The world’s first ammonia-fueled tugboat, Sakigake, has recently concluded a remarkable three-month demonstration voyage in Tokyo Bay. This pioneering vessel achieved a substantial reduction in greenhouse gas emissions, reaching approximately 95%. Developed by Nippon Yusen Kabushiki Kaisha (NYK) and IHI Power Systems Co., Ltd. (IPS), in collaboration with Nippon Kaiji Kyokai (ClassNK), the tugboat was part of Japan’s Green Innovation Fund Project, aimed at advancing new energy technologies. To combat climate change, transitioning marine transport from heavy fuel oil to more sustainable options like hydrogen and ammonia is critical.
The Sakigake’s development began in October 2021, focusing on creating vessels equipped with locally produced ammonia engines. Following its completion in August 2024, the vessel undertook tugboat operations successfully for three months, marking a significant milestone in the adoption of alternative fuels in maritime industries. Results from the demonstration voyage showed that the Sakigake maintained ammonia co-firing and greenhouse gas reduction rates exceeding 90%, with peaks of about 95% across various engine load ranges. This successful trial established ammonia as a promising candidate for the future of marine fuel.
A celebratory event was held at Yokohama port to honor the completion of the voyage, attended by dignitaries from NEDO, NYK, IPS, ClassNK, and various government ministries. Moving forward, Sakigake will continue to operate as a tugboat in Tokyo Bay, contributing to ongoing research on ammonia-fueled vessels. Additionally, NYK, Japan Engine Corporation, IPS, and Nippon Shipyard Co., Ltd. are collaborating on the development of an ammonia-fueled ammonia gas carrier, scheduled for delivery in November 2026. NEDO’s commitment to promoting the research and development of next-generation fuel vessels underscores its goal of achieving carbon neutrality in the shipping sector.