Summary
A group of Cold War bomb stores known as ‘igloos’, constructed at former RAF Wethersfield for the United States Air Force. It includes four bomb stores built in the 1950s, three to store nuclear weapons and one to hold nuclear triggers, or capsules, and a single unit with seven cells built in the 1960s to store Sidewinder missiles, all with contemporary blast walls.
Reasons for Designation
The Cold War bomb stores at former RAF Wethersfield, including four nuclear bomb stores built in the 1950s, three to store nuclear weapons and one to hold nuclear triggers, or capsules, and a single unit with seven cells built in the 1960s to store Sidewinder air-to-air missiles, all with contemporary blast walls, are listed at Grade II for the following principal reasons:
Architectural interest:
* as largely complete and rare building types in a national and international context, designed to store innovative nuclear and infra-red heat-seeking technology as deterrents against Eastern Bloc aggression;
* as surviving examples of American-designed military architecture deployed in an English context.
Historic interest:
* as structures which characterise the evolution of American/NATO strategy, tactics and technology during the Cold War.
* they embody the strong political ties and co-operation that existed between the United Kingdom and United States (‘the special relationship’) throughout the Cold War.
Group value:
* as a group of buildings which collectively have major national and international significance, illustrating how RAF Wethersfield evolved through time to support evolving strategies and missions during the Cold War, with two distinct phases of deterrence still evident.
History
Work on RAF Wethersfield began in 1941, was substantially complete by December 1942, and was finally declared finished 30 June 1943. Its original infrastructure was typical of many wartime temporary airfields. The runways were organised in a characteristic A-plan and spectacle type hardstandings provided enough space to accommodate 50 aircraft. For aircraft maintenance the airfield was equipped with two T2 hangars and to the north were open bomb stores. To provide some protection from bombing the airfield’s domestic sites were dispersed across a wide area.
Initially, it operated as a satellite airfield to RAF Ridgewell, about 13km to the north-west. In January 1944 it was assigned to RAF Bomber Command. A month later it began its long association with the United States of America when it was assigned to the United States Army Air Force’s 9th Air Force, when it was known as Station 170. Operations began in March 1944, mainly related to pre-June 1944 D-Day targets and attacks on V1 missile launch sites. In November it reverted to the RAF when it was allocated to Fighter Command. From November 1945 it assumed a training role until being put on care and maintenance in January 1947.
The outbreak of the Korean War in June 1950 saw heightened international tensions and the base was reactivated in September of the same year. In April 1951 it was occupied by RAF Fighter Command, and in June was allocated to United States Air Force (USAF). On 24 August 1951 it passed to the USAF 3rd Air Force. On 31 May 1952, the 20th Fighter Bomber Group (FBG) from Langley, Virginia, flying F-84G Thunderjets and later F-84F Thunderstreaks, was allocated to the 3rd Air Force. The 20th FBG in turn was attached to the 49th Air Division with a mission to conduct tactical nuclear operations. In February 1955 the 20th TBG’s designation was altered to the 20th Fighter Bomber Wing (FBW). In July 1958, just after the Wing converted to F-100 Super Sabres, a further name change took place when it was renamed the 20th Tactical Fighter Wing (TFW).
Throughout the 1950s and 1960s the main role of units based at Wethersfield was to provide tactical support to NATO on mainland Europe with conventional and nuclear weapons. The Cold War alterations to the airfield and its infrastructure directly reflect this mission. The main runway was extended by 1,000 (309m) to either end, runway lighting was installed and hardstandings were consolidated to 42, enough to house 84 aircraft. A 70,000-gallon (318226 litre) R-type fuel store was also added, roads were widened, and additional temporary structures were built, including distinctive American prefabricated building types such as Armseal, Quonset and Butler.
It was probably in the early 1950s that the Explosives Storage Area (ESA) was built on the centre part of the wartime bomb stores. Within this area four distinctive magazines known as ‘Igloos’ were built; three to hold nuclear weapons and the fourth to hold their detonators, or triggers. This area was defined by a double fence and monitored from raised guard towers. To the west of the ESA, and outside of its boundary fence, were five Second World War storage areas. In the early 1960s these were demolished and replaced with protected accommodation for Sidewinder air-to-air missiles.
In July 1958 the 20th TFW achieved ‘Blast Off’ or ‘Victor Alert’ status. Inside the fenced Victor Alert area armed and fuelled aircraft could be held at a high state of readiness. The area, which was established on the northern side of the airfield, close enough to be served by the ESA, had the capacity to maintain eight aircraft, each one sheltered beneath a steel-framed hangar similar in appearance to a Dutch barn. The shelters had open ends and were originally open along the lower part of their side walls. This open structure allowed the aircraft within to remain fully fuelled and armed, capable of very rapid deployment in periods of heightened alert. Aerial photography confirms that the shelters were in place by August 1961. At the centre of the group was an associated squadron headquarters building (256, 257) for the duty pilots and their ground crew. A safe within such buildings would typically hold the unit’s target folders.
