Four 8600 TEU container ships contracted by Hyundai Merchant Marine Co Ltd (HMM) for building at Hyundai Heavy Industries Co Ltd (two ships) and Hyundai Samho Heavy Industries Co Ltd (two ships) in Korea are to be powered by 14-cylinder Sulzer RT-flex96C common-rail engines. Each engine will have a maximum continuous power of 80,080 kW (108,920 bhp).
These Sulzer 14RT-flex96C engines will be built under licence from Wärtsilä Corporation by Hyundai Heavy Industries Co Ltd. The ships are due for delivery in the first quarter of 2008 and are intended for operation on the East Asia – Europe trade. They will have a service speed of 27 knots.
Mr J.S. Kwon, Senior Vice President of Hyundai Merchant Marine looked forward to the delivery of these ships, commenting, “The choice of 14-cylinder Sulzer engines with the latest common-rail technology provides us with a very economical propulsion plant for more than 100,000-horsepower.”
The Sulzer 14RT-flex96C is the most powerful marine engine on order today, and also the first low-speed marine engine to be built with more than 12-cylinders.
Technical background
The Sulzer RT-flex96C is becoming a popular engine for the propulsion of large, fast container ships with some 101 engines of this type, with seven to 14 cylinders, now on order or already in service. The first RT-flex96C engines, with eight and 12 cylinders, entered service in November and December 2004 respectively.
The 14-cylinder RT-flex96C is an extended version of an already well-established 12-cylinder RT-flex96C design, which itself was developed from the Sulzer RTA96C engine type widely applied in container ships since 1998. Extensive consideration was, however, given to the practicality of the increased numbers of cylinders and to ensure that the engines match everyone’s expectations in terms of safety, reliability and durability.
For, example, although there are numerous possibilities of firing orders for 14-cylinder engines, a firing order could be found with good vibration characteristics.
With regard to the engine structure itself, the opportunity had already been taken when adapting the structure to accommodate the RT-flex common-rail system, to introduce certain modifications in all cylinder numbers for better manufacture and which also resulted in greater stiffness and reduced stresses in the structure. The revision also took into account the 14-cylinder engines to ensure that they had adequate structural strength and rigidity without further modification.
While the crankshaft of the RT-flex96C has sufficient torque capacity for 14 cylinders, the material has been upgraded to enable an increased shrink fit for a greater design margin. The thrust bearing structure in RT-flex96C engines with a mid gear drive has been revised to reduce deformations and stresses even with the increased thrust in the 14-cylinder engine.
The Sulzer RT-flex96C is the most powerful engine type in the new RT-flex engine series which features fully electronically-controlled common-rail systems for fuel injection and valve actuation. The common-rail systems give 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 RT-flex system also has the potential for adaptation to future needs.
This common-rail system brings clear benefits for the 14-cylinder engine. As usual for large marine engines, the 14-cylinder engine has a mid gear drive for the supply unit with its fuel and servo oil supply pumps. There are thus two identical rail units, each for seven cylinders. The supply unit is fairly compact compared with the overall size of the engine.
The 14-cylinder Sulzer RT-flex96C engine is a major breakthrough for ship propulsion. It extends the power available to suit the coming generation of large containerships while combining the benefits of proven, reliable engine designs with the complete flexibility of RT-flex common-rail technology.
Media contact:
Marit Holmlund-Sund
Public Relations Manager, Ship Power
Wärtsilä Corporation
Direct tel: +358 10 709 1439
Direct fax: +358 10 709 1425
e-mail: marit.holmlund-sund@wartsila.com
Internet: www.wartsila.com
