Power systems group Rolls-Royce has won a contract to supply liquefied natural gas (LNG) power and propulsion systems to two ferries being built in Norway.The significance of the contract, with ship operator Fjord Line, is that it will be the first time ferries have been built with LNG engines, which substantially reduce harmful gas emissions.The gas-only engines will reduce nitrogen oxide emissions by about 90% while sulphur oxide and particulates emissions will be "negligible".Rolls-Royce General Sales Manager, Odd Magne Horgen, said: "These vessels will be the first international LNG-fuelled passenger vessels in operation and we are very pleased to be a part of this groundbreaking project."Each of the vessels will have a deadweight of 4,000 tonnes and a length of 170 metres. They will have 309 cabins, and room for 1,500 passengers and 600 cars. They are due to begin a regular service between the west coast of Norway and Denmark in the summer of 2013.BS