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Countless engineering advances enabled the paradigm shift in aircraft capability – but surely the most significant was the invention of the turbojet engine, developed and tested by Whittle in the 1930s and 1940s.
The aerospace pioneer’s interest in engineering and aviation began at a young age. His father, Moses Whittle, was a mechanical engineer and owner of a small engineering company, and his workshop provided a vital source of hands-on experience.
In 1923, Whittle was accepted by RAF Cranwell to train as an aircraft fitter and rigger. Out of 600 apprentices he was awarded one of only five cadetships to the RAF College at Cranwell in 1926. It was there that, at the age of 21, he wrote a thesis entitled “Future Developments in Aircraft Design,” in which he envisaged speeds of more than 500mph (805km/h) in the stratosphere – when the maximum speed of RAF fighters was 150mph (241km/h). His Cranwell professor apparently admitted that he did not understand a lot of it, according to the IMechE archive, but gave him top marks regardless.
Gas turbines
Whittle concluded that the piston engines then in use would not be able to fly the faster speeds and longer distances he desired. It was while training as a flight instructor at the Central Flying School that he first considered using a gas turbine to provide jet propulsion.
A gas turbine expert at the Air Ministry was reportedly unimpressed, and the Royal Aircraft Establishment described Whittle’s idea as impracticable. Despite this setback, Whittle filed a patent on 16 January 1930, which the government declined to keep secret – after the Second World War, copies were found in various laboratories in Germany.
Balancing act
After completing the officers’ engineering course at Henlow, the RAF sent Whittle to Cambridge University to study mechanical sciences in 1934. “I had to work like hell because I was designing the jet engine and preparing for my finals at the same time… that was a very difficult thing to do,” he said in the documentary Whittle – The Jet Pioneer.
Some of Whittle’s former colleagues interested General Enterprises in his idea. A new patent was obtained and OT Falk and Partners provided funding. Power Jets Ltd formed in January 1936, with Whittle as honorary chief engineer part-time.
An engine was initially built by British Thomson-Houston, but Whittle was unsatisfied and decided a complete rebuild was needed after a first test run in 1937. Posted to the Special Duty List and working on the engine full-time, his efforts were rewarded with promising engine tests with speeds of up to 16,000rpm in June 1939, according to FrankWhittle.co.uk.
Maiden flight
The government finally backed the turbojet, ordering a flight engine known as the W1 and enabling development of the follow-up W2. That summer the Air Ministry also signed a contract for an experimental aircraft, the Gloster/Whittle E.28/39. Named the Pioneer, Britain’s first jet made its maiden flight on 15 May 1941.
Within the year, General Motors was building Whittle engines in the US. In 1942, Whittle was sent there to assist with the American engine development.
Rolls-Royce’s involvement with the jet engine grew, and eventually the firm took over its production and development. A jet-fighter aircraft entered service in 1944. Such was the impact of the invention that Winston Churchill apparently asked for “a thousand Whittles,” according to the IMechE archive.
In 1945, Air Commodore Whittle delivered the first public address on the subject in the Institution’s first James Clayton Lecture. It was so popular that it had to be repeated.
In 1948 Whittle was knighted, and retired from the RAF owing to ill health. He was also awarded £100,000 by the government for his invention, which had already changed the course of history.
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Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.