Building No 109 (Watch Tower and Office)

Airfield Watch Tower and Office

This is an airfield observation tower and office built in 1938 to a 1934 type design. It was designed by A Bulloch of the Air Ministry's Directorate of Works and Buildings, drawn to number 1959/34. The structure combines a brick facing with a reinforced concrete frame and has flat roofs finished in asphalt.

The building comprises a square main structure at ground level with a smaller square central tower rising two additional storeys above it. The ground floor contains the main watch office, a rest room and latrines, with a tight spiral stair giving access to the observation room in the tower above. Both levels have flat roof decks—the lower one has a raised brick parapet, while the upper one has both parapet and safety railing.

The exterior features steel casements across the full width of the lower floor, with one light returned at each end and smaller lights to the other fronts. A door with over-light is positioned on the rear (west) and south sides. The upper level is fully glazed all around, though some of the original horizontal glazing bars were later removed. The building has a small plinth and continuous frieze bands with projecting toe details at roof levels.

Inside, iron stairs lead to the top floor, and the original doors and joinery have been retained.

This observation tower replaced an earlier 1927 design and is typical of designs made in 1934, of which a total of 41 were built. This example is one of only five remaining in brick construction, as after 1936 most were built in reinforced concrete. It represents the first attempt at a purpose-designed military watch office. Located at the end of the main axis through the Technical Site from the guardhouse, it closes the vista at the edge of the flying field and is strongly representative of developments on flying fields in the mid-1930s. Grouped with 'C' type hangars built under Scheme F in 1936–7, it forms a significant element of this uniquely important site.

RAF Bicester is the best-preserved of the bomber bases constructed as the principal arm of the RAF's expansion from 1923, which was based on a philosophy of offensive deterrence. It retains the layout and fabric relating to pre-1930s military aviation and the development of Britain's strategic bomber force better than any other military airbase in Britain, showing how this expansion reflected both domestic political pressures and world events up to 1939. During much of the Second World War, RAF Bicester functioned as an Operational Training Unit, training Canadian, Australian and New Zealand aircrew alongside British personnel for service in Bomber Command. The grass flying field still survives with its 1939 boundaries largely intact, bounded by bomb stores built in 1938–9 and airfield defences from the early stages of the Second World War. The Technical Site, separated from the Domestic Site, retains many original buildings, mostly from 1926 with others added during successive phases of the 1930s Expansion Period.