Rolls-Royce R engine was invaluable in the subsequent development of the Rolls-Royce Merlin engine and the Spitfire. A de-rated R engine, known as the Griffon, was tested in 1933, but it was not directly related to the production Rolls-Royce Griffon of 1939, of the same exact bore/stroke and resultant displacement figures as the "R" design. Three examples of the R engine are on public display in British museums as of 2014. Rolls-Royce realised that the Napier Lion engine used in the 1927 Supermarine S.5 Schneider Trophy winner had reached the peak of its development, and that for Britain's entrant in the next
Rolls-Royce RB.50 Trent Rolls-Royce RB.50 Trent The Rolls-Royce RB.50 Trent was the first Rolls-Royce turboprop engine. The Trent was based on a concept by Sir Frank Whittle. It was a Derwent Mark II turbojet engine with a cropped impeller (turbine unchanged) and a reduction gearbox (designed by A A Rubbra) connected to a five-bladed Rotol propeller. The Trent ran for 633 hours on test before being installed in a Gloster Meteor jet fighter which flew for the first time on 20 September 1945 at the start of a 298-hour flight test programme. A preserved Rolls-Royce Trent turboprop engine is on display at the