One of the most successful aircraft engines of the World War II era, some 50 marks of Merlin were built by Rolls-Royce in Derby, Crewe and Glasgow, as well as by Ford of Britain at their Trafford Park factory, near Manchester.
Som en af de mest succesrige flymotorer fra 2.verdenskrigs-æraen, blev der bygget cirka 50 versioner af Merlin på Rolls-Royces fabrikker i Derby, Crewe og Glasgow, så vel som af Ford of Britain i deres Trafford Park fabrik, nær Manchester.