Japan Engine Corporation (J-Eng), Kawasaki Heavy Industries, and Yanmar Power Solutions are jointly developing a large hydrogen-fuelled two-stroke marine hydrogen engine and associated fuel supply system.
J-Eng has now completed the engine, the 6UEC35LSGH, and it has been unveiled to the project stakeholders at J-Eng’s factory. The engine, said to be the first such large engine to run on hydrogen fuel, achieved a hydrogen co-firing rate of at least 95% during factory tests, reducing GHG emissions by more than 95% compared with conventional HFO-fuelled engines.
The engine is scheduled to be installed on a 17,500 dwt multipurpose vessel to be built by Onomichi Dockyard for Mitsui OSK Lines subsidiary MOL Drybulk, with onboard demonstration at sea scheduled to begin in April 2028. Nippon Kaiji Kyokai (ClassNK) will conduct safety assessments throughout each stage of the engine development and the vessel’s design, construction and operation.
According to J-Eng, to achieve carbon neutrality in international shipping by 2050, the timely development and commercial deployment of engines powered by next-generation fuels are essential. J-Eng, Kawasaki, and Yanmar Power Solutions are developing hydrogen-fuelled engines under Japanese government organisation NEDO’s Green Innovation Fund project.
The hydrogen-fuelled Engie follows J-Eng’s ammonia-fuelled large two-stroke engine, completed In August 2025, with the aim of supporting growth of Japan’s shipping and shipbuilding industries through the development and launch of a range of low-GHG emission engines.
The 6UEC35LSGH adopts a high-pressure direct injection system, which injects fuel directly into the cylinder at high pressure, enabling stable hydrogen combustion. Safety measures include a robust structure to prevent hydrogen leakage and double-walled piping for hydrogen supply lines. Approval testing was completed in the presence of ClassNK.
J-Eng’s hydrogen engine is part of ‘Blue Harmony’ project, which aims to commercialise hydrogen-fuelled vessels. When the engine is in operation on the MOL Drybulk vessel, the hydrogen fuel will be supplied by a fuel system developed and manufactured by Kawasaki. The vessel will undergo sea trials before onboard demonstration begins in April 2028. Kawasaki will develop and manufacture bunkering equipment for supplying liquefied hydrogen to vessels. The demonstration will evaluate the engine’s durability and performance under actual operating conditions.
Image: Rendering of the 17,500 dwt MOL Drybulk Vessel on which the hydrogen engine is to be installed (source: MOL Group)
