The combination of missiles and marshes and bombs and birds means it still holds a fascination for people around the world. The military history of the site dates back to 1913, when a large part of Orford Ness was taken over by the War Department. It was drained to form airfields for the Central Flying School’s Experimental Flying Section; and so began an intense seventy year period of military activity.
Experiments during the first World War included those on parachutes, aerial photography, bomb and machine gun sights, the evaluation of aircraft and the development of camouflage. Prisoners of War held in this area were used to help build the airfield and flood protection walls. In 1918 a number of German prisoners died in an epidemic, probably influenza, and were buried in Orford churchyard. Their bodies were later transferred to a war cemetery.
Perhaps the part of the site which still holds the most interest and intrigue are the atomic testing laboratories, commonly known as ‘the pagodas’ used for atomic bomb testing which can still be seen today. The first of six test cells was completed in 1956. The main section of the building is divided into two cells. Some contained a pit into which very large weapons such as Britain’s first atomic bomb, Blue Danube, could be lowered by a 10-ton crane, prior to vibration units being attached.
The laboratories were designed to mimic the rigours to which a nuclear weapon might be subjected before detonation, and included vibration, extremes of temperature, shocks and G forces. This article focuses on the main functions that each of the buildings and laboratories provided plus an insight into the rising nuclear deterrents tested in this complex.
Article Quick Links
- About the UK’s Atomic Arsenal
- Grand Slam
- Blue Danube
- Yellow Sun
- Green Bamboo
- Atomic Weapons Laboratories and Functions
- Laboratory 1 – Large Vibration Testing
- Laboratory 2 – Centrifuge Testing
- Laboratory 3 – Climatic Testing
- Vibration Test Buildings I & II
- Control Room
- Pump House & Electrical Substation
- Magazine / Armoury
The following video provides a taste of what went on in this location, the official line says that no fissile core material was tested on the site however you will see, the construction was such to contain contamination in the event of failure.
About the UK’s Atomic Arsenal
The Grand Slam was a 22,000 lb (10,000 kg) earthquake bomb used by RAF Bomber Command against strategic targets during the Second World War.
Known officially as ‘The Bomb’, Medium Capacity, 22,000 lb, it was a scaled up version of the Tallboy bomb and closer to the original size that the bomb inventor Barnes Wallis had envisioned when he first developed his earthquake bomb idea.
On 18 July 1943, work started on a larger version of the Tallboy bomb, which would become the Grand Slam. As with the original Tallboy,the Grand Slam’s fins generated a stabilizing spin and the bomb had a thicker case than a conventional bomb, which allowed deeper penetration. After the hot molten Torpex was poured into the casing, the explosive took a month to cool and set. Like the Tallboy, because of the low rate of production and consequent high value of each bomb,aircrews were told to land with their unused bombs on board rather than jettison them into the sea if a sortie was aborted.
After release from the Avro Lancaster B.Mk 1 (Special) bomber,the Grand Slam would reach near sonic speed, approaching 320 m/s, and penetrate deep underground,with the explosion causing a camouflet and shifting the ground to undermine a target’s foundation. After the Allied Operation Undergo captured the Watten V-2 rocket facility in October 1944,a single Avro Lancaster attempted to bomb the bunker’s dome from 10 November-20 November with a Grand Slam at precisely midday.
Like Tallboy, Grand Slam had not been designed to directly penetrate concrete roofs and tended to detonate prematurely or break up,but nonetheless they were still far more effective than any existing bomb.
Blue Danube was the first operational British nuclear weapon. The RAF V bomber force was initially meant to use Blue Danube as their primary armament at a time when the first hydrogen bomb had not been detonated, and the British military planners still believed that an atomic war could be fought and won using atomic bombs of similar yield to the Hiroshima bomb. For that reason the stockpile planned was for up to 800 bombs with yields of approx. 10-12 kilotons.V bomber bomb bays were sized to carry Blue Danube,the smallest-size nuclear bomb that was possible to design given the technology of the day (1947) when their plans were formulated.
Initial designs for the Blue Danube warhead were based on research derived from Hurricane,the first British fission device (which was not designed nor employed as a weapon), tested in 1952. The actual Blue Danube warhead was proof-tested at the Marcoo (surface) and Kite (air-drop) nuclear trials sites in Maralinga, Australia, by a team of Australian,British and Canadian scientists in late 1956.
Blue Danube added a ballistically shaped casing to the existing Hurricane physics package,with four flip-out fins to ensure a stable ballistic trajectory from the planned release height of 50,000 ft. It initially used a plutonium core, but all service versions were modified to use a composite plutonium/U-235 core, and a version was also tested with a uranium-only core. The Service chiefs insisted on a yield of between 10-12 kT for two reasons:firstly, to minimise usage of scarce and expensive fissile material; and secondly,to minimise the risk of pre-detonation, a phenomenon then little understood,and the primary reason for using a composite core of concentric shells of plutonium and U-235.Although there were many plans for versions with higher yields, some up to 40 kT,none came to fruition,largely because of the scarcity of fissile materials,and there is no evidence that any were seriously contemplated.
