Yanmar Power Solutions Co., Ltd., a subsidiary of Yanmar Holdings, has become the first engine manufacturer in Japan to obtain both type approval certificate*¹ and NOx certificate*² from Nippon Kaiji Kyokai (ClassNK) for its pilot-ignition hydrogen-fueled 4-stroke high-speed engine for power generation for domestic coastal vessels as part of the Nippon Foundation’s Zero Emission Ships Project.
Left: Demonstration model of a pilot-ignition hydrogen 4-stroke high-speed engine; right: Rendering of the Pilot-Ignition Hydrogen 4-Stroke High-Speed Engine.
In 2025, Yanmar Power Solutions was intensifying its land-based demonstration tests utilising a small amount of Hydrotreated Vegetable Oil (HVO) as a pilot fuel, while preparing for planned demonstration operations. As a result of the inspection by ClassNK, the company successfully obtained type approval certificate in October 2025 and NOx certificate in December 2025, both of which are required for demonstration operations. The engine specifications covered by these certifications are designated as “Electronically Controlled Gas Only Engine (Hydrogen).” Moving forward, the company will install the necessary equipment, including two hydrogen engines, onto domestic coastal vessels, paving the way for demonstration operation trials scheduled for this fall.
Yanmar Power Solutions is committed to contributing to the carbon neutrality of the shipping industry through the societal implementation of hydrogen engines, which can achieve nearly zero CO2 emissions.
*¹ Type approval certificate: To conduct assessments, tests, and inspections on marine equipment to certify to the manufacturer that the equipment complies with the specified regulations.
*² NOx certificate: A document that certifies compliance with Tier II in NOx (nitrogen oxides) regulations established by the International Maritime Organization (IMO).
For more information, visit www.yanmar.com/global/
About the Zero Emission Ships Project
This project, led by the Nippon Foundation, focuses on the development of hydrogen-powered zero-emission vessels and supports related technology development. Within this framework, the consortium involving Yanmar Power Solutions has been advancing hydrogen engine development, while also developing a hydrogen-compatible hybrid electric propulsion vessel that combines a hydrogen engine generator with batteries. The vessel design incorporates a container unit-type hydrogen power generation system on its upper deck. Uyeno Transtech Co., Ltd., a shipping company under the Uyeno Group, is responsible for the vessel’s development and construction.
