ClassNK has issued an Approval in Principle(AiP) for an ammonia fuelled gas carrier which has been jointly developed by Mitsui O.S.K. Lines, Ltd., TSUNEISHI SHIPBUILDING Co., Ltd., and Mitsui E&S Shipbuilding Co., Ltd.
Ammonia is expected to be used as a ship fuel for decarbonization since it does not emit CO2 when combusted. Meanwhile, adequate safety measures are imperative as it has been pointed out that ammonia is toxic to humans and corrosive to materials. ClassNK has been involved in projects aiming for zero-emission ships using ammonia fuel in terms of safety assessment, and has issued its "Guidelines for Ships Using Alternative Fuels” as a necessary standard to minimize the risks related to ammonia fuelled ships for the ships, crews, and environment by stipulating requirements for installation, controls, and safety devices.
The vessel uses some of its ammonia cargo as fuel, and is targeting to achieve net zero CO2 emissions while underway. ClassNK carried out the review on jointly developed design of the ammonia fuelled medium size gas carrier in line with Part C of its guidelines, and examing the risk assessment through HAZID. Upon cofirming it complies with the prescribed requirements, ClassNK issued the AiP.