History

Information on this route is incomplete - the account below has been compiled largely from planning applications and a map showing plans for the trunk network in 1988. There are loose ends and it's unclear whether the route may have been used on a temporary basis or was abandoned before completion.

Known information: planning applications were submitted for four new sites: Tatsfield (approved December 1983), Truleigh Hill (approved), Goodwood (rejected 1984) and Dean Hill (rejected 1984). Approval was given on appeal for Dean Hill in June 1986 however the site was never developed. Further details of the planning applications are shown against each site, where available. All four sites are shown on a BT map of microwave stations issued in the 1980s.

The application for Tatsfield included a map showing the overall route. This is unsuitable for inclusion (copyright and poor quality) but shows the route starting at "LTT" (London Telecom Tower) and running south via Tatsfield to Truleigh Hill. The map shows two possible routes west, either via a site in the Midhurst area or Goodwood, continuing via the existing sites at Butser Hill and Thornhill, then Dean Hill and ending at an unknown site near Upavon.

Less definitive information is found on a map of planned trunk routes. The System X "DMSU" (Digital Main Switching Unit) at Salisbury is shown with 11 GHz links apparently to London, Reading and Exeter. The planning appeal for Dean Hill notes that the site was required "...to relay signals from various sources to Salisbury where there is an important switching facility in the national trunk network...".

Also in the 1980s, BT had plans to develop an additional Satellite Earth Station. One possible site was Stert, near Devizes, another was Henstridge, Somerset. In practice by late 1986 the decision had been taken to expand existing facilities. It is possible the link beyond Dean Hill was to connect with the new Earth Station or to link via further sites to Exeter and Reading. A factor in the original plan would have been the limited capacity over the main London to Bristol route - this carried traffic from the Earth Stations at Goonhilly and Madley as well as telephony and television distribution links.

A 1988 map of the trunk network as-built shows a fibre routes to Salisbury. The planning delays and cancellation of the Earth Station may mean the original plan was abandoned or that dishes were added to existing structures at Goodwood and Dean Hill to provide a link from London to Salisbury only.