Two of Orkney’s iconic Churchill Barriers are set to become listed structures, recognising their unique place in Orcadian history.
Four barriers were built during the Second World War to protect the great natural harbour of Scapa Flow, the home of the Royal Navy during the conflict, from enemy attacks. Construction of the causeways was ordered by Prime Minister Winston Churchill after the sinking of HMS Royal Oak in October 1939 by a German U-boat.
What followed was one of the great engineering feats of the time. Four solid rock barriers were built, linking the Orkney mainland with the islands of Lamb Holm, Glimps Holm, Burray and South Ronaldsay, effectively closing off the eastern approaches to Scapa Flow.
Now, barriers number 3 and 4 are set to be listed at Category A by Historic Environment Scotland, the highest status of listing. This will mean they are recognised as being of national or international importance, joining only 8% of Scotland’s 47,000 listed buildings in this category.
Barriers 1 and 2 have not been listed because of the potential for renewable energy development plans.
The causeways were constructed by Balfour Beatty & Co Ltd, with work beginning in 1940. The design and build phase presented a range of challenges – structures of this type were not common in the mid-20th Century and the engineers had to consider the fast flowing tidal currents in the narrow and deep channels of water.
With the help of Italian prisoners of war, the construction phase used bolsters – wire cages or baskets filled with broken rock and dropped into the water of the channels. Most of this lies under the surface, with the topping and road surface built from dumped aggregate and concrete blocks. In total, around 250,000 tons of stone rubble and 66,000 concrete blocks were used to build the barriers. They were completed in 1944.
They’re more than just monuments to Orkney’s wartime heritage now. They’ve become vital transport links, connecting the south isles of Burray and South Ronaldsay to the mainland. They helped change life in those communities within just a few short years, although local residents still see themselves as islanders!
The road route is not without its challenges too – high tides and stormy seas can cause waves to crash over the top of the barriers, closing them for a time.
The barriers are also a real tourist attraction, helping thousands of people see the beautiful and unique Italian Chapel on Lambs Holm, built by the Italian prisoners of war. Barriers 2 and 3 have become excellent diving locations, with the calm waters and rusting remains of blockships perfect for beginners. The change in tides and water movement has helped develop stunning beaches at Barriers 3 and 4, bringing people, nature and wildlife to the areas.
The listing by HES will recognise the fascinating history of the barriers, helping to preserve them in the years to come, and they’ll always play in important part in the lives of local people – both in the past and well into the future.
You can cross the Churchill Barriers by heading to the village of St Mary’s in Holm, following the A961 from Kirkwall which takes you over all four causeways.