Report - - Orford Ness, AWRE & Cobra Mist - March 2017 | Military Sites | 28DaysLater.co.uk

Report - Orford Ness, AWRE & Cobra Mist - March 2017

Bent Nails

28DL Full Member
28DL Full Member
Secret military activity on Suffolk's Orford Ness peninsula dates back to the First World War when the MOD took it over and built a Royal Flying Corps airfield on the marshes.



The remoteness of this 12 mile shingle spit (Europe's longest) made it suitable for experimenting with aerial machine guns, bombs, navigation, photography and parachutes, which continued in the interwar period.

Radar's early development


The Orfordness Beacon (set up in 1929) was one of the earliest experiments in long range radio navigation, then in the mid 1930s work started on a new defence system that became known as radar.

Led by Sir Robert Watson-Watt, early work took place in the old WW1 huts before moving further down the coast to Bawdsey Manor. Their work brought about the Chain Home network, instrumental in overcoming the German threat from the air.

Second World War

Though the airfield was not used, the Aeronautical Armament Experimental Establishment was based here. Activities included "assessment of the vulnerability of aircraft to hostile fire" (English Heritage).

More buildings went up on 'The Street' and batteries were built to counter VI Flying Bomb guided missiles.

Atomic Weapons Research Establishment and 'controlled ruination'

Ballistics observation tower

From 1953 to 1971 the AWRE had a base here and conducted environmental testing on explosives including Britain's first atom bomb, Blue Danube.

According to English Heritage's detailed report, in 1960 the Establishment stated "there will be no tests involving the release of radioactive matter".

However, it describes how one former employee said tests were done with "either high explosives or their fissile/fusion components, but never both together", and "remembered being present during an overnight test on a system with components made of plutonium".

Laboratory 1


Laboratory 3


Laboratory 2


The structures were designed to contain any accident, like the Vibration Test Buildings or pagodas, whose roofs would collapse and seal any explosion with concrete and shingle.



Since 1993 this part of the peninsula has been owned by the National Trust whose policy is to allow the site to decay while minimising human interference.

Survivors of high pressure, shock, extreme temperatures and high vibrations, the buildings' main threat is the encroaching sea, constantly eroding and reshaping this fragile environment.

Cobra Mist, a $1 billion folly



Further north, construction began in 1967 on a new Anglo-American project codenamed Cobra Mist.

AN/FPS-95 441a was an over-the-horizon (OTH) radar system pointed at Moscow, designed to monitor soviet activity.

Testing began in 1971 but in 1972 problems emerged with noise interference affecting reception for which no explanation was found. Spyflight suggests the Russians could have been to blame, its signals jammed by agents in a trawler in the North Sea.

The USAF gave up and left in June 1973. Costing around £1 billion in today's money, it was the largest, most powerful and sophisticated OTH radar at the time with a broadcast signal of 10MW.

GlobalSecurity.org gives an impression of what the array might have looked like before removal in the mid 1970s.

"...a huge fan-shaped array of aerials supported on masts from 42 feet to 195 feet high. The antenna consisted of 18 log-periodic antenna strings, which radiated like spokes in a wheel from a central "hub." Each string was 2,200 ft in length and carried both horizontal and vertical radiating dipoles. The strings were separated by 7 deg in angle, and they thus occupied a 119-deg sector of a circle. The complete antenna was located over a wire-mesh ground screen, which extended beyond the strings in the propagation direction."​



Spyflight says:

"The radar was controlled from a large steel blockhouse which stood on short legs behind the array and was connected to the array by cables running to an underground chamber, lined with copper, in front of the array."​


The above photo is at the 'hub' of the fan, but no underground chamber was found. Taught lines of wire remain on parts of the ground, creating a trip hazard.

The 80 acre expanse is a haven for wildlife, from rare insects, plants and fungi to a grey canine-like animal that when startled bolted towards the main building.

Orfordness Transmitting Station - the BBC looks east

In the late 1970s the Cobra Mist site came under control of the Foreign Office as Orfordness Transmitting Station, and from 1982 to 2011 was owned by the BBC, broadcasting the World Service to continental Europe.

Wikipedia describes the three types of aerial:

"The directional aerial for 648 kHz (erected in 1981-82) consisted of a row of five 106.7 metre (350 ft) freestanding steel lattice towers of triangular cross section."​



"The directional aerial for 1296 kHz (erected in 1978) consisted of six freestanding steel lattice towers. Unlike the directional aerial for 648 kHz, they were arranged in two parallel rows with three towers in each."​


"There was also a back-up omni-directional mast radiator for 648 kHz (erected in 1983), which could only handle transmitter powers of up to 250 kW and was only used when maintenance work was being carried out on the directional antenna."​

Future plans

The site closed then transferred to private ownership in 2015. Martin Fletcher visited last year for The Economist's 1843 Magazine and described the Cobra Mist building:

"Empty halls except for one that was filled with huge grey transmitters [...] an old glass-fronted control centre, rooms within rooms to thwart electronic eavesdropping, inner sanctums with beryllium-coated steel doors and handles on the inside only. Labyrinthine passages to offices with fading maps of Europe on the walls, tool shops, a canteen, a recreation room, a sick bay, old filing cabinets and packing cases stuffed with who knows what. Internal staircases descending into the murky flood waters below."​


1843 Magazine

Interviewed, the new owner said he bought it as "it's a folly of grandiose proportions" and hopes to create local employment. Broadband, communications, a data centre and a solar farm are mooted as potential new uses for the site.

