The site's role in Britain's Cold War nuclear weapons programme was made public in 2004 when tree-felling uncovered remains of abandoned excavations for a missile silo. A survey of the site by the RAF and English Heritage has attempted to record and interpret what was previously so secret that no plans from the period exist. Spadeadam was chosen as a launch site because of its isolation combined with nearby infrastructure capable of supporting it with such as a plentiful water supply, access to the National Grid and road connections. A stretch of the road to the site from Gilsland had to be bypassed to make access easier for heavy trucks and the abandoned section is still known as "half-shaft" due to its unfortunate effect on vehicle transmissions. Spadeadam was probably intended to be one of 60 launch sites but these were never built and it was only used as a test facility for engine firings and testing electronics and ground installations.