Details
HENLOW
346/0/10010 Building 190 (Coupled general service
01-DEC-05 shed), RAF Henlow
GV II
Coupled maintenance shed. 1918, by the War Office's Directorate of Fortifications and Works; drawing No 2010/18. Walls, buttresses, internal piers and door 'pylons' in brick, Dorman Long steel trusses, steel-framed doors clad in corrugated steel sheeting, and roofs in later profiled steel.
PLAN: A double-span shed with gabled ends; roof trusses carried on external raking buttresses and internal paired piers. To each side are lean-to units, some in 2 storeys, including former boiler-house on the SE side. In 9 bays of 5.8m, total length 52m, and with two clear spans, each of 30.5m; internal clear height is 7.6m. The SE side has three 2-storey lean-to extensions corresponding to each end bay and the centre bay, and the field side is similar.
EXTERIOR: The long flanks are almost identical, with broad raking buttresses flanking half-brick curtain walls containing paired 24-pane steel casements in a continuous clerestory strip to 3 bays each side of centre, and similar low-level fenestration, but with some smaller lights in bays near the outer ends. The 2-storey units have small-pane steel lights, 2 to each level; these have been blocked to the former boiler-house, and the stack removed. The gabled ends are sheeted, above a continuous sliding track box. Full height and width doors, eight leaves to each opening, are in cross-braced steel framing exposed externally over corrugated cladding, and at each outer end is the original 'pylon' to take the stacked doors. These are plain brick, but with central reinforcing pier, and short returned stabilising ends, rising above the trace box and eaves level.
INTERIOR: The interior has a plain concrete floor, with central row of doubled brick piers, linked at the head with brick diaphragms to a segmental arch along the line of the valley gutter. There is horizontal bracing to the bays adjoining the door openings, and a series of light steel purlins carries the roof sheeting.
HISTORY: RAF Henlow was established in 1917 as the Eastern Command Repair Depot, raised to Group status in 1965 and still in RAF hands. The War Office had issued instructions for the construction of repair depots for each RFC Command, further to heightened awareness of the need to train more men in the rapid repair of aircraft and aero engines in order to sustain the war effort. Construction at Henlow - conveniently served by the Midland Railway - was begun in 1917, and some of the more substantial structures including the hangars date from this time; the last of the huts dating from this period were demolished in the 1970s. The first service personnel arrived (from Farnborough) in May 1918, and a limited output of Bristol fighters and Haviland aircraft was achieved by the Armistice. An extra area was added in early 1920, and in March of that year Henlow became the Inland Area Aircraft Depot; it was thus one of a very small number of airfields retained for use after November 1918, in its role as the RAF's flight test and maintenance centre forming a vital element within Sir Hugh Trenchard's newly-independent air force. By 1924, when it was selected as the permanent home of the School of Aeronautical Engineering, Henlow was producing 35 engines and 15 aircraft each month. In its role as a training base for skilled engineers and equipping operational stations with the latest aircraft it became, with Cranwell, Halton and Uxbridge, one of the RAF's largest bases, accommodating some 7000 of various nationalities in 1940. Basic engineering theory and management were taught at the Officers' Engineering School (formerly at Farnborough), one of the 1932 pupils being Frank Whittle. The Aircraft Riggers' School was brought in after 1935, and during the Second World War it performed a vital function as one of the RAF's largest Maintenance Units, overhauling, repairing and modifying a wide range of fighters and bombers, from Spitfires and Typhoons to Lancasters. A significant period was during the Battle of Britain in 1940: Hurricanes manufactured in Canada were crated in, assembled at Henlow and flown onto front-line bases. At one stage in 1941, in Operation Quickforce, about 100 Henlow fitters were trained for the assembly of Hurricanes on carriers en route for Malta, to which the completed planes were flown off deck. The Control Tower was at this time manufactured from packing case material, and still remains. Parachute training, including SOE officers, was another key function of the base. In 1947 the School of Aeronautical Engineering became the RAF Technical College, moving to Cranwell in 1965.
The most complete group of early buildings at Henlow comprises the five General Service Sheds which, although subjected to some external alteration, comprise the most complete ensemble of hangar buildings on any British site for the period up to 1923. This 100-ft span shed, whose span reflected the greater scale of military aircraft late in 1918, represents the first move from wood to metal trusses in RAF hangar design: it is the only example to have survived. Dorman Long and Co Ltd had in 1918 been asked by the Air Ministry to supply two types of 100-ft span trusses for aircraft sheds, the Armistice curtailing work on other sites. Unlike Buildings 186-9, this has retained its original external detail in the form of window and door fitments - although it has lost its original roof lights and stack.
The flying field has been partly developed by a golf course. The domestic site, which was subjected to an extensive rebuilding programme concentrated in the first half of the 1930s, is situated across the A6001 to the south of the technical group. This has retained an extensive group of married quarters, executed in the Garden City tradition, and barracks and office buildings dated 1933-5 which display unique architectural treatment for a military air base: the most consistently well-handled of these buildings is the officers' mess.
(Air Ministry Drawing 1528/18, RAF Museum Hendon; The History of RAF Henlow, RAF Henlow, 1998)