The first Blue Danube was delivered to stockpile at RAF Wittering in November 1953 although there were no aircraft equipped to carry it until the following year. No. 1321 Flight RAF was established at RAF Wittering in April 1954 as a Vickers Valiant unit to integrate the Blue Danube nuclear weapon into RAF service. The Short Sperrin was also able to carry the Blue Danube and had been ordered as a fall-back option,in case the V-Bomber projects proved unsuccessful. Declassified archives show that a total number of 58 were produced before production shifted in 1958 to the smaller and more capable Red Beard weapon, which could accept the Blue Danube fissile core and also could be carried by much smaller aircraft.It seems unlikely that all 58 Blue Danube weapons were operational at any given time. Blue Danube was retired in 1962.
Major deficiencies with Blue Danube included the use of unreliable lead-acid accumulators to supply power to the firing circuits and radar altimeters. Later weapons used the more reliable ram-air turbine-generators or thermal batteries.Blue Danube was not really engineered as a weapon equipped to withstand the rigours of service life. It was really a scientific experiment on a gigantic scale,which needed to be re-engineered to meet Service requirements. That re-engineered weapon became Red Beard.A similar account could be written of the first U.S. atomic bomb, Fat Man, which was quickly re-engineered after World War II.
The actual warhead being prepared for testing
Scaled model showing the warhead in its bomb casing
Yellow Sun was the first British operational high-yield strategic nuclear weapon. The name actually refers only to the outer casing; the warhead (or physics package) was known as “Green Grass” (in Yellow Sun Mk.1) and “Red Snow” (in Yellow Sun Mk.2). The ENI or electronic neutron initiator (generator) was Blue Stone.
The casing was some 21 feet (6.4 metres) long, 48 inches (1.2 m) in diameter.The Mark 1 version with the Green Grass warhead weighed 7,250 lb (3.3 tonnes). The Mk.2 version with the lighter 1,700 lb Red Snow warhead had ballast added to maintain overall weight, ballistic and aerodynamic properties, and avoid further lengthy and expensive testing, and changes to the electrical power generating and air burst fusing equipment.
Unlike contemporary U.S. bombs of similar power it did not use a parachute to retard its fall, instead, the blunt nose was intended to slow the fall of the weapon sufficiently to permit the bomber to escape the detonation, and ensured that Yellow Sun did not encounter the transonic and supersonic shock waves that had caused much difficulty with barometric fusing gates that had plagued an earlier weapon, Blue Danube.
Yellow Sun Stage 1 and Stage 2 were the original designations. Stage 1 was intended as an interim design to carry a one megaton Green Bamboo warhead of the “layer-cake” type thought similar to the Soviet JOE.4 and the US “Alarm Clock” concepts. These hybrid designs are not now regarded as truly thermonuclear, but were then thought to be a stepping-stone on the route to a fusion bomb. Stage 2 was to follow when a true thermonuclear warhead based on the Granite design became available.
The 45 inch diameter of Green Bamboo determined the 48 inch diameter of both Yellow Sun and the Powered Guided Bomb Blue Steel.
Deployment started in 1959-60. Yellow Sun Mk.1 was intended as an “emergency” weapon, and had not been engineered for reliable long-term stockpiling. It was always envisaged that a Mk.2 version would be available later fitted with a true thermonuclear warhead derived from the Granite type tested at Grapple, or an American type made available after the 1958 Anglo-US Bilateral Agreement. It was carried only by RAF V-bombers.In September 1958 a decision was made to abandon the Granite type warheads intended for Yellow Sun Mk.2 (and Blue Steel, and Blue Streak MRBM) and instead adopt the US W-28 warhead used in the US Mk-28 nuclear bomb. This was anglicised to adapt it to British engineering practices,and manufactured in Britain using British fissile materials and known as Red Snow.
Red Snow was both more powerful, lighter and smaller than Green Grass. It was always envisaged that the Yellow Sun bomb casing would be adapted for successor warheads to minimise unessential development time and cost.Yellow Sun Mk. 2 entered service in 1961, and remained the primary air-dropped strategic weapon until replaced with WE.177B in 1966.
Although the first British designed thermonuclear weapon to be deployed,Yellow Sun was not the first to be deployed with the RAF. US Mk-28 and Mk-43 thermonuclear bombs and others had been supplied to the RAF for use in V-bombers prior to the deployment of Yellow Sun. Some bombers of the V-force only ever used American weapons supplied under dual-key arrangements.
