LNG-fuelled cargo vessels ‑ a major advance in propulsion

12 In-depth Issue 13 LNG-fuelled cargo vessels – a major advance in propulsion Recent contracts placed with Rolls-Royce for ship design and gas fuelled systems mark a new direction in merchant ship propulsion. S ea-Cargo AS has ordered what are believed to be the world’s first cargo vessels to be fuelled solely with liquefied natural gas (LNG), and which have a simple mechanical drive propulsion system. On delivery from the Bharati shipyard in India in 2010, they will operate on a ten day round trip service covering Baltic, Norwegian and British ports, bunkering gas fuel at one location. They are a major breakthrough, both in the application of LNG fuel for merchant vessels, and in the way the simple but elegant Rolls-Royce solution works. An important end result will be a very large reduction in emissions compared with a similar ship using liquid fuel. CO2 emissions will be reduced by about 20 per cent NOx by about 90 per cent, particulates are negligible and sulphur oxide emissions will be zero. “We made a strategic decision take an increasing market share The new 132.8m long Sea-Cargo vessels will be able to three years ago to focus on and for complete gas installations in carry 5,600 tonnes of cargo on a draught of 6m, with up build up our competence in a variety of vessel applications, to 94teu of containers on deck and 1,140 lane-metres of this type of propulsion system everything from the bunkering roro capacity. for merchant ships. Our existing flange to propeller thrust.” “Rolls-Royce is responsible for the overall vessel design, natural gas engine technology Because the Bergen B35:40V12PG derived from Sea-Cargo’s long experience with coastal has a long proven track record in main gas engine is classed for the and short sea shipping,” says Inge Bøen, Rolls-Royce land-based installations. It was load/speed operational pattern that director merchant solutions. “We will supply all the necessary and important to build comes with mechanical coupling major equipment and systems including main engine, on this experience for the marine to a controllable pitch propeller, a reduction gear, propeller, shaft generator, tunnel bow sector, in particular on the entire gas simple single engine propulsion thruster, rudder and steering gear, automation, and the installation on board, including the system has been possible in the Sea- LNG fuel storage and handling system. engine and associated systems. Cargo roro vessels - conventional “With the new regulations for gas in all but the fact that LNG is the fuelled ships now in place, we are fuel. Cold liquid gas will be stored CO2 EMISSIONS WILL BE REDUCED now seeing an increasing demand in two insulated flasks forward of for our products and technology the engineroom, in a ventilated BY ABOUT 20 PER CENT AND NOX BY in this field. We are well positioned enclosure offset to one side to ABOUT 90 PER CENT. through our specialised teams to clear a vehicle ramp. This space will www.rolls-royce.com 13 also house the evaporator system in developing safety rules for Norway, UK and mainland Europe. that converts the liquid into a low LNG-fuelled vessels, based on the The company is owned 60 per cent pressure warmed gas and supplies company’s experience with gas by Seatrans and 40 per cent by Nor it to the gas engine, which turns engines, where more than 400 are Cargo, operating a fleet of eight the propeller through a reduction now in service on land and at sea.” multipurpose vessels offering roro, gear. The engine also supplies the Sea-Cargo AS was founded in 2001 container, heavy lift, and general vessel’s electrical load by means of a through the merging together of the cargo loaded either by side door or generator driven off the gearbox. liner activities of Seatrans and Nor through hatches. The Bergen engine uses the proven Cargo, two leading shipping lines Article by: Richard White Rolls-Royce spark ignition lean burn trading between the west coast of Editorial Consultant. combustion technology that is the key to obtaining a very high thermal efficiency together with good load and speed control in a gas-fuelled engine. “We have an agreement that Hamworthy Gas Systems will be our preferred partner for LNG storage and handling systems. This means that in addition to these roro vessels, Rolls-Royce can offer LNG propulsion systems for a wide variety of ship types ‘from the bunkering flange to propeller thrust’ together with designs and deck machinery, manoeuvring and automation The132.8m LNG fuelled Sea-Cargo vessels will be able to carry 5,600 tonnes of cargo, with up to 94teu of containers systems,” continues Bøen. on deck and 1,140 lane-metres of roro capacity. “Rolls-Royce has assisted classification societies and authorities over the past few years