First Ammonia-Fueled Tug Completes Three Months Demonstrating GHG Reduction

The world’s first commercial-use ammonia-fueled vessel, Sakigake, completed a three-month demonstration voyage. Engaged in tugboat operations in Tokyo Bay, NYK which owns the vessel reports it achieved a GHG-emission reduction of up to approximately 95 percent. They believe it illustrates the potential of ammonia as a maritime fuel.

The 272-ton tug Sakigake, which was built in 2015 as Japan’s first LNG-fueled tug, was selected for the pioneering project. When it was introduced a decade ago, the tug which is 122 feet (37 meters) in length was viewed as a proof of concept for alternative fuel operations in the class. It is again taking that role for ammonia-fueled propulsion.

The conversion program for the vessel was completed by Nippon Yusen Kabushiki Kaisha (NYK) and IHI Power Systems Co. on August 23, 2024. They worked in cooperation with Nippon Kaiji Kyokai (ClassNK) as part of a Green Innovation Fund Project sponsored by Japan’s New Energy and Industrial Technology Development Organization (NEDO).

The development project of this vessel started in October 2021 as part of NEDO’s Green Innovation Fund Project which provided for the “development of vessels equipped with domestically produced ammonia-fueled engines.” The companies worked together to develop the designs and ultimately removed the LNG-fueled propulsion system to replace it with the new ammonia-fueled propulsion. Sakigake became the world’s first commercial-use ammonia-fueled vessel following Fortescue which converted an offshore support vessel and completed certification for its ammonia system earlier in 2024.

NYK Group company Shin-Nippon Kaiyosha operated Sakigake in a three-month demonstration voyage while conducting tugboat operations in Tokyo Bay. NYK and IPS analyzed the ammonia co-firing and GHG-reduction rates during vessel operations and confirmed it consistently exceeded 90 percent. Depending on engine load rates, they were also able to achieve a 95 percent reduction in GHG emissions.

After having completed this first demonstration, the vessel will continue to be used for tugboat operations in Tokyo Bay. NYK reports it will continue to accumulate knowledge related to the development and operation of ammonia-fueled vessels.

NYK, Japan Engine Corporation, IPS, and Nippon Shipyard Co. are working together to develop an ammonia-fueled ammonia gas carrier, which is scheduled to be delivered in November 2026. This project is also sponsored by NEDO’s Green Innovation Fund Project and is part of NYK’s efforts to develop and introduce next-generation fueled vessels.