The first version, the Polaris A-1, had a range of 1000 nautical miles (1853 km) and a single Mk 1 re-entry vehicle, carrying a single W-47-Y1 600 kT nuclear warhead, with an inertial guidance system which provided a Circular error probable (CEP) of 1800 meters (6000 ft). The two-stage solid propellant missile had a length of 28.5 ft (8.69 m), a body diameter of 54 in (1.37 m), and a launch weight of 28,800 lbs (13,090 kg).
The later versions (the A-2, A-3, and B-3) were larger, weighed more, and had longer ranges than the A-1. The range increase was most important: The A-2 range was 1,500 nautical miles (2,779 km), the A-3 2,500 nautical miles (4,631 km), and the B-3 2,000 nautical miles (3,705 km). The A-3 featured multiple re-entry vehicles (MRVs) which spread the warheads about a common target, and the B-3 was to have penetration aids to counter Soviet Anti-Ballistic Missile defences. The B-3 missile evolved into the C-3 Poseidon missile, which abandoned the decoy concept in favour of using the C3′s greater throw-weight for larger numbers (10-14) of new hardened high-re-entry-speed re-entry vehicles that could overwhelm Soviet defences by sheer weight of numbers, and its high speed after re-entry. The abandoned decoy system for the B-3 (Antelope) was known to the UK where it was adopted and evolved into Super Antelope, KH.793 and later re-labeled Chevaline
The British became interested in Polaris after the cancellations of the Blue Streak and Skybolt missiles in the 1960s. Under the 1962 Nassau Agreement that emerged from meetings between Harold Macmillan and John F. Kennedy, the United States would supply Britain with Polaris missiles, launch tubes, ReBs, and the fire-control systems. Great Britain would make its own warheads and submarines.
In return, the British agreed to assign control over their Polaris missile targeting to the SACEUR (Supreme Allied Commander, Europe), always an American, with the provision that in a national emergency when unsupported by the NATO allies, the targeting, permission to fire, and firing of those Polaris missiles would reside with the British national authorities. Nevertheless, the consent of the British Prime Minister is and has been always required for the use of British nuclear weapons, including the Polaris and Trident missiles.
Confusingly, the operational control of the Polaris submarines was assigned to another NATO Supreme Commander, the SACLANT (Supreme Allied Commander, Atlantic), who is based near Norfolk, Virginia, although the SACLANT routinely delegated control or the missiles to his deputy commander in the Eastern Atlantic area, COMEASTLANT, who was always a British admiral. The Polaris Sales Agreement was signed on April 6, 1963.
British Polaris submarines were the Resolution-class ballistic missile submarines. Although one boat of the four was always in a shipyard refitting, recent declassifications of archived files disclose that the Royal Navy deployed four boatloads of reentry vehicles and warheads, plus spare warheads for the Polaris A3T, retaining a limited ability to rather quickly re-arm and put to sea the Polaris boat that was in refit. When replaced by the Chevaline warhead, the sum total of deployed RVs & warheads reduced to three boatloads.
Atomic Weapons Laboratories and Functions
The standard casing for large air dropped nuclear devices was the one used for the first generation of operational nuclear weapons, Blue Danube. It was large and measured 24ft (7.3m) in length with a maximum diameter of 5ft (1.52m) and weighed 10,000lb (4636kg), its size determined by the dimensions of its warhead. Britain’s first operational warhead, the Mark I, also contained around 2.50 tons of conventional high explosives (Cocroft and Thomas 2003, 30).
Testing of this casing had been extensively proven by trial drops over Orford Ness, and there was probably also an element of expediency and economy to use casings that were already held in stock for a number of later warheads. Given its large size, for trials work it was able to accommodate newer models of warheads, such as the interim megaton device Orange Herald. Combined with a Blue Danube casing it was known as Violet Club or Knobkerry and was issued briefly to the RAF between 1958 and 1959. The size of the Blue Danube casing, the relatively large amounts of conventional high explosives used within 1950s nuclear warheads, the proposed trial routines and safety all contributed to the form of the test buildings.
Travelling from the headquarters area the first major structure of this period encountered is Laboratory 1, or the Large Vibration Laboratory.
Laboratory 1 – Large Vibration Testing
Laboratory 1 was the first of six atomic weapons test cells constructed on Orford Ness by the Atomic Weapons Research Establishment (AWRE) from Aldermaston. It was used for both mechanical and vibration testing and for drop tests. The main section of the building is divided into two cells. The one in the foreground contains a pit into which very large weapons such as Britain’s first atomic bomb, Blue Danube, could be lowered by a 10-ton crane, prior to vibration units being attached. The cell was then sealed to allow the manipulation of the internal environment by an array of air conditioning units. The far cell contained a hydraulic ram, which was used to subject the test piece to extreme ‘g’ forces. A light aluminium roof was designed to blow off in the event of an accident. Laboratory 1 is a massive reinforced concrete structure with a large central bay measuring 30.69m (100ft) by 9.13m (30ft) and was designed to mitigate against the effects of an accidental explosion. The first major test on an atomic weapon on Orford Ness took place in this lab on August Bank Holiday 1956.
