‘World’s first’ commercial-use ammonia-fueled tugboat achieves 95% emission reduction

Tugboat Sakigake, also known as the world’s first commercial-use ammonia-fueled vessel, wrapped up its demonstration voyage, reaching a greenhouse gas (GHG) emission reduction of up to approximately 95%, the vessel’s operator NYK Line has reported.

The emission reduction was recorded during the three-month demonstration voyage which commenced after the tugboat was converted from LNG- to an ammonia-fueled vessel in August 2024.

The conversion project was completed by NYK and IHI Power Systems (IPS) in cooperation with ClassNK as part of a Green Innovation Fund Project under Japan’s New Energy and Industrial Technology Development Organization (NEDO).

During the demonstration period, Sakigake performed tugboat operations in Tokyo Bay. NYK and IPS analyzed the ammonia co-firing and GHG reduction rates during vessel operations and confirmed them to consistently exceed 90% and rise to approximately 95% in each of the main engine load ranges.

The demonstration tests during the tugboat’s operations marked “the world’s first trial, confirming that ammonia is one of the most viable and promising options as a next-generation fuel for vessels”, NYK said.

As the following step, the company intends to continue using the vessel for tugboat operations in Tokyo Bay while accumulating knowledge related to the development and operation of ammonia-fueled vessels.

In addition, NYK, Japan Engine Corporation, IPS, and Nippon Shipyard are working together to develop an ammonia-fueled ammonia gas carrier, which is scheduled to be delivered in November 2026, also as part of NEDO’s Green Innovation Fund Project; “Development of vessels equipped with domestically produced ammonia-fueled engines”.

The 40,000 cubic meter type ammonia fuel ammonia carrier will be built at the Japan Marine United Corporation (JMU) Ariake Shipyard.

After the ship is completed, the consortium will continue to operate the vessel for demonstration purposes to confirm the vessel’s performance, including environmental friendliness and the practicality of the operation manual, and to provide user feedback to shipbuilders and marine equipment manufacturers for further improvements.