The original northwest corner of the new Pyestock site was occupied by the Plant House. It shared little architectural similarities with the other buildings erected at Pyestock, being built mostly of brick. This gave the Plant House its unique appearance as a huge, squat blockhouse brooding in the corner of the site surrounded by the blued-painted, steel-cladded, multi-windowed buildings which characterised the rest of Pyestock.
Its design mirrored the Compressor House of the old Pyestock site. In this building a hall housed the necessary plant for air supplies and down one side of the building individual cubicles contained test rigs where experiments were performed on individual components or scaled-down gas turbines. The Plant House was a scaled up, symmetrical version of this building with a centralised plant hall, two valve bays either side, and rows of cubicles on either side of those.
The Plant House was initially intended for combustion and aerodynamic experimentation and its solid brick construction reflected the requirements for a sturdy building in which to carry out these tests, and one which could contain any mishap.
By 1954, the Plant House had taken shape in the emerging new site. The original plan called for a plant hall housing nine separate machines, but this proved too expensive (and would’ve been a match in size and capacity for the future Air House). Ideas were rationalised and the use of compressor/exhauster plant allowed the number of large machines to be whittled down to three: two Metropolitan-Vickers axial-flow compressor/exhauster sets and a Parsons air-bleed gas turbine. These supplied air to the pressure and suction mains controlled via a control room at the end of the hall.
Pressure and suction mains from these machines were routed to the two valve bays, either side of the plant hall. These allowed custom connections and piping to be constructed between the mains and the test rigs located in the adjoining cubicles. The pressure and suction mains were also routed outside the building, allowing other test rigs (such as Cell 1 & 2 and the 14000 HP Turbine) to be connected to a source of air.
The cubicles were large empty, two-storey spaces. Exterior doors and an overhead gantry crane allowed test equipment to be winched in, whilst a viewing room set high in the first storey allowed the scientists to view and control the experiments in relative safety. Five cubicles for combustion testing were built along the north side of the building, whilst four aero testing cubicles occupied the southern side. One of the aero cubicles, so named Aero Catherdral, was double the size of the other cubicles, obviously intended for far larger testing equipment.
The initial designers realised the Plant House had limits and designed the building with expansion in mind. The western end was a blank wall, and tentative future plans allowed the building to expand westwards, adding new cubicles and plant as necessary. However, Pyestock expanded in a very different way and the requirements for supersonic, full scale testing necessitated the building of entirely new air supplies and testing cells. (The eventual Air House and it associated supersonic cells).
Even with the new supersonic, full sized test cells, component testing was still required, and the Plant House enjoyed a long functional life at Pyestock. Whilst some of the cubicles were empty and had been obviously mothballed, and others were used as storage areas, a few were still packed with test equipment and reports, suggesting the Plant House was in use right up until the site closed.
What follows is a shortened version of the walkthrough of the Plant House which appears on my Pyestock website.
The Plant House appears battered and unkempt as can be seen from this view of the northwestern corner. Generally the building is still in good condition, despite four or five years of standing unused.
The large blue doors lead into Combustion Cubicle C1 with an additional loading door on the first storey.
Note the rather unfinished nature of the western wall. The Plant House was designed to be expanded west so this probably explains the temporary looking nature of the wall. The Plant House control room window is also in this wall – but it simply has a view of the Dry Air Main (which crosses the site from the Ceca Drying Plant to Cell 4).
Moving to the east reveals the eastern flank of the Plant House, perhaps its most picturesque side.
The ground floor doors on the eastern side all lead directly into the plant hall. A row of offices was built on top, the windows looking eastwards out towards Pyestock.
The large glass windows of the stairwells can be seen here (and these lead directly to the first floor and the offices, and to the second floor and the roof).
The door to Combustion Cubicle C5 can be seen immediately to the right of this shot.
The interior of the stairwell is dark and cold. The grime of years of use covers the glass and blocks the light. Outside, the walls of the Plant House cooling tower can just be seen.
The stairs immediately lead upwards. There is no ground floor access.
The stairs lead to the first floor corridor. This leads the entire width of the building with doors to the offices on the left and doors to the plant hall on the right.
Internal windows to the right look out into the plant hall.
Most of the offices haven’t been cleared. It would appear some have been used as storage as the site closed and others have become temporary laboratories
Welcome to the plant hall and valve bays. Our route is a walkway along the combustion valve bay. On our right, doors lead into the various Combustion Cubicles, each cubicle identified by a red nameplate.
We take the first door right into the first combusion cubicle.
Combustion Cubicle C5 is the largest of the combustion cubicles. It’s also the emptiest.
All that remains are the metal tracks upon which the test rigs were constructed. The windows of the viewing room can be seen on the left.
Ground floor doors lead out into the combustion valve bay, so we take a look.
All the piping connecting Combustion Cubicle C5 to the air mains has been carefully removed; again suggesting the cubicle has been out of use for many years.
The cubicle connection piping is still in-situ further along the valve bay.
We retrace our steps back through Combustion Cubicle C5, up the stairs and back onto the first floor walkway along the valve bay.
Combustion Cubicle C2 is also entirely dark but there’s still some controls and equipment in the viewing room. This shot is made possible by propping the door to the valve bay open and allowing a little light in.
The control panel for the Parsons air-bleed gas turbine. It appears to be comprised of electricity meters and various dials. Its main controls are located in the Plant House control room.
We've now walked the entire length of the plant hall, so we retrace our steps back towards the Plant House control room.
The plant house control room is large wooden framed room constructed on an elevated platform at the western end of the plant hall. The windows of the control room overlook the plant hall, under which are the controls for all the plant.
A desk occupies the centre of the room with an exterior window looking east behind it.
Various schematics are mounted in frames on the walls and several filing cabinets are full of the plant operating and maintenance manuals.
When the Plant House was built, the westerly view from the control room window would’ve been of the security fence, grassland and trees. Since 1961, this view was blocked by the Air House, its associated piping and the Dry Air Main.
We now return to the first floor and take the walkway across the western end of the aero valve bay. Another walkway leads east, along which are doors to all the aero cubicles.
The first door leads into Aero Cathedral, the largest of the testing cubicles. Much of the control room in the viewing room remains, although some components and equipment have been removed.
Aero Cathedral is three storeys high and double the width of the other cubicles. Overhead skylights ensure the room is light and airy unlike its neighbours.
Although the last test rig has gone, all the interconnecting pipes for connections between the test rig and the pressure and suction mains are still scattered around the floor.
This shot clearly shows the first storey viewing room and the ground level doors which give access to the aero valve bay.
All the major areas of the Plant House have now been visited. So we take the stairs back up to the first floor and leave Aero Cubicle A3 by the same door we came in by.
We now find ourselves back at the office corridor, so take the stairs back to the ground floor and out of the Plant House.
Further labelled pictures and more of the Plant House can be seen on my Pyestock site.
All the best,
Simon
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