History
Any examination of Hunters Stones invevitably raises questions about the site's proximity to and likely connections with RAF Menwith Hill. The site appeared on the 1956 Backbone map with the description "Hunters Stones (Forest Moor)". According to Navy News, HMS Forest Moor was decommissioned in 2003 after 43 years service. The site, at Nidderdale, is now operated by Babcock International and provides some services to the MOD under contract. In the 1960s, however, "It was the Royal Navy's major HF Receiver Station". (The Forest Moor site is within 2 miles of Menwith Hill but is entirely separate.)
Returning to the 1956 map, Hunters Stones was planned with the "Backbone" link running south to north between repeater stations at Saddleworth and Azerley and was to be a baseband connection point for telephony. Links to Preston and Shipton were indicated as "Standby". By 1959 these plans had been revised and the "Broadband Relay Network" featured Hunters Stones with "programmed" routes to Saddleworth and Arncliffe Wood (replacing Azerley) and the east/west route now running from "Lancaster" via "Elsack Moor" and "Shipton" and an unnamed site to "Patrington". The link from the west subsequently started at Quernmore and ran via Proctor Heights. That to the east may not have developed at all, though a spur to York was provided, and in due course Saddleworth was combined with the existing station at Windy Hill.
BT Archives has photos of an empty tower at Proctor Heights in 1963 and a small number of photos of Hunters Stones in 1967, at which point the current substantial tower was in place. The view of the tower shows one or perhaps two dishes near the top of the tower on one face and an as yet unused mounting for a horn close to the bottom of the stucture. There are photos of GEC 2 GHz and STC 4 GHz equipment and of 6 GHz equipment mounted on the waveguides - this possibly suggests the site was being equipped at the time for additional routes or interim equipment was being upgraded.
The Subterranea Britannica article on Backbone shows the "classic" view of Hunters Stones with the dish(es) at high level on one face and a much greater collection of horns and dishes close to the ground and extending to about one third of the height of the structure. Despite the interest in the site detailed photos of the tower while fully populated are hard to find. By 2001, however, a DAB tramsmitter had been added and in October 2007 a contributor to the mb21 Transmission Gallery visited the site. By this time there was very little remaining but a few deductions can be made as to the configuration of the site, at least in the final years. Aerial photographs show the main tower was supplemented by two smaller structures either side of the south eastern "leg". These seem to be oriented towards Tinshill and the presence of the main structure would make most other directions unusable. Dishes were still present on one of these structures in 2007. The small towers appear not to be "new" and their design might have been suitable to support horn antennas. It is possible, therefore, that Hunters Stones and Tinshill operated as a "twin site" with some routes served from each rather than from both. Also still present in 2007 were a small number of large dishes facing north east - towards Arncliffe Wood - these are at relatively low level on the structure. No other routes seem to have been equipped in 2007, or in an aerial view from 2002, but further analysis is possible by considering the path profiles between Hunters Stones and the known, or suspected, adjacent sites, and the orientation of the tower. In general towers were aligned so that dishes on the main routes could be parallel to one of the faces. That appears to be true Arncliffe Wood, Windy Hill and Stillingfleet. Proctor Heights and York appeared to use horns which, despite many other disadvantages, could be supported in a way which allowed them to be rotated to the required position. So, where did the "high dish" face? It turns out the path between Windy Hill and Hunters Stones is relatively "difficult" compared to that between Windy Hill and Tinshill - this may well be the reason for the later configuration of the two sites. In comparison all other links are "easy" - which explains the concentration of low-level horns and dishes in the early photo.
It is possible, therefore, that Hunters Stones and Tinshill operated as a "twin site" with some routes served from each rather than from both. By 2005, indeed, there did not appear to be any link between Tinshill and Arncliffe Wood or between Hunters Stones and Windy Hill - but a route did exist at the other site so Windy Hill/Tinshill/ Hunters Stones/Arncliffe Wood was still possible. Tinshill was originally part of the Manchester to Kirk o'Shotts television link which opened in 1951, Hunters Stones was planned for "Backbone" but the two routes became intertwined and it is entirely possible all traffic from Tinshill to Arncliffe Wood went via Hunters Stones once both sites were fully operational. The "Backbone" traffic, however, needed to be routed directly from Windy Hill to Hunters Stones, bypassing Tinshill...
Examination of the structure at York suggests it was designed for one horn, although the supporting tower might have been able to accept dishes on the same route or in other directions. The tower at Proctor Heights, on the other hand, seems to have been intended to carry one horn in each direction and with little expectation that anything else would be added. Proctor Heights was an empty tower by 2000 or earlier and the route from Quernmore to Hunters Stones seems never to have beeen expanded and presumably closed once no longer required for its original purpose (which is itself a bit of a mystery).
As to the Menwith Hill connection - it is certainly documented that cables were installed linking the site to Hunters Stones. The nature of the operation there would lead to a need for communications, definitely. Hunters Stones, in the 1956 Backbone plan, was intended to provide "baseband telephony" so was probably connected to the existing cable network in any event. With the technology before the introduction of digital exchanges it seems unlikely that general interception of UK telephone traffic could be carried out at Menwith Hill. The microwave links were just one element of the telephone network - many calls, even over a distance, would be connected via cable. It would not be possible to route the entire traffic for the country through one site, even if there had been the capability to sift out that which was "of interest". A "count the dishes" metric suggests Hunters Stones probably had less capacity than Tinshill once the London to Leeds route was fully developed - the link between them would not have the necessary bandwith for all traffic arriving at Leeds to be forwarded, and of course there were major concentrations of telephone traffic and microwave links at Birmingham, Bristol, Manchester and elsewhere. All of this (and more) would somehow have to be routed to Hunters Stones if surveillance was to be carried out in the manner suggested by some previous authors. An examination of the infrastructure shows this was really not possible during the 1960s to 1990s with an analogue telephone network. Even in a fully digital network - which was not completed until 1998 - it would still not be feasible to route the entire traffic through microwave links to Hunters Stones. Of course none of this excludes the possibility that selected traffic was explicitly routed to Menwith Hill.