Sulzer RT-flex60C engines manufactured in Korea

Wärtsilä Corporation, Trade press release 27 February 2003 at 09:00 UTC+2

A series of electronically-controlled Sulzer RT-flex low-speed marine diesel engines are in production under licence from Wärtsilä Corporation in the Ulsan works of Hyundai Heavy Industries Co Ltd in Korea.

The engines are a series of four Sulzer 7RT-flex60C engines for a series of four 30,000 tdw multi-purpose carriers contracted at Shanghai Shipyard in China by Chinese-Polish Joint Stock Shipping Co (Chipolbrok). The 7RT-flex60C has a maximum continuous power of 16,520 kW (22,470 bhp) at 114 rev/min.

The first of these engines successfully passed its official shop test in the Ulsan works on 27 January 2003. The second engine recently started its shop testing and will be demonstrated to a large group of guests on 6 March. The guests are mainly from East Asia and include shipowners, ship operators and shipbuilders, together with representatives from classification societies and other interested organisations.

Series production of Sulzer RT-flex electronically-controlled engines has been underway for just over two years. The first engine, a Sulzer 6RT-flex58T-B, passed its official shop test in January 2001 and has been in service in the bulk carrier ‘Gypsum Centennial’ since September 2001 with excellent results. This first Sulzer RT-flex engine was also built under Wärtsilä licence by Hyundai.

Two Sulzer 7RT-flex60C engines have already been completed in Wärtsilä’s Trieste factory in Italy, with the first having successfully passed its official shop test on 14 October 2002.

There are now 13 Sulzer RT-flex engines in service, completed or on order, see reference list below.

The Sulzer RT-flex60C is a forward-looking engine offering a new range of benefits to shipowners. Not only does it bring the new benefits of electronically-controlled common-rail fuel injection, such as low emissions and very slow running capability, but embodies stepwise improvements in basic diesel engine technology which will give shipowners better reliability and longer times between overhauls.

With cylinder dimensions of 600 mm bore by 2250 mm stroke, the Sulzer RT-flex60C has a maximum continuous output of 2360 kW/cylinder (3210 bhp/cylinder) at 114 rev/min. It is available with five to nine cylinders covering an overall power range of 8250–21,240 kW (11,200–28,890 bhp) at 91–114 rev/min. It thus offers optimum powers and speeds for a wide range of ‘faster’ ships such as medium-sized container ships, car carriers, reefers, etc.

The new Sulzer RT-flex60C builds upon experience gained with the latest Sulzer RTA engine designs and incorporates the latest technological improvements. It thereby offers clear and substantial benefits in terms of reliability, three years between overhauls, low maintenance costs, and low exhaust emissions.

Additional benefits come from the Sulzer RT-flex system by which electronically-controlled common-rail systems replace the usual camshaft-based systems. The key feature of the RT-flex system is that it gives complete freedom in the timing and operation of fuel injection and exhaust valve actuation. This flexibility has been employed to provide smokeless operation at all ship speeds, and steady running of the engine at very low speeds, down to about 10–12 per cent nominal speed, also without smoke. The precise volumetric fuel injection control given by the RT-flex system reduces maintenance costs through extending times between overhauls. Engine availability is increased by both the integrated monitoring functions and by the redundancy in pumps, piping and electronics of the Sulzer RT-flex system.

Reference List
The following Sulzer RT-flex engines are in service or on order:


 No Model  Shipowner Ship type  Shipbuilder  Eng.builder In service
 1 6RT-flex58T-B  Gypsum Bulk carrier Hyundai Mipo  Hyundai  2001
 2 7RT-flex60C  Agrexco  Container/reefer  ENVC/Portugal  Trieste  2003
 4 7RT-flex60C  Chipolbrok  Multipurpose  Shanghai  Hyundai  (2003/04)
 1 6RT-flex58T-B  Scinicariello  Tanker  Sumitomo  DU  (2003)
 2 5RT-flex58T-B  Andromeda  Prod. tanker  Jiangdu Yuehai  Yichang  (2004)
 3 9RT-flex60C  Safmarine  Container  Volkswerft  HSD  (2004)

Total: 13 engines totalling 209,590 kW (285,070 bhp)


Marit Holmlund-Sund
Public Relations Manager, Marine Division
Wärtsilä Corporation
Direct tel: +358 10 709 1941
Direct fax: +358 10 709 1942