According to Wärtsilä, it holds a 16% share of the marine low-speed main engine market, with MHI holding 3%. The market leader is MAN Diesel, with 81% share.

The two companies see good business potential in pooling their resources and experience to develop new small marine engines suitable for a wide variety of small ship types, including bulk carriers, product tankers, chemical tankers, container feeder vessels, and reefer ships. Such ships are employed in worldwide trades but with the smaller types being specifically employed in short-sea and coastal services. The new engines will be designed to meet the market needs for high efficiency, high reliability, compactness and environmental friendliness.

The partners will announced details of the engines to be developed under this agreement in a few months time after the initial design studies have been completed.

This agreement is an extension of a strategic alliance created by MHI and Wärtsilä in September 2005. This alliance was formed on the basis of the successful joint development by the two companies of the Wärtsilä RT-flex50 and Mitsubishi UEC50LSE low-speed engine types.

Wärtsilä has a range of low-speed marine diesel engines covering the power range of 5,650 to 84,420 kW. MHI has a range of UE low-speed marine diesel engines covering the power range of 1,120 to 46,800 kW, and also has long co-operated in the manufacture of Sulzer and Wärtsilä low-speed engines going back to an agreement signed with Sulzer in 1925. The new engine types will reinforce the respective engine portfolios in the lower power range.

The project is led by a joint working group of engineers from both companies with supervision by a steering committee including senior management of the two companies.

It is envisaged that the new engine would be built by Wärtsilä’s and Mitsubishi’s licensees world-wide.

Earlier in May, Hitachi Zosen Diesel & Engineering Co Ltd. completed its first Wärtsilä RT-flex common-rail marine diesel engine. Hitachi is the eleventh engine builder in the Wärtsilä family of engine licensees to manufacture Wärtsilä RT-flex electronically-controlled common-rail marine engines. The other engine builders are in South Korea, Japan, China, Italy, Croatia and Poland.

The 6-cylinder Wärtsilä RT-flex50-B engine built by Hitachi will be delivered to Nanjing Wujiazui Shipbuilding Co Ltd in China. There it will be installed in a 1,085 TEU (twenty-foot equivalent unit) container ship being built for a German owner. The engine has a maximum continuous power of 9,960 kW (13,560 bhp) at 124 rpm.

Hitachi has orders for a total of 26 RT-flex50 engines from shipyards in China and Brazil. The first RT-flex50 engine entered service in January 2006, and more than 200 have already been sold.