Ammonia-fueled Tugboat ‘Sakigake’ to be Classed by ClassNK

ClassNK has classed the ammonia-fueled tugboat ‘Sakigake’ completed by Nippon Yusen Kabushiki Kaisha (NYK Line) and IHI Power Systems Co., Ltd. as an ammonia-fueled vessel. This is the world's first ammonia-fueled vessel for commercial use (as of August 23, 2024, according to research by NYK). The NYK Group company Shin-Nippon Kaiyosha will employ the vessel in tugboat operations in Tokyo Bay over a three-month demonstration period.

This vessel was a Green Innovation Fund Project initiated in October 2021 under Japan’s New Energy and Industrial Technology Development Organization (NEDO) to develop vessels equipped with domestically produced ammonia-fueled engines. ClassNK is involved in the vessel safety assessment as a partner organization for this project.

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.

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Sakigake, the LNG-fueled predecessor of the ammonia-fueled tugboat.
Image courtesy NYK