Rolls-Royce has been chosen by the Royal Navy to design the power turbine system for its new combat ship.The group said this was likely to include its Rolls-Royce MT30, what it called the world's most powerful marine gas turbine.The FTSE 100 engine maker will work with the Global Combat Ship's designer, BAE Systems and engineers from the UK ministry of Defence, to design the system to propel the ship to its top speed above 26 knots.The first Type 26 ships, which replace the Navy's current Type 23 frigates, are due to be built in 2015 and the first set to enter service in the early 2020s and the last remaining in service beyond the middle of the century.Don Roussinos, President - Naval at Rolls-Royce, said: "We are delighted to be working alongside Tognum on the development of an advanced propulsion system for a fleet of ships that will be central to the Royal Navy's capability for decades to come."The Type 26 will combine a range of marine technologies, and it is the sophisticated integration of this equipment that will ensure these ships will be highly flexible and efficient, whatever the mission."Shares in Rolls Royce were up 7p, or 0.6%, to 1,138p at 13:30 on Wednesday. OH