Its concrete walls were given extra mass by the shingle traverse placed around them, which would tend to force blast vertically rather than laterally. The roof was also a relatively weak structure comprising nine steel W-shaped trusses and clad in aluminium sheeting, insulated with cork and covered in weather proof felt. The original requirement for this building was to test the Mark I atomic bomb and the Red Beard tactical weapon. It was envisaged that two chambers would be required, one for the assembly of the weapon and drop-tests with an impact loading of up to 200 tons. As it name implies in a droptest a weapon would be released from given height to simulate a ground handling mishap. A second chamber would be required for vibration tests.
Internally, the main bay is separated into two unequal portions by a substantial concrete dividing wall, and running along its northern side is a pit 3.18m (5ft 5in) wide and 2.74m (9ft) deep. On the dividing wall are traces of a screen mechanism to ensure that activities either side of the divide remained confidential. The larger Vibration Laboratory to the southeast measures 17.32m (57ft) and the smaller Drop Test Laboratory to the northwest 12.15m (40ft). Each of the bays was served by its own entrance with wooden doors to either end, creating air locks measuring 10.1m (33ft) and 9.2m (30ft). Although the original specification only called for the testing of the bomb’s central section, the air locks were long enough to accommodate a fully assembled Blue Danube and its carrying trolley.
Although manoeuvring such a large item through the southwest entrance and into the Drop Test bay would have been extremely tight.
A ledge below the top of the longitudinal walls of the central bay marks the position of a travelling crane that was used to position the bomb on the test equipment. Each of the of the entrance passages was later protected by crude steel doors fashioned from welded reinforcing rods, the presence of electric locks on the doors indicating they were added during AWRE occupancy.
Attached to the wall of the main bay are many small bore pipes that carried various services, including electric wires, hydraulic fluids, and carbon dioxide fire suppressant, and within the roof structure are the remains of large air conditioning ducts. On the northern side of the south eastern entrance passage are two rooms that probably accommodated switch and monitoring equipment, and on the south side of the south west entrance passage was a staff room and toilet cubicles.
Testing required the building to be temperature and humidity controlled and on the northwest side of the mound is a large self-contained reinforced concrete, two bay plant room measuring 21m (69ft) by 3.89m (12ft 8in). This sits within the main shingle traverse and is insulated it by a surrounding brick wall that acts a damp course. Air conditioning ducts from the main chamber enter this building and surviving plant within it indicates that it housed air conditioning plant. On the north side of the traverse is a similar self-contained structure; surviving fittings show that it mainly housed electrical switch gear, controls for the vibrating machines and carbon-dioxide supplies for the fire suppressant system.
To the northwest of Laboratory 1 is a detached rectangular reinforced concrete building, 10.92m (35ft 10in) by 6.1m (20ft). It was formerly numbered 127 and its last function was described as a Laboratory Store. Later alterations to this building, include the bricking up of the entrance on its southwest side and the replacement of wide opening with a single door, at this time a window was probably also blocked on the northwest side. Internally, a breeze block wall was inserted. These alterations may point to a change in the building’s function. The operations within Laboratory 1 were considered to be so hazardous that it was provided with a detached Control Room (142yds) to its northeast. This is an L-shaped reinforced concrete structure, originally with an open sided porch on its northeast side that gave access to the control and monitoring room to the southwest.
This comprised of two elements; a taller section to the northeast that housed air conditioning plant, some of which survives, an entrance passage; toilet cubicles and to its southwest a large open room with a suspended floor that housed the monitoring equipment, of which a few metal cabinets survive. To protect the building from any accidental explosions in Laboratory 1 its southwest side was protected by a shingle traverse – a protective mound. In late 1963, or early 1964, the Control Room was modified to serve the new Impact Facility that was being constructed to its northeast, it also suggests that experiments in Laboratory 1 may have ceased by this date. Alterations to the Control Room included the bricking up of the open porch and the insertion of double doors protected by a small projecting brick porch. Due to the change in direction for flying debris a protective brick wall and concrete roof were built to protect the toilet cubicles. Immediately to the northeast is a small brick Mess Room.
This was probably originally designed as a Store with a set of double doors facing the Control Room and windows on its northeast and southeast sides. Later the double door opening was infilled in breeze block and the window opening on the southeast side was used to create a single door. Internally, a white tile splashback sur vives on its northern wall. Unlike the Control Room, no attempt was made to protect the building from flying debris from Impact Facility. Similarly, to the south of the Messroom was an unprotected Camera Store housed in a timber and asbestos caravan, no trace of which remains.
