The Sulzer RT-flex engines with the new common-rail technology for fuel injection and valve operation are proving to be popular with shipowners resulting in a steady intake of confirmed orders.
The most recent newbuildings to be equipped with Sulzer RT-flex engines are four 110,000 tdw Aframax product tankers contracted at Dalian New Shipbuilding Ltd
in the People's Republic of China
by the Danish owner A/S Dampskibsselskabet Torm. The ships are for delivery between the first quarter 2006 and the second quarter 2007.
The tankers will each be propelled by a Sulzer 7RT-flex58T-B low-speed engine of 14,875 kW (20,230 bhp) maximum continuous output at 105 rev/min. The four engines will be built under licence from Wärtsilä Corporation by Dalian Marine Diesel Works in China.
These vessels follow on from a series of 15 similar Aframax tankers built at Dalian for various owners since 1999. The previous vessels are powered, however, by Sulzer 7RTA62U low-speed engines having the traditional camshaft-based systems
Developed by Wärtsilä Corporation, Sulzer RT-flex engines are the first low-speed engines to have electronically-controlled common-rail systems for fuel injection and valve actuation. This gives unrivalled flexibility in the way the engines operate, to deliver benefits such as smokeless operation at all operating speeds, lower fuel consumption, reduced maintenance costs and lower steady operating speeds for better manoeuvring.
The above orders bring the total number of the RT-flex engines in service and on order to 47, amounting to an aggregate power of 1.89 million kW (2.57 million bhp). These include four engines already at sea. The first series-built RT-flex production engine, the Sulzer 6RT-flex58T-B in the bulk carrier
"Gypsum Centennial", has exceeded 11,000 running hours since September 2001. Three ships have been completed this year, the Aframax tanker "Sea Lady" in Japan with
a Sulzer 6RT-flex58T-B engine, the reefer "Carmel Ecofresh" in Portugal with
a 7RT-flex60C engine, and the multi-purpose carrier
"Wladyslaw Orkan" in China, also with a Sulzer 7RT-flex60C engine.
The Sulzer RT-flex engines have been, or are currently being manufactured in the works of five licensees in Japan, Korea
and China, as well as in Wärtsilä's own factory in Trieste, Italy
. In China, RT-flex engines are being built by both Dalian Marine Diesel Works and Yichang Marine Diesel Engine Plant.