Frank Whittle

Whittle was born in Earlsdon, Coventry on June 1, 1907, the son of a mechanic. He left Leamington College in 1923 to join the RAF. Through his early days as an Aircraft apprentice (first at RAF Cranwell but latterly at RAF Halton) he maintained his interest in the Model Aircraft Society where he built replicas, the quality of which attracted the eye of his commanding officer, who also felt that Whittle was a mathematical genius.

He was so impressed that he recommended Whittle for the Officer Training College at Cranwell in Lincolnshire in 1926, a rarity for a "commoner" in what was still a very class-based military structure. For Whittle this was the chance of a lifetime, not only to enter the officer's corps, but also because the training included flying lessons. Of the few apprentices that were accepted, only about one percent completed the course. Whittle was the exception to the rule, graduating in 1928 at the age of 21, ranked second in his class in academics and an "Exceptional to Above Average" pilot.

Another requirement of the course was that each student had to produce a thesis for graduation. Whittle decided to write his thesis on future developments in aircraft design, notably high-speed flight at high altitudes and speeds over 500 mph (800 km/h). He showed that incremental improvements in existing propeller engines were unlikely to make such flight routine. Instead he described what is today referred to as a motorjet, a motor using a conventional piston engine to provide compressed air to a combustion chamber whose exhaust was used directly for thrust – essentially an afterburner attached to a propeller engine. The design was not a new one, it had been talked about for some time in the industry, but Whittle's interest was to demonstrate that at increased altitudes the lower outside air pressure would increase its efficiency. For long-range flight, using an Atlantic-crossing mailplane as his example, the engine would spend most of its time at high altitude and thus could outperform a conventional powerplant.

Whittle continued working on the motorjet principle after his thesis work, and eventually abandoned it when further calculations showed it would weigh as much as a conventional engine of the same thrust. But as he later described, while thinking about the idea he thought "Why not substitute a turbine for the piston engine?" Instead of using a piston engine to provide the compressed air for the burner, a turbine could be used to extract some power from the exhaust and power an actual compressor, like those used for superchargers. The leftover exhaust thrust would power the aircraft.

In July 1926, A. A. Griffith published a paper on compressors and turbines, which he had been studying at the RAE. He showed that such designs up to this point had been flying "stalled", and that by making the compressor blades into an aerofoil shape, their efficiency could be dramatically improved. The paper went on to describe how the increased efficiency of these sorts of compressors and turbines would allow a jet engine to be produced, although he felt the idea was impractical and instead suggested using the power as a turboprop. At the time most superchargers used a centrifugal compressor, so there was limited interest in the paper.

Whittle sent his new idea to the Air Ministry to see if there would be any interest. With little knowledge of the topic they turned to the only other person who had written on the subject, and passed the paper on to Griffith. Griffith appears to have been convinced that Whittle's "simple" design could never achieve the sorts of efficiencies needed for a practical engine. After pointing out an error in one of Whittle's calculations, he went on to comment that the centrifugal design would be too large for aircraft use, and that using the jet directly for power would be rather inefficient. The RAF returned comment to Whittle, where they referred to the design as "impracticable."

Others in the RAF were not so sure, and in particular Johnny Johnson convinced him to patent the idea in January 1930. Since the RAF was not interested in the concept they did not declare it secret, which meant that Whittle was able to retain the rights to the idea, which would have otherwise been the property of the RAF. This rejection would later turn out to be a stroke of luck.

Meanwhile Whittle moved onto the Officers' Engineering Course at RAF Henlow, Bedfordshire in 1932, and then to Peterhouse, Cambridge in 1934, graduating in 1936 with a First in the Mechanical Sciences Tripos.

Whittle's jet engine patent lapsed in 1935 because he could not afford the renewal fee of £5. But soon after this he was approached by two ex-RAF men, Rolf Dudley-Williams and J. Tinling, who wanted to expand the development of his engine. The three incorporated as Power Jets Ltd. in 1936 with a bank loan of £2,000. Work was started on an experimental engine at a factory in Rugby, Warwickshire belonging to British Thomson-Houston, a steam turbine company. The RAF still saw no value in the effort, but although Whittle was still a pilot they placed him on the Special Duty List and agreed to allow him to work on the design as long as it took no more than six hours a week.

