991/2/10021 HALL ROAD
21-FEB-03 (West side)
Building Q121 at former Royal Aircraft
(Formerly listed as:
BUILDING Q121 AT ROYAL DEFENCE AGENCY
FARNBOROUGH (24' WIND TUNNEL))
Wind tunnel and building for testing aero engines and aircraft. 1934-35. Concrete by K Holst and Company, steel by Boulton and Paul. Concrete-cases steel frame construction infilled with reinforced concrete; offices and workshops above the main test area of lightweight steel composite cladding on steel frame; timber-clad clock tower on east face.
PLAN: Rectangular block houses U-plan return chamber that clasps central test area with balance house and observors' cabin beneath. lift and drag measurement frame. Fan with mahogany blades to W side of this, adjacent to machinery for lowering models into test area. Drive shaft extends to engine room in block extending to W; to S of test area, in a shorter range, is the aeroplane shed from which a crane swung full aircraft into the test chamber.
2-5 storeys and basement. U-plan 2-storey block has high block in centre of 5 storeys in all with a central tower. 2-storey block is concrete-framed with grid-pattern mainly blank walls. Flat or low-mono-pitch roofs. Higher central section has cladding of corrugated sheeting and similar roofs. Fenestration mainly of 2-light metal casements. Tower is flat-roofed and has inter alia a long window just below the wide eaves on each side.
INTERIOR: The 24 ft wind tunnel is constructed of massed concrete and has cone with propeller-like 30ft diameter fan, which sucks the air through the open test area into a return air duct corridor fitted with deflector fins (up to 40 ft high) situated at each of the 90 degree bends which accellerate and take the air back to the test chamber entrance. Fan machinery including 2000 hp motor and associated control mechanisms. Foul air extractors at first-floor level, used when testing running engines. The upper floors functioned as offices, model preparation areas (measuring equipment remains) and workshops, and there is lifting machinery contained in the tower at 4th-floor level for the suspension of models into the test chamber. The test chamber has a balance house with steelyards for taking measurements, and above there are two balances by Sir Howard Grubb Parsons which with their attached models could be moved over the test area.
HISTORY: The open-return tunnel of 1934-5 (Q121) is the most complete and imposing example in the world after the Full Scale Tunnel at Langley in the United States. Other examples of this type, such as Johannistahl (stripped out) and Moscow (still in working order), are later and thus derivative in terms of design.
Farnborough is one of the key sites in Europe relating to the development of aviation, particularly powered flight and its impact on the human experience in the twentieth century. Despite the use of balloons as aerial observation platforms during the Napoleonic Wars and especially the American Civil War, it was not until 1879 that the Royal Engineers formed a Balloon Equipment Store at Woolwich Arsenal, which was subsequently moved to Chatham (1882), then Aldershot (1890) and finally Farnborough (1905). Its operational and training units were combined as the Balloon Factory in April 1906, the same year seeing the construction of the army's first airship shed at the Balloon School's new factory (demolished 1965) and 1910-11 the erection of two more airship sheds (moved to Kingsnorth and demolished c1930) adjacent to a new 'Portable Airship Shed'. The latter, a canvas-covered shed comprising in section a parabolic arch made up of rivetted box-section lattice units, was dismantled and now survives in two halves, the bottom half in a fabric shop and the upper half in a forge and foundry building: both of these buildings, erected in 1916-17 for the Aircraft Factory at Farnborough, are now listed grade II (as Buildings Q65 and R51). Despite the fact that the country's total of 6 airship sheds had increased to 61 by November 1918, only the examples at Farnborough and at Cardington have survived. These are survivals of importance and great rarity in a European context, particularly in view of the lack of survivals in Germany - which led the field in this technology. The balloon house of 1892-3 - moved to Farnborough from Aldershot - was listed in 1979 and demolished ten years later.
The American Samuel Cody, who had worked on the development of kites and balloons at Farnborough, designed, built and flew - in October 1908 - the British Army's first airplane. Under R.B. Haldane, whose tenure of office as Secretary of State for War between 1906 and 1911 witnessed the triumph of the materiel school of warfare in the debate concerning the future direction of Britain's armed forces, aviation was put on a scientific footing. An Advisory Committee on Aeronautics (which as the Aeronautical Research Council continued until 1980) was established in order to advise government and oversee research at the National Physical Laboratory at Teddington and the Army Aircraft Factory, as the Balloon Factory was renamed, at Farnborough. The formation of the Air Battalion of the Royal Engineers, in April 1911, formally recognised the role of military flying and the HQ of No 1 (Airship) Company was immediately established on the site: this unit became 1 Squadron of the RFC (the Royal Flying Corps) on its formation on May 13 1912, and served as the Royal Naval Air Service's Airship Detachment until the completion of Kingsnorth in March 1915. The Battalion's headquarters building (Building G1), which includes a balloon mobilisation store is an outstanding and unique survival from this period. One hangar survives from the pre-First Word War air station.
