- Engine Developed Under Japan’s Green Innovation Fund Project.
- Test Runs Conducted Under Supervision of NYK, NSY, JMU and ClassNK.
- ClassNK Certifies Safety and Environmental Performance.
Japan Engine Corporation (J-ENG) has proudly achieved a significant milestone by developing the first fully-functional, full-scale commercial engine, the 7UEC50LSJA-HPSCR (with a 50 cm bore and 7 cylinders, featuring High Pressure SCR), on August 30, 2025. This innovative engine was created as part of the Next-Generation Ship Development initiative under the Green Innovation Fund Project, which is overseen by the New Energy and Industrial Technology Development Organisation (NEDO), reports J-ENG.
Official Test Runs and Certification
Between August 27 and 30, 2025, J-ENG carried out official test runs at its factory, with oversight from NYK Line, Nihon Shipyard Co., Ltd. (NSY), Japan Marine United Corporation (JMU), and ClassNK. They verified the engine’s performance in both ammonia fuel and heavy fuel oil operation modes. Following the tests, thorough inspections of the major components were conducted, and ClassNK certified the engine for its exceptional environmental performance and adherence to safety standards.
Vessel Installation and Service Timeline
The engine is set to be shipped in October 2025 and will be installed on an Ammonia-Fueled Medium Gas Carrier (AFMGC) currently under construction at the JMU Ariake Shipyard. The vessel is expected to start its service in 2026.
Development Background and Test Runs
Before this, J-ENG had conducted around 1,000 hours of testing on a single-cylinder ammonia-fuel test engine at Mitsubishi Heavy Industries’ R&D Centre in Nagasaki from May 2023 to September 2024. Using the valuable insights gained from those tests, the company successfully manufactured the first full-scale commercial engine and began using ammonia fuel in April 2025. Over the following five months, the engine underwent an additional 700 hours of testing, focusing on optimising performance, confirming reliability, and ensuring safety features, including leak prevention and ammonia monitoring systems.
Environmental Performance Results
The trial run data showed impressive cuts in greenhouse gas emissions:
- When operating at full capacity with 95% ammonia co-firing, N₂O emissions were reduced to just 3 ppm, resulting in a more than 90% reduction in GHG emissions.
- NOx emissions were roughly half of what you’d find in heavy oil engines.
- Thanks to post-NOx SCR, unburned ammonia emissions were nearly non-existent.
- Thermal efficiency when using ammonia fuel was found to be on par with or even better than that of heavy oil.
Future Development Plans
- In addition to the 50 cm bore engine, J-ENG is also working on a 60 cm bore engine powered by ammonia to cater to a variety of ship needs. Several follow-up projects are already underway.
- To facilitate mass production, J-ENG is constructing a new factory, supported by government subsidies from the Ministry of the Environment and the Ministry of Land,
- Infrastructure, Transport and Tourism. This facility, funded through GX Economic Transition Bonds, is expected to commence operations in fiscal year 2028, producing both ammonia and heavy oil.
Contribution to Carbon Neutrality
As a pioneer in next-generation fuel engines, J-ENG is committed to:
- Encouraging the early market launch of ammonia-fueled engines.
- Speeding up the adoption of zero-emission ships.
- Supporting Japan’s shipping and shipbuilding sectors.
- Playing a role in global GHG reduction efforts and working towards achieving carbon neutrality by 2050.
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Source: J-ENG
