Scapa Flow - World War II

World War II

Primarily because of its great distance from German airfields, Scapa Flow was again selected as the main British naval base during World War II. However, the strong defences built up during WW1 had fallen into disrepair: defence against air attack was inadequate; the blockships sunk to stop U-boats from penetrating had largely collapsed; and, while there were anti-submarine nets in place over the three main entrances, they comprised only single-stranded looped wire. There was also a severe lack of the patrolling destroyers and other anti-U-Boat craft that had previously been available. Efforts belatedly began to repair the peacetime neglect, but it was too late to prevent disaster.

On 14 October 1939, under the command of Günther Prien, U-47 penetrated Scapa Flow and sank the World War I–era battleship HMS Royal Oak anchored in Scapa Bay. After firing its first torpedo, the submarine turned to make its escape; but, upon realising that there was no immediate threat from surface vessels, it returned to make another attack. The second torpedo blew a 30-foot (9 m) hole in the Royal Oak, which flooded and quickly capsized. Of the 1,400-man crew, 833 were lost. The wreck is now a protected war grave.

Three days after this submarine attack, four Luftwaffe Junkers Ju 88 bombers raided Scapa Flow in one of the first bombing attacks on Britain during the war. The attack badly damaged an old base ship, the battleship HMS Iron Duke, with one bomber shot down by an anti-aircraft battery on Hoy.

New blockships were sunk, booms and mines were placed over the main entrances, coast defence and anti-aircraft batteries were installed at crucial points, and Winston Churchill ordered the construction of a series of causeways to block the eastern approaches to Scapa Flow; they were built by Italian prisoners of war held in Orkney. These "Churchill Barriers" now provide road access from the mainland to Burray and South Ronaldsay, but block maritime traffic. An air base, RAF Grimsetter (which later became HMS Robin), was built and commissioned in 1940.