Who invented the jet engine? Sir Frank Whittle, of course. Everyone knows that, silly. Or do they?
After studying a new Imperial College London thesis, there is a danger the reader might be left perplexed. For, in aiming to write a “new history”, the text downplays the role of Whittle as the “inventor” of the jet engine. In her PhD thesis, Hermione Giffard challenges the role of the “lone inventor”, preferring to regard large corporations as true innovators.
The 323-page study is an invaluable document that reflects the author’s painstaking research into the development of the jet engine. But one is left asking: why use 1936 as the starting point? Surely the starting point for the research should be 1928 when Whittle, as a flight cadet at RAF College Cranwell, sought an alternative to the piston engine/propeller combination.
Whittle applied for a provisional patent in January 1930. The patent entered the public domain in April 1931. It was registered at the Berlin patent office in mid-August 1931, with details circulated among all aeronautical companies and research establishments.
Why is this important? Because there are several questions Giffard might have sought to address. Was the jet engine invented simultaneously in Britain and Germany, as promoted in various places in the UK and the US? Was the work really independent? And did one of the German turbojet experimental engines run before the start-up of Whittle’s engine?
In his 1945 IMechE James Clayton lecture, Whittle recorded that “testing of the engine commenced on 13 April 1937 and continued intermittently until 23 August”. Yet Giffard records that German inventor Hans von Ohain started testing his engine in March 1937, as noted by von Ohain himself – despite Ernst Heinkel writing that tests on the engine began in September 1937.
In 1932, von Ohain became a student at the aerodynamic research division of the University of Göttingen, shortly after the patent details had been lodged there. His own research into jet propulsion began in 1934. He created a design that, while running on gas, subsequently attracted the attention of Heinkel. Von Ohain desired a smooth-running aeroengine, while Whittle aimed for an engine that outperformed a piston/propeller combination and ran on liquid fuel.
Did von Ohain’s professors mention the possibility of jet propulsion? Turbosupercharger engineers at Göttingen, such as Ludwig Prandtl, Albert Beitz and Walter Enke, were surely intrigued by Whittle’s patent. It would have been the gossip of the day.
In 1936, Herbert Wagner, at Junkers Flugzeugwerke ,also launched himself into turbojet development. His engine owed nothing to von Ohain’s work, yet Giffard does not include him as one of her “heroic inventors”. The website www.scientistsandfriends.com promulgates the von Ohain/Wagner myth further. It hails von Ohain and Wagner as “the fathers of the jet engine” and notes that Whittle “also worked on the gas turbine engine”, as though he was an insignificant also-ran rather than the spark who not only ignited turbojet development but also successfully proposed centrifugal compressors. (German industry favoured axial compressors.)
Giffard sees the true hero of the genesis of the jet engine in Britain as the Royal Aircraft Establishment (RAE), Farnborough, forgetting that it was the formation of Whittle’s company Power Jets that galvanised the RAE into aero gas-turbine research. In fact, in 1929, senior RAE scientist Dr Arnold Griffith discounted Whittle’s engine. He advised the Air Ministry that the idea was not worth further attention. The RAE did not conclude the advisability of developing a turbojet until 1939. Had Whittle’s concept received full UK government backing, then the Second World War might have been shortened. Some claim that suitable high-temperature alloys for turbines were unavailable. Yet Whittle forecast that they would be developed – he even proposed turbine blade cooling.
Giffard’s conclusion reads: “The work of the RAE should get a more prominent role in the history of the turbojet than it has, while the work of Power Jets and EHFW (Heinkel) should be less prominent. Despite the visibility of Whittle and von Ohain in the literature as inventors of the turbojet, their work failed to have lasting consequences. Instead, it was the work of a relatively anonymous group at a government research establishment inspired by a relatively unknown scientist (Griffith) that proved most influential in shaping the future of the turbojet.” Really?
Although Giffard’s discourse offers useful guidance, her text contains so many gross errors of fact – not to mention missing facts – that it renders itself irrelevant as a tool for historical research. The enthusiasm for the thesis has arisen from those who have reviewed it from a standpoint of ignorance.
For example, Giffard says: “When the Second World War broke out, one company in Britain and five in Germany were seriously designing jet engines.” Yet the text points to only four: BMW, Daimler-Benz, Heinkel and Junkers. The UK firm was Power Jets.
A table shows that by 1945 Rolls-Royce and de Havilland had built 745 jet engines – one-ninth of the combined output of BMW and Junkers. US aeroengine firms Allison, Allis-Chalmers and General Electric had built 296. The British introduced the Americans to a practical form of jet propulsion in 1941, so they could not accumulate as many engines by the end of the war. Their engines were based on the British design.
Overall, this thesis is a missed opportunity.
- The Development and Production of Turbojet Aero-engines in Britain, Germany and the United States by Hermione Giffard. Imperial College London, 2011.