Corenvirons-20, Part 3

So far, during this mini series of historical stuff viewable during a brief foray outside as part of my allowed exercise under lockdown, I have been looking at reasonably old structures which show up on 19th Century maps and are still visible in the landscape today. However, for this post, the subject doesn't appear on either the 1882 or the 1903 Ordnance Survey map of the area for the very good reason that it hadn't been built yet.

I may end up using these two images several times, as there's a wealth of historical interest contained within them.

1882

2019

Once again, the field boundaries are very similar, with the only real difference between the old map and the recent satellite image being the collection of buildings near the shore below East Breckan.

These are the complex of structures which made up the Holm Battery, a coastal artillery battery, built for World War 1 and modified for World War 2, to protect the entrance to Scapa Flow via Holm Sound. As a key strategic naval harbour, the Flow was heavily defended by artillery batteries, blockships, and anti-submarine nets. However, it was through Holm Sound during October 1939 that the German submarine U-47 evaded all the defences and sunk the battleship HMS Royal Oak with the loss of 833 lives.

This incident shook the British high command out of their complacent conviction that Scapa Flow was impregnable to submarine attack and, in 1941, work began on constructing the four Churchill Barriers to permanently seal the eastern approaches to the Flow. In many of my sunset photographs taken from Tense Towers, Churchill Barrier One is often visible, linking the Orkney mainland to the island of Lamb Holm.

Corenvirons-20 data

Target: Holm Coastal Artillery Battery
Location: NGR HY493017
Distance from Tense Towers (as the dragon flies): 500m
Hazards: Cliff edges, sea spray
Mission accomplished: Yes
Comments: The U-47 began its attack on the night of Friday 13th October 1939.