Fort Halstead was a research site of theDefence Science and Technology Laboratory (Dstl), anexecutive agency of theUK Ministry of Defence. It is situated on the crest of theKentishNorth Downs, overlooking the town ofSevenoaks, southeast ofLondon. Originally constructed in 1892 as part of a ring of fortresses around London, Fort Halstead was to be staffed by volunteers in the event of a crisis.
The base became home to theProjectile Development Establishment, theMinistry of Supply and later was the headquarters of theRoyal Armament Research and Development Establishment (RARDE).[1][2]
Fort Halstead formed a part of theLondon Defence Positions, a scheme devised byLieutenant GeneralSir Edward Bruce Hamley and implemented by theSecretary of State for War,Edward Stanhope, who announced the plan toParliament in 1889. The scheme envisaged a line ofentrenchments which would be dug in the event of war to protect the southern and eastern approaches to the capital. Supporting these were to be thirteen simpleforts, known as "Mobilisation Centres", which would contain the tools, stores and ammunition for the men of theVolunteer Force, who were tasked with digging the entrenchments and manning them against any invaders.[3]
Putting these plans into action in 1890, theWar Office purchased land atHalstead, Kent, on high ground near the town ofSevenoaks. Delayed by a shortage of funds, thepolygonal fort was constructed between 1895 and 1897; it featured vaulted barrackcasemates on the west side and amagazine on the east.[4] An earthenrampart with positions for lightfield artillery pieces andmachine guns was surrounded by aditch with a concreterevetment on thescarp face. Acottage was built for a caretaker, who was responsible for maintenance and security in peacetime.[3]
The growing superiority of theRoyal Navy, and the signing of theEntente Cordiale with France, resulted in the reduced likelihood of an invasion and the London Defence Scheme was officially abandoned in March 1906. Many of the Mobilisation Centres were quickly sold; however, Fort Halstead and a few others were retained, perhaps to facilitate the dispersal of the stores removed from the other sites. After the outbreak of theFirst World War, the London Defence Scheme was revived and many of the planned entrenchments were actually dug to form an inlandstop line.[3]
Fort Halstead seems to have reverted to its intended role at this time; in 1915, a laboratory was built inside the fort for the inspection of ammunition. In 1921, the fort was sold to a retiredcolonel, who took up residence in the laboratory and let out the cottages. The rest of the site was used as a campsite for theTerritorial Army,Boy Scouts,Girl Guides, and accommodation of refugees.[5]
In 1938, Fort Halstead became the home of the Projectile Development Establishment, which was continuing work onsolid fuelled rockets that had started atRoyal Arsenal inWoolwich two years earlier. Under the direction ofAlwyn Crow, work was mainly on rockets that could be used asanti-aircraft weapons. In connection with this research, over eighty new buildings were constructed in and around the fort.[5]
The work at Halstead resulted in the 7-inchUnrotated Projectile used on ships of the Royal Navy, and a 3-inch version that was operated by the British Army in hundreds ofZ Batteries for the air defence of the United Kingdom. Further developments were theRP-3 air-to-surface anti-tank rocket and theMattress andLand Mattress surface-to-surface bombardment systems.[6]
In 1940, Fort Halstead became vulnerable to enemy action and Germans knew about the rocket development there, so Projectile Development Establishment was evacuated toRAE Aberporth.[7]
Two departments, the "Research Department" and the "Design Department", were established in 1922 atWoolwich Arsenal. During theSecond World War, the Design Department moved to Fort Halstead, followed by the Research Department. It is believed thatBritain's development of theatomic bomb, hidden under the name 'High Explosive Research' (HER) was initially based at Fort Halstead, where the first atomic bomb was developed under the directorship ofWilliam George Penney,[2] who had been appointed Chief Superintendent Armament Research ("CSAR", called"Caesar") byC. P. Snow.Operation Hurricane saw the bomb conveyed by frigate toAustralia and successfully exploded in theMontebello Islands.[2] In 1950, it is thought that the 'HER' research was moved to a new site at theAtomic Weapons Establishment,Aldermaston inBerkshire.
In 1955, the two departments were merged to give the Armament Research and Development Establishment (ARDE), which was granted the title "Royal" in February 1962.[8] In the 1980s, RARDE was amalgamated with theMilitary Vehicles and Engineering Establishment (MVEE) – formerly the Fighting Vehicles Research and Development Establishment (FVRDE) – with sites atChertsey andChristchurch, and thePropellants, Explosives and Rocket Motor Establishment based atWaltham Abbey andWestcott.
Following the December 1988Lockerbie bombing,forensic experts from RARDE's explosives laboratory examined material recovered from the crash scene, and subsequently testified asexpert witnesses at thePan Am Flight 103 bombing trial.
In 1996, the bus from theAldwych bus bombing was taken to Fort Halstead for analysis, where previously a number ofIrish Republican Army (IRA) explosive devices had been examined.
RARDE was home to a number ofmilitary simulation and war game projects, mainly aimed as assessing the effectiveness of future defence equipment procurement. After Iraq'sinvasion of Kuwait and throughout the latter half of 1990, a series of computerised war games were conducted at RARDE in preparation forOperation Granby, Britain's contribution to theGulf War.
In 2017, scientists from the Forensic Explosives Laboratory at Fort Halstead examined the wreckage of the aircraft from thecrash of a Polish Air Force Tu-154 in 2010, for traces of explosives, after being engaged by the Polish government.[9]
On 1 April 1991, theDefence Research Agency (DRA) was set up by bringing togetherRoyal Aerospace Establishment (RAE),Admiralty Research Establishment (ARE), RARDE, and theRoyal Signals and Radar Establishment (RSRE). It was anexecutive Agency of theMinistry of Defence. Four years later, when DRA was itself merged to form theDefence Evaluation and Research Agency (DERA), the forensic explosives laboratory came under media and scientific scrutiny. In 1996, amid allegations that contaminated equipment had been used in the testing of forensic evidence, an inquiry was set up under Professor Brian Caddy ofStrathclyde University to investigate the laboratory's alleged shortcomings.[10]
Following the split of DERA in 2001 intoQinetiQ andDstl, the Fort Halstead site was retained by QinetiQ who leased part of it back to Dstl. Its most recent principal functions have been research, test, evaluation and forensic analysis into explosives, and the site's explosives laboratory was again used in the investigation following the attempted21 July 2005 London bombings.[11] The facility has been the largest employer in theSevenoaks district, with 1,300 personnel working on the site in 2000.
In March 2006, QinetiQ sold the Fort Halstead site to Armstrong Kent LLP for an undisclosed sum,[12] remaining on-site as a tenant. In June 2011,Dstl announced that its facilities at Fort Halstead were to close following a review of operations at the site,[13][14] although delays in building new facilities atPorton Down[15] has meant Dstl finally left in October 2022 (taking eleven rather than the planned five years).[16]
In 2017, Armstrong Kent sold the site to Merseyside Pension Fund.[16] Current plans are for a mixed-use regeneration, with 450 new homes and a business campus, including QinetiQ.[16]
51°18′42″N0°08′58″E / 51.31171°N 0.14936°E /51.31171; 0.14936