore
winds) and the capstan is inoperative, the release of the whole chain is thelast possibility for a ship to leave the anchorage.

2009/1/26

Figure 20 of Chapter 10, "Horizontal rudder coupling flange". The right side of
the figure (representing the rudder transversal section in way of the coupling)is unclear (perhaps due to rendering of the original image) Moreover, putting
formulas for requirements inside a figure is not consistent with what usually
done in the CSR for bulk carriers, and prohibits finding such formulas bymeans of full text searching inside the Rules. Please improve the figure andmove the formulas to the textual part of the Rules.

The right side of figure 20 is illegible due to a wrong image format. We will
exchange this figure and we will move the definitions in the text. This editorialchanges will be incorporated in the next corrigenda. Please find the original
figure 20 in the attachment.

2009/7/6

Ch.3 Sec.6 [5]In CSR Tanker rules 4/2.3.4 there is a correction formula for the effective
flange area of curved primary supporting members. In CSR Bulk there is nosuch formula. Does this mean that curved flanges, e.g. in the top wing webs
and bilge webs, are to be considered 100% effective?

There is no formula to evaluate the effectiveness of the curved part in the
curved flange in CSR –BC. The formula to evaluate the effective breadth oreffective area of curved flange is necessary in order to take into account theeffect due to cross bending phenomenon.
Therefore, this matter should be submitted to the Hull Panel to make aharmonized interpretation.
Furthermore, the RCP will be considered in accordance with the harmonizedinterpretation.

2009/6/25

Ch.3 Sec.6 [2.2.5] Change in plating thickness
Main machinery seatings are typically more than double the thickness of theinner bottom. In case the seating is included in the double bottom strucure, isthe requirement Ch.3 Sec.6 [2.2.5] to be complied with? If this is the case,insert plates will often be required in the inner bottom plating.
In our opinion it is sufficient to use tapering in accordance with Ch.11 Sec.2[2.2.2]. Please advise.

The meaning of "load" in "load carrying direction" in Ch. 3 Sec. 6 [2.2.5] isconsidered to be of a global type, such as hull girder loads. Where global
loads are considered small or can be ignored, e.g. machinery seatings orreinforced openings in bulkhead, tapering according to Ch.11 Sec. 2 [2.2.2] isconsidered sufficient.

Attachment

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No.

844

Ref.

3/6.10.3.4

845 6/3.3.1.1

Type

Question

Topic

Stiffener
brackets onplanebulkheads

MinimumInterpretati thickness ofonelementary
plate panels

Datecompleted

Question/CI

2010/1/18

Ch.3 Sec.6 [10.3.4]
The requirement for arm length a for stiffener brackets is very large for long
stiffeners not subject to pressure.
Example: Bulkhead in engine room between platform deck and upper deck.
Length is 5.5 m. 9 mm plating is stiffened with HP140x8 stiffeners. The
requirement to the arm length a then becomes 550 mm for the lower brackets
and 440 mm for the upper brackets. The actual arm length a is 250 mm.
In our opinion the bracket size should be decided based on the required
section modulus for the stiffener, not the length. Please comment.

2010/9/7

Please specify where the requirement Ch.6 Sec.3 [3.1.1] applies. Does it only
apply to the cargo area, or also to other areas, such as the aft and fore partsand machinery spaces? If it applies also to the latter areas, we will get
significant increases in plating thickness for some structures, such as wash
bulkheads, platform decks, etc..

Attachment

Answer

You are right. The bracket size should be decided based on the required
section modulus for the stiffener, not the length. We will consider a rulechange proposal in order to harmonize CSR for BC with CSR for OT.

Ch6, Sec3 applies to the central part as defined in Ch1, Sec1, [2.1.3]. It also
apply to machinery space as stated in Ch9, Sec3, [1.2.2] with respect torequirements of Ch9, Sec3.
However, the minimum thickness requirement based on space in the first
sentence of Ch6, Sec3, [3.1.1] was made as the first approach at the initialdesign stage so that initial scantling has certain stiffness. Less scantling may
be accepted on members under little load.
We will consider a rule change to delete this requirement

846

7/2.2

Question

openings in
PSM

2009/9/28

Ch.7 Sec.2 [2]Please provide guidelines on how to represent openings in PSM webs in the
FE cargo hold model, similar to CSR Tanker rules App. B 2.2.1.15

The representation of openings in PSM for finite element hold models will be
addressed by the harmonisation process.

847

Table
9.1.1

Questionfore peak

2009/2/11

Reference is made to Ch.9 Sec.1 Table 1 and to KC ID 494 What is thecorrect application of Table 1 for a non-tight floor top in the fore peak? Should
this structure be regarded as platform or inner bottom?

A non tight floor in the fore peak is considered as a platform with regard to
Ch.9 Sec. 1 Tab.1

2009/6/3

Ch.11 Sec.2 [2.4.1] Abutting plate panels forming boundaries to sea below
summer load waterline
We agree that partial penetration welding is acceptable for welding of abutting
In CSR Tanker partial penetration welding is acceptable for welding of abutting plates forming boundaries to sea below summer load waterline whenplates forming boundaries to sea below summer load waterline whenthickness is greater than 12 mm as per CSR OT. We will consider a Rule
thickness is greater than 12 mm.
Change Proposal
In our opinion this should also be acceptable for CSR Bulk. Please advise.

848

Text
11/2.2.4.1

Question

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No.

849

850

Ref.

Text
6/A1.1.3.4

Text
10/1.3.3.2

Type

Question

QuestionTopic

corrugated
BHD

rudder horn

Datecompleted

Question/CI

2009/6/16

Regarding the buckling assessment of corrugated bulkhead plates, the edge
stress ratio for their web plates is defined as 1.0 according to Ch.6 App.1[1.3.4(b)]. This means that the stress distribution of such web plates isassumed to be uniform. However, due to bending, the actual stress
distributions of these web plates are not uniform. Therefore, the edge stressratio,ψ, should be -1.0 in case where applying buckling case1. Please confirm
that ψ=1.0 is correct or not.

The correct value of psi is -1.0. We will consider a Rule Change Proposal.

2009/6/16

In addition to the simplified formula for the "Unit displacement of rudder horn"(f_b) a second formula has been introduced, taking the Young Modulus
explicitly into consideration. A comparison of the units in this formula showsthat the factor 10^8 has to be changed to 10^11. This error leads to an
overestimation of the spring constant "Z", which causes an un derestimation of
the moment, acting on the lower bearing of the rudder stock Please confirm.
We propose to handle this issue as a corrigenda, because the difference inthe dimensions of "f_b" is an apparent error.

The only definition of E (Youngs modulus) is found in Ch 1 Sec 4 2.2.1. Herethe unit is given as [N/mm^2]. However, in Ch 10 Sec 1 [kN/m^2] is the unit
used for E, as can be shown for the definition of G (Modulus of rigidity). The
units for G and E have to be the same. When using the unit [kN/m^2] for E,
the factor 10^8 is correct. A corrigenda to clarify the definition of E in Ch 10
Sec 1 will be considered.

Attachment

Answer

For the case of cargo loading as attached, the height of loaded cargo fromthe inner bottom to upper surface of cargo is calculated by as follows.

851
attc

4/6.1.1.2 &FigureQuestion
4.6.2

Ore cargosurface(smallamount ofmass)

2010/1/27

The section profile is to be as per the shaded area in the attached file,assuming the plane surface of width the parameter BH/2 in the centerline andCh.4 Sec.6 [1.1.2] defines the cargo surface when the cargo hold is not loaded
the inclined parts with an angle equal to psi/2. The profile is assumed to
up to the upper deck.
maintain throughout the length of the cargo hold.
There are cases of cargo loading as attached which is differenet from Ch.4
The virtual cargo section profile is to be determined so that the consequentSec.6 Figure 2. It seems that the formulas of h_c, h_HPL, h_1 and h_2 are notcargo volume is equal to M/rho_c.
applicable.
In calculating the cargo volume,
Please advise the formulas to define the cargo surface and cargo height h_c1) the upper stool is to be disregarded,
as well as V_TS in such cases2) the volume of lower stool is to be deducted which is cut by the virtual
section profile.

Y

Anyway, as the formula in [1.1.2] of Ch 4 Sec 6 is not used for the questioned
cases, we will consider a RCP in order to deal with such cases.

852
attc

6/2.4.1.1& 6/2.2.5

Question

Steel Coil
Loading

2009/9/4

Ch.6 Sec.2 [4.1.1] defines the required net sectional area of web stiffeners.
1) Please confirm the requirement is not applicable in case of steel coil loading 1. The requirement of Ch 6 Sec 2 [4.1.1] is applicable in case of steel coilas specified in Ch.6 Sec.2 [2.5].
loading becasue the load due to steel coil is acting on the ordinary stiffener.
2) If 1) is not the case please advise how to calculate the pressure "p" in case 2. Please find the attached document. We will conisder the RCP.
of steel coil loading.

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No.

853

Ref.

2/3.1.1.1

Type

QuestionTopicmeans ofaccessDatecompleted2009/1/24

Question/CI

Attachment

Answer

According to Resolution 151(78), the SOLAS Reg.II-1/3.6 apply to "Access toand within spaces in, and forward of, the cargo area of oil tankers and bulk
The scope of application should be considered as being exactly the same as
carriers". In CSR BC Ch 2, Sec 3 the item 1.1 refers to Resolution 151(78), but
in SOLAS Reg.II-1/3.6, i.e. applicable to "Access to and within spaces in, andits title states "Means of access to cargo and other spaces", which is not
forward of, the cargo area of oil tankers and bulk carriers". The CSR-BC will
exactly the same scope of application as in SOLAS Reg.II-1/3.6. Is it
be modified accordingly by a RCP.
intentional in CSR-BC or is the scope of application to be considered as being
exactly the same as in SOLAS?

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No.

854

Ref.

Type

8/1.1.3.1 &Table
Question
8.1.1

Topic

Primary
SupportMembers

Datecompleted

Question/CI

Answer

2009/3/10

Table 1 of Ch8, Sec1 defines the members and locations to be analysed in
fatigue assessments. Each mentioned connection of primary supporting
members is analysed in only one direction. We see the necessity to evaluate aconnection from both sides. This question focus' on the connection of inner
bottom and lower stool.. Summary of experience with fatigue assessment ofheavy ballast cargo holds: + The connection of the inner bottom to thevertical/sloping plate of the lower stool is the most critical loaction + The
deformation of the double bottom and the transverse bulkhead expand thiswelding connection due the large internal dynamic pressures . + The global
bending stress plays not a dominant role. Stress ranges of the inner bottom
and the stool plating are of a comparable size + Typically the initial calculated
damages of the inner bottom AND the stool plate are considerably larger than
1. + Counter measures in one member, e.g inserted plates in inner bootom,
decrease the damage of this member, but increase the damage of the othermember.

This is already under discussion at the Hull Panel. The conclusions will beendorsed by PT1. UPDATED ANSWER AGREED 11 SEPT 2009: "Regarding
Tab 1 in Ch 8, Sec 1 of CSR-BC, the intent at the time of development of the
CSR-BC was not to check the inner bottom only, but the whole connection of
inner bottom with sloping and/or vertical plate of lower stool, which includes all
the plates. The whole connection means the connection of plating members of
inner bottom, side of lower stool, girders and floors in DB and diaphragms inlower stool. In addition, it is to be noted that, when making fatigue assessmentof such connection, if fatigue problems are found in any of the above plating
members, then reinforcements are to be considered for all the concerned
plating members. It means that Table 1 should be understood as considering
all the plating members involved in the inner bottom/lower stool connection
and not only the inner bottom plating. Table 1 will be modified accordingly at afuture date."

Attachment

As an example, the reduction of the damage of the inner bottom from 4 to 1
may increase the damage of the sloping plate up to 6 or more. The
deformation and stresses of the considered structure and the damage results
indicate clearly that this fatigue problem is a 3D-problem, where measures in
one member directly affects the other member. If we follow the definition ofmembers, to be assessed (Table 1), only the inner bottom need to comply withthe fatigue requirements, whatever the calculated damage of the stool plating
is. It seems, there are two options: 1) Assess the inner bottom - lower stool
connection from both sides. 2) Assess only the inner bottom In case of option
1, we need a modification of the table and we need an instruction, how to deal
with approved vessels (MOU, TOCA), where no fatigue assessment havebeen performed for the stool plating. In case of option 2, it has to be
demonstrated, why the damage results of the lower stool plating can beneglected.

855

Table
11/2.1 &Text
11/2.2.6.1

Questionfillet welds

2009/6/25

Leg length of fillet welds is adjusted corresponding to the corrosion addition as
required in Ch11 Sec2, Table 1, Note (2). On the other hand, weld throats inzones “a” and “b” of side frames are required in 2.6.1 without reference toTable 1. Because this requirement originates from UR S12, adjustments of
those of side frames are considered unnecessary. Please confirm the above.

Considering the fillet weld category of side frame of single side structure(connection of side frame and end bracket to side shell plate) in Tab 2 Ch11
Sec2 is not referred to one specified in Tab1 Ch11 Sec2, the note (2) of Tab1
is not applicable to fillet weld of side frame of single side structure (connectionof side frame and end bracket to side shell plate)

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No.

856

858

859

Ref.

Text
6/1.2.3

8/2.3.2.1

Type

Question

QuestionTopicbilge platingshapeparameter

Load
combinations
Interpretati
used for4/6.3.3.2
onchecking
bulkheadscantlings

Datecompleted

Question/CI

Answer

2009/6/16

Clarification of the criteria of the application of any increased thickness
required for the bilge plating to the adjacent bottom and side shell plating.
In case the straight plate of bottom or side shell shares a transversely framed
and curved EPP with the bilge plating, should the required thickness of thebilge plating be applied to the adjacent bottom or side shell plating?
Regarding this, in Tanker CSR Corrigenda 3 Section 8/ 2.2.3.2, the criteria
have been defined clearly for the application of the required thickness of thebilge plating. However, in Bulker CSR Ch 6, Section 1 [2.3], there is no clear
guideline.
Please clarify.

