Common Structural Rules for
Bulk Carriers, January 2006

Background Document
CHAPTER 12 – ADDITIONAL CLASS NOTATIONSNOTE:- This TB is published to improve the transparency of CSRs and increase theunderstanding of CSRs in the industry.
- The content of the TB is not to be considered as requirements.
- This TB cannot be used to avoid any requirements in CSRs, and in cases
where this TB deviates from the Rules, the Rules have precedence.
- This TB provides the background for the first version (January 2006) of theCSRs, and is not subject to maintenance.

COMMON STRUCTURAL RULES FOR BULK CARRIERS − BACKGROUND DOCUMENT
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COMMON STRUCTURAL RULES FOR BULK CARRIERSCOMMON STRUCTURAL RULES FOR BULK CARRIERS − BACKGROUND DOCUMENTPAGE 3 – CHAPTER 12: ADDITIONAL CLASS NOTATIONSTABLE OF CONTENTS:SECTION 1 – GRAB ADDITIONAL CLASS NOTATION ................................................................ 41.

BASIC CONCEPTS...................................................................................................................... 41.1

2.

Application.............................................................................................................................. 4SCANTLINGS ............................................................................................................................. 42.1

Plating ..................................................................................................................................... 4COMMON STRUCTURAL RULES FOR BULK CARRIERSCOMMON STRUCTURAL RULES FOR BULK CARRIERS − BACKGROUND DOCUMENTPAGE 4 – CHAPTER 12: ADDITIONAL CLASS NOTATIONSSECTION 1 – GRAB ADDITIONAL CLASS NOTATION
1. BASIC CONCEPTS
1.1

Application

1.1.1
1.1.1.a

The regulations corresponding to Regulation 6.5.1, Chapter XII of the SOLAS
Convention were set as Chapter 12. The regulation for additional class notation
assigned when the strength requirements for grab impact loads are satisfied, hasbeen added. To clearly denote the mass of the grab considered when assigning theadditional class notation, the mass of the grab considered is affixed after "GRAB."This regulation is a mandatory requirement for BC-A and BC-B ships according tothe SOLAS Convention, and optional for other kinds of ships. The minimum massof the grab considered was taken as 20 tons considering the mass of grabs generally
used in harbour facilities.

1.1.2
1.1.2.a

It is considered that for this topic, no information in addition to that shown in theRules is necessary to explain the background.

2. SCANTLINGS
2.1

Plating

2.1.1
2.1.1.a

It is considered that for this topic, no information in addition to that shown in theRules is necessary to explain the background.

2.1.2
A simplified formula using grab mass, material used, and longitudinal spacing was
given after studying regulations related to grabs of other classification societies andreferring to LRS Rules as shown in Fig. 12.1.

G rabThickness (m m )2.1.2.a

30.0
28.0
26.0
24.0
22.0
20.0
18.0
16.0
14.0
12.0
10.0

AB SLR SC SR0Fig. 12.1

2040
G rab w eight (t)60Required plating thickness versus grab weight

COMMON STRUCTURAL RULES FOR BULK CARRIERSCOMMON STRUCTURAL RULES FOR BULK CARRIERS − BACKGROUND DOCUMENT
PAGE 5 – CHAPTER 12: ADDITIONAL CLASS NOTATIONS

2.1.3
2.1.3.a

A simplified formula was given as similar to 2.1.2.a.

COMMON STRUCTURAL RULES FOR BULK CARRIERS