A-Tug complete, enters commercial trials

Japan’s first LNG-fueled vessel becomes Japan’s first ammonia-fueled vessel

Click to learn more. The ammonia-fueled Sakigake tugboat is complete, and will now enter commercial trials. Source: NYK.

NYK has announced that the tugboat Sakigake has been completed, and will enter three months of commercial trials in Yokohama harbor and Tokyo Bay. NYK Group company Shin-Nippon Kaiyosha will operate the vessel during trials. IHI Power Systems and ClassNKwere partners in the vessel development, and are also collaborating with NYK on its ammonia-fueled medium gas carrier project. The vessel features a four-stroke, dual-fuel engine developed by IHI. Successful truck-to-ship ammonia bunkering was completed at Yokohama Port in July 2024.

The predecessor, the LNG-fueled tugboat of the same name, was completed in August 2015 as the first LNG-fueled vessel in Japan. After eight years of tug service in Tokyo Bay, the vessel was docked at the NYK Group’s Keihin Dock Co. Ltd. for conversion to an ammonia-fueled vessel. The main engine, etc., were replaced with ammonia-fueled ones, and sea trials were conducted using ammonia as fuel. The completed vessel has taken the name Sakigake, hoping it will be a pioneer of ammonia-fueled vessels, just as it was of LNG-fueled vessels.

History of the Sakigake tugboat from NYK’s official press release, 23 Aug 2024

In development since 2021, the vessel retrofit took place late last year. Along with all the vessel and engine requirements, NYK have led work on the necessary regulatory and safety updates for the Sakigake to operate, including crew training. Tests conducted by IHI in 2023 indicated that emissions of dinitrogen monoxide (N₂O) and ammonia slip were “virtually zero” for the four-stroke engine.

Click to learn more. After retrofits were completed in late 2023/early 2024, successful truck-to-ship ammonia bunkering operations were carried out in July 2024. Source: NYK.