The planning of the R52 wind tunnel building in 1916 marked a critical period in Farnborough's development, for public censure over the vulnerability of the Royal Aircraft Factory's BE2c fighter had led to its closure as a site for the manufacture of aircraft by the British state. Farnborough, renamed the Royal Aircraft Establishment, was now placed at the heart of cutting-edge developments in what was already the iconic industry of the age, and after the creation of the Air Ministry in 1918 sustained by the 'largest Research and Development spending institute in Britain' (Edgerton: 35). Two new tunnels were built in 1931, one of these (the 'five foot' tunnel in R 52) being the prototype for Q121, constructed in 1934-5. With the increasing speeds and performance of aircraft another high-speed wind tunnel (R133) was planned from 1937, work for which begun in February 1939 and was completed in November 1942. These remarkable structures are with the protected tunnels at Meudon (Paris, France), Johannistahl (Berlin, Germany) and Langley Field (Virginia, United States) some the most impressive monuments to twentieth century technology in the world.
Wind tunnels (the first being built at Greenwich in 1871) were essential tools for the understanding of aerodynamics, an extension of the science of fluids which pushed at the boundaries of knowledge relating to mathematical theory and physics. It provided the key to unlocking the potential for the greater altitude, speed and handling characteristics of aircraft, developing a wide range of concepts including wing profiles, wing components and composition, plane stability criteria, strength standards, and flutter theory. The rapid changes advanced by the twentieth century's iconic industry - aviation - witnessed matching developments in the design of these tunnels, key factors in their performance being the size of the model, the speed of air flow and the atmospheric pressure. In order to reduce turbulence, and enable accurate analysis and measurement of the forces exerted on the object in the test area, wind tunnels used fans to suck air over the test area, at first blowing it out of the other end of the building (as with R52 and the tunnel at Chalais Meudon in France) and then recycling it in a closed circuit within the building, as with the 1931 extension to R52 and Q121. Tunnels of this type operate at normal air pressure, so that full-size aircraft could be craned into the test areas. The Full Scale Tunnel built in 1929-31 for NASA's predecessor the NACA at Langley, Virginia, represented a world first in this respect, Q121 at Farnborough - with its original internal fittings and its internal fin system for turning the air through 360 degrees - being the largest and most complete example in Europe. The pressurised tunnels designed from the 1920s enabled reliable tests to be carried out on small-scale models at low air speed, variable density tunnels - being surrounded by a steel shell which was filled with compressed air - allowing the density of air to be varied according to the size of the model and other factors. The first was built at Langley, Virginia, in 1923, and survives with most features intact. The much larger high speed tunnel at Farnborough (R 133) was completed in 1942, this being capable of measuring the effects of air speeds of Mach 0.8 to 1.2 at pressures from 1/10th to 3 atmospheres. This is uniquely important within a European context. The speeds of air within the tunnel - 600 mph - generated considerable heat, and thus the need for a coolant (potassium chloride brine) that kept the temperature within the test area at around 15 degrees Celsius: this need increased after modification, as speeds exceeded the speed of sound (Mach 1). The next stage in wind tunnel design was modification - first effected on the 8ft tunnel at Langley Park in 1950 - to enable testing at transonic speeds, as the projected speed of aircraft - and the need to predict the effectiveness of new designs - approached and then exceeded the sound barrier (Mach 1, broken in 1947, Mach 2 being broken in 1953). The original 10 x 7 foot high speed tunnel within R133 was very skilfully converted to transonic testing in 1951-6 by reducing its working section to 8 x 6 foot, installing slotted sides to eliminate rebound of the supersonic shock waves, and upgrading power input by 16,000 horse power. Half of this power was supplied by an axial compressor, which was also able to run a unique variable-density 2 x 1 1/2 foot wind tunnel capable of speeds up to 1100 mph (Mach 1.4), where the model can be observed through glass walls. The compressor, 2 x 1 1/2 tunnel and additional cooling facilities were built in extensions on the north side of the building. As a cooled cylinder flask constructed for high speed testing - a unique survival in Europe - the completion of this tunnel placed Farnborough at the global forefront of aerodynamic development, through its work on understanding transonic flow phenomena and shock wave effects. Four of the derivative designs (Bedford ARA of 1954 and 1956), Blackburn Bae (1961) and English Electric (1960) are still in use.