The text of Ch 6 Sec 1 [2.3.3] says: The net thickness of the bilge plating is tobe not less than the actual net thicknesses of the adjacent 2 m width bottom
or side plating, whichever is the greater. Therefore, the required thickness ofthe bilge plating should not be applied to the adjacent bottom or side shell
plating

2009/2/11

In CSR BC Ch.8 Sec.2 [3.2.1], the Weibull shape parameter is taken to 1.0. In
CSR OT App. C/2.4.1.2, this parameter is a linear function of the rule length L.
Using in CSR BC the same definition of Weibull shape parameter as in CSR
OT leads to longer fatigue life duration. As the approach used in CSR OT isalso used in BV rules and in other societies, it is therefore requested toreconsider the value of in 1.0 for this parameter in CSR BC.

Originally, the Weibull shape parameter, which is the function of L, wasdefined for the wave bending moment in the IACS Recommendation No.56 in
1999. Strictly, it depends on the RAO of the object member and consideredload environments. In the CSR-B, the Weibull shape parameter was set as 1.0
for the simplification and the effect of such treatment is confirmed being small.
The point you mentioned should be the harmonization issue and will be
discussed in the forthcoming harmonization team on fatigue.

Attachment

Reference is made to KC#402
Questions related to interpretation of the following sentence in Ch.4 Sec.6
3.3.2
Please advise the interpretation of following sentence.
"The most severe combinations of cargo induced loads and flooding loads areto be used for the check of scantlings of each bulkhead, depending on theloading conditions included in the loading manual."
2010/2/15

In ship with BC-A notation, most of ships may be intended to carry, in nonhomogeneous condition, the dry cargo in bulk with density between 0.9 and3.0. We have examined the strength of corrugate BHD according to URS18
and Ch.4. Sec.6 3.3.3. The most severe case is the flooded nonhomogeneous condition with the cargo density of 1.78 t/m3. If the loading
manual does not include the condition with the density 1.78t/m3, the case of
1.78ton/m3 is considered or not? And if the corrugated bulkhead with density
1.78 t/m3 is not considered, the ship have the limitation about the cargo withdensity 1.78 t/m3?
Please clarify!!!

This question will be considered together with KC 872. A Common
Interpretation will be made to clarify applicable loads, density and angle ofrepose for intact, flooded and fatigue condition.

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No.

860

Ref.

4/6.2.2.1

Type

QuestionTopicreference
point

Date
completed2009/1/24

Question/CI

Attachment

AnswerIn CSR-BC Ch 4, Sec 6, [2.2.1], there are two possible methods for thedetermination of the reference point B for load cases R and P: - the first one isdefined through the definition of yB and zB and the figure 3, - the second one
is defined as being the upper most point after rotation by the angle "phi". For
The interpretation is correct: only the second method (B being the upper mostsome geometries of the ship section considered, in particular depending on
point after rotation by the angle "phi"). It should be applied for local strength,
the angle of the sloping top side tank plate or when the deck is not horizontal,
direct strength and fatigue check.
the point B obtained through the two methods are different. Our interpretationis that only the second method (B being the upper most point after rotation by
the angle "phi") should be applied as it is the most physical and it is a general
method. Please confirm our interpretation?

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No.

863

866
attc

Ref.

Table
/9.2.5Figure6.2.10871
3/6.10.4.7
attc

873

875
attc

Type

Question

RCP

QuestionTopicsingle screw
ship

web stiffenerendconnections

S 18

Concentrated forces due
Interpretati
4/5.2.4.2
to unit loadon
on exposed
decks

Table
8.2.2

QuestionfatiguestrengthDatecompleted

Question/CI

Answer

2009/6/23

Ch9 Sec2, Table5 requires thicknesses t1 and t2 of cast propeller posts ofsingle screw ship. The applicable area of required thicknesses t1 and t2 is not
so clear as to distinguish required thickness at any point of post. Pleaseconfirm it.

t1 is the post minimum thickness, to be measured at the connection with theshell plating (excluding a possible tapered transition to the shell plating
thickness) t2 is the post maximum thickness, to be measured at the edge ofthe circular area with radius R. In addition, the word "to be taken not less than
19mm" and Note 1 in Table 5 should be deleted because it is impossible for
CSR ships >=90m. In order to clarify these, figure in the table and the wording
will be corrected in the next corrigenda.

2009/8/3

In the estimation of web stiffener connection ends, the definition of theparameters is to be clarified.
When fitting with large collar plate supporting stiffener flange as attachedfigure, the parameters, l_1 and l_2 as defined in the left figure of Fig. 10, arenot clear.
Please clarify the above.

In case that Ch.6 Sec.2 [4.1.3] is applied to the design in question, "scallop
width" and "slot width" in the attached figure may be treated as theparameters l1 and l2.

Y

2009/5/13

See the attached comment/question forwarded by ABS re BC CSR
Ch.3/6.10.4.7.

The requirement of Ch3/Sec6/[10.4.7] comes from S18, and is in line withSOLAS Ch. XII - SOLAS/CONF.4-Resolution of the Conference of Contracting
Governments to the International Convention for Safety of Life at Sea, 1974(November 1997) – Resolution3 –Recommendation on Compliance withSOLAS Regulation XII/5 – (Adopted on 27 November 1997). We should keep
it as is.

Y

2010/8/6

Ch4 Sec5, 2.4.2 requires concentrated force due to unit load. However, thescantling determination procedure of the structure, which is loaded with thisconcentrated force, is not clearly indicated in CSR.
Please confirm the procedure to determine the scantling of following members
in cases where a unit load is carried on an exposed deck;
1. Plating
2. Stiffeners
3. Primary supporting members, including the cases that direct strength
assessment in Ch7 applies.

The structural member under heavy concentrated load should be adequately
stiffened by local support in general, and its scantling, which is to be based on
the net scantling approach according to Ch3, Sec2, is at the discretion of theSociety.
This issue will be considered in the Harmonization of the two Common
Structural Rules.

In practice, there are some bulk carriers without heavy ballast condition. Howis fatigue strength checked? Especially, how is the coefficient αj determinedwhich is defined in Ch8, /Sec 2, /Table 2? Is it practical to incorporate αj inheavy ballast condition into that in normal ballast condition as the following
table (as attached)?

Normal ballast condition and heavy ballast condition are required for all
vessels with CSR Bulk Carrier notation for providing sufficient draught and trim
to prevent damages during navigation in Ch.4 Sec.7 [2.2.1]. In case that abulk carrier does not have a ballast hold and has only one loading condition
carrying ballast water and that the loading condition complies with the both
requirements of normal ballast condition and heavy ballast condition in Ch.4
Sec.7 [2.2.1], the loading condition may be treated as normal ballast conditionand heavy ballast condition stipulated in Ch.8 Sec.2, Table 2. Coefficientalpha_j in Ch.8 Sec.2, Table 2 should be applied accordingly.

2009/9/3

Attachment

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Type

6/1.2.6.3 &878
Question6/1.2.6.2

Topiceffective
structureDatecompleted

Question/CI

Answer

2009/3/10

In corrigenda 5, the “long superstructure” and “short superstructure” aremodified into “effective structure” and “non-effective structure” in Ch 6, Sec 1,[2.5.3] and [2.5.4]. We think Ch 6, Sec 1, [2.6.2] and [2.6.3] should also be
modified.

To be in accordance with Ch.6 Sec.1 [2.5], terms "long superstructure" has tobe change to "effective superstructure" in Ch.6 Sec.1 [2.6.2], and "shortsuperstructure" to "non-effective superstructure" in Ch.6 Sec.1 [2.6.3]

Attachment

Ch 6, Sec 2, [2.5.3] ordinary stiffeners located on hopper sloping plate or innerhull plating

879

Text
6/2.2.5.3

question

hoppersloping tanks

2009/6/16[quote]l' : Distance, in m, between load points per elementary plate panel of inner
bottom plate in ship length, sloping plate or inner hull plating, as defined in
Ch6, Sec 1, [2.7.2].
[unquote]

Your observation is correct. The definition of l' is related to the factor K3 andhence valid for both [2.5.2] and [2.5.3]. We will consider to move the definition
to Symbols or Table 1 for K3 in a corrigenda.

The title of Subsection [2.5.3] concerns hopper sloping panel and inner hullplate, excluding inner bottom plate, so the definition of l' should be modified.

Scantlings ofprimary
6/4.2.2.1,
supporting
6/4.2.3.1,
members for
Question880
6/4.2.4.1 &ships of less6/4.2.5.1
than 150m in
length definitions

883
Text
attc 6/A1.1.3.3

questionbuckling
assessment

2010/3/30

With respect to Ch 6, Sec 4, we have the following questions:
1.Subsection [2.2.1] and [2.3.1] define BDB as distance between the toes ofhopper tanks at the midship part, and define Ps, IB, Pw, IB, Ps, BM, Pw, BM
as pressures at the center of the double bottom structure. We think theposition to calculate BDB should also be the center of the double bottom
structure as that of Ps, IB, Pw, IB, Ps, BM, Pw, BM. Please consider.
2.Subsection [2.4.1] and [2.5.1] define hDS as height of the double sidestructure between upper end of hopper tank and lower end of topside tank,and define Ps, SS, Pw, SS, Ps, LB, Pw, LB as pressures at the center of lDS
which is length of the double side structure between the transverse bulkheads
under consideration. We think that the position of hDS should also be at thecenter of lDS as that of Ps, SS, Pw, SS, Ps, LB, Pw, LB. Please consider.

We agree to your opinion that B_DB and h_DS should be calculated at thecenter of double bottom and double side of the considered hold respectively.
On the other hand, it is necessary to note that B'_DB is separately defined as
the breadth at the position of the floor in Ch6 Sec4, 2.3.1.
In addition, it is necessary to define h'_DS separately as the height at theposition of the side transverse web in 2.5.1.
Accordingly, the second h_DS in the formula of t1 is changed to h'_DS in
2.5.1.
We will consider a Corrigendum.

2009/6/16

Ch6 App1, 1.3.3 requires treatments on buckling assessment of side shellplates which are stiffened vertically in the following two cases;
Case 1: with approximately constant stresses
Case 2: with distributed stresses
According to the Rules, Case 2 is applicable to side shell panel under
distributed stress over the panel height. In general, the panels in way of side
frames are such stress and Case 2, therefore, is applied to them. On thecontrary, regarding side shell panels in way of brackets above/below side
frames as shown in the attached sketch, it is considered that the stress
distribution in the panels is approximately constant. So the treatment of above
Case 1 is applied to the buckling assessment of the panels.
Please confirm the above.

Your understanding is correct.

Y

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No.

884

885

887

888

891

Ref.

Text
3/2.3.3.1

Table
3.3.1

9/2.6.5.1

Table
4A.2.59/2.3.1.2

Type

Topic

question

net scantling
approach

Question

collision
bulkhead &machinery
space front
bulkhead

Questionquestioncistern tube
thickness

FEA

Aft peakDatecompleted

Question/CI

Attachment

Answer

2009/6/24

From a viewpoint of net scantling approach, Ch3 Sec2, 3.3.1 requires that
renewal thicknesses of structural members be indicated on the structural
drawing. A renewal thickness is defined in Ch13 Sec2 as follows;t_renewal = t_as_built - t_C – t_voluntary_addition
On the other hand, superstructures and deck houses required in Ch9 Sec4 are Renewal of structures of superstructures and deck houses is to be left tobased on gross scantling as indicated in Ch3 Sec2, 2.1.1. Accordingly, it isdiscretion of each classification society. The same goes to all structures listed
considered that renewal thicknesses of superstructures and deck houses are in Ch.3 Sec.2 [2.1.1].
not in line with the above definition and consequently follow that specified ineach Class Rules. Therefore, we consider it unnecessary to indicate renewal
thicknesses of superstructures and deck houses on the structural drawing.
Please confirm the above.

2009/8/27

The question is on collision bulkhead and machinery space front bulkhead
without upper stool and lower stool.
Please confirm that only "Transverse bulkhead"-"Other parts" & "Upper parts"of "Structural member" category, in Ch.3 Sec.3 Table 1,are to be applied tothe corrosion addition on cargo hold side of these bulkheads but that "Lowerstool sloping plate, vertical plate and top plate" category needs not be applied.

The corrosion addition for lower stool plates intend to deal with the high levelof corrosion that takes place within the lower stool space. As there is no lower
stool, the corrosion addition to be considered here is the "Transverse
bulkhead / other parts".

2009/9/18

1st paragraph in Ch.9 Sec. 2 [6.5.1] reads:"The sterntube thickness is
considered by the Society on a case by case basis. In no case, however, may
it be less than the thickness of the side plating adjacent to the stern-frame."
Please confirm that the thickness of the side plating to be used is the required
net thickness?

Answer: Your understanding is correct. The thickness of the side plating to be
used is the required net thickness. This requirement has also to be consideredwithin the harmonisation.

2009/6/23

Ch4 App2, Table5 defines load cases to be analyzed in FEA. The cases
Nos.12 to 15 are in harbour conditions and their still water bending moment
are indicated as M_S,P(+) and M_S,P(-). On the other hand, Note b) of Table5 We confirm your comment and will make an editorial correction in the Rules tospecifies M_SW,P,H and M_SW,P,S as allowable still water bending moment replace M_S,P(+) and M_S,P(-) by M_SW,P,H and M_SW,P,S so as to in line
for harbour condition. It seems that M_S,P(+) and M_S,P(-) are identical towith the other tables and the Note b).
M_SW,P,H and M_SW,P,S respectively. Please confirm the above andcorrect these discrepancies.

