Summary

British Oxygen Air Separation Plant, 1957-9.

Source: Historic England

Details

The rectangular compound lies about 120m to the north of the administrative and missile assembly area and is entered through an original entrance with concrete gateposts; the southern half of the original double leaf gate remains in situ, and to either side there is a section of the contemporary tubular steel perimeter fence, each retaining original 0.5m square metal plates with BOC logos attached.

The air separation plant main building is visible as a series of substantial concrete bases forming the ground-level sub floor area. Hollow machine footings at either end with pentagonal cross sections, stand to a height of about 3m, and in the centre there are six opposed bases standing about 3.5m high. These bases supported the former first floor working area and plant units, and on their inner sides concrete corbels are interpreted as indicating the former presence of a travelling crane or supports for the superstructure. The former positions of plant and an electrical switch room at the eastern end are discernable in the remaining fabric; other functional areas are marked by variations in flooring finishes. All of the concrete work is finished to a high standard with smooth surfaces and chamfered corners. Immediately to the south of the machine footings is a long corridor with a row of concrete footings standing about 0.1m high. In its south west corner is a rectangular compartment with a tiled floor thought to be the main caustic area. Immediately to the north of the main building, the position of two small annexes containing air separation units are marked by partly exposed sections of concrete flooring. Brick footings to the south of the main building are thought to represent the remains of an annexe with a boiler house in its south east corner and an external bunded fuel store. Heated water from two compressors housed in the main building was cooled in two cooling towers whose rectangular concrete foundations lie immediately south of the main building.

The bases of tanks situated immediately to the north of the main building stored the finished products; the most distinctive is the circular platform 11m in diameter set upon an octagonal concrete base supported by 21 concrete columns that housed the liquid oxygen tank. Adjacent to this are the brick and concrete foundations of the lox pump house, obscured by tipping, and to its north the tanker filling bay is indicated by the presence of a concrete slab. To the east of the main liquid oxygen tank is the octagonal base of a nitrogen tank, and to its east are two circular concrete bases, about 9m in diameter, of former nitrogen tanks.

Extent of scheduling
For pragmatic reasons of identification, the scheduling is defined on the north, west, south and east side by the outer edge of the tarmac access road that rings the site; at the south end it extends beyond the road edge to include the pair of cooling tower bases, and at the north-east corner there is a short extension eastwards to include the original gates and surviving section of original perimeter fence.

Exclusions
Any surviving original concrete road surfaces associated with the Spadeadam Cold War rocket establishment are included in the scheduling, however, the upper, later layer of road asphalt, all modern lamp posts, fences and signage are excluded from the scheduling, although the ground beneath all of these features is included.

Source: Historic England

Reasons for Scheduling

The 1957-9 British Oxygen Air Separation Plant is scheduled for the following principal reasons:
* Rarity: a rare industrial plant type and an essential and integral component of a unique British Cold War rocket establishment believed to be the sole survivor of its type in the western world;
* Survival: significant earthwork, buried and standing remains survive at this site, which illustrate one component of a rocket test facility;
* Potential: the earthwork, buried features and standing remains will enhance our detailed understanding of both the operation and function of this plant to produce hazardous products, and its essential contribution to the successful functioning of the remote rocket establishment;
* Historic interest: reflecting UK/US cooperation, the site illustrates the development and operation of Britain’s Cold War independent nuclear deterrent; subsequently the technology developed here contributed to the development of international space exploration and to the design of the United States’ Titan II missile silos;
* 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 at Spadeadam in the most tangible and evocative fashion.

Source: Historic England

Sources

Other
Tuck, C & Cocroft W D, Spadeadam Rocket Establishment, Cumbria, 2004,

Source: Historic England