Building R52 at Former Royal Aircraft Establishment Site

Wind Tunnel Building at Former Royal Aircraft Establishment Site

This wind tunnel was constructed in 1916 for the Royal Aircraft Establishment at Farnborough. It is built of yellow brick with brown brick used to accentuate pilasters and pedimented gable ends.

The building comprises two parallel 8-bay ranges which originally accommodated two 'seven foot' open-ended tunnels. An integral 5-bay lean-to was extended to the north for a 5-foot open tunnel installed in 1929-31. The south range was extended to accommodate a return air duct of 11 by 8 feet for a low-speed tunnel inserted in the south bay in 1938.

The double-gabled west front is divided into six recessed panels by red brick pilasters which rise through the tympanae of pedimented gable ends, with stepping to the soffits of the copings. Each gabled bay features a segmental-arched double doorway; the doorway to the right (south) is blocked and obscured by a two-storey flat-roofed loading bay built in similar materials. The sides and rear are articulated in a similar manner. The building includes a tall flat-roofed extension to the south and a mid-twentieth century lean-to to the east in similar materials, along with a mid-twentieth century red brick gabled extension to the north.

The interior contains steel truss roofs. The north bay retains a 1916 electric motor from the original number 2 'seven-foot' tunnel; that tunnel was removed in 1944 and replaced by a 4 by 3 foot low-turbulence tunnel which retains control and balance rooms and features a beautifully-finished timber tunnel where air was led through gauze screens running on metal tracks via a contracting entrance into the working section. The balance mechanism from the original 'five-foot' tunnel installed in 1931 survives in working order, with remarkable sensitivity of one-thousandth of a pound.

From 1918 to 1958, the aerodynamics team was led by the internationally-recognised Miss Fanny Bradfield, who became Head of the Small Tunnels Division in 1942. The small tunnels housed in this building were used for aero-elasticity experiments, testing of Mitchell's Supermarine 'S' series of high-speed aircraft, streamlining bomb shapes and their release characteristics, and the first supersonic tests with high-speed aerofoils in 1928. The building plan and form directly relate to the dimensions and layout of the tunnels it was designed to accommodate. It is one of the world's earliest surviving wind tunnel buildings and contributes significantly to the unique grouping of wind tunnel buildings on this internationally important site.

The 4 by 3 foot tunnel, constructed after 1944, represents a critical phase in the RAE's history. It achieved the ultimate reduction in turbulence, claimed to be the lowest in the world, to facilitate high-precision testing. Its work on the release characteristics of the atomic bomb underpinned the effectiveness of the British V-force nuclear deterrent. The tunnel was also used for early experimental work on the Brabazon airliner, Malcolm Campbell's speed boat, and the narrow delta-winged aircraft that culminated in Concorde.