ClassNK grants AiP for ammonia-fuelled LPG/NH₃ carrier

Classification society ClassNK has issued an Approval in Principle (AiP) for the design of an ammonia-fuelled LPG/NH₃ carrier. The application was submitted jointly by Kawasaki Heavy Industries, Ltd. and MITSUI E&S Co., Ltd. The approval confirms the feasibility of the design from both regulatory and safety perspectives.

Ammonia is increasingly being studied as a zero-carbon marine fuel, as it does not emit CO₂ during combustion. Several research and development projects are underway to enable its practical use on commercial vessels.

ClassNK has been engaged in setting safety standards in this area. In 2021, prior to the adoption of international regulations for ammonia as a marine fuel, the society published its “Guidelines for Ships Using Alternative Fuels.” The guidelines specify requirements for installations, controls, and safety systems to help reduce risks to vessels, crews, and the environment.

In December 2024, the International Maritime Organization’s Maritime Safety Committee (MSC 109) approved the “Interim Guidelines for the Safety of Ships Using Ammonia as Fuel.” ClassNK had contributed to this framework by submitting a proposal through the Government of Japan.

For the current AiP, ClassNK reviewed the vessel’s design concept against “Part C-2: Guidelines for the Safety of Liquefied Gas Carriers Using Ammonia as Fuel (Edition 3.0.2)” and “Part C-3: Additional Safety Measures for Engine Rooms (Edition 3.0.2)” of the “Guidelines for Ships Using Alternative Fuels (Edition 3.0).” A hazard identification (HAZID) assessment was also carried out. After confirming that the requirements had been met, the AiP was issued.