IACS adopts new Common Structural Rules

DECEMBER 20, 2013 —  IACS, the International Association of Classifications Societies, has unanimously adopted new harmonized Common Structural Rules (CSR) for oil tankers and bulk carriers. The new rules will apply to all oil tankers over 150 m and bulk carriers over 90 m in length contracted for construction on or after July 1, 2015.

The CSR will be presented to the IMO which will verify their compliance with IMO goal-based standards (GBS) that will be compulsory for new building contracts signed on or after July 1, 2016.

Mr. Roberto Cazzulo, Chairman of the IACS Council, said “This is a historic achievement and the culmination of many years of hard work by technical specialists from all member societies and intensive and continuing consultation with industry and authorities at every stage. Together we have invested a huge amount of time and money to develop these rules.”

Among the main benefits of the new CSR: ship designers will be able to work to one common standard applicable to both ship types; more comprehensive structural analyses including FEM calculations covering fore and aft parts; new rule checks including new buckling, fatigue and ultimate strength criteria; all this will enhance safety and reliability of the structure.

“These harmonized rules take into account feedback from experience of the Common Structural Rules, introduced in 2006, and very extensive input from the industry,” said Mr. Cazzulo.

While the new CSR apply to tankers and bulkers, the IACS Council has also decided to take a proactive approach to structural safety of containerships, following a comprehensive review of existing technical requirements for hull structural design, construction and survey.

IACS has decided to expand the scope of current IACS unified requirements for post-Panamax containerships. These requirements will cover two important areas: scope of hull girder strength assessment and specific loading cases that will provide more comprehensive safety margins.

“The new IACS unified requirements should be considered as a proactive measure to ensure an acceptable level of consistency amongst all IACS Societies and will ensure that Class and Industry follow a state-of-the-art methodology for structural analysis of post-Panamax containerships,” said Mr. Cazullo.