World’s Largest Ferry Employs Common-Rail Technology
High-end RoPax ferry to ply Mediterranean routes with MAN engines and propellers
Daewoo Shipbuilding & Marine Engineering Co., Ltd. (DSME) of Korea, one of the world’s largest and most innovative shipyards, has ordered four common-rail 12V48/60CR Tier-II propulsion engines from MAN Diesel & Turbo SE. The prime movers will power a new RoPax ferry for Tunisian ship owner COTUNAV (Compagnie Tunisienne de Navigation).
The ferry will have a capacity of 3,200 passengers and 1,060 vehicles, and a top speed of 27.5 knots. At 210 × 30 m, the vessel will be the world’s largest ferry and contain a shopping centre, restaurants, swimming pool and multiple entertainment facilities. Delivery is due in the first half of 2012. The newbuilding will reinforce COTUNAV’s existing main routes between Tunisia, Italy and France.
The common-rail engine and injection system
The common-rail engines have an output of 14,400 kW each and represent the cutting edge of MAN Diesel & Turbo technology. The engines are well-proven and have amassed many references, especially within the cruise-ship segment.
The 48/60CR injection system uses the latest common-rail technology that allows independent setting of injection timing, duration and pressure for each cylinder. This flexibility allows optimisation of the 48/60CR’s fuel consumption, NOx and smoke emissions at any point on its operating profile, especially at part-load.
Common-rail safety concept
The common-rail system is based on an intelligently designed safety concept that features screened or double-wall high-pressure pipes, and flow-limiting valves to prevent uncontrolled injection. The system has redundant high-pressure pumps as well as twin-type pressure and speed sensors to ensure engine operation, even in the event of failures.
The 48/60CR is equipped with SaCoSone, MAN Diesel & Turbo’s proven, cutting-edge engine-management system. SaCoSone is an innovative system that gathers all functions of modern engine management together. It offers:
- integrated self-diagnosis functions
- maximum reliability and availability
- simple use and diagnosis
- quick exchange of (plug-in) modules
- trouble-free and time-saving commissioning
NOx-eliminating features of the 48/60CR
Retarded injection timing delays combustion-heat release, thus lowering combustion chamber temperature peaks and NOx emission. A new piston design provides a higher compression ratio and faster temperature reduction after ignition, further reducing NOx formation. Variable valve timing enables variations in the opening and closing of the inlet valves, thus providing an additional contribution to the minimisation of the SFOC versus NOx emission trade-off.
The RoPax ferry is a twin-screw vessel and the order includes two CP propellers that will be delivered by ALPHA. The specified propellers are MAN’s Alpha CP Propellers type VBS1800-ODF, with a propeller diameter of 5,600 mm and a power density corresponding to 1,169 kW/m2. Each propeller is driven by a twin-in/single-out gearbox and will be powered by two of the 12V48/60CR main-engines.
The ferry is designed with two separate engine-rooms with the propeller shaft-lines having different lengths of well over 40 metres. The final propeller-blade design will be hydrodynamically optimised and carefully balanced with a special focus on propulsion efficiency, low noise, and cavitation levels. The total weight of the propeller equipment amounts to almost 300 tons.
Propulsion control and manoeuvring will be managed by MAN’s Alphatronic PCS system courtesy of a complete setup with control consoles in the engine-control room, the forward bridge and the bridge wings.
La Compagnie Tunisienne de Navigation – “COTUNAV”– was established in 1959, under the guardianship of The Tunisian Ministry of Transport. Its current president is Ali Khalifa.
COTUNAV’s primary interests concern the transport of passengers on regular routes from Tunis to Marseille and Genoa aboard the company’s existing fleet of car ferries. Another major interest of the Tunisian company is its existing RoRo cargo-vessel fleet that conducts container and truck transport between Tunis, Marseille, Genoa, Naples, Livorno and Barcelona. Solid-bulk transport on routes encompassing West Africa and the Middle East is another significant activity.
Daewoo Shipbuilding & Marine Engineering Co., Ltd. (DSME) was established in 1973 at Okpo Bay, Geoje Island, in south-eastern Korea and has since developed into one of the world's premium shipbuilders. DSME’s primary focus is on the commercial, naval, and offshore and plant marine-segments, and it produces container ships, passenger ships, LNG/LPG carriers, submarines, naval destroyers and oil rigs, among many other types of vessel. The company has 31,000 employees and recorded total sales of US $10 billion in 2008.