Reasons for Designation
When the RAF was formed as the world's first independent air force in April
1918, and during the period of retrenchment which lasted from the Armistice
until the early 1920s, its founding father and first Chief of Staff, General
Sir Hugh Trenchard, concentrated upon developing its strategic role as an
offensive bomber force. His primary considerations were in laying the
foundations for a technology-based service, through the training of officers
Subsequently, more than 100 stations were built in permanent fabric between
1923 and 1939. Trenchard's expansion of the air force, given Parliament's
blessing in 1923, was centred upon the building of offensive bomber bases in
East Anglia and Oxfordshire, behind an `aircraft fighting zone' some 15 miles
deep and extending around London from Duxford in Cambridgeshire to Salisbury
This principle of offensive deterrence, although subject to fluctuations
which reflected events on the world stage and varying degrees of political
support, continued to guide the siting and layout of stations after 1933,
when Hitler's rise to power and the collapse of the Geneva disarmament talks
forced the British government to engage in a massive programme of rearmament.
The continuing development of existing bases (some dating from the First
World War), and the building of new ones thus concentrated on the
establishment of training and maintenance bases behind an eastern front line,
extending from Yorkshire to East Anglia, facing Germany.
The completeness or otherwise of inter-war bases, and the extent to which
they have retained their architectural detail, external fittings and
inter-relationships as planned groups, is closely linked to the nature and
intensity of their post-War use. Upper Heyford, for example, which was the
test-bed for the planning of Trenchard's Home Defence Scheme stations, was
greatly extended and adapted as a key USAF site in the Cold War period. Less
intensive use - at present for administration, storage and glider training -
has ensured that Bicester is the most complete representative of developments
on bomber airfields for the period up to 1939.
RAF Bicester is the best preserved of the bomber bases constructed as the
principal arm of Sir Hugh Trenchard's expansion of the RAF from 1923, which
was based on the philosophy of offensive deterrence. It retains, better than
any other military airbase in Britain, the layout and fabric relating to both
pre-1930s military aviation and the development of Britain's strategic bomber
force in the period up to 1939. The grass flying field still survives with
its 1939 boundaries largely intact, bounded by a group of bomb stores built
in 1928-1929 and airfield defences built in the early stages of the war. The
remains included in the scheduling are, along with the listed hangars and
other listed buildings, the key structures within this military landscape.
The monument includes the southern bomb stores group and a series of airfield
defence structures forming part of the former RAF Bicester Airfield site.
These fall within 11 separate areas of protection (termed here constraint
areas) as detailed below, and as listed above with their national grid
The first constraint area includes the southern bomb stores group built in
1938-1939 as one of three intended Squadron bomb stores, only two of which
were fully completed. The constraint area (the largest) includes a series of
structures based around the High Explosive bomb stores (building 224). The
bomb stores consist of two rows of three back-to-back concrete buildings with
surrounding earth banking or traverses and a gantry running along both the
north and south 'frontages' to allow bombs to be lifted onto bomb carts. The
bombs would then be taken to the Ultra Heavy Fusing point building (building
226). This curved roofed corrugated steel and earth building was built with
ten bays and could accommodate a bomb cart 'train' of High Explosive (HE)
bombs under cover where the fuses were added, having been collected from the
Component stores (building 214). Together these buildings show the methods
taken to store safely and securely the components of the bomber armament.
At constraint area 2, about 300m west of the bomb stores, lies a group of
defences consisting of two mushroom pill boxes flanking an approximately 50m
long double seagull trench - the former so named for their saucer-domed
concrete roofs (set on to a cross-wall which provided ricochet compartments
internally) and the latter for its wing-shaped plan, which maximised the arc
of fire. These defensive structures combined to form a formidable ground
defence group as part of the wider airfield defences. Constraint areas 3 and
4 include a pair of linear Defended Air Raid shelters to the east of the
southern hangar. These brick, concrete and earth structures provided cover
for defenders in the event of ground attack by enemy paratroopers and
provided some protection against bombing and strafing by enemy aircraft.
Of the three further pairs of Defended Air Raid shelters which protected the
other three hangars that form the core of the Technical site, only a single
shelter survives (constraint area 7). The shelters were linked defensively by
a series of pillboxes of which two survive within the scheduling (constraint
areas 5 and 6). These are based on the octagonal, type 27, pillbox design and
formed part of a series of fixed defensive points around the inner core and
perimeter of the air base. At the northernmost point of the scheduling lies a
small air raid shelter (constraint area 8), intended for those using the
adjacent fuel installation. Three further undefended air raid shelters,
located close to the hangars to provide protection to ground crew in the
event of air attack are also included in the scheduling. These brick,
concrete and earth structures are situated within the hangar complex
(constraint areas 9-11).
Although Bicester was first used as an airfield in 1918, it is the Trenchard
Bomber Base and the 1934 expansion period remains which make it nationally
important. Blenheims, Halifaxes and Mosquitos all flew from Bicester. Bomber
crews trained at Bicester included both British and many Commonwealth
squadrons including Australian, Canadian and New Zealand airmen. From 1944 it
was involved as a forward equipment unit for Operation Overlord (the Normandy
landings), and after the war it was the home of the principal aircraft
salvage unit for southern England. Its later use as a glider school while the
domestic site was used for logistical purposes ensured it was not
dramatically altered from its wartime layout.
Excluded from the scheduling are all modern services and their trench fills,
although the land around and beneath them is included.
The site of the monument is shown on the attached map extract.
It includes a 2 metre boundary around the archaeological features,
considered to be essential for the monument's support and preservation.