Funding development of the first engine, known as the WU (Whittle Unit) was a serious problem. Although privately funded, most potential investors shied from a project that appeared to be semi-secret yet had no RAF backing. Something seemed to be an amiss; if the project was going to work, why didn't the RAE fund it? Once again it seemed not everyone was so unconvinced of Whittle's ideas, and in October 1936 Henry Tizard, the rector of Imperial College London and chairman of the Aeronautical Research Committee, sent details of Whittle's engine to Griffiths once again. Griffiths had by this time started construction of his own design; perhaps in order to avoid tainting his own efforts, he returned a much more positive review. He remained highly critical of some features, seemingly ignoring the fact that its performance at high speed at height was the crucial aspect of the programme.

Even with these problems Power Jets were able to complete the WU, which ran successfully on April 12, 1937. Tizard pronounced it "streets ahead" of any other advanced engine he had seen, and managed to interest the Air Ministry enough to fund development with a contract for £6,000 to develop a flyable version. Nevertheless it was a year before all of the funds were available, greatly delaying development.

Meanwhile testing continued with the WU, which showed an alarming tendency to race out of control. Due to the dangerous nature of the work being carried out, in 1938 development was largely moved from Rugby to the BTH's semi-disused Ladywood foundry at nearby Lutterworth in Leicestershire. There was a successful run of the WU there in March 1938. Although the potential of the engine was obvious, the Air Ministry remained focused on the practical issues of gearing up production of existing piston engine designs.

All of these delays and the lack of funding had seriously delayed the project. In Germany, Hans von Ohain had started work on a prototype in 1935 and had already passed the prototype stage and was building the first flyable design, the Heinkel HeS 3. There is little reason to believe that Whittle's efforts would not have been at the same level or even more advanced had the Air Ministry taken a greater interest in the design. When the war started in September 1939, Power Jets had a payroll of only 10, and Griffith's efforts at the RAE and Metropolitan Vickers were similarly small.

The stress of the continual on-again-off-again development, and problems with the engine itself, had a serious toll on Whittle. He suffered from stress-related ailments such as eczema and heart palpitations, while his weight dropped to 126 pounds. In order to keep to his sixteen-hour workdays, he sniffed Benzedrine during the day, and then took tranquilizers and sleeping pills at night to offset the effects and allow him to sleep. Over this period he became irritable, and developed an "explosive" temper.

Following the outbreak of World War II the Air Ministry changed priorities and once again looked at the various advanced projects underway. By 1939, Power Jets could barely afford to keep the lights on when yet another visit was made by Air Ministry personnel. This time Whittle was able to run the WU at high power for 20 minutes without any difficulty. One of the members of the team was the Director of Scientific Research, H. E. Wimperis, who walked out of the demonstration utterly convinced of the importance of the project.

A contract for full-scale development was immediately sent to Power Jets, along with a number of tenders to various companies to set up production lines for up to 3,000 engines a month in 1942. Power Jets had no real manufacturing capability, so the Air Ministry offered shared production and development contracts to BTH, Vauxhall and Rover. However, the contract was eventually taken up by Rover only. They also sent out a contract for a simple airframe to carry the engine, which was quickly taken up by Gloster.

Whittle had already studied the problem of turning the massive WU into a flyable design, and with the new contract work started in earnest on the "Whittle Supercharger Type W.1." However, Rover was unable to deliver the W.1 production engine before Gloster's experimental airframe was ready. Whittle then cobbled together an engine built from various test parts and called it the W.1X, which ran for the first time on December 14, 1940. This engine powered the Gloster E.28/39 for taxi testing when it took to the air for a short hop on April 7, 1941.

Archive film of the early secret E.28 tests still exists. It illustrates the vivid memories of ordinary folk living nearby who were interviewed by the BBC a decade later. They recall their amazement that an aeroplane could fly with no propellers and the questions is raised in local pubs at the time: how could it possibly work? Did the mystery aircraft somehow suck itself through the air like a supercharged vacuum cleaner? It was difficult for laypeople still used to conventional aircraft to imagine that jet propulsion could work in practice.

The "full" W.1 of 3.8 kN (850 lbf) thrust ran on April 12, 1941, and on May 15, 1941 the W.1-powered E.28/39 took off from Cranwell at 7.40 pm, flying for seventeen minutes and reaching a maximum speed of around 545 km/h (340 mph). Within days it was reaching 600 km/h (370 mph) at 7600 meters, exceeding the performance of the contemporary Spitfires, astounding considering this was the very first such engine. Success of the design was now evident to all, and nearly every engine company in England started their own crash efforts to catch up with Power Jets.

The W2/700 engine flew in the Gloster E.28/39, the first British aircraft to fly with a turbojet engine, and the Gloster Meteor.

