ClassNK grants AiP for spray-form insulation system for IMO Type B LNG and ammonia fuel tanks

ClassNK has issued an Approval in Principle (AiP) for a spray-form insulation system designed for IMO Type B fuel tanks used for LNG and ammonia. The system was jointly developed by Nihon Shipyard Co., Ltd. and Hankuk Carbon Co., Ltd. The approval confirms that the concept meets relevant regulatory and safety requirements.

The certification comes as shipbuilders and operators continue exploring alternative fuels amid tightening decarbonization targets. LNG-fuelled ships have traditionally relied on IMO Type C tanks due to their cost and productivity advantages. However, for large container vessels and ships designed to run on ammonia, IMO Type B tanks are drawing interest for their cargo-space efficiency and installation flexibility.

ClassNK conducted its assessment in line with Part N of its Rules and Guidance for the Survey and Construction of Steel Ships, which incorporates the IGC Code, and Part GF, which applies the IGF Code. The review covered the design concept and demonstration tests of the new insulation system. Following verification of compliance, the classification society issued the AiP. ClassNK noted that it will continue to support the development of next-generation fuel systems through safety evaluations and related certification work.