NYK Line plans to place a 40,000-cbm ammonia-fuelled medium gas carrier into service in November 2026 with a low-speed two-stroke main engine developed by Japan Engine Corporation, according to Japan Engine Corporation.
The Japanese-flagged ship is under construction at Japan Marine United’s Ariake yard. Its 7UEC50LSJA-HPSCR main engine has a 50-centimetre bore, seven cylinders and a high-pressure selective catalytic reduction system.
J-ENG completed the engine on 30 August 2025 after about 700 hours of full-scale testing over five months. That programme followed roughly 1,000 hours of trials on a single-cylinder ammonia engine between May 2023 and September 2024.
At full load and a 95% ammonia co-firing rate, the engine produced about 3 parts per million of nitrous oxide and cut greenhouse gas emissions by more than 90% compared with heavy-fuel-oil operation. Nitrogen oxide emissions were about half those of a heavy-oil engine, while virtually no unburned ammonia remained downstream of the SCR system.
The vessel will measure 180 metres in length and 32 metres in breadth, with a moulded depth of 18.45 metres. Yara Clean Ammonia Switzerland agreed a time charter with NYK in February 2025. The ship will also use an ammonia-fuelled four-stroke auxiliary engine supplied by IHI Power Systems.
The project targets a maximum ammonia co-firing rate of 95% for the main engine, at least 80% for the auxiliary unit and an overall vessel-level greenhouse gas reduction of 80% or more.
The development is supported by Japan’s New Energy and Industrial Technology Development Organization under its Green Innovation Fund. Participants include NYK, J-ENG, IHI Power Systems and Nihon Shipyard, with ClassNK acting as a partner.
Japan Engine Corporation is an Akashi, Hyogo-based marine engineering company that develops, designs, manufactures, sells, services and licenses UE-brand low-speed marine engines and related components.
NYK Line is the shipping business of Nippon Yusen Kabushiki Kaisha. Japan Marine United Corporation is the vessel’s builder.
Yara Clean Ammonia Switzerland SA is a subsidiary of Norway’s Yara International ASA.
IHI Power Systems is the auxiliary-engine supplier, Nihon Shipyard is a member of the development consortium, and ClassNK is a Japanese ship classification society.