The RAE spearheaded the British state's technocratic approach to the support of military and - especially in the period 1945-70 - civil aviation, working in partnership with private companies by using its experts and facilities to develop new aircraft on the cutting edge of aerodynamic science. Thus the Air Ministry placed contracts for prototypes with approved firms, using the wind tunnels at Farnborough in order to monitor and pioneer advances in aeronautical research, including aerodynamic theory, construction, fuels and engines. The decision to build a large open-section tunnel (Q121) at the RAE resulted from the need to test full-size planes as well as models, and understand the effect of running engines on aerodynamic performance. It played a key role in the development of new generations of aircraft, including Sydney Camm's Hurricane, Mitchell's Spitfire and the four-engined bomber force. By the end of the Second World War, the RAE was placed at the heart of a huge technological base which employed over 1.5 million people. The high-speed tunnel of 1939-42 (R133) was used during the Second World War to test models relating to modifications to and prototypes of, most notably, the Mustang, Spitfire and Typhoon fighters, in addition to Frank Whittle's Gloster E.28/39, the first jet-propelled aircraft to be flown in the UK. In the immediate post-war years the levels of Research and Development funding increased, and Farnborough became the largest R and D establishment in Europe, developing the 'hot science' that underpinned NATO's attempts to counter the Soviet military threat. Slow progress on the establishment of the National Aeronautical Establishment, founded in 1947 at Bedford, ensured that the Aerodynamic Department at Farnborough played a critical role for much of the Cold War in devising quick-reaction aircraft that could both carry nuclear weapons and defend Britain and NATO against high-speed Soviet bombers. Particularly valuable was its unique expertise in transonic and supersonic aerodynamics. The RAE's wind tunnels had been used during the Second World War to develop work on high-speed aircraft, the immediate post-war years seeing the team at Farnborough - now bolstered by German scientists who had worked on rocket and fighter weapons programmes - take a global lead in work on experimental transonic swept-wing aircraft. This work included in 1949 the English Electric P.1 (becoming the Lightning fighter) the 'most potent interceptor in the world at the time .... to leapfrog a whole generation of fighters' (Nahum: 42-3) and the development of the 'V'-bomber force (operational from 1955) and the aerodynamics and viability of its nuclear payload. Work also included the testing of the Fairey Delta and the TSR2. Work on Mach 2 fighters then paved the way for the pioneering work on narrow delta aircraft for supersonic flight from the mid 1950s by the German scientists Dietrich Kuchemann and Johanna Weber on its theory and mathematics, followed by empirically-based testing in the wind tunnels led by W.E. Grey. This groundbreaking work put the RAE firmly in the lead on the world stage, culminating in the Concorde project. As one historian has pointed out, the RAE 'fuelled the post-war university expansion in aerodynamics', contributed its chief scientists to major players such as Lockheed and Martin-Marietta and 'throughout the Cold War ... served as the main and enduring core of European aerodynamic knowledge' (Nahum: 54).
Alan Baxter Associates, The Farnborough Wind Tunnels: Conservation Plan, 2001 (report for Slough Estates); ('The Army Balloon Shed at Farnborough', The Engineer, May 13 1910; 'Airship Sheds and Their Erection', Journal of Civil Engineers, Vol. 212, 1920; Alan Pope, Wind Tunnel Testing (2nd edition, New York, 1974), contains a list of documented wind tunnels in tabular form; James R. Hansen, Engineer in Charge: A History of the Langley Aeronautical Laboratory, 1917-1958 (The NASA History Series, Washington, 1987); Andrew Nahum, 'The Royal Aircraft Establishment. From 1945 to Concorde', in Cold War, Hot Science (Science Museum, Amsterdam, 1999); David Edgerton, England and the Aeroplane. An Essay on a Militant and Technological Nation (London, 1981); John Pudney, Laboratory of the Air. An Account of the Royal Aircraft Establishment of the Ministry of Supply, Farnborough (HMSO, 1948); Percy Walker, Early Aviation at Farnborough. The History of the Royal Aircraft Establishment, 2 vols (London, 1971 and 1974); Professor A. Thom and W.G.A. Perring, 'The Design and Work of the Farnborough High Speed Tunnel', Journal of the Royal Aeronautical Society, 1948, pp. 205-250; 'The Twenty-Four-Forty Wind Tunnel at Farnborough' The Engineer, 1935; April 5, pp. 351-3; April 12, pp. 380-2; May 3, pp. 468-71; May 17, pp. 516-19; May 24, pp. 534-7.
Listing NGR: SU8596156123