When WW1 ended, the once proud German fleet got detained at Scapa Flow as part of the cease fire terms. Of course, the German Admirals wanted to avoid handing over the fleet to the British, so they chose one last act of defiance and sunk their own ships in June 1919.
While the majority of ships got salvaged over the following years, some remained at the bottom of the sea and can still be visited today. However, the significance of these ships goes far beyond that. After the first atomic bomb tests the earth's background radiation increased significantly which caused new steel being produced to be slightly radioactive.
While this was a non-issue for normal applications, highly sensitive device (e.g. in nuclear medicine) required steel with lower radiation contamination which could only be produced very expensively or simply salvaged from a place that has never been contaminated – which brings us back to the sunken German fleet in Scapa Flow that got salvaged for its now highly valuable low background radiation steel for decades.
by LeobenCharlie
8 Comments
[deleted]
Forbidden spicy air makes for valuable sunken metal.
this is an extremely interesting fact
I had no idea. So like, is this still the case currently… is new metal not used for sensitive nuclear medicine applications?
This article does a neat deep dive (pun absolutely intended) on the before and after
https://basementballads.wordpress.com/2023/02/21/that-time-germany-sank-its-own-fleet/
Fun fact: due to above ground testing bans, and improvements to how steele is manufactured, low background steel is no longer needed for most radiation sensitive applications.
That’s a good thing, because applications that need low background steel tend to REALLY need it. Atmospheric air is still used to make steel, so there tend to be radio isotopes in regular steel, even as the amount in the atmosphere continues to fall.
It a a tale of juicy irony, the Germans then bought the scrap from the ships and made U-boats instead.
“Suck it Treaty of Versailles” – Hitler, probably
[Just like they use lead from roman shipwrecks for dark matter detectors](https://www.abc.net.au/news/science/2025-11-08/ancient-roman-shipwreck-particle-physics-dark-matter-lead/105758330)