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Churchill Barriers

Churchill Barrier 1, blocking Kirk Sound

The Churchill Barriers are a series of four causeways in Orkney, Scotland, with a total length of 1.5 miles (2.4 km). They link the Mainland in the north to South Ronaldsay, via Burray, and the two smaller islands of Lamb Holm and Glimps Holm.

The barriers were built in the 1940s primarily as naval defences to protect the anchorage at Scapa Flow, but now serve as road links, carrying the A961 road from Kirkwall to Burwick.

The barriers are numbered from north to south. In 2016, Historic Environment Scotland designated barriers 3 and 4 as Category A listed buildings.[1]


U-47 used the partially blocked channel between Lamb Holm and the Mainland to attack HMS Royal Oak in October 1939.

On 14 October 1939, the Royal Navy battleship HMS Royal Oak was sunk at her moorings within the natural harbour of Scapa Flow by the German U-boat U-47. Shortly before midnight on 13 October U-47, under the command of Günther Prien, entered Scapa Flow through Kirk Sound between Lamb Holm and the Orkney Mainland. Although the shallow eastern passages had been secured with measures including sunken block ships, booms and anti-submarine nets, Prien was able to navigate the U-47 around the obstructions at high tide. He launched a torpedo attack on the battleship while it was at anchor in Scapa Flow. The U-47 then escaped seaward using the same channel by navigating between the block ships.

In response, First Lord of the Admiralty Winston Churchill ordered the construction of several permanent barriers to prevent any further attacks. Work began in May 1940 and was completed by September 1944. The barriers were officially opened on 12 May 1945, four days after the end of World War II in Europe.


The contract for building the barriers was awarded to Balfour Beatty,[2] although part of the southernmost barrier (between Burray and South Ronaldsay) was sub-contracted to William Tawse & Co. The first Resident Superintending Civil Engineer was E K Adamson, succeeded in 1942 by G Gordon Nicol.

Preparatory work on the site began in May 1940, while experiments on models for the design were undertaken at Whitworth Engineering Laboratories at the University of Manchester.

The bases of the barriers were built from gabions enclosing 250,000 tons of broken rock from quarries on Orkney. The gabions were dropped into place from overhead cableways into waters up to 59 feet deep. The bases were then covered with 66,000 locally cast concrete blocks in five-ton and ten-ton sizes. The five-ton blocks were laid on the core, and the ten-ton blocks were arranged on the sides in a random pattern to act as wave-breaks.


A project of this size required a substantial labour force, which peaked in 1943 at over 2,000.

Much of the labour was provided by over 1,300 Italian prisoners of war who had been captured in the North African Campaign, and were transported to Orkney from early 1942 onwards. As the use of POW labour for war effort works is prohibited under the Geneva Conventions, the works were justified as "improvements to communications" to the southern Orkney Islands.

The prisoners were accommodated in three camps, 600 at Camp 60 on Lamb Holm and the remaining 700 at two camps on Burray. Those at Camp 60 built the ornate Italian Chapel which survives and has become a tourist attraction.


Panoramic view of barriers 1, 2, and 3.


  1. ^ "Two of the Churchill Barriers listed by HES". The Orcadian. 25 November 2016. Retrieved 28 November 2016.
  2. ^ "Churchill Barriers". Undiscovered Scotland. Retrieved 19 September 2017.

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