River Wissey Lovell Fuller

De Havillands Part 3

December 2013

The deHavilland Propeller Co kept busy in the post war years, they  developed a reinforced plastic propeller blade, lighter than aluminium,  that enabled larger propellers to be made without increasing the  centrifugal loads at the root.  They also built a large wind turbine,  24m diameter.  It was installed near St Albans, unfortunately they were  years ahead of their time and there was not a great interest in those  days.  They became a very versatile engineering company, moving away   from their original products but retaining the name, possibly for  security reasons.   Headquarters were in Hatfield but later moved to  Stevenage whilst production took place at the factory at Lostock.  They  developed instruments for measuring vibrations that were in demand and  they started work on guided missiles in the late 1940s.  They produced  air turbine cold air units for aircraft cooling systems and turbine  driven alternators for aircraft and missile applications. The Ministry invited them to develop infra red sensors for detecting aircraft exhausts and later developed the infra red homing air to air missile that became the ‘firestreak’ which  was widely adopted for use  by the RAF. At the same time, with the growing interest in rocket propulsion, the  Engine Co established a separate Rocket Division.  Their first developments in this field were for reusable assisted take off rockets, the Vee bombers, Vulcan and Victor needed a long runway for take-off when carrying a full load and there was a perceived need for  jettisonable rockets to assist.  Their first engine was the DH Sprite,  and that was followed by the Super Sprite, both were successful and  aircraft trials went well.  The bigger challenge was to produce a  controllable variable thrust engine for use as a main power plant in a  manned aircraft, the result was the DH Spectre, a turbo pump liquid  propellant engine.  The Spectre 1 was designed for use in the prototype  mixed power plant aircraft, the Saunders Roe SR53, the Spectre 1 passed  its type test in 1957, the first (and possibly only) rocket engine to  pass a UK type test for a manned aircraft application. Early flight testing of the SR53 went well, some flights achieving supersonic speeds.    The SR53 was intended as a test plane from which the SR177 interceptor  would be developed, the SR177 was to have had the Spectre 5 rocket  engine, a more compact and lighter version, wih the Gyron Junior as the  turbojet, when the defence cuts were introduced, the SR1277 was  cancelled and work on the SR53 was suspended. With the development of homing anti-aircraft missiles the V- bombers were seen to be increasingly vulnerable, the move was towards replacing aircraft with long range missiles, as an interim move, however, the UK had what was described as a “stand off bomb” but what might now be  called a cruise missile.  It was a rocket powered missile launched from a V-bomber 500 miles from the target- this was code named Blue Steel.  The Mark 1 version was powered by a twin version of the DH Spectre,  comprising a Spectre 5 twinned with a Spectre 4 (a fixed thrust engine).But long range missiles were regarded as the new way of delivering  nuclear weapons, the USSR and the USA were developing their ICBMs  (Inter-Continental-Ballistic-Missiles ) and the UK government, at that  time the only other nuclear power, decided to build their own ICBM, code  named Blue Streak.  The Propeller Co was contracted to oversee the  project but various companies were subcontracted, Rolls Royce were to  build the large rocket engines, a number of the deHavilland rocket  engine personnel went to Rolls to work on the project .  The Blue Streak  project progressed some way but that also became a victim of the cuts,  but the work was not wasted, Blue Streak, with its Rolls Royce engines  was modified and developed to provide the successful first stage of the  European space programme rockets, it was the only rocket to have 100%  reliability. Meanwhile the aircraft company went on to design and build the  successful DH 125 twin engine executive jet, the first of its type in  the world, and the DH Trident, a three engine short haul and feeder  liner that was popular on the London- Europe routes.  The Trident was the first plane with the three engine layout, the first to accomplish a blind landing in service and was the fastest subsonic, medium size liner, regularly flying at speeds in excess of 610mph, and that was over 50 years ago.They also designed  the DH 146, a small/medium liner that subsequently became the BAe 146, a  short take-off very quiet four engine high wing monoplane that is still  in use today, including as one of the Queen’s flight. In 1961 deHavilland sold the aircraft company and the propeller company  to Hawker Siddeley, a decision no doubt influenced by Sir Geoffrey’s  advancing age and the loss of both of his sons, together with pressure   from the government to reduce the number of companies engaged on  government sponsored work.  The engine company was sold to Bristol  Siddeley and the Stag Lane site was sold, the work was transferred to  the DH airfield site at Leavesden.  These two companies were relatively  short lived, Hawker Siddeley combined with the remaining major UK  aircraft manufacturers to create British Aerospace and Bristol Siddeley  were taken over by Rolls Royce.  Rolls Royce concentrated the military  jet engines and the Concorde engines at the old Bristol Co’s site near  Bristol, the former deHavilland engine company on the site at Leavesden  was devoted to design and manufacture of helicopter engines. The former propeller company formed the basis for the highly successful BAE Dynamics. The old Aeroplane Company had an enviable record as a pioneering company  and, despite its misfortunes, produced some very good aeroplanes.   Subsequently it formed a component part of British Aerospace with its  contribution to Airbus.

deHavilland was a pioneering organisation, from the early days of World  War I to the race winning Comet racer and the highly successful  Mosquito. They produced the first jet engines, the first jet liner, the  first variable thrust aircraft rocket engine, large scale windmills,  heat seeking missiles and many other developments.  Sadly, although  British Aerospace and Rolls Royce, who absorbed some of the deHavilland  organisation, have gone from strength to strength, as a nation we failed  to capitalise on all the engineering talent that existed in this country  in the 60s and 70s as our governments and the City turned their backs on  manufacture. Ron Watts

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