History

The route between Edinburgh and Newcastle was a relatively late addition to the Post Office network, however it re-used sites from the 1952 Manchester - Kirk o'Shotts television link. Despite the history, Edinburgh - Newcastle did not carry vision circuits as all television traffic was routed via Carlisle as part of overall network development.

Contract 300522 was awarded to GEC in September 1966, for completion in September 1969, at a cost of £208,609. The bid from STC was higher (but no other detail was given). The requirement was for a 4 GHz system with two channels each carrying 1800 circuits, plus protection channel. The link would run from the new Edinburgh terminal at Craiglockhart then via the "1952" sites: Blackcastle Hill, Corbys Craggs and Pontop Pike, continuing to Newcastle by cable. The existing sites had received new structures as part of earlier "Backbone" development and were also used for a Linesman radar link. A site at Wooler, considered but not used for the 1952 television link, was brought into use. Addition of the Edinburgh - Newcastle telephony link was essentially a "join the dots" process however new antennas would be required at Craiglockhart. It is possible the horn antennas in place at other sites for the L6 GHz "Backbone" system would have been suitable however operational experience and the development of dish antennas with better performance may have led to dishes being used at other sites.

The new station at Craiglockhart was provided with a "Type 4A" modular tower - possibly the first to be built. Wooler received a low-height gantry based on "Standard Tower" components and Pontop Pike had gained at least one "Standard Tower" by this stage. Towers of the "pylon" style had been provided at Blackcastle Hill and Corbys Craggs.

Little is known of the subsequent expansion of this route. Possibly other channels were added at 4 GHz. The L6 GHz system used for Backbone was an early version with 960-circuit capacity - it may not have been feasible to add additional channels in this band. By the 1980s, however, digital systems at 11 GHz were introduced to create a network for System X and the link between Edinburgh and Newcastle is known to have formed part of the digital trunk network. Photos show the main dishes at Wooler were removed between 2007 and 2009. The site at Craiglockhart is one of very few to be completely abandoned: sold for housing development in 2014 after demolition of the tower and building.