Wärtsilä will supply its Wärtsilä 25 ammonia auxiliary engine, together with a NOx reducer (SCR) and gas valve unit (GVU), for two new 51,350m3 capacity midsize LPG/liquid ammonia carrier vessels.
The engine will support reduced emissions and improved operational efficiency, while helping the vessels meet evolving sustainability requirements. The ships are being built at Nantong CIMC Sinopacific Offshore & Engineering (SOE) shipyard in Shanghai and will be owned by a joint venture between Navigator Gas and Norway-based Amon Maritime, Navigator Amon Shipping. Wärtsilä will supply the propulsion system, including a CP propulsion solution designed to optimise efficiency and reliability.
As the shipping industry transitions to decarbonised operations, Wartsila believes ammonia is emerging as a promising carbon free marine fuel capable of achieving the IMO’s net-zero-emissions target for 2050. Wärtsilä has played a leading role in developing engine solutions able to operate with alternative fuels, and in 2023 introduced the marine sector’s first commercially available four-stroke engine-based solution for ammonia fuel. The ammonia-fuelled engine is designed to support the industry’s transition towards lower-emission vessel operations.
Kaj S Pilemand, Director of Vessel Operations, Navigator Gas, said: “Wärtsilä has demonstrated industry-leading capabilities in enabling future low and zero-carbon fuels to become viable. By selecting the Wärtsilä 25 ammonia engine, we expect to dramatically reduce the ships’ environmental impact, while supporting compliance with evolving regulatory requirements.”
The ammonia engine aligns with the shipping industry’s accelerating shift towards decarbonised operations. When running on sustainable ammonia, total GHG emissions can be reduced by at least 90% compared to equivalent diesel engines. In addition, the Wärtsilä propulsion system optimises vessel operations by integrating the entire shaft line arrangement. The CP propeller system is designed to deliver high efficiency, operational reliability, and reduced emissions.
Stefan Nysjö, VP Power Supply, Wärtsilä Marine, added: “This project reflects the continued momentum behind carbon-neutral and zero-carbon fuels, with ammonia emerging as one key pathway. It also highlights the growing demand for flexible, propulsion solutions that support new, more sustainable operating models. In short, these vessels have been designed for lower-emission operations, and Wärtsilä’s solutions will support those ambitions.”
The Wärtsilä equipment is scheduled for delivery to the yard commencing in June 2027.
Image: Wärtsilä’s 25 Ammonia engine, which will equip two new midsize gas carriers (credit: Wärtsilä Corporation)
