Air Base 200 Apt–Saint-Christol (or Sault Saint-Christol Airport), is a former French Air Force installation located in the municipality of Saint-Christol, near Apt, in the Vaucluse department. Between 1971 and 1996, it served as the support base for the ballistic missiles of the French nuclear deterrent deployed on the Albion Plateau. The site was operated by the 1st Strategic Missile Group of the Strategic Air Forces and comprised eighteen missile silos. Following the dismantling of the missile facilities, the site was renamed Quartier Maréchal Kœnig. Since 1999, it has housed the 2nd Foreign Engineer Regiment of the French Army and a listening station operated by the General Directorate for External Security (DGSE).
History
Context
Following the end of the Second World War, France initiated military and civilian nuclear programs with the creation of the Atomic Energy Commission (CEA) in October 1945, under the Provisional Government of the Republic led by Charles de Gaulle. During the subsequent years, the context of the Cold War reinforced French ambitions to develop nuclear weapons as part of a deterrence strategy. Under the Fourth Republic, this program progressed slowly and remained largely classified.
Within the NATO framework, French forces stationed in Germany became familiar with nuclear weapons from 1960 onward, although these tactical weapons remained under exclusive United States control. At the same time, several developments highlighted the limitsOn 30 October 1953, the doctrine proposed by the Eisenhower administration stated that any attack against American troops would trigger a massive retaliation, unless doing so would be detrimental to national security. of the U.S. doctrine of “massive retaliation” adopted in 1953, including the absence of U.S. diplomatic support for France during the Suez Crisis and the adoption of the “flexible response” strategy in the early 1960s. These elements contributed to the perception within the French military leadership that the United States would commit its strategic nuclear forces only in the event of a direct threat to its own territory, while restricting its response in a European conflict to tactical nuclear use. In this context, French leaders considered that a national strategic nuclear force under French control could play a deterrent role by influencing U.S. decision-making within an integrated Western command structure. Such a capability was also viewed as a means of ensuring France’s participation in strategic consultations and affirming its status as a major power, in line with the objectives articulated by Charles de Gaulle. This perspective led French authorities to seek the development of a diversified nuclear arsenal comparable in scope to that of the superpowers, reflecting the desire to avoid dependence on any single category of weaponry controlled by another state.
Development
In 1960, following his election as President of the Republic, Charles de Gaulle initiated the development of France’s strategic nuclear forces by ordering a fleet of strategic bombers from Dassault Aviation and launching programs for ground-based ballistic missiles and nuclear-powered ballistic missile submarines. In May 1963, he defined the main components of France’s nuclear deterrent, which were to include Mirage IV aircraft equipped with nuclear bombs, land-based ballistic missiles fitted with nuclear warheads, and submarine-launched ballistic missiles deployed on nuclear-powered submarines.
Responsibility for the deployment of the strategic ground-to-ground ballistic missiles (SSBS) was assigned to the Air Force. The Army did not oppose this choice, as it favored the development of more flexible tactical nuclear weapons, while the Navy advocated the use of nuclear-powered ballistic missile submarines (SNLEs), considered less vulnerable. Air Force officials argued that a submarine could be destroyed by a single torpedo, whereas neutralizing the SSBS force would require at least one nuclear warhead per missile, each housed in a hardened silo.
From 1963, studies were carried out in Corsica, the Vosges, the Massif Central, and the Drôme to identify suitable missile deployment sites. In April 1965, the Albion Plateau was selected over the due to its low population density and limestone soil, which facilitated silo construction and was capable of absorbing the effects of a nuclear blast.
Construction At the beginning of 1966, a plan was implemented to construct 27 silos and three launch control centers (PCT) over 785 hectares, as well as Air Base 200 Apt–Saint-Christol (BA 200) over 406 hectares. The project was assigned to the Engineer Corps.
The installation faced public opposition, including protests from artists and intellectuals. In February 1966, René Char contributed to a poster titled La Provence point Oméga, illustrated by Pablo Picasso, declaring: "Let those who pierce the noble terrestrial bark of Albion measure this well: we are fighting for a site where snow is not only the she-wolf of winter but also the alder of spring. The sun rises there upon our demanding blood, and man is never imprisoned by his fellow man. In our eyes, this site is worth more than our bread, for it cannot itself be replaced."