2009/9/8

Ch9 Sec2, 3.1.2 requires “Floors are to be provided with stiffeners located atintervals not exceeding 800 mm.” in its last sentence. We are of following
opinions; - This requirement is applicable only in way of and near the rudder
post, propeller post and rudder horn. - Intervals of stiffeners depend on the
thickness of floor as required in Ch3 Sec6, 5.2.1 Please confirm the above.

The last sentence of Ch9 Sec2, 3.1.2 “Floors are to be provided with stiffeners
located at intervals not exceeding 800 mm.” is applicable only in way of andnear the rudder post, propeller post and rudder horn. This requirement should
be applied in addition to Ch3 Sec6, 5.2.1.

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No.

Ref.

7/3.2.1.1 &
892
Table
7.3.1

893

896

Text
10/1.8.3.1

Text
6/4.1.5.1

Type

Topic

questioncorosiondeductionquestion

corrosion
allowancequestionprimary
supporting
members

Datecompleted

Question/CI

Answer

2009/7/28

For the current CSR/BC rules and current practice of the class societies, withregard to the fine mesh FEM model of the transverse set of Primary Support
Members mentioned in the second figure in 7/3 Tab 1, is the portion of themodel representing the single side skin frame to be modeled by deducting
1.0Tc or 0.5Tc?

Regarding the fine mesh FEM model of the transverse set of Primary Support
Members mentioned in the second figure in 7/3 Tab 1, the portion of themodel representing the single side skin frame to be modeled by deducting
0.5tc.

2009/6/26

There appears to be an editorial error in the equation for t(k), the corrosion
allowance for nozzle plate thickness t(0) with t(0) greater than 10mm: The
present formula is: t(k) = min [0.1 ((t(0) / (sqrt k)) + 0.5) , 3.0] The formula
should be revised to: t(k) = min [0.1 ((t(0) / (sqrt k)) + 5.0) , 3.0]

There is an editorial error in the equation of t(k), corrosion allowance fornozzle plate when t(0) is greater than 10mm. The formula should be changed
to: t(k) = min [0.1 ((t(0) / (sqrt k)) + 5.0) , 3.0] This modification will be includedin the next corrigenda.

2009/6/26

Ch.9 Sec.2 [4.3] specifies scantling requirements of primary supporting
members in aft part. The minimum thickness of floors is defined in [4.3.1].
However for other PSMs such requirement is not so clear. Please advise on
the following questions:[A] [4.3.4] refers to Ch.6 Sec.4 requirements for deck PSMs. Do theserequirements include Ch.6 Sec.4 [1.5.1]?
[B] Please confirm that:(1) there is no requirement to minimum thickness for PSMs other than for
floors, i.e., there is no minimum thickness requirment for deck PSMs, sidetransverses, side girders, etc.; or(2) there is no requirement to minimum thickness for PSMs other than for
floors and deck PSMs, i.e., there is no minimum thickness requirements forside transverses, side girders, etc.

Attachment

A1) Yes, deck PSM have to fulfill the requirements of Ch.6 Sec.4 considering
the loads defined in Ch.9 sec.2 [2.2], and in particular the minimum web
thickness defined in Ch.6 Sec.4 [1.5.1].
A2) No, the requirement for a minimum web thickness defined in Ch.9 Sec.2[4.3.1] applies to all the PSM except those of the deck (see answer A1 herein).
A rule change will be issued for clarifying this.

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No.

902

Ref.

4/3.2.2,
4/3.2.3 &4/3.2.4

Type

RCP

Topic

margins of
SWBM &SWSF

Datecompleted2009/7/16

Question/CI

Attachment

AnswerSince scantling approval is based on the hull girder bending moment andshear force values contained in the preliminary loading manual, which may besubject to change (and possibly be higher) in the final loading manual. It isbelieved that the CSR Tanker guidance notes recommending that during initialdesign a margin be placed on the Still Water Bending Moment and Still Water
Shear Force is a very good provision in the rules and that similar guidancenotes be contained in the CSR Bulk Carrier Rules. Reference is made to CSR
Tanker Sec.7, 2.1.1.6 and Sec.7, 2.1.3.6, which are as follows:
Guidance note: It is recommended that, for initial design, the permissible hull
girder hogging and sagging still water bending moment envelopes are at least
5% above the hull girder still water bending moment envelope from theloading conditions in the loading manual, to account for growth and design
The definition of the margins to be applied on the hull girder bending moment,
margins during the design and construction phase of the ship.
shear force... is the responsibility of the designer at each step of its project.
Rules are to be applied on the values given by the designer.
This subject will also be submitted to the harmonisation team.
Guidance note: It is recommended that, for initial design, the permissible hull
girder still water shear force envelopes are at least 10% above the hull girder
shear force envelope from the loading conditions in the loading manual, toaccount for growth and design margins during the design and construction
phase of the ship.
It is believed that like guidance notes for margin on bending moment andshear force values should be included in CSR Bulk Carriers for application
during initial design both for values in intact and flooded condition. It isbelieved that the values of margins that are applied to Tankers would also beappropriate for Bulk Carriers.

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KCID
No.

903

Ref.

Text
2/1.2.1.1

TypequestionTopiccollision
bulkheadDatecompleted2009/6/26

Question/CI

Attachment

AnswerRegarding the arrangement of collision bulkhead in Ch 2, Sec 1, [2.1.1], thetext of the requirement is coming from SOLAS Ch. II-1, Part B, Reg. 11 andstates that "A collision bulkhead is to be fitted which is to be watertight up to
We agree with your comment and will update the rules accordingly.
the freeboard deck. This bulkhead is to be located at a distance from theforward perpendicular FPLL of not less than 5 per cent of the length LLL of theship or 10 m, whichever is the less, and not more than 8 per cent of LLL ".

However, this text is modified by Annex 2 of MSC 216(82), which is enteredinto force since 1st january 2009, and wich states in SOLAS Ch. II-1, Part B-2,
Reg 12.1 that "A collision bulkhead shall be fitted which shall be watertight up
to the bulkhead deck. This bulkhead shall be located at a distance from theforward perpendicular of not less than 0.05L or 10 m, whichever is the less,and, except as may be permitted by the Administration, not more than 0.08L
or 0.05L + 3 m, whichever is the greater." The text in CSR-BC should be
modified accordingly. More generally, the requirements in CSR-BC comingfrom SOLAS and modified by MSC 216(82) should be updated accordingly.

906

Text
10/1.9.2

907 4/6.1.1.2 &attc 4/6.1.1.1

question

Q&A

materialfactorInternalpressures &forcesappliedduring FEM
analysis

2009/6/24

2010/4/14

The material factor "k" in Ch.10, Sec.1 [9.2.2], [9.2.3] and [9.2.4] and the
The material factor in the scantling equations for rudder horns, in particularmaterial factor "K" in Ch.10, Sec.1 [9.2.5] should be replaced with "k(r)" as
those for materials with minimum yield strength less than 235 N/mm^2, are notdefined in Ch.10, Sec.1 [1.4.2]. This correction will be made in the next
clearly defined in Ch.10, Sec.1 [9.2] and should be clarified.
corrigenda.

Please see the attached PDF file containing 2 questions about CSR for bulk
carrier in Chapter 4 section 6 Internal Pressures and Forces when applying
them in the FEM analysis.

Q1a)Static cargo pressure at Pos 1 and Pos 2 are not the same, since the shapeof cargo gives a reduced hc outside Bh/4 from centerline. In your example thestatic pressure will be pCS = ρC x g x KC (ha + hDB − z).
b)At your position 4 the cargo pressure will be zeroc)In your example pCS = ρC x g x KC (hb + hDB − z) should be used.
d)In your example hd should be used.
YQ2a)For calculation of hc, psi does not need to be considered because anequivalent horizontal surface is assumed.
Static pressure at top side plate is to be zero since Kc is defined to be zero for
top side plate, upper deck and sloped upper stool.
b)In your example the static cargo pressure is the same in region 1 and 2.
c)In your example hc should be used.

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KCID
No.

910

911

912

913

914
attc

Ref.

Tables
4.A2.1 &4.A2.3

6/1.2.3.2

4/6.

4/6.

Text
6/2.3.3.1

Type

Topic

Loading
Questioncondition
accelerations

RCP

bilge plating
thickness

RCP

sloshingpressure

RCP

min pressure
for decks in
ER

RCP

Date
completed

Question/CI

Answer

2009/9/4

Loading condition No 1 considers homogeneous loaded cargo. According toNote 2 a density of 3t/m has to be used. Please confirm that GM and k_R ofthe real homogeneous loading condition (density << 3t/m) has to be used inthis context and not a higher GM value, which considers the lower COG of thistheoretical cargo. From our point of view the aim of this loading condition is tocreate maximum sea pressure at side shell without counterpressure due tocargo. Higher accelerations, based on the theoretical density of 3t/m, need not
to be considered.

LC1 is a homogeneous loading condition with a density of 3.0 t/m3 which has
to be included into the loading manual. The corresponding calculated valuesof GM and kr have to be used in FEM analysis and not those of a loading
condition with a lower density. If these values are not available, default values
have to be used as per Ch.4 Sec.2 tab.1.

2009/8/3

Ch6 Sec1 [2.3.2]
Our understanding is that the for formula net thickness of bilge plating isYour understanding is correct, and we will make an editorial correction to
based on buckling of thin cylindrical shells subjected to external pressure.
clarify this.
Hence, please specify that only the external pressures are to be considered in
the formula.

2009/9/4

Minimum pressures for ballast tanks Please consider including minimum
sloshing pressures for ballast tanks, similar to CSR Tanker 7/4.2.4.

2009/7/16

Minimum pressure for platform decks in engine room.
Please consider including minimum pressure for platform decks in engine
rooms, similar to CSR Tanker 7/2.2.4.

Requirement
Ch6 Sec2 [3.3.1] Side frames in ballast holds
s for side
2010/10/20 Please consider the attached Rule Change Proposal regarding requirements
frames in
to side frames in ballast holds.
ballast holds

Attachment

Bulker CSR does not have the structural scantling formula according tosloshing pressure for ballast tanks. To include design pressure and scantling
formula for sloshing, sufficient ramification study should be carried out. It will
be discussed during harmonization process with considering the necessity ofsloshing estimation in ballast tanks of bulkers.

A minimum thickness is currently required for platform plating in the engine
room.
As this differs from the CSR OT approach, this will be submitted to theharmonisation team.
As notified in the Technical Background, the requirement Ch.6 Sec.2 [3.3.1] isbased on requirement S12.4.1 of the draft text of IACS UR S12 Rev.4 agreed
at the WP/S meeting of 8-10 April 2003.
In order to agree with URS12, the m-factors must be adjusted.
The new m-factors will be presented to the Hull Panel and to theHarmonization Team in a CI.
Once the new m-factors approved, they will be modified in CSR BC.

Page 155 of 181

YIACS Common Structural Rules Knowledge Centre

KCID
No.

918

919

Ref.

6/1.3.2.3bi
s2

Type

CI

7/4.3.2.2 &Question
3.3

Topic

Thickness of
supporting
floor ofcorrugatedbulkhead

Fatigueassessment
for weldedintersection
betweenbent plate
and plane
plate

Date
completed

Question/CI

Attachment

Answer

2010/5/12

With regard to required net thickness of supporting floor of corrugatedbulkhead (Corr.BHD.) with lower stool, please reply to the following questions.
1.In 6/1.3.2.3 bis2 of RCN No.1-8, the wording of “by the first sentence” in thesecond sentence should be deleted because there is no relevant sentence in 1:
6/1.3.2.2.
Your observation is right: The wording of “by the first sentence” in the second
sentence should be deleted because there is no relevant sentence in
2.It is noted that the requirement of 6/1.3.2.2 (required plate thickness in
6/1.3.2.2.
flooding) is not applicable to lower stool side plating in ballast hold because it
is only applicable to the plating which constitutes the boundary of
2:compartments not intended to carry liquids. According to 6/1.3.2.3 bis2 of RCN Yes, you are correct. Required thickness of supporting floor in way of ballast
No.1-8, on the other hand, required thickness of supporting floor in way ofhold is to be based on the required thickness of 6/1.3.2.2. Imaginary required
ballast hold is to be based on the required thickness of 6/1.3.2.2. Our
thickness of lower stool side plating in ballast hold needs to be calculated inunderstanding is that imaginary required thickness of lower stool side plating
accordance with 6/1.3.2.2 in order to obtain required thickness of thein ballast hold needs to be calculated in accordance with 6/1.3.2.2 in order tosupporting floor in way of ballast hold.
obtain required thickness of the supporting floor in way of ballast hold because
the concept of 6/1.3.2.3 bis2 comes from UR S18 (Flooding requirement ofCorr.T.BHD). But please confirm.

2010/1/27

With regard to fatigue assessment for welded intersection between bent plate
and plane plate, KC292 said that " the parts indicated in the question are notrequired to carry out the fatigue assessment".
Howerver, CSR in Bulk Carrier says that the correction factor λ at 7.4.3.2.2
and (K2, K3) correction coefficient at 7.4.3.3.3 is considered for bent type. (i.e.
bilge hopper to floor)
Please clarify the applied spots among structure. relative sentences are to bedeleted if intersection for bent type is not required to carry out the fatigue
assessment.

Fatigue cracks are found on bilge hopper knuckle part of bend type,accordingly, fatigue strength assessment on bilge hopper knuckle part of bend
type should be carried out.
At the bilge hopper knuckle part of bend type, fatigue crack mainly occurs
from weld toe of transverse web welding, and penetrates the knuckled
connection between hopper plate and inner bottom plate. Therefore the mostimportant stress in fatigue strength assessment is the longitudinal stress on
the knuckled connection between hopper plate and inner bottom plate. It isnecessary to assess the stress in fatigue assessment.

