Common Structural Rules for Bulk Carriers and Oil Tankers (CSR BC & OT)

In December 2013, IACS—the International Association of Classification Societies—adopted a new set of rules called the Common Structural Rules for Bulk Carriers and Oil Tankers (CSR BC & OT). The CSR BC & OT harmonised requirements found in the Common Structural Rules for Bulk Carriers (CSR-BC) and Common Structural Rules for Oil Tankers (CSR-OT). The requirements in the CSR BC & OT apply to bulk carriers of 90 m of more in length and double hull oil tankers of 150 m or more in length whose contracts for construction are dated on or after 1 July 2015. All IACS member classification societies are required to enforce the CSR BC & OT requirements after they officially take effect on 1 July, 2015.

Following the adoption of the CSR BC & OT by IACS, ClassNK officially incorporated its requirements into the ClassNK technical rules as “Part CSR-B&T”.

What is the “CSR BC & OT”?

The "CSR BC & OT" is, as its name suggests, a harmonised version of requirements found in IACS’ two sets of Common Structural Rules, CSR-BC and CSR-OT, which were adopted in December 2005, and went into effect on 1 April 2006.

The actual development work of these two CSRs was split up and assigned to two separate project teams. During the development stage, the requirements for each CSR were originally intended to be as closely harmonised as possible. Both teams, however, began following different approaches, even with respect to fundamental technical schemes, towards their goal for the sake of expediency and due to time constraints.

Relevant industry members soon began requesting that IACS develop a common approach and treatment for certain items that were common to both CSRs regardless of ship type. In response, IACS announced that it was going to begin development work on combining CSR-BC and CSR-OT into a single unified version which would be known as CSR BC & OT. The harmonisation work officially started in 2008.

In the meantime, the IMO had approved its Goal-based Standards (GBS). Therefore, IACS decided that all GBS requirements which are to be covered by the CSRs also needed to be dealt with in the CSR BC & OT in order to ensure that they would be GBS compliant. These GBS requirements are covered in the final adopted version of the CSR BC & OT.

From the beginning, ClassNK has been deeply involved in the development of the CSR BC & OT as an active participant in almost all 10 of the project teams which were established for the project. Making use of its many years of experience in ship classification as well as its vast wealth of technical expertise and knowledge, ClassNK played a leading role in ensuring that the development work on the CSR BC & OT reached a successful conclusion.

ClassNK Rules for Common Structural Rules for Bulk Carriers and Oil Tankers(Part CSR-B&T)

(Provisions of the CSR BC & OT main text, Rules for the Survey and Construction of Steel Ships [Part CSR-B&T], Rule Change Notice, Q&A, Technical Background, etc.),


Software for Common Structural Rules for Bulk Carriers and Oil Tankers(CSR BC & OT)

(Introduction to the “PrimeShip-HULL” software, which includes rule calculation systems and a direct strength analysis system for use with the CSR BC & OT)