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Montreathmont Camp Radio Station

Montreathmont radio station
Communications block
© J M Briscoe
Montreathmont Camp Radio Station was located in a clearing in Montreathmont Forest on Montreathmont Moor, a partially forested tract of moorland in the Valley of Strathmore in Central Angus, lying four miles (6.5 km) south of Brechin. The station was situated about 900 metres west of the crossroads of the Brechin to Arbroath road with the B9113 Forfar to Montrose road. The forest is now a commercial coniferous plantation managed by the Forestry Commission Scotland.
The station began as a secret listening post and codebreaking centre which operated as an outstation of Bletchly Park (Station X) during World War II, and continued to monitor communications during the Cold War, until it was rendered obsolete and closed during the 1990s. Sold off in 2004, proposals to develop a wind farm led to disputes between the developer and locals.
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World War II
The special communications listening post was built during World War II and became operational in early 1943. It has become apparent that this was the largest facility of its kind in Scotland, and second largest in Britain after Hanslope Park.[1] Since the war ended, it seems that very little has been revealed about activities at the station, since all personnel stationed there were required to sign the Official Secrets Act as part of their service, however information is beginning to become more freely available. What has become clear is that it was one of the major substations of Bletchley Park, [2] more popularly known as Station X, the codebreaking centre which cracked the highly complex German Enigma code.
The official designation of the station given by Bletcheley is "Special Communications Units Nos 3 and 4 Montreathmont", however the station address was simply given as "PO Box 25", and volunteer interceptors, usually radio amateurs, would use this address to pass on details of any interesting signals they picked up. PO Box 25 was not unique to Montreathmont, but was used for all mail being directed to the Radio Security Service (RSS), which operated all the listening posts and was a branch of the Secret Intelligence Service (SIS), MI6 section 8, and had its beginnings in the Voluntary Interception Service (VIS).[3]
Radio station
The station site was carefully chosen to provide optimum conditions for reception. The ground at Montreathmont was reported to have a relatively high iron content, which works to increases the efficiency of aerials mounted above it. The station worked continuously, monitoring the airwaves around the clock in three 8-hour shifts commencing at midnight each day, and requiring the large camp which was sited 900 metres south of the station.
The station was equipped with a DF (direction finding) scanner which was mounted on the roof of the main DF centre building. The site was also provided with a power supply and back up generator. The aerials were arranged around the main building such that their directional characteristics were exploited to maximum effect in the direction of Continental Europe and Germany.
Camp
During the war, staff at the station included Canadian and Polish soldiers. The camp held about 400 personnel, while the the radio station employed a further 150 operators during each of its three 8-hour shifts which provided 24-hour listening cover.
The camp employed a number of building types, including Nissen huts and 'Canadian' type huts. The latter is unfamiliar, but photographs appear to show a construction similar in shape to a Nissen hut, but with a pronounced peak, rather than semicircular design of the British hut, and what appears to be a wooden sheet construction, overlaid by a flexible, waterproof sheet material, so is quite different from the metal construction of the British shelter, and may reflect the Canadian weather if this is the original source of the design.
ULTRA
According to the history of Bletchley Park, Montreathmont had 52 codebreaking machines installed, which ran continuously, day and night, decoding enemy messages. The station is described as having played a significant role in ULTRA, the name given by British Intelligence to information obtained from decrypted German communications, so called because the information was considered above Top Secret, or Ultra Top Secret. Such information was so valuable, its use was only sanctioned when it could be demonstrated that the intelligence could have been obtained from another source, so that the enemy would not be alerted to the fact that their codes had been compromised.
Montreathmont complemented listening activities carried out at Hanslope Park, Bletchley Park's major intelligence listening post. Unfortunately, Hanslope's location in Buckinghamshire was less than ideal, and signals from Germany could be garbled and incomplete. By having a distant station in Scotland, the fading and drifting of the high frequency (HF) signals could be countered, and problematic signals at one listening site could be perfectly clear at the other, allowing complete messages to be assembled from the available parts.
Cold War
In 1947, the military left the site, and the station became a Diplomatic Wireless Station, part of the Diplomatic Wireless Service, and was manned by civilian personnel from the Civil Service.
In 1966, the station was finally closed, having become surplus to requirements and rendered obsolete by continuing advances in communications technology. The masts were dismantled soon after and the deserted buildings used for storage, possibly until the 1990s. By the mid 2000s, most of the buildings had been demolished, leaving only a few of the original buildings and huts on the site, which was surveyed by RCAHMS in 2006.[4]
Accommodation puzzle
Although the listening station was provided with its own camp 900 metres (over half a mile) south of its own location, which we are told could hold around 400 personnel, the same account given in the References contains a statement to the effect that there was no accommodation on site, "There was no accommodation at the camp so we were billeted in Forfar or Kirrie", (Mr Henry Jeffery).
This may reveal disinformation, in the sense that it suggests a possible alternative reason for the camp, not as accommodation for personnel, but for the 52 codebreaking machines referred to by Bletcheley, above. Such equipment was largely mechanical, employed valves, produced vast amounts of waste heat and noise, both acoustic and electrical, and could have interfered with listening if they had been installed in the same buildings as the radio receivers, and at the heart of the aerial farm, which was already struggling to detect enemy transmissions from Europe. The type of machine used is not described, but if it was the British bombe as used to read Enigma messages, then each machine would have been about 7 feet wide, 6 feet 6 inches tall, 2 feet deep, and weighed about a ton.
Siting the decoding machinery half a mile away from the receiving equipment would have been an easy and effective solution to the problems of interference, and leaking a disinformation story about the building being for personnel would have been reasonable.
Site sale and development
In 2004, Montreathmont Moor, 200 acres with a 50 foot mast, was put on the market by the Scottish Executive for offers over £95,000.[5]
In 2008, the site was noted to have become the source of a dispute between local residents and a developer attempting to install an eleven turbine wind farm.[6]
References
1 ⇑ Special Communications Units Nos 3 and 4 Montreathmont
2 ⇑ Bletchley Park, National Codes Centre
3 ⇑ Box 25, The RSS from 1939 to 1946.
5 ⇑ Enigma station is put up for sale, BBC News, July 24, 2004,
6 ⇑ Flicker noise from turbines a worry for Montreathmont plans, Brechin Advertiser, June 6, 2008
External links
Aerial views
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