Chain Home - Operations

Operations

The Chain Home stations were arranged around the British coast, initially in the South and East but later the entire coastline, including the Shetland Islands. They were first tested in the Battle of Britain in 1940 when they were able to provide adequate early warning of incoming Luftwaffe raids. Their early deployment had allowed the U.K. time to develop a well-integrated communication system to direct responses to enemy formations detected.

Chain Home had many limitations. With fixed antennas facing the sea, the Observer Corps had to be employed to report aircraft movements once the coast was reached. With detection poor below 5,000 ft (1,500 m), Chain Home Low stations were placed between Chain Home stations to detect aircraft down to 2,000 ft (610 m) but only out to 35 mi (56 km) from the coast, about one third the range of Chain Home.

Calibration of the system was carried out initially using a flight of mostly civilian-flown, impressed Avro Rota autogyros flying over a known landmark, the radar then being calibrated so that the position of a target relative to the ground could be read from the position on the display CRT. The Rota was used because of its ability to maintain a relatively stationary position over the ground, the pilots learning to fly in small circles while remaining a constant ground position despite a headwind.

During the battle, Chain Home stations — most notably the one at Ventnor, Isle of Wight — were attacked several times between 12 and 18 August 1940. On one occasion a section of the radar chain in Kent, including the Dover CH, was put out of action by a lucky hit on the power grid. However, though the wooden huts housing the radar equipment were damaged, the towers survived owing to their open steel girder construction. Because the towers were untoppled and the signals soon restored, the Luftwaffe concluded the stations were too difficult to damage by bombing and left them alone for the remainder of the war. Had the Luftwaffe realised just how essential the radar stations were to British air defences, it is likely that they would have expended great effort to destroy them.

The Chain Home system was dismantled after the war, some of the original sites being used for Chain Home's replacement system, ROTOR, but some of the tall steel Chain Home radar towers remain, converted to new uses. One such 360-foot (110 m) high transmitter tower (picture below) can now be found at the BAE Systems facility at Great Baddow in Essex (2008). It originally stood at Canewdon, and is said to be the only Chain Home tower still in its original, unmodified form.

Among the tallest timber structures ever built in the United Kingdom, at least two of the wooden reception towers were still standing in 1955, at Hayscastle Cross. Unlike the transmitter tower pictured here, those at Hayscastle Cross were guyed.

The wooden reception towers at Stoke Holy Cross were demolished in 1960 .