In Ch.3 Sec.6 [10.4.5], it is stated that "In general, the first vertical corrugation
connected to the boundary structures is to have a width not smaller thantypical width of corrugation flange".

920

3/6.10.4.5

Question

corrugated
BHD

2009/7/16

Q1. We assume that "boundary structures" is side shell plate.
Please advise correct interpretation of "boundary structure".
Q2. We understand that the width of first vertical corrugation connected to side
shell plate is more than typical width of corrugation flange.
Please clarify the meaning of above paragraph whether our understading iscorrect or not.

A1: Boundary structure is the ship side structure.
A2: The first corrugation is to be at least as width as a "typical" corrugation of
the bulkhead. A larger width is not mandatory.

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No.

Ref.

Type

Topic

Date
completed

Question/CI

Attachment

AnswerPlease inform us which one is the exact CSR requirement for rudder stock
between A and B as below.
922

10

926

Text
3/6.4.1.1

928

Text
7/1.1.5.1

Text
9/2.4.2.3(tanker) &930
Text
9/1.4.3.3(bulker)

Questionrudder stock
reqs

questionbuilt-up
stiffener

questionquestionFEA

max netthickness

2009/7/16

A : Forged steel for rudder stock shall be weldable type in any case.
B : No. Forged steel for rudder stock whether weldable or not can be decided
by Builder.

As specified in UR W7, forged steel for rudder stock shall be weldable type inany case.

2009/6/24

Ch.3 Sec.6 [4.1.1] Bulb section, equivalent built-up stiffener.
It is not clear if the text and Fig.1 are referring to net or gross dimensions of
the bulb profile and the equivalent built-up profile. Please clarify if t'w, tw, h'w,
bf and tf are net or gross dimensions

t'w, tw, h'w, bf and tf used in Ch.3 Sec.6 [4.1.1] are net dimensions. A
corrigenda will be prepared to clarify it.

2009/6/26

According to CH7, Sec1, 1.5.1 the most severe loading regime shall be usedin FEA. We noticed during the work in PT3 that several Societies use deckloads according to CH4, Sec5, 2. in FEA. From our point of view thenegotiation of deckloads causes a more severe situation, because theupwards directed deformation of the TWT in full load condition is reduced bydeck loads. This can be judged comparing the buckling strength of the sloped
plate of the TWT with and without deck loads. Another aspect of the definitionof deck loads makes the usage in FEA disputable. In hogging and sagging
condition and for all drafts are the "dynamic" deck loads the same. We request
a clear advise of the application of deck loads in FEA (Yield, buckling and
Fatigue check) for different loading conditions and load cases.

This question is now relevant to the harmonisation between CSR BC and CSR
OT and will be submitted to the relevant project team. In the meantime, theloads to consider on the deck for FEA calculations are defined in Ch.4 Sec.5[2].

2009/6/23

Incorrect reference number in 2008RCN1-4
The last sentences of Ch9 Sec1, 4.3.3 and Ch9 Sec2, 4.2.3 indicate thereference to the requirement of maximum net thickness of web of ordinary
stiffener in Ch6 Sec2.
However the reference number is incorrect, because the maximum web
thickness requirement has been moved from 2.2.2 to 2.2.3 in Ch6 Sec2 during
finalization of the RCP.
Please correct the reference number of the last sentences of Ch9 Sec1, 4.3.3
and Ch9 Sec2, 4.2.3 as follows; “The net dimensions of ordinary stiffeners areto comply with the requirement in Ch 6 Sec 2, [2.2.3] and [2.3].”

Your comment is correct. The reference number of the last sentences of Ch9
Sec1, 4.3.3 and Ch9 Sec2, 4.2.3 should be as follows: “The net dimensions ofordinary stiffeners are to comply with the requirement in Ch 6 Sec 2, [2.2.3]
and [2.3].” This will be corrected in the next corrigenda.

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No.

Ref.

Type

Topic

Date
completed

Question/CI

Attachment

AnswerThis question has to be considered within the scope of the harmonisation. The
position expressed by ABS hereafter will be submitted to the relevant
harmonisation team.
ABS proposal:
Bilge and drainage store tanks would generally contain a combination of oil
and water.
However, in the extreme case they may contain salt water only. Considering
stiffeners of FOT the two sided corrosion addition (without t-reserve) is 1.4mm-> 1.5mm and in the case of a Ballast Tank the two sided corrosion addition
would be 2.4mm -> 2.5mm.
It is believed that a two sided corrosion addition of 2.0mm to 2.5mm would beappropriate.
Considering the amount of the structure to which this would be applied, and“fitting” of this category of tank into the existing categories of compartments it
is recommended that these be treated as Ballast Tanks.

931

Table
3.3.1

Question

corrosion
addition

2009/7/24

Please clarify the corrosion addition for bilge tank/drainage store tank.

932

9/1.2.3.3

Questionbottom girder
spacing

2009/7/16

Chapter 9 Section 1 [2.3.3] requires in the fore part that ”In case of transverse
framing, the spacing of bottom girders is not to exceed 2.5m”. Is a spacing ofbottom girders of 2.7m acceptable considering the similar Q & A in KC759?

2009/7/16

We, from HHIC-Phil had a discussion regarding the Painting Specification of
our Bulk Carrier which will be constructed in our yard by next year. The
Painting Specification was prepared in accordance with the CSR and PSPC
Rules together with the paint maker's recommendation and building
specification. Regarding this matter we encountered a problem on theinterpretation of the CSR for Bulk Carriers on the Transverse bulkhead Areas
to be coated. If we apply the CSR strictly, the painting demarcation line of thetransverse bulkhead will vary according to the position of the frame end
your interpretation is correct.
brackets.
We would like to request an interpretation of the Common Structural Rules(CSR) regarding the cargo hold painting demarcation line for Single Side Bulk
Carrier. Please see the attachment to give us some clarification on the painted
areas and no-painting areas of the cargo hold corrugated transverse bulkhead
and the likes.
Thank You very much in advance. Your kind attention and prompt reply would
be much appreciated.

933
attc

3/5.1.3.4

CIcargo holdpainting spec

The spacing of bottom girders of 2.7m may be used when the structure isverified by means of FEA deemed appropriately by the Society, using directly
calculated slamming loads.

Y

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KCID
No.

937

938

Ref.

4/8.2.2.2 &4/8.5.1.3

11/2.2.2.2

Type

CI

RCP

Topic

Short voyage
loading
conditions

Welding ofplates ofdifferent
thicknesses

Datecompleted

Question/CI

Answer

2010/4/9

Reference is made to Chapter 4, Section 8, 2.2.2 and 5.1.3.
1) Does short voyage condition have to be considered on a mandatory basis?
2) If the submitted Loading Manual does not include short voyage condition is
it to be included in the Loading Manual?
In KC ID 492, the reply is:where a short voyage alternate loading condition with more severe filling thanthe minimum loading condition in [2.1.1] and [2.1.4] is specified in the loading
manual, strength check for such more severe loading condition should be
carried out in accordance with the CSR requirements.
Please clarify?

A1)
Short voyage condition is not a mandatory basis. If the ship is not intended tomake such voyage, it is not relevant to add it to the loading manual.
As a consequence, the ship will not be able later on to practice short voyages
with more severe loading conditions than those described in the loading
manual.
A2)
Ch.4 Sec.8 [2.2.2] gives an extensive list of loading conditions to beconsidered when they are pertinent.
Thus if short voyages are not envisaged for the ship, they need not be
included in the loading manual.
A corrigendum will be issued on Ch.4 Sec.8 [2.2.2] and [5.1.3].

2010/3/30

Attachment

Ch.11, Sec.2 /2.2.2 of CSR-B specifies as following;“In the case of welding of plates with a difference in as-built thickness equal toor greater than 4mm, the thicker plate is normally tapered.”
However, the requirement in Sec.6/5.2.2.2 of CSR-T does not require plates
The tapering requirement will be harmonized to be in line with CSR OT. We
with a difference in thickness equal to 4mm. Moreover, based on experience,
will consider a rule change according to your comment.
we consider that this requirement of CSR-B need not include 4mm.
Please revise this requirement of CSR-B so that the wording "equal to or" isremoved and that it reads "as-built thickness greater than 4mm."943

11/2.1.4.1&2

RCP

Documentati
on to besubmitted
relating towelding and
NDE

Ch.11 Sec.2 [1.4.1] is rewritten as follows:
QUOTE
the welding plan to be submitted for approval has to contain the necessary
data relevant to the fabrication by welding of the structures.
UNQUOTE
2010/5/12

Ch.11 Sec.2 [1.4.1] and [1.4.2] need to be rewritten in order to follow UR Z23
5.1.5.

Ch.11 Sec.2 [1.4.2] is rewritten as follows:
QUOTE
the NDE plan to be submitted for aproval has to contain the necessary data
relevant to the locations and number of examinations, and the method of NDE
applied.
UNQUOTE
This will be done within a corrigenda.

Page 159 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

944
attc

Ref.

Table
3.1.4

Type

QuestionTopic

categories ofstructuralmembers

Datecompleted2009/9/1

Question/CI

Attachment

AnswerQ1: Yes, your understanding is correct and "Deck Plate 2" is regarded as"PRIMARY" category, except that "Deck Plate 2" is to be regarded as of
Ch.3 Sec.1 Table 4 defines the category of structural member, regarding"SPECIAL" category when the strake contains the strength deck plating at thewhich, Q1: Is the deck plate strake (Deck Plate 2 in the attachment) in way of corners of cargo hatch openings.
hatch side girder to be regarded as of "PRIMARY" category?
Q2: In the Table 4 "Deck plate at longitudinal bulkhead" is categorized as
Q2: The design is provided with longitudinal watertight bulkhead separating"SPECIAL". However UR S6 (Rev.4), which is the basis of Table 4, adds thethe topside space into two compartments. Is the deck plate strake (Deck Plate Note [2] to "Deck plate at longitudinal bulkhead" as follows:"Excluding deck
1 in the attachment) above longitudinal bulkhead to be regarded as ofplating in way of inner-skin bulkhead of double hull ships". This exception may"PRIMARY" category? Please advise.
be applied similarly to the longitudinal bulkhead in the topside space in theattachment. Accordingly "Deck Plate 1" may be regarded as of "PRIMARY"
category.
We noticed that paragraph 9.5.4 of Ch3, Sec6 is not in line with IACS UISC208.
The requirement stated in the CSR-BC

945

3/6.9.5.4

RCP

protection ofhatches

2009/7/30

QUOTE
9.5.4
Wire rope grooving in way of cargo holds openings is to be prevented by fitting
suitable protection such as halfround bar on the hatch side girders (i.e. upper
portion of top side tank plates)/hatch end beams in cargo hold or upper portionof hatch coamings.
UNQUOTEThe correction of this paragraph to be in line with IACS UI SC208 is alreadyincluded in the RCP2-6". It will be changed as follows:" For ships with holds designed for loading / discharging by grabs and having
the additional class notation GRAB[X], wire rope grooving in way of cargoholds openings is to be prevented by fitting suitable protection such as halfround bar on the hatch side girders (i.e. upper portion of top side tankplates)/hatch end beams in cargo hold and upper portion of hatch coamings."

leads to the wrong assumption that exclusive protection of hatch girder OR
hatch coaming is sufficient.

948

No ref.
given

Question

Structural
drawings

2010/8/4

The CSR Rules require that the structural drawings are to indicate for eachstructural element the gross scantling and the renewal thickness.
In case of CSR Tanker, the drawings indicating the new-building and renewal
thickness are specified in the concrete (CSR Tanker Sec 3 2.2.3.1), but it is
not specified in detail for Bulk carriers. So it is not clear which drawings should
include new-building and renewal thickness.
For the survey of existing ships, etc., the new-building and renewal thickness
should be indicated in all structural drawings and these drawings should bespecified in the Rules. Please clarify.
(for example name of drawings)- Midship section- Construction profile & Deck plans- Shell expansion- Bulkhead construction

Renewal thickness shall be indicated for the structure covered by the
structural drawings held in the Ship Construction File specified in UR Z23, 10.
For example, the drawings are shown as follows, but not limited to:- Midship section- Transverse sections- Shell expansion- Decks and profiles- Double bottom- Double side (for DSS)
- Cargo hold bulkheads- Fore part strucure- Aft part structure- Machinery space structure- Cargo hatch covers- Cargo hatch coamings

Page 160 of 181

YIACS Common Structural Rules Knowledge Centre

KCID
No.

949

Ref.

3/5.1.3.4

Type

CI

Topic

coating oftransverse
bulkhead
areas

Date
completed

Question/CI

Attachment

Answer

It is specified in CSR Background Document that the requirements of 1.3.3
and 1.3.4 are in accordance with UR Z 9. According to 1.3.4, some area oftransverse bulkhead (below horizontal level located at distance of 300 mm
below the frame end bracket for single side bulk carriers or below the hoppertank upper end for double side bulk carriers) may not be coated. But according
to UR Z 9, all area of tranverse bulkhead including stool are to be coated.
Please clarify the coating area.
2009/9/3

The coating of transverse bulkhead is to be considered as per Ch.3 Sec.5
Quote: UR Z 9 ~ and all internal surfaces of the cargo holds, excluding the flat [1.3.4] as the requirement of UR Z9 should be applicable to the stool plating,tank top areas and the hopper tanks sloping plating approximately 300 mm
sloped or not.
below the side shell frame and brackets, are to have an efficient protective
coating ~ Unquote
Quote: CSR Bulk Carriers Ch3 Sec 5 1.3.4 The areas of transverse bulkheads
to be coated are all the areas located above an horizontal level located at a
distance of 300 mm below the frame end bracket for single side bulk carriers
or below the hopper tank upper end for double side bulk carriers. Unquote

Page 161 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

950

Ref.

