Publication Account
Date 1996
Event ID 1016265
Category Descriptive Accounts
Type Publication Account
Permalink http://canmore.org.uk/event/1016265
There are four barriers spanning the sounds between mainland, Lamb Holm, Glims Holm, Burray and South Ronaldsay, a total length of some 2.3km. They were built during the Second World War with the object of blocking the four eastern approaches to Scapa Flow, as part of an attempt to create a safe anchorage for the British Home Fleet. Massive concrete blocks were made and set in position by Italian prisoners-of-war and, after the war, the barriers were surfaced as a foundation for the modern road. The predecessors of the barriers, the block-ships sunk during the First World War for the same strategic purpose, can be seen alongside.
The first stage in the construction of the barriers was to lay down a rubble base: in some places the water was up to 18m deep, and it took a quarter of million tons of stone and rubble to complete the foundation, most of it from a quarry on Lamb Holm. The casting yard for the concrete blocks was at St Mary's Holm, where some 66,000 blocks were made, weighing five or ten tons each, and these were laid on top of the rubble base. The barriers also provide an insight into the results of human intervention in the natural environment, because over the four decades since they were built there has been a massive accumulation of sand against them.
Information from ‘Exploring Scotland’s Heritage: Orkney’, (1996).
