ww1 and ww2 balfour battery at hoxa head guarding the southern entrance to the scapa flow, orkney, scotland, uk

12-pounder anchorage balfour base batteries battery boom nets booms british fleet buchanan command post emplacements flotta flow german gun-emplacements guns head hoxa hoy induction loops longhope naval north atlantic sea ocean orkney pennant radar scapa scotland searchlight searchlights ship shipping site six-pounder margaret39aph39s hope submarines torpedo u-boat u-boats underwater mines wartime world war ww1 ww2