The W2/700 engine flew in the Gloster E.28/39, the first British aircraft to fly with a turbojet engine, and the Gloster Meteor.A newer design known as the W.2 was then started. Like the W.1 it featured a "reverse flow" design of the burners, in which the heated air from the flame cans was piped back towards the front of the engine before entering the turbine area. This allowed the engine to be "folded", with the flame cans lying around the turbine area, and therefore making for a shorter engine.

Power Jets also spent some time in May 1940 drawing up the W.2Y, a similar design with a "straight through" airflow that resulted in a longer engine and (more crucially) driveshaft, but with a somewhat simpler layout. In order to reduce the weight of the driveshaft as much as possible, the W.2Y used a large cylindrical shaft almost as large as the turbine disk, "necked down" at either end where it connected to the turbine and compressor.

The Air Ministry was eager to obtain an operational jet aircraft, and authorised BTH to press ahead with a twin-engined jet interceptor, which would evolve into the Gloster Meteor. The Meteor was intended to use either the W.2 or the similar Halford H.1 (later named "Goblin") but de Havilland later decided to keep all the Halford's for their own design, the de Havilland Vampire.

Rover

In 1941 Rover set up a new laboratory for Whittle's team along with a production line at their disused Barnoldswick factory, but they also set up a parallel effort with their own engineers at Waterloo Mill, Clitheroe. Here Adrian Lombard attempted to develop the W.2 into a production quality design, dispensing with Whittle's "reverse flow" burners and developing a longer but simpler "straight-through" engine instead. Work at Barnoldswick continued on Whittle's original design, now known as the W.2B/23, while Lombard's new design became the W.2B/26. Whittle was upset by this course of events, feeling that all work should concentrate on producing a single design as soon as possible.

By late 1941 it was obvious to all that the arrangement between Power Jets and Rover was not working. Whittle was frustrated by Rover's inability to deliver production-quality parts, as well as with their "we know better than you" attitude, and became increasingly vocal about his complaints. Likewise Rover was losing interest in the project after the delays and constant harassment from Power Jets.

Rolls-Royce

Earlier, in 1940, Stanley Hooker of Rolls-Royce had met with Whittle, and later introduced him to Rolls' CEO, Ernest Hives. Hooker led Rolls' supercharger division, which was naturally suited to jet engine work. Hives agreed to supply key parts to help the project, and it was Rolls engineers who helped solve the surging problems seen in the early engines. In early 1942 Whittle contracted Rolls for six engines as well, known as the WR.1, identical to the existing W.1.

The problems at Rover became a "public secret", and eventually Spencer Wilkes of Rover met with Hives and Hooker at the Swan and Royal pub near the Barnoldswick factory. They decided to trade the jet factory at Barnoldswick for Rolls' tank engine factory in Nottingham. A handshake sealed the deal. The handover took place on January 1 1943, although the official date was later. Rolls soon closed Rover's parallel plant at Clitheroe, although they continued development of the W.2B/26 that had been developed there.

Testing and production was immediately stepped up. In December Rover had tested the W.2B for a total of 37 hours, but within the next month Rolls-Royce tested it for 390 hours. The W.2B passed its first 100 hour test at full performance of 725 kgf (7.11 kN) on May 7, 1943. The prototype Meteor airframe was already completed, and took to the air on June 12, 1943. Production versions started rolling off the line in October, first known as the W.2B/23, then the RB.23 (for Rolls-Barnoldswick), and eventually the Rolls-Royce Welland. Barnoldswick was too small for full-scale production and turned back into a pure research facility under Hooker, while a new factory was set up in Newcastle-under-Lyme. The W.2B/26, as the Rolls-Royce Derwent, opened the new line and soon replaced the Welland, allowing the production lines at Barnoldswick to shut down in late 1944.

Although the Luftwaffe beat the British efforts by a few weeks, largely due to the delays at Rover, Whittle's efforts were nevertheless far more influential. The engines that powered the Meteor were much more reliable than their German counterparts, which would typically last 10 hours or less, and sometimes exploded on their first startup. The equivalent British engine would run for 150 hours between overhauls and had twice the power-to-weight ratio and half the specific fuel consumption. By the end of the war every major engine company in Britain was working on jet designs, and practically every other design in the world was based on the Whittle pattern, or licensed outright. It was not until the late 1950s that most engines powering US and USSR fighters were no longer directly related to the Whittle's original work.

