WWII, Coastal Defence/Chain Home Low Station M136 (Generator House), The Cliffs, Pakefield.
Original visit photos from 2013 – www.flickr.com/photos/139375961@N08/shares/9QptB12vKi
– Coastal Defence/chain Home Low Station M136 –
The site of a Coastal Defence/Chain Home Low (CD/CHL) Radar Station at Pakefield. It was built by the British Army to monitor shipping and aircraft during World War II. CD/CHL sites opened from 1941 and comprised either a Nissen hut or brick/concrete operations block with an aerial gantry mounted on the roof and a separate standby set house for the reserve power.
Staff were billeted where possible, but some stations had a small layout of domestic hutting situated within one mile of the site. The station closed by December 1942 and by 1978 the site was used for quarrying. Aerial photography from 1978 shows that the site was a quarry and its associated buildings. It is unclear if any of these buildings were originally part of the radar stations.
Chain Home Low (CHL) was the name of a British early warning radar system operated by the RAF during World War II. The name refers to CHL's ability to detect aircraft flying at altitudes below the capabilities of the original Chain Home (CH) radars, where most CHL radars were co-located. CHL could reliably detect aircraft flying as low as 500 feet. The official name was AMES Type 2, referring to the Air Ministry Experimental Station at Bawdsey Manor where it was developed, but this name was almost never used in practice.
The system had originally been developed by the British Army's research group, also based at Bawdsey, as a system for detecting enemy shipping in the English Channel. It was built using the electronics being developed for the aircraft interception radar systems, which worked on the 1.5 m band. This high frequency (200 MHz), for the era, allowed it to use smaller antennas that could be swung back and forth to look for returns, in contrast to the enormous fixed antennas of the 6.7 m wavelength (45 MHz) Chain Home system.
When the war began, the Luftwaffe began mine-laying missions where the bomber aircraft would fly almost all of their mission at low altitude. Chain Home could only see targets above 1.5 degrees over the horizon, so these aircraft only became visible at short range. Robert Watson Watt seized several dozen of the Coastal Defense (CD) systems that were in final construction and installed them at CH stations and key locations along the seashore to fill this critical gap in the coverage.
CHL remained an important part of the Chain network for the rest of the war, and was retained in the post-war era until it was replaced during the ROTOR upgrades by the AMES Type 80. The electronics, notably the high-power transmitter, was also re-used in a number of other systems, including the AMES Type 7.
CHL traces its origins to early experiments with aircraft interception radar systems in 1936. These were developed as a short-range radar that would be used to close the gap between Chain Home's (CH) approximate 5 miles accuracy and the visual range of a night fighter pilot at about 1,000 yards. Developed by a team at Bawdsey Manor led by ''Taffy'' Bowen, the new radar had to operate at much shorter wavelengths in order to limit the antenna sizes to something that could be practically fit on an aeroplane. After considerable experimentation, the team settled on a set working at 4ft 11in wavelength, about 193 MHz in the VHF band.
In early experiments with the new set, the team found that detection of other aircraft was problematic due to their target's relatively small size, but especially due to reflections off the ground. The latter caused a very strong signal that appeared to be at a range equal to the aircraft's current altitude, and everything beyond that was invisible in the resulting clutter. This meant that a typical night bombing run by German aircraft at 15,000 feet altitude would only become visible at that range, far less than the desired minimum of 5 miles (26,000 ft).
These same experiments demonstrated an unexpected side-effect. As the aircraft flew around over Bawdsey, which is located on the coast of the English Channel, the team found strong constant returns that they later realised were the cranes at the Harwich docks, miles away. Other smaller returns were quickly identified as boats in the Channel. These were being detected at ranges far beyond the maximum range against aircraft, in spite of the antennas not being designed for this role.
The potential of this discovery was not lost, and Robert Watson-Watt asked the team to demonstrate the concept in a real-world setting. A series of military exercises in the Channel in September 1937 provided a perfect test. On 3rd September the team's test aircraft, Avro Anson K6260, detected several Royal Navy ships in the Channel, and the next day repeated this performance in spite of almost completely overcast skies. Albert Percival Rowe of the Tizard Committee later commented that ''This, had they known, was the writing on the wall for the German Submarine Service''.
Information sourced from –
www.heritagegateway.org.uk/Gateway/Results_Single.aspx?ui...
en.m.wikipedia.org/wiki/Chain_Home_Low
WWII, Coastal Defence/Chain Home Low Station M136 (Generator House), The Cliffs, Pakefield.