Laboratory 2 – Centrifuge Testing
Laboratory 2 is constructed from reinforced concrete with a large central bay 30.67m (99ft 9in) by 9.05m (29ft 9in) oriented roughly east to west. To increase the available height in the chamber, its A-frame, angle iron roof trusses are raised 0.6m (2ft) above the tops of the walls. The roof was originally clad with cork insulation board covered in aluminium sheets and protected by an outer asphalt coat. Within the roof structure was an internal catwalk to give access to the lighting and large central cork clad, metal air conditioning duct. Internally, below the tops of the walls are projecting ledges that supported the rails for an overhead crane.
This was used to manoeuvre test pieces within the building, and for the installation and maintenance of the centrifuge. To the north and south of the main chamber are side aisles running the full length of the central chamber. These too have concrete walls but are roofed with horizontal beams with curved breeze blocks between them; above they are covered by the shingle mound. Each of the side aisles had an emergency escape exit, both again later secured by crude steel doors. The main entrance to the central bay was from the east where a T-shaped road layout provided enough space for a vehicle and trailer to reverse into the building.
The concrete entry porch was originally closed by wooden doors, but in common with the other earlier laboratories it was later secured by crude steel doors with an electrical alarm or catch. In common with Laboratory 1 the distance between the wooden doors would have probably been large enough to accommodate a fully assembled Blue Danube casing and its trolley. The building can also be entered from the west through another large entrance, also with an entrance passage secured by double wooden doors, and later crude steel gates. Entry from this aisle into the main chamber was through two openings in the main side wall, which would have restricted the size of items that could be taken through. Adjacent to this entrance are two staff amenity rooms.
At the northern end of the chamber was a Napier centrifuge, this was housed in a ground level, circular brick built feature 30ft (9.14m) in diameter, which could be entered by doorways to the east and west. The centrifuge was supported on a central base plate and above by two rolled steel joists to the north and south, which have subsequently been removed for scrap, leaving only their end sections embedded in the side walls. Below the tops of the walls are projecting ledges that carried rails for a travelling crane.
The centrifuge arm was 16ft (4.88m) in diameter, was capable of supporting a test piece weighing up to 1,000 lbs (453.6 kg), and was rated at 100,000 ‘g’ lb (AWRE nd, 13). In the south bay adjacent to the centrifuge is a large red concrete mounting block that probably held some of the control equipment for the centrifuge. At the western end of the central bay is a raised control room, accessed from a flight of concrete steps on the north wall.
At the western end of the building is a large reinforced concrete plant room, which is divided into two bays. To the north is a small control room and to the south was a large air conditioning plant. Surviving drawings indicate that the plant room was modified in 1963, alterations include the insertion of a single door to give access to the control room and the addition of a brick outshot to house a transformer and rectifier.
A number of features and documentary sources suggest that the centrifuge is a secondary feature. In contrast to the remainder of the structure the circular feature surrounding the centrifuge was brick built rather than concrete. Unfortunately, the wall surfaces are painted and also in part covered by grime and vegetation growth, which makes any assessment of the relationship of this feature to the original structure difficult. The entrances to either end are also large enough to accommodate a large trailer and potentially a full size Blue Danube casing. Within the main chamber the working area to the east of the centrifuge also appears disproportionately large. In addition amongst the surviving drawings is a record plan of the centrifuge installation dated June 1962 and plans for the extension of the plant room dated September 1963 (UKAEA Lab No.2 Centrifuge Details of plant room extension SW/S7851/Lab2/AD18339 24 9 63).
Laboratory 3 – Climatic Testing
This laboratory was primarily used for the climatic testing of nuclear weapons. Its function was to either warm or chill a weapon to simulate the variations of temperature that it might face in service. This building is also of reinforced concrete construction with a barrel vaulted roof and is entered from its south end through a concrete canopy, the southern wall of which was revetted with shingle.
To manoeuvre the heavy test objects into position there was a hoist mounted on a beam secured to the underside of the canopy and roof of the main chamber, traces of its fittings may still be seen. Entry into the chamber was originally through double wooden doors, but in common with the other earlier laboratories security was strengthened by the addition of crude welded steel doors.
At the top of these doors is a slot for the overhead lifting beam indicating that the doors were added while the building was operational. Internally, it comprised a large central chamber, 24.5m (80ft 5ins) by 6m (19ft 6in), which is divided into two sections. To the south was the preparation area and on its walls are the remains of electric conduits and small bore pipes for electric cabling.
