More information : SP 68 68. Construction of the Royal Ordnance explosives Filling Factory No.18 Burghfield was authorised in 1940. Construction of the factory began in November 1940 and production was underway by August 1942. It was one of the last six Royal Ordnance filling factories built during the Second World War. In common with the other factories in this later group it was smaller than the earlier factories and was restricted in the variety of munitions it manufactured. In this instance its primary purpose was to manufacture 20mm Oerlikon cannon shells. Production of munitions ceased at the end of the war and the factory was mothballed as a war reserve. In the 1953 the factory was extensively reconstructed at a cost of £3 million for the production of missiles. (1-1a)
The Second World War Royal Ordnance Explosives Filling Factory No 18 described above in (1) was recorded from aerial photographs of the 1940s during the Silchester Iron Age Environs Project . The ordnance factory covers an area measuring 1177 m by 1123 m. A railway spur leads off the north east corner of the site to join up with the Reading and Basingstoke Railway. This feature was recorded during the Silchester Iron Age Environs mapping project. (2)
The ‘Gravel Gerties’ at the Atomic Weapons Establishment (hereafter GGs and AWE) Burghfield are of national importance. There are two pairs of virtually identical structures, differing only in date and in history (in terms of which nuclear weapons were assembled here).
AWE Burghfield is located on the site of a Second World War Royal Ordnance Factory which was subsequently redeveloped, from 1954 onwards, for the assembly, disassembly and inspection of nuclear warheads. It is the only such facility in Britain with many of its buildings and structures purpose-built for this specialised activity. The GGs are at the heart of this process and are the structures in which the warhead assembly and disassembly takes place, all other structures being ancillary and in support of them. There are two pairs of GGs. The pair to the south is the earliest. Construction was well advanced by February 1960 and are presumed to have been completed late in the same year or in 1961 given their association with the Red Snow warhead (see below). They are a physical manifestation of the 1958 United Kingdom and United States Agreement for co-operation on the Uses of Atomic Energy for Mutual Defence Purposes, more commonly known as the Mutual Defence Agreement, under which both countries agreed to share atomic information. This coincided with the beginning of the manufacture of the United Kingdom’s Red Snow warhead. This was operational by 1962 and was used in both free fall bombs and in the Blue Steel stand-off missile and was the UK version of the US W28 warhead. The second, northern pair was completed in 1989. This was right at the end of the Cold War in a year that saw the section of the Iron Curtain between Austria and Hungary taken down and Soviet troops gradually withdrawing from Eastern Europe as communist governments in this area fell. For Britain and the United States this was a year of continuing cooperation with Margaret Thatcher at No 10 Downing Street and George Bush taking over from Ronald Reagan in the White House. The United Kingdom was still in the throes of a massive defence construction programme and this later pair of GGs was built as part of the Trident warhead programme. Both pairs of GGs continue in use today. In historic terms, the southern GGs, dating from 1960, are clearly the earliest of the two sets: They may have been based on those constructed in Pantex, Texas, the only other place where this design was employed, or may have evolved in parallel as part of the US-UK Mutual Defence Agreement . This is itself a measure of the strength of the special relationship between the US and the UK. Up to that point, nuclear weapons had been tested and manufactured at a variety of locations, including AWE Aldermaston, Berkshire and assembled at aerodromes and bomb stores.
The NSPA is a polygonal complex contained within a double security fence which can be clearly seen on aerial photographs. Within the NSPA are two pairs of GGs, steel towers which are part of the lightning protection scheme for the site, ancillary buildings and a figure of eight armoured corridor which connect the GGs to their ancillary buildings. The ancillary buildings are typically of single skin brick walls with flat roofs and asbestos cladding. Functionally they include stores, plant rooms and administrative accommodation. They were built in several phases with the earliest buildings on the site dating from between 1940 and 1961 and therefore pre-dating the GGs. There are then two further main stages of development relating to the construction of the 1960s and the 1980s. The corridors are of similar construction to the ancillary buildings and were also built in two phases relating to the two phases of GG development. They are covered walkways which were armoured (encased with a hardened structure) in the 1990s as part of an upgrade to security measures across AWE sites nationally.
There are some tall lighting conducting towers around the site which are of a steel lattice form. As mentioned above, the GGs have two distinct phases of development with the 1960s pair to the south and the 1980s pair to the north. They are two pairs of independent
systems for assembly, disassembly and maintenance although their architecture is the same. The GGs consist of circular chambers with external earth bunding. They have domed ceilings with gravel suspended over the chamber on a mesh of steel cables designed to smother and contain any accidental explosion of conventional high explosives used in nuclear warheads. They are not designed or intended to contain nuclear explosion as this is not anticipated: nuclear warheads comprise a conventional high explosive (which acts as the initiator) and a fissile core with in-built safety precautions to prevent a nuclear accident.
We propose that no further action be taken with regard to the southern pair of GGs; although of national importance, designation is manifestly not appropriate due to a combination of a number of factors: national security; the significant flood risk; proposals for essential redevelopment in the near future, and that a near identical pair of GGs exist on site. We would advise, however, that the 1960s GGs should be the subject of archaeological recording prior to their demolition. The northern 1980s pair do, in our opinion, pass the test of national importance as well as being appropriate for scheduling and we would propose that these are considered for scheduling. (3) |