Details
TL 20 NW HATFIELD COMET WAY
(West, off)
77/8/10046
The Flight Test Hanger,
Offices, Fire Station and
Control Tower. British
Aerospace
II*
Flight hangar, offices, fire station and control tower for the de Havilland Comet. Main hangar 1952-3, offices and tower completed 1954. The architects were James M Monro and Son, with Structural and Mechanical Development Engineers Ltd designers of the aluminium structure, and J Bak engineer for the foundations. Hangar of HE 10 aluminium alloy, covered with an insulated aluminium curtain wall. North slopes of the roof are glazed, with aluminium glazing bars, south slopes are covered with insulated aluminium decking covered with bitumen felt. Some steel framing in office block on west wall, which is clad in brick.
The main structure consists of twelve portal frames at 30ft centres. They span 217ft between pinned bases and give a clear floor area 200ft wide by 330ft long with a clear height of 45ft. The legs of the portals are eight feet wide and the horizontal girder portions have a constant depth of ten feet throughout their span, excepting for a greater depth at knee positions to counteract the heavy fixings and loadings. Concrete flooring incorporates prestressed tie beams to take up the side thrust of the portal frames. South elevation entirely filled with sliding and folding `Esavian' doors. Windows in aluminium frames, those to north elevation with saw-tooth profile. The control tower of six storeys was noted for its early use of non-reflective plate glass and its air conditioning. Below it four floors with curved balcony fronts whose pattern of diagonal bracing is repeated in the fenestration. Similar curved front to three-bay firestation with double doors with deep eaves canopy. Simpler aluminium glazing to office range.
Interior of the main shed is a clear-span space. Staircase to the control tower with `molecule and lightning' steel balustrade distinctive of 1950s' contemporary styling. The control room retains original fixed desk and controls.
In 1941-2 de Havilland began to develop a jet engine, the Goblin, which was incorporated into the design of the Vampire jet fighter in 1943-4, and developed further as the Ghost. de Havilland's prime interest, however, was in civil aviation, and in 1946 they designed the world's first jet passenger liner, the Comet. Filling a gap in the market, and seen as the future of British aviation, sixteen were ordered as early as 1947. The first commercial service was in May 1952. But between 1953-4 three Comets exploded in the sky, and 111 people were killed. Tests revealed fatigue to the thin aluminium alloy shell, which caused the pressurised cabin to explode. The o2,000,000 analysis which confirmed the fault provided a model testing system for subsequent jet aircraft, including the problem-free Comet 4, inaugurated in 1958 - just ahead of the Boeing 707 - and was followed by the DH Trident. The hangar was commissioned for testing and maintaining the Comet.
`Here is a structure every bit as dramatic as the jet liners it shelters' (Aluminium in Modern Architecture). The aluminium alloy span of 200' is only one seventh the weight of an equivalent steel structure. Apart from the savings in material, the light weight of the structure permitted prefabrication of unusually large sub-assemblies. The main structure was erected in only thirteen weeks. The Comet hangar was the most sophisticated example of aluminium construction, and was also the world's largest permanent aluminium structure at the time, comparable with the demolished Dome of Discovery at the Festival of Britain and larger and more innovative than the hangar at London Airport (now also demolished). Aluminium construction enjoyed something of a boom in the early 1950s, with steel in short supply and aircraft companies with experience in using aluminium looking to diversify. British Standards for aluminium buildings and improvements in alloys were recognised by the government in 1953, and the Comet hangar was the first building to make use of them. `The Comet flight Shed has aroused world wide interest in that it is the largest aluminium hangar constructed. By ingenuity in design, attention to detail and the utmost co-operation between the Architect and Contractor, a very fine result was achieved. It is particularly fortunate that the appearance is enhanced by the addition of an annexe building' (The Structural Engineer).
Sources
The Engineer, 23 January 1953, pp.127-8
The Builder, 23 January 1953, p.165
Architects' Journal, 29 January 1953, pp.169-70
Architect and Building News, 29 January 1953, pp.143-5
Architectural Design, May 1954, pp.124-5
National Builder, February 1953, pp.215-17
John Peter, Aluminium in Modern Architecture, vol. I, Louisville, Kentucky, 1956, pp.154-5
The Structural Engineer, October 1958, p.327.
Listing NGR: TL2127308842
