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Power Jets Ltd.

Power Jets Ltd. was the company founded by Frank Whittle and nationalised in 1944 which later moved to Pyestock in Hampshire. When my father Leslie Knight moved with his family in August 1949 to the Minley Estate a mile or so north of the N.G.T.E. site, many of his work colleagues and our new friends and neighbours spoke with Leicestershire accents. There was much talk of ‘Whetstone’ which I accepted, without enquiring further, was the Leicestershire home of Power Jets Ltd. ID cardIf I had been more inquisitive I may have discovered that Dad too had worked in Leicestershire instead of being in ignorance for 55 years until I stumbled upon his Identity Card which showed his address before 67 Twelve Acre Crescent as being 9 New Walk, Leicester. New Walk is one of Leicester’s most desirable streets and now a conservation area.

The surviving documents from that period reveal little of what Leslie Knight may have done at Whetstone. However he was most likely a draughtsman. He had been offered such a job at the Ministry of Aircraft Production in 1942 but was not released by the R.A.F. It is known that he gave up his job with Blundells Engineering Co. in June 1947 and he was instructed by telegram to report to the Ministry of Supply on 29th July. He was with Power Jets in time to receive a copy of the Director’s, Roxbee Cox letter to employees when he left to become Chief Scientist to the Ministry of Fuel and Power in August 1948.

Any research into the history of Power Jets Ltd is likely to reveal its base as being in Lutterworth but they had grown out of their Ladywood Works by 1942 and it was then used only as a training school. Papers from as late as 1948s consistently refer to ‘The School of Gas Turbine Technology’ at Lutterworth with research and development at Whetstone and Pyestock.

Whilst little is recorded about my father’s time at Whetstone and I don’t recall him speaking of his time there, his old files reveal the interesting fact that Pyestock was operational by 1944. The files also contain a number of photographs, unfortunately with little accompanying description but they are nevertheless presented below with the information that exists.

Malcolm Knight 20 September 2007.

Test cellsEngine testWhittle jet
Test cells under construction and a Whittle jet under test.
PumpEngine testGrinding machine
A ‘precimeter’ and pump. A turbine attached to a ‘water brake’. A grinding machine.
A precimeter was a thrust measuring instrument developed and made by Power Jets Ltd.
Despite the grinding machine with the inscription ‘Power Jets Ltd’ suggesting that the company built its own engines, the files explicitly state that British Thomson Houston Ltd. made the engines designed by Power Jets. Independent jet engine manufacturers are listed as
Armstrong Siddeley, Bristol Aircraft, de Havilland, G.E.C. America, Metropolitan Vickers, Napier, Rolls Royce and Rover.
EngineEngineF2 engine
Unidentified engine. Unidentified engine. An F2 engine.
F2 engineWellington bomberWellington bomber
An F2 engine wing mounted to a Gloster F9/40 ‘Meteor’ aeroplane, and a Whittle engine fitted to the tail of a Wellington bomber W5516/G used as a flying testbed. These photographs are from 1945.