3/6.10.4.9

Type

CI

Topic

weldingrequirements

Datecompleted

Question/CI

Answer

2009/9/4

This requirement comes from of UR S 18 like as 10.4.7 and 10.4.8. But I thinkthat the requirement specified below quotations is different from UR S 18.
According to UR S 18, full or deep penetration welding can be used forconnection between plating of supporting floor and inner bottom. But in Ch 3
Sec.6 10.4.9, only full penetration welding can be used for it. On the other
hand, not only full penetration but deep penetration is accepted in therequirement of Ch 11, Sec 2, 2.4.4. Please clarify which type of welding isright.

You are right: both full and deep penetration welding can be used forconnection between plating of supporting floor and inner bottom. The
sentence, “The weld of corrugations and floors or girders to the inner bottom
plating are to be full penetration ones”, in Ch3 Sec6 10.4.9 will be revised as:
Corrugated bulkhead plating is to be connected to the inner bottom plating by
full penetration welds. The plating of supporting floors or girders is to beconnected to the inner bottom by either full penetration or deep penetration
welds.

Attachment

Quote: UR S 18. 4. 1 (c) Alignment At bottom, if no stool is fitted, thecorrugation flanges are to be in line with the supporting floors. Corrugatedbulkhead plating is to be connected to the inner bottom plating by full
penetration welds. The plating of supporting floors is to be connected to theinner bottom by either full penetration or deep penetration welds. Unquote
Quote: CSR Bulk Carriers Ch3 Sec 6 10.4.9 At bottom, if no lower stool isfitted, the corrugation flanges are to be in line with the supporting floors or
girders. The weld of corrugations and floors or girders to the inner bottom
plating are to be full penetration ones. Unquote

951

952

10/1.9.2

3/1.2.3.1

CI

RCP

Materialfactor for
rudder horn

Grades ofsteel

2010/3/8

2009/7/21

Regarding material factor for rudder horn, there is a discrepancy between KC’s
906 and 797. KC 906 says that material factor k (or K) in 10/1.9.2.2, 9.2.3,
9.2.4 and 9.2.5 should be the factor defined in 10/1.1.4.2. KC 797, however,says that the material factor K in 10/1.9.2.5 should be the factor in 3/1.2.2.1
Your understanding is correct and is applicable to Ch.10 Sec.1 [9.2].
except for cast steel where the factor should be that in 10/1.1.4.2. We are of
A corrigenda will be issued for this correction.
opinion that for cast steel the material factor should be in 10/1.9.2.2, 9.2.3,
9.2.4 and 9.2.5 should be the material factor in 10/1.1.4.2 and for others thematerial factor should be that in 3/1.2.2.1, which are in line with UR S10 and
LR Rules. Please clarify.

Correction of wrong reference number.
The last sentence of Ch.3 Sec.1 [2.3.1] states;"For strength members not mentioned in Tab 3, grade A/AH may be used."
Please correct the reference "Tab 3" into "Tab 4".

954

3/6.4.4

CI

Ordinary
stiffeners shear section

2009/9/10

For the yielding check of shear sectional area Ash of ordinary stiffeners as
required in Ch 6, Sec 2, [3] of CSR-BC, the actual shear sectional area of theordinary stiffener needs to be calculated. However, it is not stated in CSR-BC(Ch 3, Sec 6, [4.4]) how to calculate the actual shear sectional area of such
stiffener, and in particular if the net thicknesses of attached plate and flange, ifany, are to be included in this calculation. In CSR-OT (Ref Section 4, 2.4.2.2),
thicknesses of attached plate and flange, if any, are included in thedetermination of the "effective shear depth dshr" used for the yielding check of
the shear sectional area. Our interpretation is that both CSRs should have thesame approach, i.e. the one of CSR-OT.

You are right. The strength members are considered in Table 4, not in Table
3. We will prepare corrigenda to correct it as following:
For strength members not mentioned in Tab 4, grade A/AH may be used.

It is agreed that the way to calculate the actual shear sectional area of
ordinary stiffener should be defined in CSR-BC Ch 3, Sec 6, [4.4]. It is also
agreed that both CSRs should have the same approach, i.e. the one of CSROT. It means that the thicknesses of attached plate and flange, if any, are to
be considered for the calculation of the actual shear sectional area of an
ordinary stiffener.

Page 162 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

961

962

Ref.

Table
3.3.1

6/3.6.1.1

Type

Topic

Question

Normalballastdraught

Question

Buckling
check ofcorrugatedbulkheads

Datecompleted

Question/CI

Attachment

Answer

2009/9/3

Definition of “normal ballast draught” According to Ch.3, Sec.3, Table1 Note(7), “Outer side shell between normal ballast draught and scantling draught is
to be increased by 0.5mm”.
Your interpretation is correct.
We understand that the definition of “normal ballast draught” is same as that in
Ch.6, Sec.1 [2.2.1], which has been interpreted as the minimum design lowest
ballast waterline amidships in KC ID409. Please confirm the above.

2009/9/4

Shear buckling check of bulkhead corrugation webs
When Ch.6, Sec.2, [3.2.6] was moved to Ch.6, Sec.2, [3.6.1] by RCN1 (1 July
2008 Consolidated edition), shear force Q which was used for the shear
buckling check of bulkhead corrugation webs was clarified as “Shear force atthe lower end of a corrugation” as defined in original requirement, UR S18,
[3.2]. We understand that shear buckling check of bulkhead corrugation webs
in Ch 6, Sec.3, [6.1.1] is also applicable only to the lower ends of corrugation.
Please confirm the above.

Your interpretation is correct. We will consider a Corrigendum to clarify it.

Please advise the answer to the question on the design with the following nonTable
homogeneous loading conditions in the loading manual:
4.6.1, Text
Design with- cargo density is 3.0 and cargo hold is not loaded up to upper deck,
4/6.3.3.2,
non- cargo density is lighter than 1.78 (for instance 1.7) and cargo hold is loaded
963 6/1.3.2.1, Question homogeneou 2009/12/16
This question is considered together with KC 851, 859 and 972
up to upper deck.
6/1.3.2.3,
s loading
For this design is local strength check required for intact condition and flooded
6/2.3.2.3 &condition
condition for the above loading conditions according to Ch.6 Sec.1 [3.2.1] &6/2.3.2.6[3.2.3] and Ch.6 Sec.2 [3.2.3] & [3.2.6] (or [3.6] by RCN1-8)?

964

4/6, 4/7 &
4/8

CI

Cargo
density limits
for BC-A and
BC-B ships

2010/6/29

For BC-A and BC-B ships, there is a design loading condition in Ch 4, Sec 7,[2.1] requiring maximum draught with cargo density 3 t/m3. On the other hand
there are cargoes which have density higher than 3t/m3. We would like tohave interpretations on the two following questions:a) Is a limit in cargo density of 3t/m3 clearly stated in CSR-BC?
b) In case of loading conditions within the loading manual having density
higher than 3t/m3, are they specific checks to carry out in addition of thosecorresponding to 3t/m3?

a)The cargo density of 3.0 t/m3 is required as design basis for BC-B and BC-A
vessels as stated in Ch.4 Sec.7 [1.2] and [2.1]. Based on the design loading
conditions according to Sec.7, hold mass curves will be created according to
Sec.8 which will control the loading and unloading of the vessel in operation.
There is no limitation on cargo density in operation unless additional feature
notation {maximum cargo density x.y t/m3} specifies the maximum cargodensity less then 3.0 t/.m3.
b)If specific cases (with high density or no) are requested by the Owner, thosecases can be included in the Loading Manual and those cases should bespecifiquely studied (on a case by case basis).

Page 163 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

966
attc

Ref.

Table
11.3.1

Type

RCP

Topic

Structural
testing ofballast holds

Datecompleted2009/9/11

Question/CI

Attachment

Answer

Structural Testing Requirements of CSR Rules for Bulk Carriers as applied toBallast Holds
LR Ship Rules; Part 3; Chapter 1; Section 8; Table 1.8.1 requires structural
testing of the water ballast holds in bulk carriers with the head, not less than,up to the top of the hatch coaming.
CSR Rules for BC; Ch. 11; Section 3.1; Table 1 requires structural testing toTable 11.3.1, which comes from UR S14, is kept as it is until UR S14 is
the greater of the head of water up to the top of overflow or 0.90 m head ofamended.
water above top of hatch. Excluding bulk carriers under 90 m in length, all new
bulk carriers will now be designed against these CSR Rules. Weather tighthatch cover seals for floodable cargo holds, are not suitable to retain a head ofwater, without leakage, so the application of the CSR Rule requirement cancause confusion for owners and shipyards.

We believe this testing should be carried out to the top of the hatch coamingwith the hatch covers in place. Therefore we recommend that the text of the
CSR Rules for structural testing of the Ballast Hold in Bulk Carriers isamended in accordance with IACS Guidelines for Procedures of Testing
Tanks and Tight Boundaries:
CSR Rules for BC, Chapter 11, Section 3.1, Table 1 should be amended to :“The greater of - top of the overflow, or - top of cargo hatch coaming”
Note 2 to this table should also be amended in the final sentence to “in holds
for liquid cargo or ballast with large hatch covers, the highest point of tanks is
to be taken at the top of the hatch coaming."

968

6/3.1.1.2

Question

Flooding
requirementsof CSRbulker

2010/9/2

Buckling check is required for longitudinal members in intact condition only.
Please explain how the buckling requirement of URS17 (axial bucklingaccording to URS11) is satisfied for at lease BC-A and BC-B ships.

According to KC 460, the buckling check is covered by HULS.
Further consideration including the necessity of additional buckling check inflooded condition will be requested to the Harmonization Team.

Page 164 of 181

YIACS Common Structural Rules Knowledge Centre

KCID
No.

970

Ref.

9/2.4.2.3

Type

Question

Topic

Net
thickness of
web ofordinary
stiffeners

Datecompleted2010/3/30

Question/CI

Attachment

AnswerCSR BC Ch.9 Sec.2 [4.2.3][QUOTE]The net thickness of the web of ordinary stiffeners, in mm, is to be not lessthan the greater of:• t = 3.0 + 0.015L2• 40% of the net required thickness of the attached plating, to be determinedaccording to [4.1].
Your understanding is correct.
[UNQUOTE]
40% of the net required thickness of the attached plating, to be determined
The requirements of the net thickness of plating according to [4.1] only include according to [1.1.2] and [4.1].
the requirements of net minimum thickness, net thickness under intact
conditions and net thickness under testing conditions. We think the net
thickness requirement under flooded conditions, to be determined according to[1.1.2], should be considered for the net required thickness of the attachedplating.
Please consider.

Page 165 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

971

972

973

974

Topic

Date
completed

9/1.4.3.3 &Question
9/2.4.2.3

stiffeners

CSR BC Ch.9 Sec.1 [4.3.3] and Sec.2 [4.2.3].
[QUOTE]The reference number of the last sentences of Ch9 Sec1, 4.3.3 and Ch9
The net dimensions of ordinary stiffeners are to comply with the requirement in
Sec2, 4.2.3 should be as follows: “The net dimensions of ordinary stiffeners
2009/10/27 Ch 6, Sec 2, [2.2.2] and [2.3].
are to comply with the requirement in Ch 6 Sec 2, [2.2.3] and [2.3].” This will
[UNQUOTE]
be corrected in the next corrigenda.
We think the reference to [2.2.2] should be corrected to [2.2.3]. Pleaseconsider.

6/4.4.1.1

Loads onpillars

2010/3/8

There is only the formula about critical column buckling stress of pillars but noclear interpretation on how to calculate the loads on pillars in CSR BC 6/4.4.1.
We will consider a Rule Change to include a design load for pillar scantling
According to our experiences, the loads on pillars are similar between BC andcalculation similar to CSR OT
OT, so we think a similar design load for pillar scantling calculation as 8/3.9.5
in CSR OT should be provided.

Question

Hull girder
ultimate
strengthWith respect to hull girder ultimate strength
1. The scantling requirements by hull girder ultimate strength are to be applied
within 0.4L amidships in 9/1.1.1.2 of CSR OT. For CSR BC, It is noted that thenormal stresses are to be checked within L, please clarify whether the
2010/10/12
scantling requirements by hull girder ultimate strength are to be applied within
L in CSR BC or not.
2. Our understanding is that the modifications to CH5/Appendix 1 in bulker
rcn1 to July 08 are also applicable to CSR OT, please confirm.

QuestionNet
thickness ofstool side
plating

Our understanding is that the following sentence in 6/1.3.2.3 bis1 of CSR BC
is only applicable to upper stool, please confirm.
[QUOTE]The net thickness of the lower portion of stool side plating is to not be lessthan 80% of the upper part of the bulkhead plating required by [3.2.3], asapplicable, whichever is the greater, where the same material isused.[UNQUOTE]

Ref.

Bulker
5/App.1 ,Tanker
9/1.1.1.2

6/1.3.2.3
bis1

Type

Question

2010/3/8

Question/CI

Attachment

Answer

1. This issue will be submitted to the Harmonisation teams.
2. We confirm the modifications to CH5/Appendix 1 in CSR/Bulk Carrier RCN1
to July 08 are also applicable to CSR OT. The Rules will be amended toincorporate those modifications.

Yes, your understanding is correct. We will consider a corrigenda to clarify
this.

Page 166 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

975

977

978

Ref.