In December 1961 the airfield received national attention when 600 people from the Committee of 100 (a direct action, anti-nuclear protest group) attempted to breach its perimeter. The ‘Wethersfield Six’, charged under the Official Secrets Act, received substantial prison sentences for their role in organising the demonstration.
Less than a year later during the October 1962 Cuban Missile Crisis the 20th TFW’s Super Sabres were placed on heightened alert.
Recorded debates in the House of Commons in 1967 reveal further construction work at Wethersfield valued at £500,500. This was the last large building campaign and the airfield’s further development as an operational fast jet airfield was inhibited by its proximity to the rapidly expanding civil airport at Stansted.
The 20th TFW remained until 1 April 1970 when it moved to RAF Upper Heyford, Oxfordshire. The base remained with the 3rd Air Force and the management of the airfield was assigned to the 66th Combat Support Group (CSG). It was then designated as a Dual Operating Base and later a Standby Deployment Base or Standby Operating Base, for the 10th Tactical Reconnaissance Wing (TRW) stationed at Alconbury, Cambridgeshire. A further change of designation came in July 1976 when it became an Operational Location A (OLA).
In 1979, Wethersfield was chosen as the main UK base for the 819th Rapid Engineer Deployable Heavy Operational Repair Squadron Engineers (RED HORSE) until it was stood down in August 1990. To provide communications support for this squadron elements of the 2166th Communications Squadron were also based at Wethersfield.
After the departure of the engineers, the airfield was designated RAF Wethersfield Radio Relay Site. The site was returned to the Ministry of Defence on 19 April 1991 and the last US personnel left in June 1992. Since that date the Ministry of Defence Police (MDP) has been the main occupant of the airfield, operating alongside fire brigade practice activities and Air Training Corps glider training.
The closure of RAF Wethersfield was announced in 2016 with an expected closure date of 2020. This has, however, been delayed and final disposal is now scheduled to take place in 2025.
Details
A group of Cold War bomb stores known as ‘igloos’, constructed at former RAF Wethersfield for the United States Air Force. It includes four bomb stores built in the 1950s, three to store nuclear weapons and one to hold nuclear triggers, or capsules, and a single unit with seven cells built in the 1960s to store Sidewinder missiles, all with contemporary blast walls.
MATERIALS: the nuclear bomb and trigger stores consist of earth-covered reinforced-concrete boxes and the Sidewinder missile stores comprise earth-covered corrugated-steel barrel vaults, all with reinforced concrete headwalls, back walls, wingwalls and blast walls, the latter revetted in earth at the rear, and heavy-duty steel doors.
PLAN: the nuclear bomb and trigger stores stand within a rectangular area, aligned north-west to south-east, bounded by a 1950s concrete service road. Three nuclear bomb stores stand side-by-side some 40m apart on the west side, all aligned north-east to south-west, while the trigger store stands in the north-east corner on a north-west to south-east axis, all with detached blast walls on an identical alignment on the opposite side of the service road. From its two northern corners a 1960s concrete service road defines a smaller rectangular area, aligned north-east to south-west, to which the Sidewinder missile store stands on the north side with a detached blast wall on the opposite side of the road, both aligned north-east to south-west.
EXTERIOR: the front of each bomb and trigger store consists of a central headwall flanked by wingwalls, all extending above the top and sides of earthen mounds covering rectangular boxes of reinforced concrete. At the centre of each headwall are top-hung, sliding, double-leaf, steel doors beneath a concrete hood, each accessed by a concrete apron from the adjoining service road. Ventilation to each store is provided by louvered openings in the headwall and ventilator stacks at the rear
The Sidewinder missile store comprises a single structure with a long headwall flanked by wingwalls, all extending above the top and sides of an earthen mound covering seven barrel-vaulted bomb stores constructed from corrugated steel. The front of each bomb store has a hinged, double-leaf, steel door beneath a concrete hood, accessed from the adjoining service road by a concrete apron. Ventilation to each store is provided by louvered openings in the headwall and ventilator stacks at the rear.
INTERIOR: the bomb and trigger stores all have reinforced-concrete walls and ceilings and concrete slab floors. A metal hook for loading and unloading operations, assembly and maintenance functions is embedded in the ceiling of the three nuclear bomb stores. Although the external appearance of the trigger store is identical to the three nuclear bomb stores, its internal depth is shallower and contains a small vault/safe in which the nuclear triggers were stored. The interior of two of the bomb stores were subdivided in the late C20/early C21 with concrete blockwork.
The interiors of the seven Sidewinder missile stores are comprised of corrugated-steel barrel vaults sprayed with asbestos for fireproofing and anti-condensation insulation purposes. The floors are formed of concrete slabs. Openings in the rear walls connect to external ventilation stacks.
SUBSIDIARY FEATURES: standing immediately to the front of each bomb store, on the opposite side of the service road, are reinforced-concrete blast walls revetted in earth at the rear.
