NYK Completes World’s First Commercial-Use Ammonia-Fueled Vessel

Japan’s NYK working in conjunction with IHI Power Systems has completed the conversion of a tugboat operating in Tokyo Bay to run on ammonia-fueled propulsion. The project which began four years ago marks the first successful deployment of a commercial vessel fueled by ammonia. The project was reviewed, and the vessel now classed by ClassNK.

The conversion project, which was awarded in August 2022, is based on the 272-ton tug Sakigake which was built in 2015 as Japan’s first LNG-fueled tug. At the time it was viewed as a proof of concept for alternative fuel operations in the class and it is again taking that role for ammonia fueled propulsion. The NYK Group company Shin-Nippon Kaiyosha will now employ the vessel in Tokyo Bay over a three-month demonstration period.

The vessel measures just 122 feet in length. NYK reported that the project which was under Japan’s New Energy and Industrial Technology Development Organization (NEDO), is part of an effort to develop vessels equipped with domestically produced ammonia-fueled engines. They had to overcome numerous challenges in handling and operating on ammonia.

After eight years of tug service in Tokyo Bay, the vessel was docked at the NYK Group's Keihin Dock Co. in October 2023 for conversion to an ammonia-fueled vessel. The main engine and fuel tanks were replaced for ammonia, and sea trials were conducted using ammonia as fuel.

Bunkering of the Sakigake, which is also being called A-Tug, took place for the first time in Yokohama, Japan in July. The bunkering was completed using the truck-to-ship method, marking the first time the tug has been fueled with ammonia and followed two similar bunkering operations earlier this year in Singapore for Fortescue’s converted OSV which became the first large ship to be bunkered with ammonia as part of testing and certification by the Singapore authorities.

As part of the development of vessels equipped with domestically produced ammonia-fueled engines through NEDO’s Green Innovation Fund Project, NYK is also conducting research and development on an ammonia-fueled medium gas carrier with Japan Engine Corporation, Nihon Shipyard Co., IHI Power Systems, and ClassNK. This vessel is scheduled for delivery in November 2026.

The NYK Group reports it will continue to utilize the knowledge gained through the research and development of these vessels to contribute to the decarbonization of the shipping industry. The group plans to promote and expand the use of ammonia-fueled vessels.