Rules & Classification
Technical Bulletin 2016

Following major structural failures of large containerships in recent years, a review of existing requirements with a focus on structural performance was initiated by IACS. IACS established a project team to conduct the review and propose some improvements. The now-published Unified Requirements S11A and S34, which came into force on 1st July 2016, were the main outcome of this work. Bureau Veritas was heavily involved in the project team and took the opportunity of these new IACS requirements to completely update its own structural rules for containerships, published as ‘NR625’. The two first papers of this section present the work of the project team to redefine the hull girder wave loads, and the results obtained using the newly developed loads and strength assessment procedures in UR S11A for a number of existing containerships.

In the context of the development of the new rules for containerships, work has also been carried out to normalize and generalize the so-called ’wave parameter’. The wave loads part of the rules has been completely redesigned, using modern methodology and computational tools, and this work is presented in the third and fourth papers.

The active development of new and innovative mooring systems, such as permanent jetty mooring for FSRUs or floating offshore wind turbines, has created a critical need for techniques, technologies and regulations to ensure safety, reliability and efficiency. In the context of the development of new rules and guidance notes, Bureau Veritas has carried out several analyses and mooring studies, detailed in the two penultimate papers in this section.

In 2016, the new IGC Code entered into force. Amongst the new rules, those dealing with the inspection for fatigue of type B tanks have drawn attention. The requirement to use the crack propagation calculation for designs, in addition to the Miner sum, raised challenging questions. The last paper of this section presents these requirements and analyses their application to a typical design.

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