ClassNK has issued an Approval in Principle (AiP) for a design concept of large liquefied CO2 carriers of 50,000 m³ and 23,000 m³ jointly developed by Kawasaki Kisen Kaisha, Ltd., Mitsui O.S.K. Lines, Ltd., Nihon Shipyard Co., Ltd., Nippon Yusen Kabushiki Kaisha, Mitsui & Co., Ltd., Mitsubishi Corporation, and Mitsubishi Shipbuilding Co., Ltd.
While Carbon dioxide Capture and Storage (CCS) projects are proceeding worldwide, demand for liquefied CO2 carriers that transport CO2 from the capture site to the storage site is expected to expand. This AiP is a step toward standardizing hull designs, which is necessary in order to realize a sufficient number of liquefied CO2 carriers to meet such demand. The handover ceremony of AiP certificate was held at the "Gastech2024" exhibition in Houston, USA.
ClassNK carried out a design review of the ships based on part N of its "Rules and Guidance for the Survey and Construction of Steel Ships", which incorporates the IGC Code, an international code for the construction and equipment of ships carrying liquefied gases such as liquefied CO2 and LNG in bulk. ClassNK issued AiP after it was confirmed that the prescribed requirements were met.
This AiP includes a tank safety assessment process based on a fracture mechanics technique called Engineering Critical Assessment (ECA) to omit post-weld heat treatment (PWHT), which can be a bottleneck in tank manufacturing.