Yes there certainly were searchlights on the Common during the war,but these were wheeled units not needing foundations. I'm guessing they would have been sited nearer the centre of the Common to maximise the field of view,tall trees and all that.You may find this interesting or probably not! http://www.skylighters.org/howalightworks/index.html As far as I know(Dad told me :o) ) the nearest AA battery was in the centre of Gunnersbury Park along with Barrage baloons,which I remember seeing being used for parachute training in the 50s (Acton TA I think). I really think the remains on the Common are those of an Air Raid shelter,whether it was for civilians or used as a default centre for Local Government or somesuch I'd like to ascertain. There is a similar sized bunker in Southall that was used as a default war room (NW region) and as a Civil Defence bunker until the 80-90s.
Tony Wood ● 5785d