Summary
Blue Streak underground silo, 1958-60.
Reasons for Designation
The 1958-9 Blue Streak underground silo is scheduled for the following principal reasons:
* Rarity: considered to be the free world's first in-silo launch weapon system concept and an essential and integral part of a unique British Cold War rocket establishment believed to be the sole survivor of its type in the western world;
* Survival: significant earthwork and buried remains survive at this site which illustrate one component of the rocket test facility;
* Potential: the physical remains will enhance our detailed understanding of the design and development process of Britain's nuclear deterrent as well as serving as a tangible and evocative symbol of Britain’s aspirations to superpower status;
* Historic interest: although the work on the missile silo was cancelled along with the Blue Streak programme in April 1960, the technology directly influenced subsequent United States' designs including the Titan II missile silos, which remained operational until 1987. For this it has international technological claims;
* Group value: as part of a single phase, grand scheme site conceived for a single rocket programme, the relationship of each site to the others and the wider landscape adds group value and enhances the national importance of the whole;
* Period: the peril from the threat of mutually assured nuclear destruction, which characterised the Cold War period is inherent in the remains of the Spadeadam rocket facility in the most tangible and evocative fashion.
History
In 1955, the open and largely uninhabited moorland to the north of Gilsland, Cumbria, was selected as the site for the Spadeadam Rocket Establishment. Its role was to support the development of the intermediate range ballistic missile (IRBM) Blue Streak; this was based on the American Atlas missile, but wholly British built. It was to be a liquid fuelled missile tipped with a nuclear warhead with a range of around 1,500 nautical miles (2,413km), sufficient to reach Moscow from the United Kingdom. It was envisaged that from the mid-1960s that it would replace manned aircraft as the United Kingdom’s main nuclear deterrent. However, the missile project was cancelled in April 1960 and after a period of uncertainty by the mid-1960s Blue Streak was adopted as the first stage of the Europa 1 rocket being developed by the European Launcher Development Organisation (ELDO). In December 1971, Britain withdrew from ELDO and the project was finally cancelled in April 1972. The rocket test facilities were closed and the site was dismantled.
The establishment was designed and managed for the Ministry of Aviation by the project’s principal contractors, de Havilland, who were responsible for the missile’s airframe, and Rolls-Royce, who designed the engines. The British Oxygen Corporation also operated a plant on the site to produce liquid oxygen, and liquid and gaseous nitrogen. The test facilities were initially designed to assist in the development of the missile, they would then act as a proof facility, testing each of the 60 missiles it was planned to place in silos in eastern England. In its heyday the Rocket Establishment represented a world class rocket test facility and the most advanced in Europe. It was also the model for similar facilities at Woomera, South Australia, from where a number of successful launches of the Europa I rocket were undertaken.
The establishment occupied about 3240 hectares; most of this remained open providing the necessary safety distances between facilities. Construction work began in 1957 and represented a major civil engineering undertaking. A new road was constructed to the north of Gilsland and a large temporary navvy camp, of which few traces survive, was built to the south of the main entrance. An extensive road network supported across the boggy ground on brushwood fascines and embankments connects the various test areas. The split in responsibilities between the various contractors and their different roles in the project is reflected in the layout of the facilities at Spadeadam. They may be broken down into five self-contained areas; administration and missile assembly, British Oxygen Corporation plant, component test area, Priorlancy Rigg engine test area, and the Greymare Hill missile test area. An innovative underground launcher facility was also begun, but cancelled.
In parallel with the development of the Blue Streak intermediate range ballistic missile, work was also undertaken on the development of an underground launching facility, or silo. This was a novel technology, and studies in the United Kingdom were as advanced as those in the United States and Soviet Union. To examine the initial concepts scale models were built at the Rocket Propulsion Establishment, Westcott, Buckinghamshire. In late 1958 work was authorised on a full-scale mock-up at Spadeadam and at Woomera, Australia. Excavations for the foundations were started, but following the cancellation of the missile project were halted by April 1960. Although abandoned by the United Kingdom, the research undoubtedly contributed to the design of the United States’ Titan II missiles silos. An American historian of that project commented that ‘Blue Streak was the free world’s first in-silo launch weapon system concept’.
Details
The earthwork remains of the foundations for the experimental underground launcher facility (U1) lie 600m to the south-east of Greymare Hill in the bottom of the valley of a small stream called the Cheese Burn.
The excavated hole for the underground launching facility’s foundations is roughly circular in shape and measures about 32m in diameter, the northern side has a well-formed curved plan and a good profile. Around its lip, close to where the stream enters, are traces of concrete blocks that were used to line the excavation. Running approximately north to south across the centre of the hole are three rows of boards, these measure 1ft 2in x 2in (34cm x 5cm) and are fixed to vertical posts 3 3/4-in (9cm) square. They are joined together with well-finished lap joints and bolts, and are further strengthened by U-shaped cleats hammered between the joints. To the west some of the boards have been removed. The boards are thought to represent shuttering put in place to support the sides of the hole during excavation. To the west of the hole a by-pass channel was dug to divert the Cheese Burn around the excavation. At its western end are the remains of a sluice comprising two concrete walls into which are set two vertical 2 x 4-inch (5 x 10 cm) steel channels into which blocking boards could be inserted into the 2.99m wide gap. Beyond the sluice an earthwork channel is visible along the southern valley scarp and to the south of the hole. To the north of this sluice the original line of the stream was straightened and its sides lined with rocks, some cemented into place. The base of the stream is very hard and may have been surfaced in asphalt. Close to the hole is another sluice constructed in a similar manner to that described above, although here the gap is 3.06m.
Extent of scheduling
On the south side this is defined by the top of the scarp of the by-pass channel; to the west it then follows the west side of the artificial channel as far as the westernmost sluice. From here the boundary follows the northern side of the Cheese Burn and then the upper edge of the scarp defining the excavation. It follows this scarp edge to c.50m to the east of the excavation where the southern bypass joins the stream. At this point it crosses the stream to join the upper edge of the by-pass channel scarp. To the north of the scheduled area there are a series of spoil mounds up to 2m in height which do not form part of the scheduling as their archaeological potential is considered to be limited.
