Tuesday, 28 June 2011

NGTE Pyestock - June 2011

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) 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.

Following the 1971 creation of the Ministry of Defence Procurement Executive, both the Admiralty Engineering Laboratory and the Admiralty Oil Laboratory were amalgamated within the NGTE. The establishment closed in 2000.

 The Air House

The Air House was built in 1961. 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.

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 4

The largest test cell on site, 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. 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 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.

Cell 3 West

Cell 3 West is the last altitude test cell built on site. 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 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.

Roof topping on the Bramshot Cooling Towers


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