To the rear was an insulated chamber 13.5m (44ft 4in) in length, which was separated from the preparation area by a cement covered expandomesh wall and a metal clad sliding door carried on an overhead rail. This slid into a corridor to the west that also gives access to a small switch room. The working area of the rear chamber measured 9.14m (30 ft) by 3m (10ft) by 3m (10ft) and its floor, set on four dwarf concrete walls, was capable of supporting 6 tons.
The temperature range that could be achieved varied between plus 60° to minus 60° centigrade, and while undergoing thermal tests an object might also be subject to vibration. To support the functions of this building it was equipped with large plant rooms. Set into the western side of the shingle traverse is the Condense Pump House a large reinforced concrete building 16.98m (55ft 8in) by 6.3m (20ft 8in). It is divided into two rooms. To the south is a small switch room, which may be entered through double external doors as well as from the main chamber along the corridor for the sliding door. The other chamber is larger and housed air conditioning and plant, it too could be entered through external doors or from the main chamber. Outside of its entrance is a support for four gas cylinders that probably held carbon dioxide bottles as part of the building’s fire suppressant system. On the northwest corner of the building are a series of small rooms that held various pieces of plant and toilet cubicles.
Vibration Test Buildings
The most distinctive structures built during this phase were the Vibration Test Buildings, commonly referred to as ‘The Pagodas’. The specification for the Vibration Test Buildings included the ability to withstand the accidental detonation of 400lbs (181.4kg) of high explosives. The report on their design noted that ‘the design of such a building is beyond normal architectural or structural practice’ (Millington 1971).
Responsibility for the design of the structure lay with the Southern Works Organisation of UKAEA and GW Dixon ARIBA was identified as the architect. Interestingly, a similar design had been used in the early 1950s at the Explosives Research and Development Establishment, Waltham Abbey, Essex, for the design of firing points with heavily armoured central chambers and control rooms and camera positions to either side. No reference was apparently made to these structures and in order to determine the best design for the new buildings experiments were carried out at AWRE Foulness using small amounts of explosives and 1/10 scale models.
The initial design was for a monolithic structure with a single entrance; a detonation in this structure completely destroyed the model and produced large fragments. This was modified by replacing the roof with laminated strawboard over the test cell and mounding its walls with gravel to add to the mass of the structure.
The design was further refined by supporting the roof on columns and also by adding to its mass by placing gravel on its top. The roof also overhung the test cell to contain the danger of lying debris being ejected from the building. When a model of this design was tested the roof and mound rose up, with part of the force of being vented through the gap between the top of the cell and the roof, the columns then gave way allowing the roof to fall back into the cell.
The Vibration Test Buildings are identical in design and the following description of is largely applicable to both structures. It comprises a large reinforced concrete central cell 16.47m (54ft) by 7.30m (24ft) covered by a massive reinforced concrete roof supported on sixteen reinforced concrete columns.
To the south and east of the main chambers are self-contained plant rooms. The main access to the building is from the south through an entrance passage which was originally sealed by a pair of outward opening metal covered wooden doors. On its western side, adjacent to the main entrance passage is a blocked doorway that led to a small staff room and toilet. Inside the building, on the eastern side of the passageway one set of stairs gives access down to the main test cell and another up to a walkway around the top of the chamber. At the end of the passageway is a lift pit, which allowed test pieces to be lowered on to the floor of the main test cell.
To assist in manoeuvring heavy objects there are a number of substantial steel eyelets screwed into the underside of the roof. A travelling crane also ran on rails mounted on a ledge beneath the windows, a loose plate on the floor recorded ‘Becker twin Lift Maximum Working Load 40 tons serial A-2647-2’. The floor of the main cell is formed of parallel and narrowly spaced steel I beams for test rigs to be firmly secured to the structure. To either side are cable ducts now filled with shingle. At the same time as being vibrated objects might also be placed in jackets to simulate extremes of heat and cold, or in a portable altitude chamber to mimic the effects of altitudinal changes.
Set into the north wall are seven steel plates with vertical cruciform slots that were also used for securing tests rigs or monitoring equipment. Below these are eight pipe opening from the service passageway to the north. In the south wall are three steel plates with horizontal slots, above the top plate is stencilled the figures 1ft to 27ft and below it 1m to 7.5m.
The walkway around three sides of the cell was originally protected by a handrail and there is another handrail fixed to the main wall. Running around the wall is a cable conduit and attached to the wall are various pipes for carrying electrical wires, switches, junction boxes and pressure gauges. Signs on the wall above the lift pit record ‘Telephone Instrument Room’, ‘Vac Pump Running, Vac Pump Stopped’ with associated light fittings.
