Wärtsiläs RT-flex50 successfully tested

The first two of the latest Sulzer RT-flex50 common-rail marine engine type developed by Wärtsilä Corporation, have successfully completed official shop tests and class type approval tests at Wärtsilä’s licensee Diesel United Ltd in Japan.

With five to eight cylinders, the Sulzer RT-flex50 low-speed marine diesel engine covers a power range of 5,800 to 13,280 kW and is ideally suited to the propulsion of bulk carriers in the Handymax to Panamax size range, product tankers and feeder container vessels.

The Sulzer RT-flex50 is based on the Sulzer RTA50 engine jointly developed by Wärtsilä and Mitsubishi Heavy Industries Ltd in Japan. Instead of the traditional camshaft-controlled systems of the RTA50, the RT-flex50 incorporates the latest electronically controlled common-rail technology for fuel injection and valve actuation. The new technology provides great flexibility in engine setting, bringing benefits in lower fuel consumption, lower minimum running speeds, smokeless operation at all running speeds, and better control of other exhaust emissions. As with all new marine engines nowadays, it is fully compliant with the NOx emission regulation of Annex VI of the MARPOL 1973/78 convention.

Two six-cylinder engines were involved in the tests at Diesel United’s works in Aioi, Japan, each with a contracted maximum continuous power of 9,720 kW at 124 rpm. The first engine completed its official shop tests on 21 July 2005 after a comprehensive programme of testing as is usual for a new engine design.

The second engine completed its official shop test on 13 August 2005. In the presence of representatives from the principal classification societies, it also successfully passed the type approval tests for Sulzer RT-flex50 engines and for the WECS-9520 electronic control system which is now incorporated in Sulzer RT-flex engines.

The first 6-cylinder RT-flex50 engine is for export to Korea for a 37,000 dwt product tanker under construction at Hyundai Mipo Dockyard and the second engine will be delivered to Shanghai Edward Shipbuilding in China for installation in a 19,625 dwt cargo vessel.