IACS Common Structural Rules Knowledge Centre

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

313

544
attc

690

Ref.

12/1.2.3

12/ 1.2.1

12/1.2.1.3

TypeTopicQuestiontransverselower stool

CI

Inner bottom
platingQuestion

Grabrequirement(tGR)

Datecompleted

Question/CI

Is the formula tGR to be applied to not only sloping side plating but vertical side
2006/12/21
plating of transverse lower stool?

AttachmentAnswer

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

2008/4/25

A1) Yes the whole inner bottom plating has to be dimensioned according to Ch.12
Our interpretation of 2.1.1 to 2.1.3 of CH12, Sec1 is the following:
Sec.1 [2.1.2].
a) the whole inner bottom plating has to be dimensioned according 2.1.2
A2) The interpretation of Ch.12 Sec.1 [2] is as follow:b) the sloped hopper tank plating and the sloped or non-sloped lower stool plating
Ch.12 Sec.1 [2.1.1] is applicable to plating of inner bottom, hopper, lower stool
have to be dimensioned according 2.1.3 up to a height of 3m above the innerside plating and inner hull up to a height of 3m above inner bottom.
bottom (vertically measued)
Ch.12 Sec.1 [2.1.2] is applicable to the plating of inner bottom.
c) in case of a hybrid-bulker the inner longitudinal wall, welded directly on theCh.12 Sec.1 [2.1.3] is applicable to plating of hopper, lower stool side plating,inner bottom wihout a hopper plate, has to be dimensioned according 2.1.3 up to
inner hull up to a height of 3m above inner bottom.
a height of 3m above the inner bottom
A3) Yes, inner longitudinal walls of an hybrid bulker have to be dimensioned withd) The coaming, deck girders below coaming, top wing sloping plate and upper
respect to Ch.12 Sec.1 [2.1.3].
stool plating have not be increased due to the GRAB-notation
A4)No, coaming, deck girders below coaming, to wing sloping plates and upper
Please confirm these interpretations.
stool plating are not concerned by Ch.12 Sec.1.

2008/3/13

Is the Grab requirement (tGR) specified in Ch.12 Sec.1 [2.1.3] applicable to
Swinging of the grab by the operator may provoke great impacts on the bottom of
plating of Collision and Engine Room Bulkhead within 3.0m from inner bottom? Or
any side of a hold. The requirements of Ch.12 Sec.1 [2.1.3]are applicableis there any other paragraph requiring reinforcement against grab handling toregardless of the design and the function of a cargo hold bulkhead.
these bulkhead plates?

In 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 theinner bottom.
In such cases, the GRAB requirement in Ch.12 Sec.1, [2.1.3] is applicable to thelower part of the corrugated bulkhead up to 3m above the inner bottom.
980

12/1.2.1.3

Interpretati
onApplicabilityof GRAB
requirement

2010/8/20

We agree that the grab requirement is only applicable to the faces of corrugations.
However, grab configurations do not come into contact with such corrugation
We will consider a corrigenda to clarify this.
webs because the width and depth of corrugations are always smaller than thoseof grab appliances (i.e. less than 1m).
We are of the opinion that the GRAB requirement is only applicable to the faces ofsuch corrugations.
Please confirm.

Page 1 of 3Y

IACS Common Structural Rules Knowledge Centre

KCID
No.

998
attc

Ref.

12/1.2.1.3

TypeInterpretati
on

Topic

Applicabilityof GRAB
requirement

Datecompleted2010/8/4

Question/CI

Answer

Attachment

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 their configuration
Grab requirements are not applicable to web of corrugations.
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.

YPage 2 of 3

IACS Common Structural Rules Knowledge Centre

KCID
No.

Ref.

1029 12/1.2.1.3

TypeRCP

Topic

Transverse
corrugatedbulkheads atlower stools
as transverse
bulkhead
platingDatecompleted2010/3/30

Question/CI

Attachment

Answer

The requirements in Ch.12 apply to the following structural elements when theyWith regard to the paragraph of Ch.12, Sec.1 [2.1.3], we would request thatexist in the hold:transverse corrugated bulkheads situated on lower stools are ruled out fromapplication of the 'transverse bulkhead plating'.
- plating of inner bottom
The paragraph in Ch.12, Sec.1 [2.1.3] contains 'transverse bulkhead plating' as a
- hopper tank sloping plate
result of Rule Change Notice No.1 (effective from 1 July 2009) which may cause a- plating of transverse lower stool (if it exists)
confusion as to whether this newly added word implies a transverse corrugated- flange plating of transverse corrugated bulkheadbulkhead on lower stool or not, all the more for small bulk carriers provided with- plating of transverse plane bulkhead
lower stools of which the height is less than 3.0m.
- plating of inner hull
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
up to a height of 3m above the lowest point of the inner bottom.
313 and 544)'. Besides, TB for RCN No.1-4 explains that 'inner hull up to a heightof 3.0m from the lowest point of inner bottom is applied to this requirement'.
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 lowerstools, especially for those of small bulk carriers. The current passage containing'transverse bulkhead plating' should be interpreted to limit to transverse bulkheadplating where lower stools are not fitted. KC is therefore requested to update thepassage in future Rule Change Notice.

Page 3 of 3

KC#544skLt LR
202530
3540
45
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60

800 mm1200 mt ABS 1999 t ABS 2001 t CSR inner t CSR hopper t inner CSR mod NK
22.57
10.79
18.24
17.53
15.53
11.27
24.47
10.79
19.55
18.78
16.78
12.52
26.02
10.79
21.07
20.04
18.03
13.77
27.33
10.79
22.49
21.29
19.28
15.03
28.47
10.79
23.80
22.54
20.54
16.28
29.47
10.79
25.03
23.79
21.79
17.53
30.36
10.79
26.19
25.04
23.04
18.78
31.17
10.79
27.28
26.30
24.29
20.04
31.91
10.79
28.31
27.55
25.54
21.29

40.00

35.00

t LR
t ABS 2001
t CSR innert CSR hoppert inner CSR mod NK
t ABS 1999

30.00

25.00

20.00

15.00

10.00
1520

2530

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KC#998

GRAB

Corrugation flanges and webs areperpendicular to each other.

Corrugation Width = 800 mm

Corrugation Depth = 900 mm
CLGRAB

Grabs do not contact
corrugation webs