Monument record ORF 163 - Control Room, circa 1956

2007: Field survey of the Atomic Weapons Research Establishment by Historic England (S1).
Structure F4: F4 is sometimes described as a Laboratory although its function was as a control and monitoring building for Laboratory 1 (F3)and later the Hard Impact Facility (F5). It is an L shaped building covered by a shingle traverse, constructed mainly of reinforced concrete but with brick elements and is covered by a flat concrete roof sealed with asphalt. The building was originally entered from the east through a reinforced concrete porch with an open side to the south and a three light metal Crittall window in its east wall. The north exterior side of the porch is blank except for the remains of electrical fittings. Perhaps around 1963, when the building became the control centre for the Hard Impact Facility, the open southern side was bricked up and and a brick porch with double wooden doors added. To the west of the porch is a taller three bay structure with a projecting wing wall from the southeast corner to retain the shingle traverse. The south bay housed two toilet compartments and is lit by a three light Crittall window. In the central bay is a blocked double entrance. In the angle of the L is a later brick wall laid to stretcher bond with a concrete roof shielding the toilet compartment and the former entrance. The southwest bay is entered through the main covered porch area and retains some air conditioning plant. This in turn gives access to large monitoring room with a suspended floor to the west, which retains a few metal cabinets. On the roof of the porch section is a small galvanised metal header tank enclosed by Burwell white bricks.

SCHEDULED ANCIENT MONUMENT (S2).