Bulk Carriers and Oil Tankers
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Common Structural Rules for Bulk Carriers and Oil Tankers 01 January 2021 Release COMMON STRUCTURAL RULES FOR BULK CARRIERS AND OIL TANKERS TECHNICAL BACKGROUND RULE REFERENCE This document is an updated version of the Technical Background Rule Reference for Common Structural Rules for Bulk Carriers and Oil Tankers following the publication of the 01 Jan 2021 Rules. The document was updated on the basis of “TBRF Change Proposal (Jan 2021)”, “TBRF Change Proposal (Feb 2021) (Based on KCs)”, “Technical Background for Rule Change Notice 1 to 01 Jan 2020 version” and “TBRF Change Proposal (June 2021)”. Table of Contents Part 1 : General Hull Requirements Part 2 : Ship Types PART 1 GENERAL HULL REQUIREMENTS Table of Contents Chapter 1: Rule General Principles Chapter 2: General Arrangement Design Chapter 3: Structural Design Principles Chapter 4: Loads Chapter 5: Hull Girder Strength Chapter 6: Hull Local Scantling Chapter 7: Direct Strength Analysis Chapter 8: Buckling Chapter 9: Fatigue Chapter 10: Other Structures Chapter 11: Superstructure, Deckhouses and Hull Outfitting Chapter 12: Construction Chapter 13: Ship in Operation - Renewal Criteria PART 1 CHAPTER1 RULE GENERAL PRINCIPLES Table of Contents SECTION 1 Application 1 Scope of Application 2 Rule Application 3 Class Notations 4 Application of the Rules of the Society SECTION 2 Rule Principles 1 General 2 General Assumptions 3 Design Basis 4 Design Principles 5 Rule Design Methods SECTION 3 Verification of Compliance 1 General 2 Documents to be Submitted 3 Scope of Approval 4 Workmanship 5 Structural Details 6 Equivalence Procedures SECTION 4 Symbols and Definitions 1 Primary Symbols and Units 2 Symbols 3 Definitions SECTION 5 Loading Manual and Loading Instruments 1 General Requirements 2 Loading Manuals 3 Loading Instrument 4 Loading Specific to Bulk Carriers PT 1, CH 1, SEC 1 – APPLICATION COMMON STRUCTURAL RULES 1 SCOPE OF APPLICATION 1.1 General 1.1.1 These regulations clearly define the application of harmonised Common Structural Rules (CSR-H) for bulk carriers and oil tankers. 1.1.2 These regulations give the typical structural arrangement of the ships concerned by the Rules. 1.1.3 Technical background is not considered necessary. 1.2 Scope of application for bulk carriers 1.2.1 The Rules apply to bulk carriers of length 90m and greater of typical arrangement fitted with a double bottom structure and side structure of single skin or double skin construction and constructed generally with a single deck and, in the cargo holds, with topside tanks and bilge hopper tanks. The word “generally” means that ships fitted with top side and hopper tanks have a typical bulk carrier arrangement, but CSR are applicable to other arrangements, for example hybrid type bulk carriers. A hybrid bulk carrier is a bulk carrier where at least one cargo hold is constructed with hopper tank and topside tank. It clearly means that these Rules apply to bulk carriers without topside nor hopper tanks in some holds and having hopper tank and top side tank in remaining hold. This is in line with the interpretation of the expression “constructed generally with single deck, top-side tanks and hopper side tanks in cargo area“, which means, according to MSC Res. 277(85), that ships are not considered outside the definition of bulk carriers only on the grounds that they lack some or all of the specified constructional features. The expression “intended primarily to carry dry cargoes in bulk” is to be understood in the same way as MSC Res. 277(85). The text of MSC Res. 277(85) says: ““primarily to carry dry cargo in bulk” means primarily designed to carry dry cargoes in bulk and to transport cargoes which are carried, and loaded or discharged, in bulk, and which occupy the ship’s cargo spaces exclusively or predominantly”. Ore carriers and combination carriers are excluded from the scope of application of the Rules due to their typical arrangement (see Figure 1). TECHNICAL BACKGROUND RULE REFERENCE PT 1, CH 1, SEC 1/PAGE 1 PT 1, CH 1, SEC 1 – APPLICATION COMMON STRUCTURAL RULES Figure 1: Typical structural arrangement for Ore Carriers The Rules also exclude from its scope of application the following ship types: • Woodchip carrier. • Cement, fly ash and sugar carriers provided that loading and unloading is not carried out by grabs heavier than 10 tons, power shovels and other means which may damage cargo hold structure. • Ships with inner bottom construction adapted for self-unloading. The same ship types are excluded from MSC Res. 277(85). The definition of bulk carriers covered by the Rules is in accordance with the International Convention for Safety of Life at Sea (SOLAS) and MSC Res. 277(85), excepted for the pure ore carriers and combination carriers due to their typical structural arrangement as mentioned above. The references to SOLAS and MSC Res. 277(85), adopted on 28 November 2008 are given for reference. 