Searchlights in the Tyneside area were manned by men of the Royal Artillery attached to the Northumberland Fusiliers, under the control of fighter command. When the Royal Artillery were posted on the south coast in advance of the D-Day invasion, the 225th Anti Aircraft Artillery (Searchlight Batallion) USA took over. Their headquarters was at Debdon Gardens in Newcastle (HER 5559). Many of the searchlight sites were used as low security POW camps after the American troops left, accommodating the prisoners who were working on local farms. The use of searchlights as anti-aircraft defences began in World War One and despite the introduction of Radar technology before World War Two, searchlights were still very necessary, used to guide anti- aircraft fire and to direct interceptors at night, as well as forcing enemy bombers to fly higher, reducing bombing accuracy. They could also be used to help friendly fighters back to base. Most searchlight sites consisted of a circular earthwork, usually 10m in diameter for a 90cm light. There would have been a number of ancillary huts on site, such as domestic buildings and generators (Lowry 1996, 63 and http://www.skylighters.org).
Usworth TT237 (HER 5534)