6/1.3.2.3
bis2

5/1.3

Table
3.3.1

Date
completed

Question/CI

Thickness &material
requirements
Questionforcorrugatedbulkheads

2010/3/8

Rule Ref.: CSR BC 6/1.3.2.3 bis2
[QUOTE]The net thickness and material of the supporting floors and pipe tunnel beams
of corrugated bulkhead, when no stool is fitted, are to be not less than those of
the corrugation flanges required by [3.2.3].
When a lower stool is fitted, the net thickness of supporting floors are to be notless than that of the stool side plating required by the first sentence of [3.2.2].”[UNQUOTE][3.2.2] and [3.2.3] are requirements of flooding condition, which areinconsistent with KC ID210 as followers:
QUOTE: KC ID210
In applying this requirement 6.4.2, the net thickness and. material properties
required for the bulkhead plating, or when a stool is fitted, of the stool side
plating mean that they are required by the scantling requirement except for the
grab loading and under flooded condition.
UNQUOTE
Please clarify above.

Applicationof shearstress check2010/3/12

From Ch.5 Sec.1 [3], we know that the check of normal stress apply along thescantling length of the hull girder. How about the application of shear stresscheck and permissible still water shear force? Do they also apply along thescantling length? Please clarify.

2010/3/30

Ch3 Sec3 Table 1, Corrosion addition for lower stool
Reference is made to KC 243. The corrosion addition for hopper plating issmaller than for the lower stool plating. Our understanding is that the reason
for this difference is that the hopper plating is cooled down by the ballast water
inside in ballast conditions. The lower stool is normally void, so the lower stool We agree with your interpretation.
plating will not experience the same cooling effect.
Based on the above, it seems reasonable to apply tc=3.7 mm instead of
tc=5.2 mm to the lower stool plating if the stool is arranged as ballast watertank. Please confirm our interpretation.

Type

QuestionInterpretati
on

Topic

Corrosion
addition forlower stool

Attachment

Answer

We agree that the reply to KC 210 is inconsistent to the original requirementsof IACS UR S18 which reads; “the thickness and material properties of the
supporting floors are to be at least equal to those provided for the corrugation
flanges.” Only requirement for GRAB notation should be excluded. It was also
the original intention of KC210.
Reference is made to KC 918 for additional information

The check of shear stress and permissible still water shear force apply along
the scantling length of the hull girder.
A corrigenda will be considered to clarify this.

Page 167 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

Ref.

Type

Topic

Date
completed

Question/CI

Attachment

AnswerIn a bulk carrier having a ship length of around 160m, lower stools may not be
fitted below transverse bulkheads and corrugation may be fitted directly on the
inner bottom.
In such cases, the GRAB requirement in Ch.12 Sec.1, [2.1.3] is applicable tothe lower part of the corrugated bulkhead up to 3m above the inner bottom.
980

12/1.2.1.3

Interpretati
onApplicabilityof GRABrequirement

2010/8/20

However, grab configurations do not come into contact with such corrugation
webs because the width and depth of corrugations are always smaller thanthose of grab appliances (i.e. less than 1m).

We agree that the grab requirement is only applicable to the faces ofcorrugations. We will consider a corrigenda to clarify this.

We are of the opinion that the GRAB requirement is only applicable to thefaces of such corrugations.
Please confirm.

982

983

1/1.1.1.6

4/3.

CI

Definition of"assigned
freeboard"

Question

Longitudinalstrengthcheck atfloodedcondition

2010/6/29

Ch 4 Sec.7, 1.2.3 specifies that “the maximum loading condition draught is tobe taken as the moulded summer load line draught.”
In the above context, Ch1 Sec1, 1.1.6 defines that “the scantling draught
considered when applying the present Rules is to be not less than that
corresponding to the assigned freeboard.” We understand that the term“assigned freeboard” means the moulded summer load line draught.
On the other hand, we understand that the draught of ships to which timber
freeboards are assigned corresponds to the loading condition of timber, andthat the requirements of the individual Classification Society may apply to thisdraught.
Please confirm that our understanding is correct.

Your understanding is correct.
The term “assigned freeboard” means the moulded summer load line draught.
The draught of ships to which timber freeboards are assigned corresponds tothe loading condition of timber, and the requirements of the individual
Classification Society may apply to this draught.

2010/3/16

The query is regarding Chapter 4- Section 3 of CSR for Bulk Carriers, i.e.
Longitudinal Strength Check at Flooded condition.
1. Do we have to assume structural damage to the Hull in this case?
2. Or, is it the water ingress from the deck through the Hatch?
3. Please explain if we have to consider the damage from side or the water
ingress from top, which results only in hold flooding.

For Ch.4 Sec3, Longitudinal Strength Check at Flooded condition, water
ingress of the cargo hold is assumed without any structural damage or filling ofadjacent compartments.

Page 168 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

987
attc

Ref.

4/7.3.6.1&
3, Fig4.A1.1

Type

RCP

Topic

Harbourmass curves
for BC-A
loaded holds

Datecompleted

Question/CI

Answer

Attachment

2010/3/16

We have found that the CSR-BC is unclear about how to construct the mass
curve for the harbour condition for loaded holds.
Please refer to the attached sketch.
Ch 4, Sect 7, 3.6.1 results in line 1 (red).
Ch 4, Sect 7, 3.6.3 results in line 2 (blue).
Depending on the geometry of the vessel, Ch 4, Sect 7, 3.6.3 may result inline 3 (green).
Ch 4, Appendix 1, Figure 1 (a) results in line 4 (black).
Various arguments can be made to support the construction of each line.
Line 1 comes from a load condition that has been analysed for the design andis therefore well supported.
Lines 2 and 3 are based on a simple empirical formula within the Rules. We
are not aware of cases of double bottom failure within harbour for UR S25
ships, hence the empirical formula appears valid. However, where the vesselgeometry produces line 3, rather than line 2, their would be a good case forincreasing the harbour maximum to line 1, which is verified by calculation.

Ch.4 Sec.7 [3.6.1] and [3.6.3] are both valid and acceptable hence the final
curve (upper limit) should be larger of the two curves. We agree that Fig.1 (a)should be corrected as suggested (Line 2) based on [3.6.3].

YLine 4 is not backed by text in Ch 4, Sect 7 and I suggest that the labelling ofAppendix 1, Figure 1 (a) is incorrect and that the brackets should be removed
so that “1.15(MHD+0.1MH)” becomes “1.15MHD+0.1MH”.
Could this please be investigated with a view to IACS placing an interpretationon the Knowledge Centre and/or issuing a Rule Corrigenda item.
Please also note this should be considered in conjunction with KC item 633
which is under study by IACS.

995

4/5.2.1.1

CI

FE cargohold model weather
loads

2010/5/7

Ch. 4, Sec. 5, Para. 2.1.1 states: "The external pressures on exposed decks
Yes, the weather loads shall be applied to FE cargo hold model. In order toare to be applied for the LOCAL SCANTLING CHECK of the structures on
clarify the Rules, the relevant paragraph is suggested to be modified as “Theexposed deck but -----" This is under Para. 2.1 "General" and, therefore, Para.
external pressures on exposed decks are to be applied for the scantling check2.2 Load cases H1, H2, F1 and F2" and Para. 2.3 "Load cases R1, R2, P1 andof the structures on exposed deck but not applied for fatigue strength
P2" are controlled by Para. 2.1. In addition, the weather loads require to beassessment." (local removed from the sentence)
applied to the structures on exposed deck only. Please clarify if the weather
This will be done in the next Corrigenda.
loads need to be applied to the FE cargo hold model or not?

Page 169 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

Ref.

Type

998
Interpretati
12/1.2.1.3
on
attc

999
attc

8/4.2.3.4

Topic

Applicabilityof GRABrequirement

Datecompleted

Question/CI

2010/8/4

In a bulk carrier having ship length of 160m around, lower stools may not be
fitted below transverse bulkheads and corrugation may be fitted on inner
bottom directly.
In such cases, GRAB requirement in Ch.12 Sec.1, [2.1.3] is applicable to thelower part of corrugated bulkhead up to 3m above inner bottom.
However, GRAB will not contact such corrugation webs due to theirconfiguration as follows;- corrugation width and depth are less than 1m, and;- corrugation flanges and webs are perpendicular to each other.
Please refer to an arrangement of such a bulk carrier as attached.
We are of the opinion that GRAB requirement is not applicable to corrugation
webs.
Please confirm it.

With respect to Ch.8 Sec.4 [2.3.4]
1. Please specify the definition of the tank top longitudinals in the sentence “…
no inertial pressure is considered for the tank top longitudinals…”.
2. When calculate the inertial liquid pressure pBW,ij(k),SF for full-filled tank or
half-filled tanker, the coordinates of the calculation point taken at the liquidsurface should be clarified.

Calculationof stress due
Question
to liquidpressure

Attachment

AnswerGrab requirements are not applicable to web of corrugations.

Y

A1 "the tank top longitudinals" in Ch.8/Sec.4/[2.3.4] mean the longitudinals on
the top structure of the tank.
A2 For the half-filled tanker, when calculating the inertial liquid pressure
pBW,ij(k), z=z_SF, y=y coordinate of the calculation point of the longitudinal
stiffener.
xB, yB and zB are considered in A4 of KC #359

1001

9/1.7

Q&A

Forecastle
requirements

2010/5/12

CSR BC Ch.1 Sec.4 [3.13.1][QUOTE]
Ref. ILLC, as amended (Resolution MSC.143(77) Reg. 3(10,g))
A forecastle is a superstructure which extends from the forward perpendicular
1.The requirements of forecastle given in Ch.9 Sec.1 Fore Part should be
aft to a point which is forward of the after perpendicular. The forecastle maytransferred to Ch.9 Sec.4 Superstructures and Deckhouses.
originate from a point forward of the forward perpendicular.
This will be considered in the next Corrigenda.
[UNQUOTE]
2. The requirements of forecastle structure, such as forecastle deck,
From the above definition, a forecastle is defined as a superstructure, but the
supporting member, ordinary stiffener and etc., should not be included. A
requirements of forecastle are given in Ch.9 Sec.1 Fore Part.
reference of the forecastle to bow flare reinforcement in Ch.9 Sec.1 should be
We propose that
made.
1.The requirements of forecastle given in Ch.9 Sec.1 Fore Part should beThis will be considered in the next Corrigenda.
transferred to Ch.9 Sec.4 Superstructures and Deckhouses.
2.The requirements of forecastle structure, such as forecastle deck, supporting
member, ordinary stiffener and etc., should be added.
Please consider.

1003

9/1.5.2.1

Questionintermediate
longitudinal

2009/12/16

For clarity, please give the definition of intermediate longitudinal, referred in
Ch.9 Sec.1 [5.2.1].

Intermediate longitudinals (additional stiffeners) are stiffeners installed in thespacing between ordinary stiffeners (so the stiffener spacing is halved).

Page 170 of 181

YIACS Common Structural Rules Knowledge Centre

KCID
No.

1004

Ref.

3/6.4.1.1

Type

Topic

1005

6/1

Question

1006
attc

7/4.3.2

Question

Hot spotstress bylinearinterpolation

2/3.1.2.1

Question/CI

Attachment

AnswerIn CSR BC, a bulb section may be taken as equivalent to an angle section,
which is defined in Ch.3 Sec.6 [4.1.1]. From our experience, for some kinds ofbulb sections, the section properties of bulb sections are comparable to thoseof equivalent angle sections; for others, they are not.
For example: the inertial moment about the horizontal neutral axis of a bulb
Your comment is noted. Ch.3, Sec.6, [4.1.1] will be modified. The following
200x10
Question bulb sections 2009/12/16
paragraph will be included in [4.1.1]: The sections properties of bulb profiles
1. Equivalent to an angle section, I=1019cm4.
should be determined by direct calculations. Otherwise... [4.1.1 as it is now].
2.Direct method. For Holland Profile, I=1017cm4.
For Russian Profile, I=1083cm4.
In CSR OT RCN2, the descriptive method, calculating the section properties ofa bulb section, is deleted, and a direct method should be adopted.
The two set of rules should be harmonized.

Yield
strength ofnonrectangular
EPP

1007

Date
completed

Interpretati
on

Safe accessto cargoholds

When assess the yield strength of non-rectangle EPP, such as EPP of
2010/10/20 watertight transverse webs of wing tanks, how to measure the longer or
shorter side of EPP?

2010/1/18

Rule Ref.: Text 7/4.3.2 (bulker)
How to obtain the hot spot stress by a linear extrapolation method is not
specified in the CSR BC. We find that there are several methods, as shown in
the attachment. Please confirm which one should be adopted.

The method to obtain hot spot stress by linear interpolation will be consideredduring the Harmonization process between CSR OT and CSR BC. In themean time it may be left to the discretion of the individual class society

2010/2/1

Requirement in Ch 2, Sec 3, [1.2.1] mentions that "Safe access to cargoholds, cofferdams, ballast tanks and other spaces in the cargo area are to be
direct from the open deck and ......" . In addition requirement in [1.2.3] statesthat "Each cargo hold is to be provided with at least two means of access as
far apart as practicable. In general, these accesses are to be arranged
diagonally......".
In case of a bulk carrier having a forecastle extending afterward the forward
bulkhead of forward cargo hold, the forward access may be arranged from themain deck but inside forecastle spaces, which cannot be considered as beingfrom the "open deck"
Our interpretation is that such forward access is allowed provided that theforecastle spaces are considered safe, i.e. not intended for the carriage of oilor hazardous cargoes.

It is agreed that the forward access to the forward cargo hold may bearranged from main deck inside forecastle spaces provided that those spaces
are considered safe, i.e. not intended for the carriage of oil or hazardous
cargoes.

Since this issue involves both CSR BC and OT, it will be submitted to theharmonization team.

Page 171 of 181

YIACS Common Structural Rules Knowledge Centre

KCID
No.

1009

1012

Ref.

