National Gas Turbine Establishment

National Gas Turbine Establishment

Coordinates: 51°16′59″N 0°48′26″W / 51.282957°N 0.807098°W / 51.282957; -0.807098 The National Gas Turbine Establishment (NGTE Pyestock) in Fleet, part of the Royal Aircraft Establishment (RAE), UK was the prime site in the UK for design and development of gas turbine and jet engines. It was created by merging the design teams of Frank Whittle's Power Jets and the RAE turbine development team run by Hayne Constant. NGTE spent most of its lifetime as a major testing and development center, both for experimental developments as well as supporting the major commercial engine companies.

Like many companies at this time, the newly merged venture was nationalised, and the search for a suitable site for turbine development began. Pyestock, a former golf course in a secluded wooded spot between Farnborough and Fleet was chosen, as the activities at the NGTE would be top secret and (one presumes) the surrounding woodland would dampen the phenomenal noise. Construction began in 1949, but the site was not as we know it. Instead of the massive test cells there today, testing was done on a much smaller scale in test "cubicles" inside buildings like the Plant House. When the possibility of supersonic jets arose, the site underwent a massive expansion to the north west, with the massive Air House and several huge test cells being built circa 1961.

For over 50 years Pyestock was at the forefront of gas turbine development and was almost certainly the largest site of its kind in the world. V bomber, Harrier and Tornado engines were all rigorously tested on site, the power of the air house allowed Concorde's engines to be tested at 2,000 mph, every single gas turbine installed in the Royal Navy were checked here, captured Soviet engines were discretely examined - and all this on terra firma, without a single plane taking off.

NGTE Pyestock closed down in 2000. The Pyestock campus is now in the state of being decommissioned pending the building of a large business/industrial park.



In 1942 the Royal Aircraft Establishment (RAE) Turbine Division moved to new facilities in Pyestock. In 1944 Power Jets Ltd. (set up by Frank Whittle and two colleagues in 1936) merged with the RAE Turbine Division and was nationalised to form Power Jets (Research and Development) Ltd. In 1946 it was reconstituted as a division of the Ministry of Supply to form the National Gas Turbine Establishment.

The Admiralty Marine Engineering Establishment (formerly the Admiralty Fuel Experimental Station which developed the Admiralty three-drum boiler) was taken over by the NGTE in 1965.

Following the 1971 creation of the Ministry of Defence Procurement Executive, both the Admiralty Engineering Laboratory (1917-1977) and the Admiralty Oil Laboratory (1953-1977) were amalgamated within the NGTE.[1] In 1995 the establishment became part of DERA.[2] The establishment closed in 2000.

The Buildings

Air House

The Air House is an incredibly modern structure for 1961. The eastern side is sheet glass, and there are eight huge blue exhaust pipes rising the full length of the building that correspond to the eight compressor/exhauster sets inside. Those iconic blue pipes lead away from the building, which transported the fast moving air to/from the test cells.

The Air House had two functions; either blowing air or sucking air, all at very high speeds. It could produce wind speeds of up to 2,000 mph for Cell 4. There are eight identical GEC compressor/exhauster sets which aggregated to 352,000 horsepower, which was believed to be the largest installation of its kind in the western world.

This is the final design for the compressor/exhauster sets from the late 1950s. They are made up of an in-line arrangement (from left to right) of an 8,000 horsepower steam turbine, then two low-pressure compressors, a high-pressure exhauster, a 27MW 11kV synchronous motor that provided 36,000 horsepower, and finally the barring gear and the exciter (a small generator that provides a current needed to start the main motor).

The 8,000 horsepower steam turbine, which was powered by the sites boiler house, gave the compressor sets a kick start before it was synced with the grid. They could also be used whilst they were being run but this was expensive and only used on the supersonic tests.

Cell 3

Cell 3 is mostly underground and is a supersonic replacement of Cell 2, allowing for higher speeds and a greater engine temperature range. There is a fairly large building above ground. But that was just to allow engines to be lowered into the test chamber from a huge crane. The test chamber itself is almost entirely underground.

Cell 3 West

Cell 3 West is one of the more recognisable buildings at Pyestock despite its comparatively small size, due to the large blue and white round opening on the front of the test chamber. The last altitude test cell built on site, Cell 3 West is just that - west of Cell 3. Although not as physically large as the other cells, it was one of the largest internally allowing icing tests (testing to see how ice affects a turbines performance) to be carried out on engines and helicopter rotors. Behind the large white opening on the above picture is the test chamber, a large round space full of pipes, wires, nozzles, control panels and air vents. The engine or turbine would be suspended from a black structure on the roof of the cell, and the air would be blasted through the black pipe at the rear. There was a widespread rumour that the cells structure was actually a submarines hull.

Cell 4

The largest test cell on site and also the most featureless (externally, that is!), Cell 4 was built in 1965, at a cost of £6.5 million, as part of the Concorde programme but also to test other supersonic jet engines. The massive test cell, unique in the world, takes up most of the huge steel clad structure and looks almost unreal with its mass of pipes, blast doors and electronics. It is connected to the Air House by those notorious blue pipes and was designed to simulate Concorde's flying conditions - Mach 2 (1522 mph) at 61,000 feet, but could test Concorde's engines at a maximum wind speed of 2,000 mph.

The sheer amount of energy required to run the air house (see below) at the speed needed was too great for the sites small power station to cope with. This meant that, although the power station could be used as an additional "top up", electricity had to be taken from the National Grid - an exceptionally difficult task. By the early 1970s, Pyestock had to negotiate with the CEGB, the Central Electricity Generating Board - the national electricity supplier - simply to have enough electricity generated. So as not to put such a strain on the grid, Cell 4 could only realistically be powered up at night.

Number 9 Exhauster

Pyestock's designers built the Air House on a huge scale, thinking it could supply adequate suction for the supersonic test cells. But they could not have anticipated the phenomenal force required by Cell 4 - even with all eight exhausters running the suction was insufficient. Their solution was to build another exhauster set (an exhauster is a large turbine that sucks air at very high speed) directly next to Cell 4. As there are eight in the Air House, this one was named number 9.

It is a Parsons "multi-stage axial-flow exhauster". It was used mainly by Cell 4 but also occasionally by Cell 3 and Cell 3 West. It was driven by a 6,000 horsepower synchronous motor, with power being taken first from the sites Power Station, and then when 3,000 rpm was reached it was synchronised with the National Grid.

Write up content: George Webb (Clebby)


Pyestock was used for several scenes in the 2005 film Sahara by Breck Eisner, based on the best-selling book of the same name by Clive Cussler. Internal sections of Cell 3 and Cell 4 and were suitably reworked for the film. These were to represent the internal working of the solar powered waste disposal facility that was the source of the pollution illness that is the main thread throughout the film.


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