Mitsui E&S starts ‘world’s first’ test run of large-bore low-speed ammonia dual fuel engine

Japanese ship equipment manufacturer Mitsui E&S has commenced test operation of the large-bore low-speed ammonia dual fuel engine as “a major step” toward decarbonizing the shipping industry.

As the company revealed, the test operation of the MITSUI-MAN B&W 7S60ME-C10.5-LGIA-HPSCR ENGINE with a maximum continuous output of 17,430 kW started on February 10, 2025, at its Tamano factory.

According to Mitsui, this is the world’s first test run with an ammonia fuel on a large-bore, low-speed, two-stroke commercial engine.

In addition to the engine, the company is developing peripheral equipment with the support of the New Energy and Industrial Technology Development Organization (NEDO) as a part of an ‘Integrated project for development and social implementation of ammonia fueled ships’, and during this test run, the verification of the safety and performance of the ammonia fuel supply system and other peripheral systems will also be carried out.

The engine and fuel supply system will be delivered to the vessel developed under the above-mentioned project.

Mitsui noted that the test run builds on research & development (R&D) work by its licensor, German engine maker MAN Energy Solutions (MAN ES), which has recently reached new milestones by running both single-cylinder and full-engine ammonia-fueled tests at its Research Centre Copenhagen (RCC).

Last year, MAN ES and Mitsui E&S conducted the “world’s first” hydrogen combustion operation of a large marine engine.

The hydrogen combustion operation of a large marine 2-stroke test engine with a bore size of 50 cm was completed on the premises of Mitsui E&S’ Tamano factory in Japan.

In collaboration with MAN ES, Mitsui E&S converted one of the four cylinders of a MAN B&W ME-GI (Gas Injection) engine to hydrogen operation. The hydrogen was supplied from a hydrogen gas supply system that Mitsui E&S developed in 2023.