Churchill Barriers The Churchill Barriers were built in response to the sinking in October 1939 of HMS Royal Oak by the German U47. Scapa Flow was the main base of the British Home Fleet in both World Wars and as such was poorly defended at the outset on both occasions. The Barriers now provide road access to Burray and Soth Ronaldsay, which in strong easterly winds can be hazardous due to large waves. Barrier #1 from NE Barrier #1 panel Barrier #1 rough sea Barrier #2 from NE Barrier #2 Barrier #2 Barrier #3 "Reginald" Barrier #4 aerial Barrier #4 aerial Barrier #4 aerial Barrier #4 aerial Barrier #4 Cara Sands Barrier #4 "Collindoc" Barrier #4 aerial Barriers aerial from N Barrier #1 Graemeshall battery Holm Sound "Pontos" Weddell Sound