At the northeast corner of the cell is a doorway to the rear service passage running east to west along the north side of the building. To the east a flight of stairs gives access to the eastern plant room. To the west another set of stairs provides access to the northern side of the lift pit, the upper walkway and to an emergency escape passage through the north side of the traverse. To the south of the main cell is a freestanding Burwell brick-built plant room. The main plant room is entered through two sets of double doors on its south side, internally are four machinery mounting plinths. Attached to its west wall is a metal cabinet that probably housed equipment to operate the hydraulic compressor for the internal lift.
At the eastern end of the building is a store room with a blocked doorway to the south. To the east of the main cell is another large freestanding Burwell brick plant room running along the eastern side of the Vibration Test Building. At its southern end is a large, now open, bay that housed water coolers, this comprises a flat concrete roof with roof vents, that was supported on two steel girder portal frames and a brick wall to the south with a door opening. To aid ventilation its side walls were infilled with wooden louvered vents and probably for decorative effect the vertical steel columns were originally covered with copper sheeting. Internally, there is a central walkway and cable conduits, now filled with shingle. A now blocked door in its north wall gave access to the main plant room.
At the southern end of the main plant block was an electrical transformer in a self-contained room bay and to its north three large openings closed by metal concertina doors. Internally, the eastern section of the main plant room, which housed amplifiers, a solid concrete floor remains, while to the west the floor was supported on concrete piers. This was probably to allow the use of under floor cabling and ventilation pipes.
At the northern end of the plant room is a bricked up door opening that formerly gave access to the passage way running along the north side of the main building. One difference between the two Vibration Test Buildings, is that in the northeast angle of building 1, is a concrete vehicle ramp. A historic photograph (Kinsey 1981, 108) shows a mobile air conditioning van on this ramp, with two large diameter pipes connecting back to the building, as well as electrical leads plugged into fittings on its north wall.
Work on the Centrifuge began sometime after 1965, and a typescript Property Services Agency building list dates it to 1966. It was constructed at the western extremity of the site to the west of the Vibration Test Building and within the existing site boundary.
To provide access to the new building a single track concrete roadway was constructed westwards from the Control Room. The design of the Centrifuge building suggests that it too was designed to handle devices containing explosives. It is a single rectangular concrete structure with gable ends and is covered by a light, pressed-metal roof sheeting with insulation board beneath supported on three rolled steel joists with angle-iron purlins. Its north and east sides, which face other. Also visible in this view are three of the four concrete piers that supported the centrifuge’s frame. The rear door led to the emergency escape way, buildings, are covered by a shingle traverse.
To the north is a metal flag pole, which may have also functioned as a lightning conductor. The building was entered from its west side, to the south a double door opening and the north a single door. Both have subsequently been sealed with breeze blocks, and more recently the National Trust has inserted a steel-framed door into the blocked southern opening.
Internally, is a sunken brick-lined centrifuge pit, which is 8.06m (26ft 6in) in diameter and 2.68m (8ft 9in) deep. To the south the base of the pit is accessed from a flight of concrete steps. At its centre is a metal plate that supported the central metal spindle of the centrifuge, a cable duct passes from the centre to a self-contained basement equipment room to the northeast. Equally spaced around the wall of the brick lined pit are four concrete piers columns on top of which are metal mounting plates, which are set below the main floor level.
These were probably used for mounting a cruciform framework to support the top of the central spindle. In operation the top of the centrifuge was floored over, also confirmed by a row of now inaccessible coat hangers set high on the north wall. Along the top of each of the long walls is a ledge that supported the rails of a travelling crane, which was used to install and service the crane and lift test pieces into place. At the northern end of the building are two self-contained equipment rooms, the one to the west, which could also be entered from the outside. In the east wall is a blocked doorway that led to an emergency escape passage through the shingle traverse. Adjacent to the main south door is a small wash and toilet room.
The Control Room was constructed for the remote operation and monitoring of the Vibration Test Laboratories and climatic control laboratory. It is constructed in a simple, functional and contemporary style in Burwell White bricks that contrast with the red asphalt covered lower sections of the metal framed bay panels.
Littering the ground in front of this building are fragments of yellow Perspex, which was probably used to glaze this building. Although, it has been suggested that the yellow Perspex may have been inserted by a film company. It is divided into two sections, to the west the slightly taller portion housed control and monitoring equipment, and to the east were staff facilities. The building is entered at the eastern end through an inset covered porch, which is surfaced in red and yellow flag stones arranged in a chequer board design.
Entry into the building was past the messengers’ room, located on the west side of the entrance and to its rear is a windowless switch room. On the opposite side of the entrance was the cloak room. Along the rear wall is a ladies lavatory, cleaners’ room and a gents’ locker room and lavatory. At the eastern end of the corridor is a small tea room and to its south a large mess room. The taller western section of the building is split into two by a longitudinal east to west corridor.
At its eastern end to the south is a store room and on the opposite side of the corridor a dark room. To their west and to either side of the corridor were six almost identical bays, although the two in the southwest corner form a single large room.