Today the site though quiet, remains unwelcoming to visitors.
Last edited:

"Bert" Weedon

Alan "Bert" Weedon, ex Bawdsey, ex Orfordness
28DL Full Member
I was an RCA engineer at Orfordness from November 1970 to August 1972, and was heavily involved in the testing and commissioning.
I can probably answer most specific questions.
The radar was over the horizon, refracting through the ionosphere, going and coming back, so the signal was very weak when it arrived.
We used some very fancy signal processing and I can assure you there was no Russian interference we could not handle.

Some unknown person gave an interview on an episode of BBC Coast and told us his wild theories, they were from the pub in Orford.

We received so many signals from Russia that it appeared to be heavy noise. We recorded data and analysed it off line on a big Xerox
computer and then we were seeing trains in Russia in 1972. Pretty good eh?

The reason it closed was that
1. there was a need for further heavy computer investment to enable real time digital processing
2. there was the possibility of trading it off during the SALT II talks in Finland against something in Russia
3. originally it was planned to be installed in Turkey, and Suffolk was the second political choice. However much of Russia's cold war activity
was on their northern coast and when Orfordness beamed almost due north, the magnetic/electric fields at the north pole created great
difficulties/interference (Think of the Aurora Borealis). The radar would work much better if it was positioned in Iceland or Greenland, and then it would look east and not be influenced by the Earth's north pole.

The site produced an awful lot of good scientific research, which enabled OTH radar to develop. There are 3 OTH radars operating in
Australia today, covering their land and sea approaches.

Ian Tickle

28DL Member
28DL Member
Hello to all on this thread,
I was the 'unknown person' interviewed on Coast way back in 2006 when I was working at the site as an engineer for the BBC World Service transmitter company. The BBC came to the site wanting a good story for the sites orignal use. At the time I knew that there had been several reasons why the site suddernly closed after a very short span - the production company thought that the Russian trawler story broadcasting local 'noise' would make the best story, so that is the one we all went with. It was certainly no wild theory, as during my 9 years at the site, I meet many English RCA engineers as well as American personnel who gave us lots of facts and information about the sites actual history. We tried to document much of it on site - I left in early 2012 so I don't know if its still there.
I certainly didn't intend to mislead or deceive the audience of the BBC program.


Ian Tickle
Engineer Orfordness, 2003 - 2012.

"Bert" Weedon

Alan "Bert" Weedon, ex Bawdsey, ex Orfordness
28DL Full Member
Thanks Ian, I am glad you put the record straight. It was imposssible to jam this radar, so I felt other people would not be impressed to learn that after spending a billion, the Russians could stop it. I can't write much more, as signing the official secrets act is life long committment!


28DL Member
28DL Member
I live in Aldeburgh and wondered if a) I could land my boat on the ness and b) walk around cobra mist and the radar masts to take some photos for a project. Anyone got any ideas??



A fellow of infinite jest
Regular User
I live in Aldeburgh and wondered if a) I could land my boat on the ness and b) walk around cobra mist and the radar masts to take some photos for a project. Anyone got any ideas??
What you need is someone local who has a boat who wants to try it... Oh wait, that's you!

Unless there are signs every 50 metres suggesting criminal trespass, the worst that can happen is you'll be asked to leave and even that's pretty unlikely! Go and look. Looking forward to your photos.


28DL Full Member
28DL Full Member
What you need is someone local who has a boat who wants to try it... Oh wait, that's you!

Unless there are signs every 50 metres suggesting criminal trespass, the worst that can happen is you'll be asked to leave and even that's pretty unlikely! Go and look. Looking forward to your photos.
When I went in my boat, unfortunately someone saw us and told us they would report us? not sure who to. if we didn't leave...


28DL Full Member
28DL Full Member
You can walk it if you like 3 hours of shingle, defiantly possible, we got caught but they soon left us too it after we "walked back home". Spent the night on the beach and checked the place out in the morning. Also, you can walk below the high water line and not get bothered by anyone, no one owns that land (apart from the queen). This is what the cobra mist guys said at least. Also, there is a tv program about it, channel five so its not brilliant but still got a lot of history: https://www.my5.tv/portillos-hidden-history-of-britain/season-1/portillos-hidden-history-of-britain

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