L-R: Masaki Matsunaga, Corporate Office/Director of Plan Approval and Technical Solution Division, ClassNK. Toshi Nakamura, Executive Officer, NYK Line. Yuichi Tamura, Division Director/Engineering & Technology Center, IHI Power Systems Co., Ltd.

The joint research project aims to create the world's first tugboat using ammonia as fuel, and is currently expected for delivery and demonstration in the port of Yokohama in financial year 2024.

According to a timeline released by NYK Line, IHI Power System is on the hook for developing and fabricating the four-stroke engine while NYK Line is handling hull design, construction, sea trials, regulatory clearance, operation, demonstration and commercialisation of the vessel.

The project falls under Japan’s New Energy and Industrial Technology Development Organization’s (NEDO) Green Innovation Fund for the development of a domestically produced, ammonia-fuelled engine.

Ammonia is among the front-runners in certain vessel segments for the maritime fuel of the future as burning the fuel does not emit any carbon, and the process of creating ammonia can be done in a zero emissions manner by using renewable electricity.

Burning ammonia does create nitrous oxide, itself a powerful greenhouse gas, and so the control of nitrous emissions is one of the main design challenges facing IHI Power System. Other challenges include increasing ammonia in the fuel mix while maintaining stable operation and safely containing and controlling ammonia, which is itself toxic.

The result of research and development efforts so far is the design for A-Tug, which solves the challenges of using ammonia as a fuel while maintaining the normal footprint and layout of a tugboat.