Осколки истории: почему затонувшие в 1919 году немецкие корабли в Шетлендских островах стали бесценным ресурсом для науки

At around noon on June 21, 1919, the crews of 74 interned German warships at anchor in a bay in the Orkney Islands opened the seacocks of their vessels and began to sink them. The German High Seas Fleet had been surrendered to Britain seven months earlier under the terms of the Armistice that ended the First World War. Its fate remained undecided while the Allies argued about how to divide it up. Rear Admiral Ludwig von Reuter, the German commander, believed the ships would soon be seized outright as spoils of war. He gave the order to scuttle. The British were caught off guard. Their guard ships managed to beach a handful of the German vessels, but 52 of the 74 sank to the seafloor of Scapa Flow. It remains the largest single-day loss of naval shipping in history. Most of those ships were later raised and scrapped. A few were not. And decades later, for reasons no one in 1919 could have foreseen, the ones that were left behind became strangely valuable. What happened in Scapa Flow Scapa Flow is a natural deep-water anchorage between the islands of the Orkney archipelago, north of the Scottish mainland. It had served as the Royal Navy’s principal base during the First World War, and after the Armistice it became the holding site for the interned German fleet. The 74 ships anchored there were the pride of the Imperial German Navy — battleships, battlecruisers, light cruisers, and torpedo boats, many of them less than five years old. Their crews lived aboard under reduced conditions through the winter of 1918-19 while diplomats in Paris negotiated the peace. When von Reuter learned that the terms of the Treaty of Versailles would require the ships to be handed over, he acted on standing orders that dated back to before the Armistice. If the ships were about to be seized, they were to be destroyed. On the morning of June 21, he transmitted the coded signal for scuttling to the fleet. The operation succeeded. Nine German sailors were killed by British gunfire during the scuttling. The rest were interned as prisoners of war. Most of the fleet lay at the bottom of Scapa Flow within a few hours. The salvage that stopped In the decades that followed, most of the wrecks were removed. Marine salvage rights were sold to private companies. The most prolific of these was Cox and Danks Ltd., founded by an English scrap merchant named Ernest Cox, who bought 28 of the wrecks and developed innovative compressed-air techniques for refloating them. By the outbreak of the Second World War in 1939, the majority of the sunken fleet had been raised, towed to shipbreaking yards, and melted down for scrap. Salvage operations continued on and off through the 1970s. By 1979, when the last commercial salvage effort ended, 45 of the 52 sunken ships had been recovered. Seven remained on the seafloor. These are the wrecks that are still there today — three battleships (the Kronprinz Wilhelm, the Markgraf, and the König) and four light cruisers (the Brummer, the Karlsruhe, the Dresden, and the Cöln), plus various smaller vessels and torpedo boats. They are now designated protected historic monuments under Scottish law, and popular sites for recreational diving. The reason a specific commercial interest in these wrecks has returned in recent decades is not primarily historical or archaeological. It is metallurgical. Why 1945 changed everything Modern steel manufacturing depends on atmospheric air. Both the Bessemer converter and the basic oxygen process, which together account for essentially all mass-produced modern steel, use blasts of ambient air to remove carbon from molten iron. Before 1945, that atmospheric air was clean. After 1945, it stopped being clean. The first atmospheric nuclear tests, beginning with the Trinity test in New Mexico in July 1945 and continuing through American, Soviet, British, French, and Chinese testing programmes over the following decades, released large quantities of specific radioactive isotopes into Earth’s atmosphere. Cobalt-60, caesium-137, americium-241, and other fission and activation products spread globally within weeks and remained in circulation for years. Any steel manufactured after 1945 was blown through with air that contained these isotopes. Trace quantities of the contamination became embedded in the finished steel itself. The amounts are tiny — measured in fractions of a becquerel per kilogram — but they are detectable. For most applications, this level of contamination does not matter at all. For a specific set of applications, it matters enormously. Instruments designed to detect extremely faint radiation — such as particle physics detectors, medical whole-body counters, and space-based radiation sensors — require enclosures made from materials that themselves emit as little radiation as possible. Modern steel is too noisy for these purposes. The specific solution has been to source steel from before the atomic age. Pre-1945 steel was smelted with clean atmospheric air. It contains no post-nuclear contamination. Its residual radioactivity has decayed away almost entirely — cobalt-60 has a half-life of just over five years, and after several decades even the initial contamination has essentially vanished. Old shipwrecks are one of the few large accessible sources of pre-1945 steel in bulk. The German ships at Scapa Flow are one of the largest such caches in existence. The commodity that shouldn’t exist Since the 1950s, small quantities of steel have been quietly harvested from the Scapa Flow wrecks and channeled into scientific instrumentation. The specific practice was, for decades, semi-legal and not much discussed in public. Divers cut small sections of plate from accessible hull sections. Metal traders moved the material through opaque supply chains. Physicists and medical device manufacturers used it in the specific instruments that require it, without asking too many questions about provenance. More recently, the situation has changed. UK law now protects the Scapa Flow wrecks as historic monuments, and unauthorised removal of metal from them is illegal. Legitimate demand for low-background steel is met increasingly by regulated salvage of other pre-1945 shipwrecks, of which several are available in less protected locations. The specific need for the material is also, quietly, declining. Post-1963 partial nuclear test ban treaty, atmospheric contamination has been gradually decreasing, and modern steel manufacturing techniques have become cleaner. Some current-generation detectors can now use ordinary modern steel with only minor adjustments. The specific window in which Scapa Flow steel was genuinely irreplaceable is narrowing. But the wrecks themselves remain. Seven ships of the Imperial German Navy still sit on the seafloor of Scapa Flow, their hulls slowly deteriorating, their steel still uncontaminated by the atomic age, more than a century after their crews opened the seacocks and let them sink. What began as an act of defiance in 1919 became, entirely by accident, one of the strangest scientific resources on Earth — a specific batch of pre-nuclear metal that no manufacturing process can now replicate. The ships were meant to disappear. Some of them are still doing physics.