Construction of Launch Control Center 1 took place from November 1966 to March 1969. Work on Launch Control Center 2 began in July 1969 and was completed in March 1970. Construction of Launch Control Center 3 and its associated silos was started but halted in December 1968 due to budget restrictions. The operational facilities involved 260,000 cubic meters of rock excavation, 540,000 cubic meters of earthworks, and 150,000 cubic meters of concrete. During the same period, the surrounding road network was upgraded to accommodate military convoys.
In 1967, the 1st Strategic Missile Group, part of the Air Force, was established to manage the facilities on the Albion Plateau. Additional units were created to ensure site security, including the EP 21.200 Protection Squadron in 1968, which consisted of a command section, a canine unit, and four paratrooper companies. The first MR 31 nuclear warheads were delivered to Air Base 200 in August 1969.
Operational missiles
The first operational unit, equipped with nine S2 missiles, entered service on 2 August 1971, followed by a second unit on 23 April 1972. In the early 1980s, these missiles were replaced by S3 missiles, with the first operational S3 SSBS unit entering service on 1 June 1980 and the second on 31 December 1982.
Initially, it was planned that the S3 missiles would be replaced around 2005 by a land-based version of the M5 missile, whose development began in 1992. In 1994, the M45 missile was announced as a successor to the S3. Both projects were ultimately abandoned following the announcement of the dismantling of the installations in 1996.
Aerial surveillance of the silos was initially conducted using Sikorsky H-34 helicopters. On 1 May 1976, was established and stationed at the base, operating SE.3130 Alouette II, MH.1521M Broussard, SA-330Ba Puma, and AS-555UN Fennec aircraft. From 1971 to 1996, BA 200 and the Albion Plateau were described as among the most heavily guarded sites in France.
During the operational period of BA 200, the airfield accommodated a wide variety of aircraft, including those carrying foreign heads of state.
Dismantling and conversion On 22 February 1996, President Jacques Chirac announced the closure of the base and the dismantling of the missiles on the Albion Plateau, citing changes in European geostrategy following the collapse of the Eastern Bloc and the aging of the missiles, which were costly to maintain and not scheduled for modernization.
It was initially planned to convert the base into a ; however, the project was abandoned following concerns from local residents regarding noise. Subsequently, the Ministry of Defense announced that a military presence would be maintained on the site through the stationing of an engineer regiment of the French Foreign Legion.
Missile dismantling operations began on 16 September 1996, and the site was declared denuclearized at the end of February 1998. The nuclear warheads were transferred to the Valduc center.
From June 1996 to August 1998, the was stationed at the air base before relocating to Dijon and later to Orange. The 1st Strategic Missile Group and Helicopter Squadron 4/67 Durance were disbanded on 31 August 1998.
The 2nd Foreign Engineer Regiment was established on 1 July 1999 and assumed control of the site, with BA 200 becoming the Maréchal Koenig Barracks.
In 2003, the Directorate-General for External Security (DGSE) installed a listening station at the base.
Installations
Of the 27 planned launch zones and three fire control posts, only 18 launch zones and two fire control posts were completed.
Launch zones On the surface, the only visible element of a launch zone was the technical building, which housed equipment for site maintenance. The majority of the launch zone was located underground beneath a reinforced concrete slab measuring 50 by 50 meters and 9 meters thick. At its center, a steel-and-concrete shaft—the silo—extended to a depth of 30 meters. A 140-ton, 1.5-meter-thick door covered the silo and, upon launch order, could be moved along rails by cables operated with pyrotechnic actuators. The design of the sites was based on the American Minuteman missile silos, with dimensions adapted for the smaller French S2 missile.
For maintenance, a two-ton armored door provided access to an elevator leading to the −6 and −9 meter levels of the silo. Retractable scaffolding at these levels allowed access to missile components, including the warhead and interstage section. The missile rested on a supporting ring suspended by cables designed to absorb seismic waves from surface explosions. Each silo was also accompanied by a buried auxiliary shelter containing support equipment, including backup generators.
Each launch zone was located at least 3 kilometers from its nearest neighbor to ensure that a single attack could not simultaneously destroy multiple sites, as the mechanical effects of a nuclear explosion are relatively limited and two simultaneous detonations reduce the overall impact on surrounding structures. The system occupied a limited footprint: only a 200-meter square area around each launch zone was secured with three layers of fencing, consisting of a perimeter fence defining the controlled area, an intermediate fence, and an electrified fence. The remaining areas of the plateau, which were inhabited, remained in agricultural use.
List of launch zones