September 8, 2008
Wärtsilä and MHI introduce new low speed diesels
Wärtsilä is introducing two new low-speed marine diesel engines at its licensees' conference in Lucerne, Switzerland this week.
The engines have been developed in co-operation with Japan's Mitsubishi Heavy Industries Ltd as part of a strategic alliance between Wärtsilä and Mitsubishi agreed in September 2005.
The power range of the new engines is 3,500-9,000 kW. They have cylinder bores of 350 and 400 mm, and each is available either as a Wärtsilä RT-flex electronically-controlled common-rail engine or a Wärtsilä RTA mechanically-controlled engine.
Mitsubishi Heavy Industries Ltd will develop UEC-LSE series engines based on the RTA design
The new engines extend the low-speed engine range available from Wärtsilä to lower powers for many types of small and medium-sized commercial vessels.
They are designed to give the best powers and speeds for a wide variety of ship types, such as handysize bulk carriers and product tankers, general cargo vessels, reefers, feeder container ships, and small LPG carriers.
The market for the new engines in such vessels is world-wide though there is a greater volume of such newbuildings from shipyards in East Asia, especially China, Korea, Japan and Vietnam.
The key benefits of the new engines will be in compliance with IMO Tier II emissions regulations, low fuel consumption, low cylinder oil feed rate, high reliability, and long times between overhauls. They will also be able to provide optimum fits to the ships in terms of power, propeller speed, dimensions, weight, and electrical power consumption, as well as being competitive in manufacturing costs.
The Wärtsilä RT-flex35, Wärtsilä RTA35 and Mitsubishi UEC35LSE engine types have cylinder dimensions of 350 mm bore by 1550 mm piston stroke, and a maximum continuous power of 870 kW/cylinder at 167 rev/min.
The Wärtsilä RT-flex40, Wärtsilä RTA40 and Mitsubishi UEC40LSE have cylinder dimensions of 400 mm bore by 1,770 mm piston stroke, and a maximum continuous power of 1,135 kW/cylinder at 146 rev/min.
All these engine types will be available with five to eight cylinders, so that the RT-flex35, RTA35 and UEC35LSE cover an overall power range of 3.475 to 6.960 kW at 142-167 rpm, while the RT-flex40, RTA40 and UEC40LSE cover an overall power range of 4.550 to 9.080 kW at 124-146 rpm.
The Wärtsilä RT-flex35 and RT-flex40 engines incorporate the latest common-rail technology with full electronic control of fuel injection and exhaust valve operation. The RTA35, UEC35LSE, RTA40 and UEC40LSE have traditional mechanically-driven camshafts with fuel injection pumps, exhaust valve actuator pumps, etc. Otherwise both versions have the same principal characteristics and design features.
The first 350 mm-bore engine, an RT-flex type, is planned to be delivered in the first quarter 2011. The first of the 400 mm-bore type will follow twelve months later.
The Wärtsilä RT-flex and RTA engines will be manufactured by Wärtsilä's licensees while the Mitsubishi UEC-LSE engines will be produced by Mitsubishi and its licensees.