VESSEL REVIEW | Yuan Tuo Yi – China's first ammonia-fuelled tug enters service

The first ammonia-fuelled tug to be built in China has been handed over to its new owner.

Classed by both China Classification Society and the American Bureau of Shipping, Yuan Tuo Yi (远拖一) was designed and built jointly by the Dalian University of Technology and local shipyard COSCO Shipping Heavy Industry.

Part of a broader technology demonstration initiative

Development of the tug began in 2022 with the aim of validating the concept of ammonia propulsion for vessels. Construction began in January 2024 and was completed before the end of that year. The tug also completed its first ammonia bunkering operation around that same time.

Yuan Tuo Yi has an LOA of 38 metres (120 feet), a beam of 11 metres (36 feet), a design draught of 3.7 metres (12 feet), a depth of 4.8 metres (16 feet), and a gross tonnage of 496. A CRRC Dachai 12V240H dual-fuel engine with a total installed power of 4,100 kW (5,500 hp) drives an azimuthing thruster via a shaftline to deliver a bollard pull of 60 tonnes and a design speed of 12.5 knots.

Versatile harbour support platform

The tug is fitted with an exhaust gas aftertreatment system to help further reduce its emissions. The main engine has been modified to run primarily on ammonia, which will be fed by two type C high-pressure tanks fitted on the main deck, though the engine can still operate on diesel if ammonia is not readily available. The ammonia fuel supply system was provided by COSCO Shipping Heavy Industry Technology (Weihai).

Yuan Tuo Yi is also outfitted for external firefighting thanks to the installation of a main engine-driven pump.