Japan Engine Corporation (J-ENG) on Friday (18 September) said it has completed land-based testing of the world’s first hydrogen-fuelled engine for large commercial vessels, the 6UEC35LSGH. During factory testing, the engine achieved a hydrogen co-firing rate of at least 95%, reducing GHG emissions by more than 95% compared with conventional heavy-fuel-oil engines. By adopting a high-pressure direct injection system, which injects fuel directly into the cylinder at high pressure, J-ENG said the engine achieves stable hydrogen combustion. Safety measures were also implemented, including a robust structure to prevent hydrogen leakage and double-walled piping for hydrogen supply lines. “Approval testing was conducted in the presence of ClassNK and was completed successfully,” the company said. The engine will be installed on a 17,500 DWT multipurpose vessel to be built by Onomichi Dockyard for Mitsui O.S.K. Lines and MOL Drybulk. Hydrogen fuel will be supplied to the engine through a marine hydrogen fuel system, consisting of marine hydrogen fuel tanks and a fuel supply system, developed and manufactured by Kawasaki Heavy Industries. In addition, Nippon Kaiji Kyokai (ClassNK) will conduct safety assessments throughout each stage of the engine’s development and the vessel’s design, construction and operation. The vessel will then undergo sea trials before onboard demonstration testing begins in April 2028. Kawasaki will also develop and manufacture bunkering equipment for supplying liquefied hydrogen to vessels. “The demonstration will further evaluate the engine’s durability and performance under actual operating conditions,” J-ENG added.   Photo credit: J-ENG Published: 22 September, 2026