1.3 Scope of application of oil tankers 1.3.1 Length and structural arrangement application Technical background is not considered necessary. 1.3.2 Cargo temperature application This requirement is in accordance with CSR OT (July 2010) Sec 2, 3.1.8.4. Ships with cargo design temperature outside the range (0°C to 80°C) are subject to additional requirements as specified by the Society. TECHNICAL BACKGROUND RULE REFERENCE PT 1, CH 1, SEC 1/PAGE 2 PT 1, CH 1, SEC 1 – APPLICATION COMMON STRUCTURAL RULES 2 RULE APPLICATION 2.1 Rule description 2.1.1 Rule structure Technical background is not considered necessary. 2.1.2 Numbering Technical background is not considered necessary. 2.2 Rule Requirements 2.2.1 Part 1 Technical background is not considered necessary. 2.2.2 Part 2 Technical background is not considered necessary. 2.2.3 Application of the Rules Technical background is not considered necessary. 2.2.4 General criteria Technical background is not considered necessary. 2.3 Structural requirements 2.3.1 Materials and welding The rule requirements associated with the selection of materials for structural components are based on the location, design temperature, through thickness stress, and criticality of the component, see Sec 2, [3.4.4] and Ch 3, Sec 1. The rule requirements are based on the assumption that the material is manufactured in accordance with the rolling tolerances specified in IACS UR W13 (Rev 5, February 2012). 2.4 Ship parts 2.4.1 General Technical background is not considered necessary. 2.4.2 Fore part The structure in the forward part is defined as structure forward of the collision bulkhead in principle, but the scope of applicability of the structural regulations for slamming of the forward bottom and bow flare extends also to the structural parts aft of the collision bulkhead. To avoid duplication and for convenience, the regulations are included in those for the forward part. 2.4.3 Cargo area Technical background is not considered necessary. TECHNICAL BACKGROUND RULE REFERENCE PT 1, CH 1, SEC 1/PAGE 3 PT 1, CH 1, SEC 1 – APPLICATION COMMON STRUCTURAL RULES 2.4.4 Machinery space The pump room is included in machinery space for strength assessment purpose although SOLAS Ch II-1, Reg. 3.16, as amended; considers the pump room as part of the cargo area. The reference to SOLAS is given for information. 2.4.5 Aft part Technical background is not considered necessary. 2.4.6 Superstructures and deckhouses Technical background is not considered necessary. 2.5 Limits of application to lifting appliances 2.5.1 Definition This requirement specifies the fixed parts of lifting appliances considered as an integral part of the hull, to be checked under the CSR requirements. 2.5.2 Rule application for lifting appliances Technical background is not considered necessary. 2.5.3 Structures supporting fixed lifting appliances Technical background is not considered necessary. 2.6 Novel designs 2.6.1 Technical background is not considered necessary. 3 CLASS NOTATIONS 3.1 Class notation CSR 3.1.1 Application This requirement defines the class notation CSR. Ships complying with the requirements of these Rules will have the notation CSR placed in the ships public class. Mandatory or voluntary procedures which previously resulted in class notations that are made redundant by these Rules will no longer be applied to ships covered by the notation CSR. Additionally, current notations from the Societies that indicate compliance with specific guides or requirements that augment this standard will also be added to the ships public class records. 3.2 Class notation for bulk carriers 3.2.1 Additional service features BC-A, BC-B and BC-C This incorporates the requirements of IACS UR S25.3 (which is no longer in force). For improvement and transparency, the additional service feature {Block loading} is included when the ship is intended to operate in alternate block load condition. TECHNICAL BACKGROUND RULE REFERENCE PT 1, CH 1, SEC 1/PAGE 4 PT 1, CH 1, SEC 1 – APPLICATION COMMON STRUCTURAL RULES 3.2.2 Additional class notation GRAB [X] The External Advisory Group IACS used for consultation during harmonisation of CSR-BC and CSR-OT, advised that GRAB(20), the design basis in CSR-BC, is too low for larger vessels carrying iron ore and coal, compared to actual grabs used at terminals. The IACS Hull Panel followed up this feedback by collecting information on actual grab weight from owners association and IACS members and the following feedback were noted : Extract of information received Source (Grab weights refer to weight of empty grabss) Most heavy grabs are found in Rotterdam and are 37t . Class 1 Grabs with weight 22-28 t are quite common. Industry org.