The first network of early warning radar stations built around the coast of Britain before and during WWII was code-named Chain Home (CH). Two stations were built on the Isle of Man, at Bride in the north and Scarlett in the south, near Castletown, and were online by September 1940.
Operated by the RAF, as all CH stations were, the IoM facilities were designated as Advance Chain Home stations, brought online with temporary short timber masts supporting the transmitter arrays, in advance of the availability of 325-foot guyed steel masts. CH Bride closed in 1942, as it duplicated an area already covered by stations in Scotland and Ireland. CH Scarlett closed the same year, as it was too close to Ronaldsway airport and the fleet air arm training unit, HMS Urley, based there.
Scarlett was replaced by a new CH station at Dalby, on the western side of the island, which operated for the remainder of the war. Scarlett CH had two Type B operations blocks, without protected roofs, each with two sets of equipment; and two Type C blocks, covered with earth, each with one set of equipment. All four blocks remain, in farm use.