History

The cross-channel link from London to Lille was built in two stages: the section between Tolsford Hill and Fiennes, continuing to Loos entered service in 1959. This provided a permanent television circuit in the 4 GHz band, replacing an interim link via Dover (Swingate) and Cassel which had been set up by the BBC and their French counterparts in the early 1950s.

The original equipment used at Tolsford Hill was manufactured by STC and their French counterpart LMT. A 600-circuit telephony link was added in 1960, with another 600 circuits in 1965 and a further 960 in 1971. Together with the associated "protection circuits" these systems would have used all but one of the available channels in the 4 GHz band.

Contract 21807 was awarded to STC in 1957 on a non-competitive basis with estimated cost of £70,000 for "Folkestone - Lille" - it's unclear how the overall cost of building and running this link was split between the parties involved: UK and French telecommunications bodies and the European Broadcasting Union. At this stage only one site was built in the UK, at Tolsford Hill. A square-section stayed mast was provided, together with a permanent building derived from one of the standard repeater station designs. The cost was reported as £78,316 10s by April 1965. Two new sites were required in France: Fiennes and Cassel. Both of these used concrete towers with circular "galleries" - a style which was used extensively in France. The terminal station at Loos, near Lille, had been in use since around 1951 for a link to Paris.

Initially the "inland" circuits between London to Tolsford Hill were carried over the London to St Margaret's Bay (Dover) cable route. On some occasions the BBC set up ad-hoc links to and from Tolsford Hill using outside broadcast equipment. A more permanent, but still interim, SHF link was set up for the 1966 World Cup, running from the BBC at White City, via Fairseat then direct to Tolsford Hill. This operated on the 7 GHz broadcast links band, possibly to avoid problems in commissioning the permanent link via Flimwell which would use the Lower 6 GHz band and entered service at the end of 1969. The contract was awarded to STC at a cost of £xxx. A 4 GHz system was added a few years later, this contract also being awarded to STC.

The two intermediate sites at Fairseat and Flimwell were each provided with a "Standard Tower" and building of the standard type. The original mast at Tolsford Hill remained in use until the 1970s when the current concrete tower was completed.

The reason for late completion of the inland section is unclear. The tower at Fairseat was in use by 1966, as was the "new" Post Office Tower, however archive photos show the building at Flimwell still under construction during late 1967, with the first antenna installed in November 1969. As a direct path was possible between Fairseat and Tolsford Hill the "dog leg" via Flimwell may seem unnecessary however it was likely included to keep path lengths within limits and to avoid frequency co-ordination problems between the UK and French networks.

In addition to the cross-channel telephone and vision circuits, the section between London and Tolsford Hill was also used by the regional ITV contractor (Southern Television, later TVS and and Meridian) to interconnect their studios and trasmitters within the franchise region.

Further expansion of telephony occurred in 1974 and 1975 when two new 1800-circuit systems were added to the Tolsford Hill - Fiennes link, operating on L6 GHz. This contract was awarded to GEC - STC withdrew from the market in the early 1970s. It is likely additional capacity would have been added on the London - Tolsford Hill section at the same time. By the time of closure there were systems operating at 4 GHz and L6 GHz over the inland section. A map of international circuits dated 1974 shows 6,000 circuits available between London and Tolsford Hill via SHF. Some of this traffic was routed via Broadstairs and an undersea cable to Belgium and some via St Margaret's Bay and cable to France, however the capacity over the SHF route between Tolsford Hill and Lille was more than six times that of the cables landing in France. The original cross-channel 4 GHz telephony equipment from the 1960s was replaced around 1982, increasing the capacity in that band from 600 + 600 + 960 to 3 x 1260 circuits. Thomson CSF solid state equipment was used but the links remained analogue at this stage.

Plans were made in the early 1980s for a new London - France link, crossing between Archers Court (Dover) and Bolougne. This was to be an 11 GHz digital system due to become operational around 1986, however at the time of writing (March 2026) the completion date has not been confirmed. 11 GHz digital links were installed between London and Tolsford Hill but it is not known whether these continued via Fiennes.

Only basic information is known of the history of the French section of the route, however at some point a second station, Lambersart, near Lille was used for some links. This may have been due to limited capacity on the 1951 structure at Loos. From Lille other connections were available towards Belgium.

As a footnote, the European Broadcasting Union (EBU or "Eurovision") was formed in 1950 with the first live television broadcasts made in June 1954. The interim link co-ordinated by the BBC and the permanent link via Tolsford Hill acted as the UK's connection to a network which extended from Glasgow to Rome and via the Netherlands to Copenhagen by mid-1954. For many years dedicated EBU vision circuits were provided within the UK network. A later extension to Belfast provided an onward connection to Dublin.