Advancing the state of the art
Sea-Cargo orders LNG-fuelled multipurpose RoRo vessels using Rolls-Royce technology

Sea-Cargo AS operates a fleet of multipurpose RoRo vessels, primarily on North Sea routes linking the west coast of Norway, mainland Europe and the UK. These vessels can handle cargo of all types: RoRo, containers, side door whether palletised or conventional, through hatch or heavy lift.
The company was formed in 2001 by putting together the liner activities of two leading companies; Seatrans and Nor Lines, who own 60% and 40% of Sea-Cargo respectively.
Capacity on the various routes has been increased yearly since the start, and will be further increased to cope with cargo traffic on routes vacated by a passenger/cargo operator.
Now, Sea-Cargo has defined its next generation of vessels, ordering four RoRo vessels that will be built in India for delivery in 2009 and 2010, with options for four more. The new vessels are 132.8m long, have a dwt of abt. 5,600 tonnes on a draught of 6m – with abt. 1150 lane meters. They are further fitted with a 50 tonnes container crane.

With focus on reducing exhaust emissions from short sea and coastal vessels, Sea-Cargo identified liquefied natural gas (LNG) as the future fuel of choice. The company turned to Rolls-Royce for assistance in designing the vessels and for the propulsion and equipment solution. The outcome of these discussions were that newbuildings no. 3 and 4 (hull 357 and 358) will be built with a full LNG propulsion package – believed to be the first ever designs of its type. The vessels will operate on a weekly service between the west coast of Norway, UK and the Continent.

These RoRo vessels are a major breakthrough, both in the application of LNG fuel for merchant vessels, and in the way the simple but ele¬gant Rolls-Royce single engine single screw mechanical drive solution works. An important end result will be a very large reduction in emis¬sions compared with a similar ship using liquid fuel. CO2 emission will be reduced by about 20%, NOx by about 90%, particulates neg¬ligible and sulphur oxide emissions will be zero.
The design is developed in close cooperation between Sea-Cargo, Seatrans and Rolls-Royce – derived from a two year research program headed by Seatrans in close cooperation with Rolls-Royce and Marintek. Rolls-Royce will supply all major equipment and system elements, including main engine, reduction gear, propeller, shaft generator, tunnel bow thruster, rudder and steering gear, automation, and the LNG fuel storage and handling system.
Rolls-Royce can offer LNG propulsion systems ‘from the bunkering flange to propeller thrust’. The Bergen B35:40V12PG main engine uses proven Rolls-Royce spark ignition lean burn combustion technology that is the key to obtaining a very high thermal efficiency combined with good load and speed control in a gas-fuelled engine. It is classed for the load/speed operational pattern that comes with mechanical coupling to a controllable pitch propeller.

A simple single engine propulsion system has been possible in the Sea-Cargo RoRo vessels – conventional in all but the fact that LNG is the fuel. Cold liquid gas will be stored in two insulated LNG tanks each 240m3 forward of the engine room, in a ventilated enclosure offset to one side to clear a vehicle ramp and minimising the impact on cargo capacity. The gas engine turns the propeller through a reduction gear and also supplies the vessel’s electrical load by means of a generator driven off the gearbox.
These new vessels put Sea-Cargo in the forefront in offering efficient and flexible sea freight services with the minimum of emissions per tonne-kilometre of cargo transported.

Meer informatie: Sea-cargo agencies BV - www.sea-cargo.no, tel. + 31 20 58 778 00, e-mail: info@sea-cargo.nl