Monument record ORF 153 - Vibration Test Building circa 1960

2007: Field survey of the Atomic Weapons Research Establishment by Historic England (S1).
Structure E3: The Vibration Test Building is a large reinforced concrete structure, comprising a central chamber with a heavy concrete roof suppor ted on pillars, and protected by a shingle traverse on its east, north and south sides. To its south and east are freestanding brick plant rooms. In the centre of the centre of the building is a large central chamber dimensions, 16.47m (54ft)by 7.30m (24ft). It was entered from a passageway to the south through large wooden outward opening doors covered with metal sheeting with a small pedestrian single door to the east. Outside of the main door a single exterior door gave access to the toilet room, which was lit by a metal framed 3 light window and a small window in its east wall. Inside the main door way to the west is a small recess that may have contained a fire hose. On the opposite side a staircase gives access down to the working floor of the central chamber and beyond it another staircase to the east gives access to an upper walkway around the central chamber. Returning to the entrance passage in its ceiling are 4 very substantial eyehooks for lifting ropes. At the north end of the entrance passage is a lift pit. 5.2m (17ft)by 4.88m (16ft)and 3.45m (11ft 4ins)deep. On its north and south walls cut off bolts mark the former position of metal plates. In the southeast corner of the pit is a recessed vertical channel for electrical pipes and 3 pipes possibly for hydraulic fluids The base of the main test chamber is 1.5m(5ft) above the level of the lift pit floor and measures 9.75m (32ft)by 4.88m (16ft), the height to the to the upper walkway is (12ft) 3.67m. The base of the chamber appears to be formed from a series of I beams, which allowed test equipment to be secured in various places on the floor. Set into the north wall are 7 vertical, metal plates with cruciform slots, these likewise were probably used for securing test equipment. On the east wall are 4 similar horizontal plates, stencilled between the central plates and to the north of the northern plate are the figures 54, 60 , 66, these indicate the height above the floor surface (in inches). On the south wall are 3 horizontal metal plates with a central slot in each above the middle plate are stencilled numbers 1-30 ft and below the plate are stencilled the numbers 1-7.5m, at 0.50m intervals. Below the bottom plate there is a stencilled ‘C Fold’ the C is possibly earlier as it seems to be partially overpainted.

To either side of the chamber are cable ducts infilled with shingle, along the base of the north wall are 8 pipe openings, 3 of which are sealed by bolted circular plates. Along the base of the east wall is the remains of an air-conditioning system (not in-situ), at the southeast corner a passage leads back to the air-conditioning plant on the east side of the building. Surrounding the test chamber is an upper walkway which was formerly protected by a moveable handrail, whose fittings survive. Between the walkway and the outer wall is a cable duct on the north and south walls. There is also a fixed handrail and on the south, east and north walls along with various electrical pipes switches and junction boxes and a single rectangular cable duct. In the north east corner is a vertical ladder that gave access to the window level. Attached to the east wall is a large square section air-conditioning duct leading to the plant room to the south. On the north, east and south walls of the test chamber are inserted pipes, 4 each on the north and south walls and 3 on the east which connect back to the cable ducts around the edge of the walkway. Below these on each of the walls are pairs of circular threaded fixings.

The building’s roof is a massive concrete slab supported on 16 square columns, the under side of the roof is 8.75m (28ft 6ins)from the floor of the chamber. On the underside of the roof and on the walls are various screw threaded holes for eyehooks, used to position heavy test equipment.

The openings between the columns were originally filled with wooden framed windows and glazed with perspex sheets. A ledge along the south and north walls of the main chamber carried rails for an overhead travelling crane. At the northeast corner of the main test chamber a doorway gives access to a service corridor running east-west along the north side of the building. For most of its length mounted on its north wall were large cork insulated air conditioing pipes. To the west a flight of stairs provides access to the top of the north lip of the lift pit and to the upper walkway around the test chamber this flight of stairs also gives access to a now blocked door to the emergency exit in the north wall. To the east a second flight of stairs gives access to the plant room attached to the eastern side of the building, a sign on one of the switches records ‘Minerva cell DC supply isolation relay’. On the upper west wall of the test chamber a sign records ‘telephone instrument room’ below it is a light fitting, to the south are the remains of light fittings and wooden batons for a sign.

To the south and detached from the main test chamber is an air conditioning plant of brick cavity wall construction faced with Burwell whites laid to stretcher bond with a flat concrete roof supported on RSJs. This building measures 11.62m (38ft 1ins)by 6.04m (19ft 10ins)and is 4m (13ft). The block is divided into two by a brick partition wall the larger bay to the west was entered through two pairs of wooden doors, above the eastern opening is a wooden louvred vent which connects back to the air-conditioning plant and above the western door there is a wooden 2 light window. Between the thetwo sets of door openings there is a large 3 light window at eaves height. Internally are 3 large concrete machinery mounting plinths and 1 smaller plinth, sections of metal air-ducts also survive and a metal switch cabinet. In the north wall is a larger square opening formerly with a wooden louvred vent and to the west a small square opening which carries the ducting back towards the entrance passage. An opening in the partition wall carries the ducting into the smaller and now sealed eastern bay. The main western bay was lit by 8 lamps and on its east wall a sign by a pipe warns ‘unfit for drinking’. The smaller east bay was lit by a 3 light metal framed window (now blocked) at eaves height. On the north wall a square section duct connects back to the main chamber.

Along the eastern side of the complex is another freestanding plant room of brick cavity wall construction and faced with Burwell whites and also has a flat concrete roof. It is divided into 3 bays, at the northeast corner the eastern wall of this bay is rebated back from the main elevation and was formerly entered through double door (now sealed), its northern side is lit by a 4 light steel framed window set at eaves height. To its west is a large rectangular opening housing 2 large diameter air conditioning pipes that connect back to the pipes in the northern service corridor. To the northeast of these openings is a low concrete plinth. An historic photograph (Kinsey 1981, 108)shows a mobile air conditioning unit connected to the two large air conditioning pipes, and cables leading back to the north wall of the building. Returning to the main eastern side, there are 4 bay openings, the southern bay, which housed a transformer, is now sealed in breeze block. The remainder of the bays have metal concertina doors, internally there was a suspended floor whose concrete piers remain, to the rear is a cable or pipe duct one arm connects back to the main test chamber and also to the bays to the north and south. The roof is supported on steel RSJs and is lit by 3 roof lights and 18 pendant lights. A number of junction boxes, air-conditioning ducts and small-bore electrical ducts remain.

At the southern end of the main plant room is an open framed plant room constructed from 2 I section portal frames with a southerly wall of brick cavity wall construction faced in Burwell whites. In this wall is a large door opening to eaves height, the side walls to east and west were formerly infilled with wooden louvred vents with 5 light windows above. The building was also vented by 2 wooden framed clearstories. The exteriors of the vertical metal columns were protected by copper sheeting. Internally, there is a central walkway with now shingle filled cable ducts to either side, a single door (now blocked) led back into the south bay of the main plant block. Along the west side of the building is a much decayed section of steel duct work. Various electrical pipes remain attached to the north wall.

To the north is the remains of a flag pole which seems to have also acted as a lightning rod.

SCHEDULED ANCIENT MONUMENT (S2).