Coast Defence/Chain Home Low Station M72
Coast Defence/Chain Home Low Station M72 is a former radar station near Grove Point on the eastern cliffs of the island, south of the Grove. The station, designated M72 (Eastcliff), was constructed by the British Army during World War II as an early warning radar system, allowing shipping and aircraft movement to be monitored and targeted.
History
Coast Defence/Chain Home Low (CD/CHL) stations were borne out of the need to detect and assist in the direction of fire at enemy surface shipping, at a time when there was an anticipated German invasion of Britain. The War Office developed their plans for a network of CD/CHL stations in 1940. These stations were independent of the RAF's own network of Chain Home Low stations, which provided early warning system against hostile aircraft, and allowed RAF fighters to intercept the enemy more quickly and efficiently. The British Army's Coast Defence radar was developed in 1938 for detecting and directing fire at enemy surface shipping. When it was found to be effective in detecting aircraft flying as low as 500 feet, something the original Chain Home could not accomplish, CD was also adopted by the RAF and renamed Chain Home Low (officially known as AMES Type 2) to replace their original Chain Home network.
The earliest of the Army's CD/CHL stations became operational in early 1941. Two sites were established at Portland during that year: M72 (Eastcliff) was sited on the east side of Portland and M73 (Westcliff) on the west side. Many of the CD/CHL stations followed a standard design, consisting of a combined transmitter, receiver and operations block with an aerial gantry mounted on the roof, and a separate standby set house for reserve power. The M72 station was in operation by November 1941.
M72 was used to detect shipping and aircraft, and produce the range and bearings of a target. This information would be passed to Portland's fire command post and/or the naval plotting room of HM Naval Base Portland's underground operational headquarters, both of which had direct lines of telephone communication with the station. It was from the F.C. post that information and orders to engage an enemy vessel could be given to the area's batteries. Reports on aircraft would be passed from the F.C. post to the gun operations room at Nottington House in Weymouth, from where local anti-aircraft defence was coordinated.
In 1942, a number of CD/CHL stations were transferred to the RAF under the "Triple-Service" agreement, which saw radar coverage for shipping and aircraft unified. While the transfer included the M73 station at West Cliff, the M72 station at East Cliff remained part of the Army's independent chain of nineteen stations. In F.C. Portland's fighting book, M72 was described as "not very accurate as regards [to] bearing and has practically no arc to the west". During 1942, the Chain Home Extra Low (CHEL) station K73 was established by the RAF within the Verne Citadel, which provided improved detection of aircraft (flying as low as 50 feet) and shipping. The new station was considered "the most useful set as far as F.C. is concerned" and provided "very good results as regards [to] both range and bearing". With the opening of K73, M72 became surplus to requirements and was closed on 25 November 1942.
To date, M72's brick-built operations block and the nearby concrete standby house are still on site. The surrounding land is now used for agricultural purposes and the South West Coast Path runs directly past the operations building.
References
The following is an A-Z list of references for this page.
1) Building Radar: Forging Britain's Early-warning Chain, 1939-45 - Colin Dobinson - Methuen Publishing Ltd - 2010 - book
2) Pastscape - Chain Home Extra Low Station K73 - website page
3) Pastscape - Coastal Defence/Chain Home Low Station M72 - website page
4) Pastscape - Coastal Defence/Chain Home Low Station M73 - website page
5) The National Archives - Fire Command, Portland - WO 192/150 - fort record book - 1941-44 - website page
6) Wikipedia - Chain Home - website page
7) Wikipedia - Chain Home Low - website page
History
Coast Defence/Chain Home Low (CD/CHL) stations were borne out of the need to detect and assist in the direction of fire at enemy surface shipping, at a time when there was an anticipated German invasion of Britain. The War Office developed their plans for a network of CD/CHL stations in 1940. These stations were independent of the RAF's own network of Chain Home Low stations, which provided early warning system against hostile aircraft, and allowed RAF fighters to intercept the enemy more quickly and efficiently. The British Army's Coast Defence radar was developed in 1938 for detecting and directing fire at enemy surface shipping. When it was found to be effective in detecting aircraft flying as low as 500 feet, something the original Chain Home could not accomplish, CD was also adopted by the RAF and renamed Chain Home Low (officially known as AMES Type 2) to replace their original Chain Home network.
The earliest of the Army's CD/CHL stations became operational in early 1941. Two sites were established at Portland during that year: M72 (Eastcliff) was sited on the east side of Portland and M73 (Westcliff) on the west side. Many of the CD/CHL stations followed a standard design, consisting of a combined transmitter, receiver and operations block with an aerial gantry mounted on the roof, and a separate standby set house for reserve power. The M72 station was in operation by November 1941.
M72 was used to detect shipping and aircraft, and produce the range and bearings of a target. This information would be passed to Portland's fire command post and/or the naval plotting room of HM Naval Base Portland's underground operational headquarters, both of which had direct lines of telephone communication with the station. It was from the F.C. post that information and orders to engage an enemy vessel could be given to the area's batteries. Reports on aircraft would be passed from the F.C. post to the gun operations room at Nottington House in Weymouth, from where local anti-aircraft defence was coordinated.
In 1942, a number of CD/CHL stations were transferred to the RAF under the "Triple-Service" agreement, which saw radar coverage for shipping and aircraft unified. While the transfer included the M73 station at West Cliff, the M72 station at East Cliff remained part of the Army's independent chain of nineteen stations. In F.C. Portland's fighting book, M72 was described as "not very accurate as regards [to] bearing and has practically no arc to the west". During 1942, the Chain Home Extra Low (CHEL) station K73 was established by the RAF within the Verne Citadel, which provided improved detection of aircraft (flying as low as 50 feet) and shipping. The new station was considered "the most useful set as far as F.C. is concerned" and provided "very good results as regards [to] both range and bearing". With the opening of K73, M72 became surplus to requirements and was closed on 25 November 1942.
To date, M72's brick-built operations block and the nearby concrete standby house are still on site. The surrounding land is now used for agricultural purposes and the South West Coast Path runs directly past the operations building.
References
The following is an A-Z list of references for this page.
1) Building Radar: Forging Britain's Early-warning Chain, 1939-45 - Colin Dobinson - Methuen Publishing Ltd - 2010 - book
2) Pastscape - Chain Home Extra Low Station K73 - website page
3) Pastscape - Coastal Defence/Chain Home Low Station M72 - website page
4) Pastscape - Coastal Defence/Chain Home Low Station M73 - website page
5) The National Archives - Fire Command, Portland - WO 192/150 - fort record book - 1941-44 - website page
6) Wikipedia - Chain Home - website page
7) Wikipedia - Chain Home Low - website page
Gallery
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