GPO Radio Laboratory – Backwell – Then and Now April 2017

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First Bit:
This is not a proper report, but it feels like too much for the ‘Before-and-After’ section. These are archive photos dug up during the researching that have never been on Google images before, so It seems only fair that the world should now ogle them and my pathetic attempt at aligning some then-and-now photos.

Exploring this ‘lovely hillside’:
I’ll admit that I am a nutter for anything technical, particularly stuff that is well built.
Following the DP Bristol 2017 meet DeadFormat and I headed over to study what remains of Backwell.
Why? You might ask – after all there is almost nothing left to look at. (If you can answer that question for me then please let me know what the answer is.) Backwell is currently awaiting planning permission for four luxury homes to be stuck on a lovely hillside, so it might be a case of now-or-never. Plus! Her Majesty’s Government paid for it, so I will be enjoying it.
DeadFormat has written about this stroll in a charming humorous tone. I suggest you try his report if you want to read a delightfully British and more interesting writeup. I however enjoy researching and writing about such outposts of technology.

GPO Radio Laboratory – Backwell – Then and April 2017
Backwell PO Radio Laboratory first came about around 1937. Some of its earliest work was to develop air conditioning for telephone exchanges.

The earliest photos show VHF Television signals being transmitted to Castleton (another laboratory in Monmouthshire) by 1945. The station was actually further down the hillside.
By 1958 the new site further up the hill was working in conjunction with a station in Slough for Tropospheric tests (effectively transmitting Satellite TV, but avoiding clouds), note the dishes:
The final experiment was for 120MBPS Data links with Castleton again, note the new mast:

This unassuming shed [red arrow] is the only surviving building from the earliest radio station:
It is still in its original location, seen here as the closest building to the camera on the RHS:

This hut was used for the 1950s experiments in the first “compound”:

Not a perfect alignment of the site driveway:
It was always intended to be a lesser published (but not really top secret) operation. Despite this, 24 hour Security was provided from the 'White House' - the curved front building, and an on-site fire station (upper LHS) was added.
New buildings were under construction but reportedly never finished at the time of closure, they can be seen at the top RHS of the driveway
Not much is recorded about the technologies developed onsite, but some archives and equipment have been taken into the National Collection BT Archives at Holborn Telephone Exchange.

The site became redundant after 1975 but was still in use for some sort of British Telecom work in the early 1980s.
Along with the site sewage and water treatment works, it was sold in 1993 to a BT Manager. This is what it looked like then. His executors of will are currently applying to build four houses on the site.

Well now. That is a photographic potted history of the place that made your TV, Skybox and even mobile internet possible.

Cheers everyone. Regards, Electric.

Archive photos, Originator unknown.

Hugh Jorgan

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Nicely done. I like the idea of adding "before" and "after" photos. Comparing with the "before" photos you are able to see how much derelict the place has become.


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Fascinating, I've visited one or two former Post Office Radio sites like Criggion and Rugby - shame this one is so far gone, but I enjoyed the archive images. :)


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In 1939, with the outbreak of war, some staff were moved from the Post Office research laboratories at Dollis Hill, London to a small laboratory at Backwell Hill, Somerset and another at Rugby.

At Backwell they attempted to foil the German air raids over Bristol. Their roles included beam bending. This involved projecting beams around Bristol to provide intersections to the German beams in the surrounding countryside. Fuel dumps were placed where these beams intersected and when the incendiary bombs were dropped the theory was that these dumps would catch fire, and the heavy bombs would be dropped on the ensuing fire away from the city.

On one occasion a member of the staff was sent to research German radio transmissions. They posed as a crew member on a cement barge travelling between England and the Netherlands. They got caught in a storm, the hatch to the hold was destroyed and water entered the cement hold. The barge was wrecked on the Scottish Coast, but everyone managed to survive.

After the War the staff at the Backwell Hill Radio Research Station were employed on communications research.

This included measuring the noise from clouds using a dish located on Bodmin Moor. They then worked on ways of filtering out this noise

Dish on Bodmin Moor.jpg

Photo of the Dish on Bodmin Moor circa 1958

This research helped pave the way for satellite communications.

The staff at Backwell Hill were then heavily involved in the first transatlantic TV broadcast from Goonhilly Down to America in the 1960s (Telstar). Their role was to design and build the equipment and dish to test Arthur, the first dish at Goonhilly. When the first TV transmission happened on the 23 July 1962 staff from Backwell Hill were operating Arthur. They had to manually align the dish with the point that the Telstar came over the horizon and then using gears (no computers) follow it for 20 minutes until it disappeared over the other horizon.

The Radio Research Station at Backwell Hill was closed in the early 1970s and the staff transferred to Martlesham Heath, Suffolk where they were involved in projects that included research into suitable wavelengths for mobile phone communications.

(Source: Discussion with the late Ted Jarvis 2008. Ted was a senior member of the Backwell Hill staff)

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