Continued development

With the W.2 now proceeding smoothly, Whittle was sent to Boston, Massachusetts in mid-1942 to help the General Electric jet programme. GE, the primary supplier of turbochargers in the US, was well suited to quickly bringing jet production online. A combination of the W.2B design and a simple airframe from Bell Aircraft flew in autumn of 1942 as the Bell XP-59A Airacomet.

Whittle's developments at Power Jets continued, resulting in the improved W.2/500, and later the W.2/700. Both were fitted for testing on Meteors, the W.2/700 later being fitted with an afterburner ("reheat" in British terminology), as well as experimental water-injection to cool the engine and allow for higher power settings without melting the turbine. Whittle also turned his attention to the axial-flow championed by Griffiths, designing the L.R.1. Other developments included the use of fans to provide more mass-flow, either at the front of the engine as in a modern turbofan, or at the rear, which is much less common but somewhat simpler.

Whittle's work had caused a minor revolution within the British engine manufacturing industry, and even before the E.28/39 flew most companies had set up their own research efforts. In 1939, Metropolitan-Vickers set up a project to develop an axial-flow design as a turboprop, but later re-engineered the design as a pure jet known as the Metrovick F.2. Rolls-Royce had already copied the W.1 to produce the low-rated WR.1, but later stopped work on this project after taking over Rover's efforts. de Havilland started a jet fighter project in 1941, the Spidercrab—later called Vampire—along with their own engine to power it: Frank Halford's Goblin (Halford H.1). Armstrong Whitworth also developed an axial-flow design, the ASX, but reversed Vicker's thinking and later modified it into a turboprop instead, the Python.

With practically every engine company now producing their own designs, Power Jets was no longer able to generate realistic income. In April 1944 Power Jets was nationalized, becoming the National Gas Turbine Establishment at the original Ladywood experimental site. In 1946 it was reorganized with the RAE divisions joining them.

After the War

Whittle, disenfranchised, quit what was left of Power Jets in 1948. Long a socialist, his experiences with nationalization changed his mind, and he later campaigned for the Conservative Party. He also retired from the RAF, complaining of ill health, leaving with the rank of Air Commodore. Shortly afterwards he received £100,000 from the Royal Commission on Awards to Inventors, partly to pay him for turning over all of his shares of Power Jets when it was nationalised. He was made a Knight of the Order of the British Empire (KBE) in that same year.

He soon joined BOAC as a technical advisor on aircraft gas turbines. He travelled extensively over the next few years, viewing jet engine developments in USA, Canada, Africa, Asia and the Middle East. He left BOAC in 1952 and spent the next year working on a biography, Jet: The Story of a Pioneer. He was awarded the Royal Society of Arts' prestigious Albert Medal that year.

Returning to work in 1953, he accepted a position as a Mechanical Engineering Specialist in one of Shell Oil's subsidiaries. Here he developed a new type of drill that was self-powered by a turbine running on the mud pumped into the hole that was used as a lubricant during drilling. Normally a well is drilled by attaching rigid sections of pipe together and powering the cutting head by spinning the pipe, but Whittle's design meant that the drill had no strong mechanical connection to the head frame, allowing for much lighter piping to be used.

Whittle left Shell in 1957, but the project was picked up in 1961 by Bristol Siddeley Engines, who set up Bristol Siddeley Whittle Tools to further develop the concept. In 1966 Rolls Royce purchased Bristol Siddeley, but the financial pressures and eventual bankruptcy due to cost overruns of the RB211 project led to the slow wind-down and eventual disappearance of Whittle's "turbo-drill" once again. The design would eventually appear only in the late 1990s, when it was combined with continuous coiled pipe to allow uninterrupted drilling at any angle. For instance, the "continuous-coil drilling" can drill straight down into a pocket of oil, and then sideways through the pocket to allow the oil to flow out faster.

In 1976 Whittle emigrated to the US, and the next year he accepted the position of NAVAIR Research Professor at the US Naval Academy, Annapolis. His research concentrated on the boundary layer before his professorship became part-time from 1978 to 1979. The part time post enabled him to write a textbook on gas turbine thermodynamics. It was at this time that he met von Ohain, who was working at Wright-Patterson Air Force Base. At first upset because he believed von Ohain had only developed his engine after seeing Whittle's patent, he eventually became convinced that von Ohain's development really was his own. The two became good friends, and often toured the US giving talks together. In 1991 von Ohain and Whittle were awarded the Charles Stark Draper Prize for their work on turbojet engines.