Original visit photos from 2013 – www.flickr.com/photos/139375961@N08/shares/9QptB12vKi
– Coastal Defence/chain Home Low Station M136 –
The site of a Coastal Defence/Chain Home Low (CD/CHL) Radar Station at Pakefield. It was built by the British Army to monitor shipping and aircraft during World War II. CD/CHL sites opened from 1941 and comprised either a Nissen hut or brick/concrete operations block with an aerial gantry mounted on the roof and a separate standby set house for the reserve power.
Staff were billeted where possible, but some stations had a small layout of domestic hutting situated within one mile of the site. The station closed by December 1942 and by 1978 the site was used for quarrying. Aerial photography from 1978 shows that the site was a quarry and its associated buildings. It is unclear if any of these buildings were originally part of the radar stations.
Chain Home Low (CHL) was the name of a British early warning radar system operated by the RAF during World War II. The name refers to CHL's ability to detect aircraft flying at altitudes below the capabilities of the original Chain Home (CH) radars, where most CHL radars were co-located. CHL could reliably detect aircraft flying as low as 500 feet. The official name was AMES Type 2, referring to the Air Ministry Experimental Station at Bawdsey Manor where it was developed, but this name was almost never used in practice.
The system had originally been developed by the British Army's research group, also based at Bawdsey, as a system for detecting enemy shipping in the English Channel. It was built using the electronics being developed for the aircraft interception radar systems, which worked on the 1.5 m band. This high frequency (200 MHz), for the era, allowed it to use smaller antennas that could be swung back and forth to look for returns, in contrast to the enormous fixed antennas of the 6.7 m wavelength (45 MHz) Chain Home system.
When the war began, the Luftwaffe began mine-laying missions where the bomber aircraft would fly almost all of their mission at low altitude. Chain Home could only see targets above 1.5 degrees over the horizon, so these aircraft only became visible at short range. Robert Watson Watt seized several dozen of the Coastal Defense (CD) systems that were in final construction and installed them at CH stations and key locations along the seashore to fill this critical gap in the coverage.
CHL remained an important part of the Chain network for the rest of the war, and was retained in the post-war era until it was replaced during the ROTOR upgrades by the AMES Type 80. The electronics, notably the high-power transmitter, was also re-used in a number of other systems, including the AMES Type 7.
CHL traces its origins to early experiments with aircraft interception radar systems in 1936. These were developed as a short-range radar that would be used to close the gap between Chain Home's (CH) approximate 5 miles accuracy and the visual range of a night fighter pilot at about 1,000 yards. Developed by a team at Bawdsey Manor led by ''Taffy'' Bowen, the new radar had to operate at much shorter wavelengths in order to limit the antenna sizes to something that could be practically fit on an aeroplane. After considerable experimentation, the team settled on a set working at 4ft 11in wavelength, about 193 MHz in the VHF band.
In early experiments with the new set, the team found that detection of other aircraft was problematic due to their target's relatively small size, but especially due to reflections off the ground. The latter caused a very strong signal that appeared to be at a range equal to the aircraft's current altitude, and everything beyond that was invisible in the resulting clutter. This meant that a typical night bombing run by German aircraft at 15,000 feet altitude would only become visible at that range, far less than the desired minimum of 5 miles (26,000 ft).
These same experiments demonstrated an unexpected side-effect. As the aircraft flew around over Bawdsey, which is located on the coast of the English Channel, the team found strong constant returns that they later realised were the cranes at the Harwich docks, miles away. Other smaller returns were quickly identified as boats in the Channel. These were being detected at ranges far beyond the maximum range against aircraft, in spite of the antennas not being designed for this role.
The potential of this discovery was not lost, and Robert Watson-Watt asked the team to demonstrate the concept in a real-world setting. A series of military exercises in the Channel in September 1937 provided a perfect test. On 3rd September the team's test aircraft, Avro Anson K6260, detected several Royal Navy ships in the Channel, and the next day repeated this performance in spite of almost completely overcast skies. Albert Percival Rowe of the Tizard Committee later commented that ''This, had they known, was the writing on the wall for the German Submarine Service''.
Information sourced from –
www.heritagegateway.org.uk/Gateway/Results_Single.aspx?ui...
en.m.wikipedia.org/wiki/Chain_Home_Low