Sunken 1919 German warships supply rare low-background steel for high-tech uses

Following the cease-fire of World War I, 74 German warships were held in the Royal Navy anchorage at Scapa Flow. Fearing that Britain would claim the vessels, Rear-Admiral Ludwig von Reuter gave a covert order on 21 June 1919, leading crews to flood the ships and sink 52 of them. Early salvage operations recovered much of the metal for standard scrap, but the steel produced before the July 1945 Trinity nuclear test remained free of atmospheric isotopes such as Cobalt-60 and Strontium-90.

Scientists later discovered that this low-background steel is ideal for constructing housings for Geiger counters, medical imaging devices and deep-space probes, where even trace radiation can skew results. Seven of the original wrecks, including the battleships König, Markgraf and Kronprinz Wilhelm, are now protected as historic monuments under Scottish law, and the site has become a renowned diving location rather than a source of metal. The demand for this rare material underscores the lasting legacy of the Scapa Flow scuttling in modern technology.