The official shop test of the first modern large diesel engine with common-rail fuel injection, a Sulzer 6RT-flex58T-B, has been successfully completed. This revolutionary engine has no camshaft and runs with electronic control of all key engine functions to give flexibility in operation and reduced exhaust emissions.The engine has a maximum continuous power of 12,750 kW and was built under licence from Wärtsilä by Hyundai Heavy Industries at their Ulsan works in Korea. It will be installed in a 47,000 tdw bulk carrier being built at Hyundai Mipo Dockyard in Korea.

As this is the first production engine built with the Sulzer RT-flex common-rail system, its manufacture has involved very close co-operation between the above and Hyundai Mipo Dockyard. This RT-flex engine was first started on 5 January 2001, and completed its official shop test on 16 January. The success of these tests on the first production engine was largely the result of the comprehensive research and development programme undertaken on a full-sized research engine in the Diesel Technology Center in Switzerland.
This new engine is basically an upgrade of the existing RTA58T-B low-speed marine diesel engine with the Sulzer RT-flex system to give a camshaftless engine. Common-rail technology with full electronic control is applied to the fuel injection, the exhaust valve operation, and the starting air system. All these functions are controlled within the Sulzer RT-flex concept using the WECS 9500 engine control system.

The RT-flex common-rail fuel system operates on the same grades of heavy fuel, up to 700 cSt viscosity, as is usual for standard Sulzer RTA-series engines.