The Rolls-Royce RB.39 Clyde was

Rolls-Royce Rolls-Royce (always hyphenated) may refer to: * Rolls-Royce Limited, a British manufacturer of cars and later aero engines, founded in 1906, now defunct Automobiles * Rolls-Royce Motor Cars, the current car manufacturing company incorporated in ...

's first purpose-designed

turboprop A turboprop is a turbine engine that drives an aircraft propeller. A turboprop consists of an intake, reduction gearbox, compressor, combustor, turbine, and a propelling nozzle. Air enters the intake and is compressed by the compressor. ...

engine and the first turboprop engine to pass its civil and military type-tests. As with subsequent Rolls-Royce gas turbines, it was named after a river, the

River Clyde The River Clyde ( gd, Abhainn Chluaidh, , sco, Clyde Watter, or ) is a river that flows into the Firth of Clyde in Scotland. It is the ninth-longest river in the United Kingdom, and the third-longest in Scotland. It runs through the major cit ...

Design and development

The Clyde used a two-shaft design, with an axial compressor based on that of the Metrovick F.2"World Encyclopedia of Aero Engines – 5th edition" by

Bill Gunston Bill Gunston (1 March 1927 – 1 June 2013) was a British aviation and military author. He flew with Britain's Royal Air Force from 1945 to 1948, and after pilot training became a flying instructor. He spent most of his adult life doing resear ...

, Sutton Publishing, 2006, P.195 for the low-pressure section, and a single-sided centrifugal compressor scaled up from the

Merlin Merlin ( cy, Myrddin, kw, Marzhin, br, Merzhin) is a mythical figure prominently featured in the legend of King Arthur and best known as a mage, with several other main roles. His usual depiction, based on an amalgamation of historic and leg ...

46 supercharger as the high-pressure stage, both mounted on the HP shaft and driven by a single stage HP turbine. A single stage power turbine drove the front mounted propeller reduction gearbox via the concentric LP shaft. A fairly novel feature of this compact gearbox was the power output to contra-rotating propellers."Not much of an Engineer" by

Sir Stanley Hooker Sir Stanley George Hooker, CBE, FRS, DPhil, BSc, FRAeS, MIMechE, FAAAS, (30 September 1907 – 24 May 1984) was a mathematician and jet engine engineer. He was employed first at Rolls-Royce where he worked on the earliest designs such as ...

, Airlife Publishing Ltd, 1984, P.227 The Clyde was a long engine with the axial LP compressor in front of what was, in effect, a scaled-down Derwent engine. Accessories were grouped around the axial compressor which conveniently narrowed towards the rear. Cooling for turbines and turbine bearings came from a small impeller on the main shaft as well as air taken from the axial and centrifugal compressors. Testing of the development engines exceeded expectations with the engine soon being rated at 4,030 eshp. During testing potentially destructive vibrations were found originating in the straight-cut spur gears in the reduction gearbox. The engine was selected as the main engine of the Westland Wyvern TF Mk.2 strike aircraft. However, despite the promising performance of the test engines Ernest Hives felt that pure-jets such as the Avon were the future and the Clyde programme was terminated, forcing

Westland Westland or Westlands may refer to: Places *Westlands, an affluent neighbourhood in the city of Nairobi, Kenya * Westlands, Staffordshire, a suburban area and ward in Newcastle-under-Lyme *Westland, a peninsula of the Shetland Mainland near Vaila ...

s to use the less than satisfactory

Armstrong Siddeley Python The Armstrong Siddeley Python was an early British turboprop engine designed and built by the Armstrong Siddeley company in the mid-1940s. Its main use was in the Westland Wyvern, a carrier-based heavy fighter. The prototypes had used the Rolls ...

on the production Wyverns. and so Rolls-Royce's first production turboprop would be the

Dart Dart or DART may refer to: * Dart, the equipment in the game of darts Arts, entertainment and media * Dart (comics), an Image Comics superhero * Dart, a character from ''G.I. Joe'' * Dart, a ''Thomas & Friends'' railway engine character * Da ...

Engines on display

A part sectioned example is on display at the

Rolls-Royce Heritage Trust The Rolls-Royce Heritage Trust is an organisation that was founded in 1981 to preserve the history of Rolls-Royce Limited, Rolls-Royce Holdings and all merged or acquired companies. Five volunteer led branches exist, three in England, one in Sco ...

, (Derby).

Specifications (Clyde)

References

Notes

Bibliography

* Gunston, Bill. ''World Encyclopedia of Aero Engines''. Cambridge, England. Patrick Stephens Limited, 1989. * * King, H. F
"The Two R's: A Commemorative History of Rolls-Royce Aero Engines. (article and images).
''

Flight Flight or flying is the process by which an object moves through a space without contacting any planetary surface, either within an atmosphere (i.e. air flight or aviation) or through the vacuum of outer space (i.e. spaceflight). This can be a ...

'' No. 2363, Volume 65, 7 May 1954. {{Rolls-Royce aeroengines 1940s turboprop engines

Clyde Clyde may refer to: People * Clyde (given name) * Clyde (surname) Places For townships see also Clyde Township Australia * Clyde, New South Wales * Clyde, Victoria * Clyde River, New South Wales Canada * Clyde, Alberta * Clyde, Ontario, a tow ...