These rooms were used for housing control and monitoring equipment, which was supported on a raised floor, the under floor void probably accommodated air conditioning pipes and cabling. To reduce noise the upper sections of these rooms and their ceilings are lined with square pierced, plaster-board panels.
Pump House & Electrical Substation
To the east of the Control Room, is a simple rectangular brick Electrical Sub Station, comprising to the south a large room that housed the transformers and to its north a smaller switch room. The building was protected by a carbon dioxide fire suppressant system, with a three cylinder holder in the larger room feeding into red painted pipes; the system could also be activated by a red switch on the building’s exterior.
To its east is the brick Pump House, in site plan this building is a truncated T-shape with a large central plant room and two small self-contained bays to either side. The full description for this building noted it contained the combined pump house for fire mains, condensate and appliance room. In the large central room was an electric and diesel pump, the western bay was described as the Condensate Building, which presumably handled condensed water from a steam heating system. To the rear of this building were two large Braithwaite water tanks supported on low concrete walls with a total capacity of 72,000 gallons (372, 312 litres). Only the tank to the west remains.
Magazine / Armoury
The Magazine is a reinforced concrete building comprising an entrance passage,two storage bays and a rear ventilation passage.The west and east sides of the building are revetted by a shingle traverse and there are traces of lightning conductor copper straps on the structure.The exposed roof surfaces of the Armoury are covered in Asphalt.To the east the entrance passage comprises a drive through barrel vaulted passage, orientated roughly north to south surfaced with a hard smooth concrete surface.
Its total width is 4.58m (15ft)and internally it measures 5.18m (17ft)in height to the vault ceiling.Its entrances were closed at either end by now missing wooden outward opening doors,width 3.35m (11ft) set 2.68m (8ft 10ins)from the end of the south passage.To the south of the southern doors in the west wall is a recess containing the remains of an electrical control panel.To the west of the main doors are smaller wooden pedestrian doors clad on either side with metal sheeting, a sign on their exteriors reads ‘emergency exit keep clear’, above each of these doors are the remains of adjustable metal louvred vents.A small plastic sign on the north door records ‘No.1A’, a similar sign on the south door records ‘No.2A’. Within the passage at eaves height are fixing plates on the west and east walls that probably mark the position of an overhead travelling crane.
On the walls of the passage are a number of sealed magazine lights.To the west of the passage are two self-contained barrel-vaulted storage bays, formerly closed by double wooden outward opening doors, width 3.05m (10ft), height 3.63m (13ft). Entry to both the bays was over a toeboard,batons and screw holes at the entrance mark their positions.Internally the south bay measures 7.45m (24ft 6ins) x 4.55m (15ft), height 5.12m (16ft 10ins), its floor is surfaced in grittless asphalt and it is lit by two sealed florescent light units.It is ventilated to rear by a rectangular opening sealed by a plywood unit covered in aluminium with four copper vents.The north bay is larger and measures 9.15m (30ft) x 7.45m (24ft 6ins)with a height of 5.12m (16ft 10ins),its floor is also covered by grittless asphalt and it was lit by four florescent lights, to the rear it was vented by two rectangular vents with wooden covers.
At some point there has been a fire in the north bay.Above each of the internal storage bays is a vertical ventilation shaft capped by a metal vent.The two bays vent to a passage way to the west which is entered from the south through a single wooden door, its entrance way revetted against the shingle traverse by concrete wing walls.Within the passage way is a metal header tank, an electrical switch box and junction box, possibly for heaters.This building also housed the bomb/munition disposal teams equipment..
AWRE Orfordness was one of only a few sites in the UK, and indeed the world, where purpose built facilities were created for testing the components of nuclear weapons. At the height of the Cold War AWRE and the Royal Aircraft Establishment used Orford Ness for developmental work on the Atomic Bomb. Only 20 photographers are allowed to enter the site each year however we have arranged a special visit for TalkUrbex.com members, there are only 10 spaces so check the Talk Urbex forum for details.
Hope you have enjoyed this detailed archive of information about this site.
Alexander, M & Cocroft, W 2009 COLD WAR RESEARCH & DEVELOPMENT SITE. English Heritage
Research Department Report Series 10-2009
Bradford, S & Griff, J 2010 National Trust – Orford Ness. The National Trust
Pike, J 2005 Global Security.org Weapons of Mass Destruction – Orford Ness, United Kingdom Nuclear Forces
BBC Suffolk, 2008 Places Feature – The mystery of Orford Ness
Fender200, 2007 A history of this secret military test site in Suffolk, UK
Grand Slam Bomb image – Wikimedia.org
Yellow Sun & Blue Danube Images – Nuclearweaponsarchive.org
Polaris Head Images – Absoluteastronomy.com