2/3.2

9/2.4.3.1 &KC ID 896

Type

CI

Q&A

Topic

Definition of
single sideand doubleside bulk
carriers

Net
thickness of
PSMs

Date
completed2010/1/18

Question/CI

Attachment

AnswerIn Ch 2, Sec 3, [2], some requirements are applicable specifically to single
side bulk carriers (as in [2.9] and [2.11]) and some others are applicable todouble side bulk carriers (as in [2.8] and [2.10]).
There is no definition in CSR-BC on what is a single side bulk carrier and what
The proposed interpretation is correct. Definitions of single side and double
is a double side bulk carrier.
side bulk carriers will be added to CSR-BC, in accordance with those of
As these requirements are originally IMO requirements for means of access, it
SOLAS Ch XII/1.
is assumed that single side and double side bulk carriers are definedaccording to SOLAS Ch XII/1. Please confirm this interpretation.
If this interpretation is correct, it should be convenient to add such definitions
in CSR-BC.

With reference to KC ID 896:
The answer to KC ID 896 is quoted below:[Quote]A1) Yes, deck PSM have to fulfill the requirements of Ch.6 Sec.4 considering
the loads defined in Ch.9 sec.2 [2.2], and in particular the minimum web
thickness defined in Ch.6 Sec.4 [1.5.1].
A2) No, the requirement for a minimum web thickness defined in Ch.9 Sec.2[4.3.1] applies to all the PSM except those of the deck (see answer A1 herein).
A rule change will be issued for clarifying this.
[Unquote]
2010/5/12

KC 896 is categorised as a Rule Change as defined in PR32, hence
Ch.9 Sec.2 [4.3.1] only specifically mentions floors. No mention is made of any implementation date will be decided by Hull Panel.
other PSM. However, Answer 2 (A2) goes beyond the scope of Ch.9 Sec.2[4.3.1]. A2 implies that all PSM, except those decks, are required to apply theformula given in 4.3.1. If A2 is applied, there will be a large impact on
scantlings.
In addition, we consider that a technical background clearly explaining thedifference between the minimum net thickness of deck PSMs and other PSMs
in the same space should be provided.
Therefore, please confirm the effective application date of KC ID 896 and if
necessary, please revise the answer to KC ID 896.

Page 172 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

1017
attc

Ref.

Table
10.3.3

Type

RCP

Topic

Minimum
breaking
strength ofmooring lines

Extension of
longitudinal
9/3.3.1.2 & Interpretati
structure1018
9/3.1.3.2
onwithin themachinery
space

Date
completed

Question/CI

2010/2/16

Editorial correction of values in the equipment number table:
Minimum breaking strength of mooring lines corresponds to equipment
number as defined in Ch.10 Sec.3, Tab.3, and Tab.3 originates from IACS
Recommendations, No.10, Tab.5.
Therefore, the minimum breaking strength of mooring lines in the both tables
are coincident, however, some of the values are different as attached.
Accordingly, please correct the wrong values in CSR as defined in
Recommendations, No.10.

2010/3/30

Attachment

Answer

You are right.
Tab. 3 will be modified accordingly in the next Corrigenda.

Y

It would appear reasonable to limit extension of side shell longitudinal
structure for 0.3 times the length of the machinery space to side shell
We understand from KC Question ID 700 and 728 that the extension of
structure above the lowest level of the top side tank, subject to the condition
longitudinal structure for at least 0.3 times the length of the machinery space is that abrupt structural discontinuities between longitudinal and transversely
only required for the upper portions of the side shell. Due to generally finer hull framed structure are to be avoided and that hull girder strength, ultimate
form in way of the engine room, particularly for the lower part of the aft crossstrength and prescriptive buckling checks of the cross-sections and side shell
section, it is not always practical to extend longitudinal side shell structure aft panels in the machinery space are performed and satisfied. The extension ofof the engine room forward bulkhead for the stipulated 0.3 times of the length longitudinal stiffeners of the upper part of the side shell is to be maintained inof the machinery space. Such extension, especially in the lower part of the hull view of the generally higher stresses in this area, the relative ease of providing
cross-section below the level of the topside tank, may require deeper side
such extension and to improve strength margin in this region of higher stress.
shell web frame structure resulting in a reduction in usable volume and floor
Due consideration is to be given to proper tapering of major longitudinal
area in the engine room space. In every case the hull girder strength, ultimate members as required by Ch. 9/3.1.3.2. Notwithstanding the above, bottom
strength of the cross-section aft of the engine room forward bulkhead areshell and bilge longitudinal stiffeners in the aftermost cargo hold of larger andchecked and prescriptive buckling check of side shell panels in the machinery full form vessels are to be extended into the engine room to the extent
space are carried out.
practicable.
We agree with your proposal and a CI will be issued to this effect.
Side shell plate panels in the lower hull cross-section are not planar but have acurvature that provides added buckling resistance. Furthermore thesatisfactory service experience of numerous bulk carriers of all sizes that havebeen built without such a specific extension of side shell longitudinal structure
could be considered. We request the urgent confirmation of the above
interpretation and/or issuance of a CI to this effect.

1022 11/3.2.3.1

CI

Minimumpressure forhose testingin rules & UR
S14 2.3

2010/3/8

Ch.11 Sec.3 [2.3.1] hose testing.
The Rule requires a minimum pressure of 0.2X10^5 Pa. However, in IACS UR
S14 2.3, the minmum pressure for host testing is 2X10^5 Pa. Please clarify
whether there is a typo in CSR Bulk Rules or not. If not, please provide
relevant background for CSR.

There is a typo in CSR BC.
Ch.11 Sec.3 [2.3.1] will be corrected as follows:
The minimum pressure in the hose, at least equal to 2•10^5 Pa, is to be
applied at a maximum distance of 1,5 m

Page 173 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

1023
attc

Ref.

4/6.1.1.1

Type

RCP

Topic

Definition of
the dry cargo
uppersurfaceDatecompleted

Question/CI

Chapter4_CSR-BC_Sec6_[1.1.1]The definition of the dry bulk cargo uppersurface.
It is specified in Ch4/6/1.1.1 of CSR Bulk Carrier that ” When the dry bulk
cargo density is such that the cargo hold is loaded to the top of hatchcoaming, the upper surface of the dry bulk cargo is an equivalent horizontal
surface to be determined in considering the same loaded cargo volume in theconsidered hold bounded by the side shell or inner hull, as the case may be.”2010/6/29
Regarding the above definition of “the hold bounded by the side shell or innerhull", it seems not very precise and might cause some misunderstandings.
Take a typical dry bulk cargo hold for example, three different possible
boundary definitions marked in red as shown in the attached graphic
illustration might be some possible understandings.
Two optional proposals for the revision are as below.

Attachment

Answer

The Figure 2 in your attachment is correct.
In order to describe the equivalent horizontal surface more clearly, acorrigenda is to be carried out.
The first paragraph is to be modified as following:
When the dry bulk cargo density is such that the cargo hold is loaded to the
top of hatch coaming, the upper surface of the dry bulk cargo is to be taken as
an equivalent horizontal surface determined by considering the same cargovolume loaded in to a cargo hold with boundaries formed by inner bottom,
hopper if any, and side shell for single side skin or inner side for double side
skin.

Y

Figure 1 in Ch4/Sec6 will be modified accordingly to illustrate the boundary
definition

1) “When the dry bulk cargo density is such that the cargo hold is loaded tothe top of hatch coaming, the upper surface of the dry bulk cargo is anequivalent horizontal surface to be determined in considering the same loadedcargo volume above the lower intersection of topside tank and side shell or
inner side in the considered hold bounded by the side shell or inner hull.”
2) “When the dry bulk cargo density is such that the cargo hold is loaded tothe top of hatch coaming, the upper surface of the dry bulk cargo is to betaken as an equivalent horizontal surface determined by considering the samecargo volume loaded in to a cargo hold with vertical boundaries formed by thetransverse bulkheads and side shell or inner side. The spaces occupied by thetopside tanks and the upper bulkhead stool should be considered as part ofthe cargo hold space in the determination of this equivalent horizontal surface.

1025
attc

4/6.1.1.1

CI

Hc value ofdry bulk
cargo in fullfilledcondition

2010/5/17

Chapter4_CSR-BC_Sec6_[1.1.1] Hc value of the dry bulk cargo in full-filledcondition Regarding the hc value for cargo hold being loaded up to the top of
hatch coaming: Ch4/Sec6/1.1.1 specifies the procedure of calculating theheight of dry cargo upper surface. Meanwhile a formula for calculating the hc
For holds of cylindrical shape, the volume of upper stool is ignored when hC isvalue is given specifically for holds of cylindrical shape.
calculated by the formula in Ch.4 Sec.6 [1.1.1].
Question: For a typical bulk carrier, upper stools are generally arranged in the
cargo hold. Obviously, the hc value should be different by using the above twoprocedures. Which procedure should be used? In other words, should thecargo hold with upper stools be considered as one of cylindrical shape or not?

Page 174 of 181

YIACS Common Structural Rules Knowledge Centre

KCID
No.

1026

1027

Ref.

4/3.3.1.3

1/1.3.2.1

Type

Topic

CI

Wave
inducedbending
moment(0.4Mw) fortarget BM in
harbourcondition

RCP

Additional
GRAB
notation forships using
grab

Date
completed2010/5/12

Question/CI

Attachment

Answer

Chapter4_CSR-BC_Sec3_[3.1.3] Wave-induced bending moment(0.4Mw) fortarget BM in harbor condition
It is specified in Ch4/3/3.1.3 of CSR Bulk Carrier that the vertical wave
The wave-induced bending moment 0.4Mwv should be included in the target
bending moment Mwv,p in harbour condition equals to 0.4Mwv. It is not clearlybending moment in harbour condition for direct strength analysis.
specified whether 0.4Mwv should be included in the target bending moment inThis will be specified in the next corrigenda.
harbour condition for direct strength analysis.
Please be kindly requested to provide clarification

2010/3/30

According to CSR BC Chap1/1.3.2.1 additional class notation GRAB[X], GRAB
is mandatory for ships having notation “BC-A“ or “BC-B”. I understand that thisrequirement is result from UI SC208 and SOLAS XII/6.5.1 and there are no
As said in the CSR BC, Ch.1 Sec.1 [3.2.1], the assignation of the GRAB
restrictions for GRAB in UI SC208 if any ships want to have notation GRAB.
notation to a BC-C ship is voluntary and is intended to scope heavy grabs
Chap1/1.3.2.1 for ships with notation BC-C causes confusion. For example,(over 20t of unladen weight).
the notation GRAB is not mandatory for ships with BC-C to carry coal of cargo
Making this notation mandatory for all ships loaded or unloaded by grabs may
density less than 1.0 t/m3. All of us know that grab may be used to discharge
induce increases in scantlings even for lighter grabs; this is not the intent of
coal.
these rules.
Therefore, Please correct a few sentences of Chap1/1.3.2.1 as follows:
The text is kept as it is.
Mandatory for ships having one of the additional service features BC-A or BCB, according to [3.1.2].
=> Mandatory for ships using GRAB.

1028 10/1.3.3.2

TB of unit
displacement
Question
formulae f_b
and f_t2010/3/12

Coefficients of rudder horn formulae in Ch.10, Sec.1, 3.3.2
Please clarify the technical background of the unit displacement formulae f_b
and f_t.
f_b : This formula has been delivered by multiplying the maximum
displacement of cantilever beam by coefficient 1.3. Please show the technicalf_b and f_t in Ch.10 Sec.1 [3.3.2] are in line with UR S10.
background of the coefficient 1.3.
f_t for steel : This formula has been delivered by substituting torsional stiffness
factor J_th into the general formula of f_t. The coefficient obtained by thesubstitution 3.168(=7.92 * 4 / 10) does not match the coefficient 3.14 used inthis formula. Please show the technical background of the coefficient 3.14.

Page 175 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

Ref.

1029 12/1.2.1.3

Type

RCP

Topic

Transverse
corrugatedbulkheads atlower stoolsastransverse
bulkhead
platingDatecompleted

Question/CI

2010/3/30

With regard to the paragraph of Ch.12, Sec.1 [2.1.3], we would request thattransverse corrugated bulkheads situated on lower stools are ruled out fromapplication of the 'transverse bulkhead plating'.
The paragraph in Ch.12, Sec.1 [2.1.3] contains 'transverse bulkhead plating'as a result of Rule Change Notice No.1 (effective from 1 July 2009) which may
cause a confusion as to whether this newly added word implies a transverse
corrugated bulkhead on lower stool or not, all the more for small bulk carriers
provided with lower stools of which the height is less than 3.0m.
It is noted that TB for RCP 4-4 explains that 'this change is made to clarify therequirement by specifying the areas concerned by this calculation (refer to KC
ID 313 and 544)'. Besides, TB for RCN No.1-4 explains that 'inner hull up to aheight of 3.0m from the lowest point of inner bottom is applied to thisrequirement'.

Attachment

Answer

The requirements in Ch.12 apply to the following structural elements when
they exist in the hold:- plating of inner bottom- hopper tank sloping plate- plating of transverse lower stool (if it exists)- flange plating of transverse corrugated bulkhead- plating of transverse plane bulkhead- plating of inner hull
up to a height of 3m above the lowest point of the inner bottom.
This includes transverse corrugated bulkheads with or without lower stool.

Notwithstanding these explanations, neither of the two TBs has implemented
clarification on application of transverse corrugated bulkheads on lower stools.
It is apparent that the Ch.12, Sec.1 [2.1.3] will result into unreasonable andimpractical arrangements and scantlings for corrugated bulkheads with lower
stools, especially for those of small bulk carriers. The current passage
containing 'transverse bulkhead plating' should be interpreted to limit totransverse bulkhead plating where lower stools are not fitted. KC is therefore
requested to update the passage in future Rule Change Notice.

