A military site just outside Ipswich has always had an air of mystery about it, writes John Norman, of The Ipswich Society.

East Anglian Daily Times: The towers at the site of Suffolk Aviation Heritage Museum in Kesgrave. Picture: CONTRIBUTEDThe towers at the site of Suffolk Aviation Heritage Museum in Kesgrave. Picture: CONTRIBUTED (Image: Archant)

I write today’s article under false pretences. I knew nothing of the history of the United States military establishment on the junction of Bell Lane and Foxhall Road, other than it was clearly a key site during the Cold War – and like most installations at that time, the more important in the military hierarchy, the more secret it became.

We are not even sure when the Foxhall Transmission station was built. Was it in the 1930s (the oldest building on the site has Art Deco features typical of pre-war RAF buildings) or was it the 1960s (it doesn’t appear on earlier maps but, then, lots of secret installations were omitted).

Furthermore, we don’t know its original purpose, which branch of the military was first to use the facility, or to which other establishments it was connected. However, we do know the Americans were there in the ’70s and ’80s.

What we know for sure is that the facility originally consisted of eight aerials, each with a satellite dish standing high above an array of unmarked military buildings. Three of the towers remain, standing tall in the middle of a field, a tantalising distance from the highway but providing no invitation to visit.

East Anglian Daily Times: Listening and speaking... in secret. Picture: CONTRIBUTEDListening and speaking... in secret. Picture: CONTRIBUTED (Image: Archant)

The classified military establishment propaganda of the Cold War prevails. We know we are not allowed in, so we don’t even try. The site is surrounded by high chain-link fencing and sinister notices threatening prosecution under the Official Secrets Act if we step over the line. Inside, typical mid-century temporary buildings that are generally well past their best: some vandalised and repaired, others robust enough to withstand the ravages of time.

The building that housed the generators and fuel store (a facility of this importance was expected to go on working irrespective of what else was happening beyond the wire) has recently been adopted by the Suffolk Aviation Heritage Group. They are preparing the museum for their Easter opening. Perversely, the exhibition does not tell the story of the site but has a wealth of information, models and drawings of military aircraft each with a Suffolk connection.

The Foxhall transmission station was self-contained. There were dormitories, a dining hall with kitchen and club room. The personnel stationed here were single enlisted men, carefully screened and selected for their known discretion and ability to “keep the secret”. Their main source of R&R appears to have been the baseball diamond in one corner of the compound.

The newest building at Foxhall was the main ops’ room, the radio room: the room where the switching and interception of telephone calls took place, and the room from which coded messages were sent to the States.

Since it was constructed in 1984 this building has been known as The Dead Building. Although it looks like a bungalow (from the air) it is in fact a very robust concrete box: a hardened shelter with shutters on the windows, lined with sheet steel so no radio signals (or mobile phone signals) can penetrate or escape, other than those scrambled and transmitted.

My research has established, after following a number of false but speculative trails, that Foxhall was, most recently, part of the United States Defence Communications System, or DCS, under the direction of the US Airforce Communications Command (AFCC), a detachment of the parent AFCC at Bentwaters/Woodbridge. When the US 81st Tactical Fighter Wing left Bentwaters in 1992, the Foxhall facility also ceased operations.

Getting a coded signal back to the States, both during the Second World War and the Cold War, proved incredibly difficult. Originally analogue, the signal was transmitted through the same cables as used by the public service. Experiments with medium wave radio and microwaves confirmed their limited range. The solution was Operation Tea Bag: a scheme to connect telephone switching stations from across Europe, as far south as Italy, to Foxhall for forward transmission across the Atlantic.

The station was known as an Autovon Exchange or Troposphere Forward Scatter radio station, and housed transmitters for three TFS radio systems and two terrestrial microwave radio links.

Today. communication is via satellite and distance is no handicap. We’ve come a long way in 50 years.