Churchill Barriers Travel Guide

The Churchill Barriers were conceived as a direct response to a tragic event early in World War II. In October 1939, the German U-Boat U-47 penetrated the existing naval defences at Scapa Flow, a major Royal Navy base, and sank the battleship HMS Royal Oak with heavy loss of life. This exposed the vulnerability of the harbour’s eastern entrances, which were protected only by sunken blockships and anti-submarine nets that proved inadequate. Winston Churchill, then First Lord of the Admiralty, ordered the construction of permanent causeways to seal off these channels and prevent further enemy incursions.

Work began in May 1940 under contract to Balfour Beatty and continued until September 1944. The barriers link the Orkney Mainland to South Ronaldsay via the islands of Lamb Holm, Glimps Holm, and Burray. The foundations were built using gabions filled with around 250,000 tonnes of local broken rock, dropped into waters up to 18 metres deep from overhead cableways. These were covered with approximately 66,000 concrete blocks weighing five to ten tonnes each, arranged to form robust wave-breaks. The total length of the four causeways is about 2.3 kilometres (1.4 miles).

A significant labour force was required, peaking at over 2,000 workers. From early 1942, more than 1,300 Italian prisoners of war captured in North Africa were brought to Orkney to assist with construction. They were housed in camps on Lamb Holm and Burray. Despite initial resistance due to Geneva Convention concerns, the POWs contributed significantly to the project. One enduring legacy of their presence is the Italian Chapel on Lamb Holm, a beautifully decorated Catholic chapel created by the prisoners in their free time, now a cherished cultural landmark.

Although built for military defence, the barriers were officially opened as public roads on 12 May 1945, just after Victory in Europe Day. They transformed local transport by linking several islands, replacing ferry services and enabling easier movement and economic integration. Over time, the barriers have been upgraded and maintained by local authorities. The southern two barriers have been designated Category A listed status, recognizing their national and international significance as historic structures.

The barriers altered the local environment, with the most southerly barrier blending into the landscape as dunes accumulated, effectively joining Burray and South Ronaldsay. The remaining blockships near the barriers have become popular dive sites, attracting visitors interested in maritime history. The barriers stand as a powerful reminder of Orkney’s strategic role in wartime and the resilience of its communities.

In recent years, responsibility for the barriers passed from the Ministry of Defence to Orkney Islands Council. Climate change and increasingly severe weather have begun to affect the structures, with some sections at risk of deterioration. Ongoing conservation efforts aim to preserve the barriers both as vital transport links and as historic monuments reflecting a pivotal chapter in 20th-century military history.