日本发动机水素船用发动机再度官宣完成，但核心事实已于3月公开

KOBE, Japan -- Ship engine maker Japan Engine and partners have completed a new hydrogen-fueled engine for large vessels that can slash greenhouse gas emissions by more than 95% compared with conventional models, it was announced on Tuesday.
The engine, developed under a project run by the Japanese government's New Energy and Industrial Technology Development Organization (NEDO), was unveiled to industry representatives Monday. Kawasaki Heavy Industries and Yanmar Power Technology were also involved in its development.
Japan Engine bills this as the world's first hydrogen-powered engine designed for such large commercial vessels as tankers and container ships. "We aim to change the game through the early commercialization and widespread adoption of this next-generation engine," President Ken Kawashima said at the unveiling ceremony.
The company began land-based testing of the engine in March and recently obtained approval from ship classification organizations confirming that its performance and safety measures meet practical-use standards. Japan Engine holds close to a 10% share of the global market for low-speed engines used in large vessels, making it one of the top three players in the field.
The first engine is scheduled to be installed as early as January 2027 on a newly built vessel owned by Mitsui O.S.K. Lines and constructed by Onomichi Dockyard. Mitsui O.S.K. plans demonstration operations between fiscal 2028 and fiscal 2030. "We want to use the vessel to transport steel products and biomass fuel," said Koichi Hirata, a senior managing executive officer at Mitsui O.S.K.
NEDO selected Japan Engine's hydrogen engine project as one of its funding programs in 2021 and plans to subsidize it by up to about 21 billion yen ($135 million) through fiscal 2030.
One of the main technical challenges in developing hydrogen engines is controlling hydrogen's high combustibility and its tendency to leak because of its small molecular size. Japan Engine says it addressed the issues by developing technology that injects hydrogen precisely when needed, helping stabilize combustion.
As the shipping industry shifts toward decarbonization, whether hydrogen or ammonia -- which is cheaper than hydrogen but carries such disadvantages as toxicity and odor -- becomes the dominant alternative fuel will depend on such factors as prices and geopolitical developments.
Japan Engine, which also completed an ammonia engine in 2025, says that neither of its two major overseas competitors in the large-ship engine market is currently developing hydrogen engines. The company hopes its dual-track strategy in both hydrogen and ammonia propulsion will give it an edge in the race to commercialize next-generation engines.
Japan Engine struggled with low profitability for years following its establishment in 2017, posting operating margins below 5% through the fiscal year ended March 2023. Under Kawashima, the company shifted its focus from maximizing engine sales profits to generating revenue through maintenance services and engine-licensing agreements with other manufacturers.
Its operating margin rose to 18% in fiscal 2025, six times that from three years earlier. Its stock has also more than sextupled in price over the same span -- including a boost after the shipbuilding industry was named as one of Prime Minister Sanae Takaichi's 17 strategic fields to invest in. The stock is trading around 11,000 yen.
Kawashima said ammonia engines are expected to start making a meaningful contribution to earnings around the fiscal year ending March 2030. Japan Engine is targeting commercialization and profitability for hydrogen engines during the 2030s as well.