The single-shaft engine , named after the river of the same name in the English county of Derbyshire , has a centrifugal compressor , nine combustion chambers and an axial turbine . The prototype W.2B / 26, still manufactured by Rover , ran on the test bench for the first time in March 1942. The more powerful series version Derwent Mk.I (B.37) went into production in autumn 1943 and initially delivered 8.9 kN of thrust, which could be increased to 10.9 kN for the Mk. IV. The last variant was the Derwent Mk.8 (RB.40) with a thrust of 16.0 kN at an air throughput of 28.5 kg / s and a speed of 14,700 min −1 .
A Derwent with only seven combustion chambers and no thrust nozzle became the first Rolls-Royce Trent (RB.50) to be the world's first turboprop engine : an additional turbine stage powered a five- blade propeller via a second shaft . A converted Gloster Meteor completed the world's first turboprop flight with two Trent RB.50s on September 20, 1945.
The Derwent engine was developed into the larger Rolls-Royce Nene (RB.41) as early as 1944 . It was used in the following aircraft types, among others:
- Paul Duffy, AI Kandalov: Tupolev: The Man and His Aircraft edition of 173 Reference Series, published by SAE, 1996 ISBN 978-1-56091-899-8 , page 102