1030

3/5.1.4.1

RCP

Protective
coating inballast holds

2010/4/14

Regarding the protective coating in ballast holds, the paragraph of 3/5.1.4
should be deleted in order to be in line with IACS UR Z9.
CSR for Bulk Carriers January 2006 Background Document Chapter 3 saysthat “This regulation (3/5.1.4.1 Protection of ballast hold spaces) is inaccordance with IACS UR Z9.” And Z9 stipulates the same requirement ofprotective coating in both ballast holds and other cargo holds, which isequivalent to 3/5.1.3 of CSR BC Rules.
However, 3/5.1.4 requires that all internal surfaces of ballast holds are to havean effective protective coating (It is noted that IACS KC 400 exempts inner
bottoms in ballast holds.), and are beyond the requirement of Z9.

This KC is same as KC400, that is, Ch.3 Sec.5 [1.3] should have be modified
to include dry cargo holds which may carry water ballast and [1.4] should bedeleted. A corrigenda will be considered.

Therefore, 3/5.1.4 should be deleted so that 3/5.1.3 can cover both ballast
holds and other cargo holds..

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IACS Common Structural Rules Knowledge Centre

KCID
No.

Ref.

1034 10/3.3.2.4

1039

1040

9/5.2.2.1

6/4.3.1.2

Table1042 4/A2.1,2,3,
4,5,6

Date
completed

Attach
ment

Type

Topic

RCP

Installation of
spare anchor
onboard2010/2/24

CI

Requirementof ballast
hold andhatch coverof the ballast
hold2010/5/17

Regarding the requirement of Ch.9, Sec.5, 2.2.1, we would like to confirm thata ballast hold is not included in ballast tanks and other tanks, and a hatch
cover of the ballast hold is required to be weathertight.

Your interpretation is correct. A hatch cover of the ballast hold is required to
be weathertight.

RCP

Allowable
stress factors
for floors
adjacent tostools ortransverse
bulkheads

2010/5/5

According to UR S20.3.1, allowable shear stress for floors adjacent to thestools or transverse bulkheads may be taken sigma_F/3^0.5. On the other
hand, in CSR-B of Ch.6, Sec.4, [3.1.2], there is no description about thistreatment. It seems that to apply this treatment to CSR-B is rational because
this requirement has come from UR20.
Please consider a RCP to add this treatment into CSR-B.

In CSR-B of Ch.6, Sec.4, [3.1.2], the following treatement will be added:
allowable shear stress for floors adjacent to the stools or transverse bulkheads
may be taken sigma_F/3^0.5 as notified in UR S20.3.1.
A corrigenda will be issued.

RCP

Loading
conditions to
be includedin Trim &Stability
bookletQuestion/CI

In order to follow the relevant requirement of UR A1.4.2, please add afollowing sentence to Ch.10, Sec.3, 3.2.4 of CSR Bulk Carriers.
"Installation of the spare anchor on board is not compulsorily required."

Answer

The installation of the spare anchor is not compulsory required. The text is inline with UR A1 and kept as is.

Otherwise please revise Table 1 in Ch.10, Sec.3 of CSR Bulk Carriers in thesame way as Table 11.4.1 in Sec.11 of CSR Oil Tankers.

2010/6/29

We do not consider the "standard loading condition for direct strength
analysis" listed under Appendix 2 of CH4 is required to be included in the Trim
& Stability booklet.
For example, for LC No.6 "Multi Port-3" in Table 1 in Ch.4 Appendix 2, thedesign value of the sagging bending moment will become quite large if animaginary loading condition is prepared on purpose to realize the condition
corresponding to LC6. Thus, we would say it is not so reasonable in practice
to include such an imaginary loading condition in the Trim & Stability booklet.

We agree to your comment that loading conditions indicated in Appendix 2 in
Ch.4 are not required to be included in the Trim & Stability booklet.
The loading conditions applicable for loading manual is specified in Chapter 4
Section 7 and 8.

Would you have any further question, please don't hesitate to contact the
In order to avoid unnecessary argument between Class & Builder, we suggest IACS Permanent Secretariat.
that the additional statement should be provided which specifies that it is not
required to prepare the loading conditions to realize the LCs indicated in the
Appendix 2 and that such loading conditions need not to be included in the
Trim & Stability booklet.

Page 177 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

Ref.

Type

Topic

Date
completed

Question/CI

CSR-B Ch.3, Sec.6, 6.5.2 Bilge keel
The following requirement is to prevent cracks propagated to bilge strakes
from these occurred in bilge keels due to longitudinal bending moments.
“The bilge keel and intermediate flat are to be made of steel with the sameyield stress as the one of the bilge strake.”
1046 3/6.6.52

Question

Steel grade
requirementof Bilge Keel2010/8/4

For bilge strakes, even when the use of HT steel is not required by Ch.5,
Sec.1, 4.5 for longitudinal strength consideration, HT steel may be used forconvenience of design.
However, in light of the above, we consider that this requirement may bedispensed with if bilge keels are not located in the HT zones specified Ch.5,
Sec.1, 4.5.

1047

1051

4/7.2.1.1

Text
5/1.2.2.2

Max cargomass incargo holds
at maxdraught
conditionwith 50% ofconsumables

Attachment

AnswerSince a large number of comments from shipowners have been received
about bilge keel and prevention of damage to its ends, it was decided that thematerial of the bilge keel should have the same strength as the bilge strake.
Similar to long hatch side coamings of 0.15L specified in the IACS UR S6, if
the length of the bilge keel is greater than 0.15L, the material of the bilge keel
is required to be the same as that of the bilge strake.
The material requirement for the bilge keel is also found in Ch3/Sec6/[2.3.1].
The intermediate flat is to be made of steel with the same yield stress as theone of the bilge strake in order to ensure continuity of material.

In Ch.4 Sec.7 [2.1.1] is written: "For the determination of the maximum cargomass in cargo holds, the condition corresponding to the ship being loaded at
maximum draught with 50% of consumables is to be considered."Is this defined for the short voyage conditions?

Ch.4 Sec.7 [2.1.1] defines the upper limit for the cargo mass in holds, i.e. thepay load, by considering only 50% of consumables at full draught. This has
not to be considered as a mandatory design loading condition.
This definition of the upper limit is not to be confused with definitions of shortvoyage conditions.

In CSR BC, there is no clear definition of a "homogeneous loading" condition.
This definition is important to know whether or not it is possible to make ashear reduction according to Ch5, Sec1, 2.2
Defenition of
We think it's possible to use the definition of homogeneous loading condition
Homogenous
given in URS 18:
Interpretati
loading2010/10/20 "...homogeneous loading condition means a loading condition in which theoncondition toratio between the highest and the lowest filling ratio, evaluated for each hold,make shear
does not exceed 1,20, to be corrected for different cargo densities."
reduction

We agree with your proposal to use the definition of homogeneous loading
condition given in URS 18 in CSR for Bulk Carriers:"...homogeneous loading condition means a loading condition in which theratio between the highest and the lowest filling ratio, evaluated for each hold,does not exceed 1,20, to be corrected for different cargo densities."CI

2010/5/12

The definition will be included in the Rules.

Please let us if you confirm this proposition

Page 178 of 181

IACS Common Structural Rules Knowledge Centre

KCID
No.

Ref.

1054
4/6.1.1.1
attc

Type

Topic

Hc value ofdry bulk
cargo in fullInterpretati
filledoncondition(Ref to KC ID
1025)

Date
completed2010/8/11

Question/CI

With reference to KC ID 1025, it seems that the answer do not fully cover ourquestions. It is true that the formula should be used to calculate hc for holds ofcylindrical shape. However, our question is "Should we consider the cargohold with upper stools as one of cylindrical shape or not?".
Most of CSR PT3 members assume that cylindrical shape means that a cargo
is longitudinally cylindrical along its entire length and no upper stools should
be arranged. For a typical bulk carrier with upper stools, our calculation shows Yes, we consider a cargo hold as having a cylindrical shape if it maintains athat the two methods in Ch4/Sec6/1.1.1 of CSR-BC will result in different hc
cross sectional shape over the hold length with or without upper stools.
values.
Therefore, we are expecting an answer of Yes or No with explanations to thequestion "should the cargo hold with upper stools be considered as one ofcylindrical shape?". If Yes, the explanations are expected. If No, clear
statements of the rule may be needed. Detailed calculation procedure is
attached.

Keel Plating
The following requirements for keel plating can be found:
Ch3, Sec6, 6.2.1. Minimum breadth of the keel "b".
Ch6, Sec1, Table 2 Minimum thickness of keel
Ch6, Sec1, 2.4.1 The net thickness of the keel plating is to be not less than
the actual net thickness of the adjacent 2 m width bottom plating.
1055 Text
attc 6/1.2.4.1

Attachment

AnswerMeasuremen
Interpretati
It is not mentioned, if the adjacent 2 m width bottom plating has to bet of adjacent 2010/10/20
onmeasured from the edge of the actual keel strake or from b/2. Some current
plate width
ship designs have an actual keel plating width of more than 3 times the size ofb (see attachment). If Ch6, Sec1, 2.4.1 is interpeted in a way that the adjacentplate width has to be measured from the edge of the actual keel strake, thewidth of affected bottom plating and the potential increase of the thickness
depends on this arbitrary strake width. We propose to initiate a Common
Interpretation (CI) or to include the outcome of this question in next RCP toclarify that the adjacent plate width has to be measured from b/2 of CL.

Firstly, we do not agree with your interpretation: as for bilge plating, theadjacent 2m are to be considered from the edge of the keel strake, this is inorder to avoid large discrepancies in thicknesses for welding.
In addition, considering the adjacent 2m starting from b/2 will in most caseinclude the keel strake which may lead to misinterpretations.
Consequently the rules are kept as they are and no interpretation is emitted.

Page 179 of 181

YY

IACS Common Structural Rules Knowledge Centre

KCID
No.

Ref.

Type

Topic

Date
completed

Question/CI

1065

Refer to Chapter 3/ Section 2.
QuotedIndication of
3.3 Available information on structural drawings
gross and3.3.1 The structural drawings are to indicate for each structural element
Interpretati
renewalthe gross scantling and the renewal thickness as specified in Ch 13, Sec 2.2".
3/2.3.3.1
2010/11/15
onthickness in
Unquoted
the structural
Our understanding of this paragraph could only be interpreted that all
drawings
structural drawings submitted to the IACS class are to indicate for eachstructural member the Gross and RENEWAL THICKNESS.
We would appreciate if our understanding is correct.

1074
attc

9/3.2.2

Interpretati Definition ofonMargin Plate

There is no definition of “Margin Plate” in CSR Bulk Carrier.
1. Rule Application of CSR Bulk Carrier: Chapter 9, Section 3/2.2. Table 1:
Minimum Thickness Application of Margin Plate.
2. Since there is no definition about “Margin Plate” in CSR Bulk Carrier Rule,
we are using the “Margin Plate” definition in CSR Tanker (Ref. Sec.4/ Table
2010/11/15 4.1.1)
3. According to the definition of terms in CSR Tanker, we may think of thefollowing two cases;
Case 1 & Case 2 (see attachments)
4. Does you consider both cases are Margin Plate? or One of two cases is
Margin Plate?

1077
attc

Bulker
3/6.5.7

Question

RCP

1082
attc

2/2.5.1.1

Attachment

AnswerAs you mention, Chapter 3 Section 2 3.3.1 states that for each structuralmember, gross scantling and renewal thickness should be indicated.
However, for clarification of extension and alternative methods we refer toKC777, KC948 and KC1058.
A common position will be issued by the harmonization project.

The definition of Margin Plate in Ch9/Sec3/Table 1 should be given and in linewith CSR OT in which the definition comes from IACS Recommendation
82,"Surveyor’s Glossary, Hull terms and hull survey terms".
Both Case 1 and Case 2 are Margin Plate.
A corrigenda will be considered.

Y

Depth of cutHarmonisation request for depth of cut-outs and naming of cut-outs/slots?
2010/11/10
outs(Original request: Please refer to attachment)

Your comment is noted. We will retain your comment for consideration during
the harmonisation of the two CSR Rules.

Y

Definition
We consider that a rule change for CSR Bulk Carriers should be immediately“T1”
implemented as follows:
specified in
The definition “T1” specified in Ch.2/Sec.2/5.1.1 of CSR for Bulk Carriers
Ch.2/Sec.2/5
based on Reg.39(1) of ILLC should be amended according to.1.1 of CSR 2010/11/15
Res.MSC.223(82) as attached.
for Bulk
In addition, other requirements referred to in International Conventions may
Carriers
need to be amended accordingly.
based onPlease consider.
Reg.39(1)The text will be amended accordingly.
As other international texts are included in CSR BC, a complete review will bemade and its results will be included in a future rule change.

Y

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IACS Common Structural Rules Knowledge Centre

KCID
No.

Ref.

1091 2/2.5.1.1

Type

RCP

Topic

Table 3/1.4-3
3/6.7.3.6
11/1.1.1.1

Datecompleted

Question/CI

2011/6/6

The spelling of 'shear strake' shall be corrected to 'sheer strake' in thefollowing sections..
1. Chapter 3, Section 1 Table 4-3:
Shear strake at strength deck
2. Chapter 3, Section 6
7.3.6 Sheer strake...If the shear strake is rounded, its radius, in mm, is to be not less than 17ts,
where ts is the net thickness, in mm, ofthe sheer strake.
3. Chapter 11, Section 1
1.1 Cut-outs, plate edges
1.1.1...This also applies to cutting drag lines, etc., in particular to the upper edge ofshear strake andanalogously to weld joints, changes in sectional areas or similar
discontinuities.

Attachment

AnswerThank you for your comment. This will be considered in the next editorial
correction.

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