The Weird Story of the Spontaneously Exploding Submarines

On the morning of January 17, 1955, Eugene P. Wilkinson, commander of the U.S. Navy submarine USS Nautilus, transmitted one of the crucial consequential messages within the historical past of naval warfare: underway on nuclear energy. Previous to this, navy submarines have been extra aptly termed submersibles, with nearly all of their time spent on the floor. Nuclear propulsion lastly remodeled the submarine into what proponents had envisioned all alongside: a stealthy, highly effective weapon in a position to lurk beneath the waves for weeks and even months at a time. However the pursuit of the true submarine predates the event of nuclear energy, and for a quick interval throughout and after the Second World Struggle, a number of navies experimented with a propulsion know-how so harmful that submarine crews risked being dissolved alive. That is the unstable story of the peroxide submarines.

The Battle of the Atlantic, fought between the Allied navies and the U-boats of the German Kriegsmarine, was the longest single battle of the Second World Struggle, lasting from the very first day of the battle to the final. And early on, it appeared as if the Germans may really win. By early 1941 the U-boats had diminished Britain’s yearly imports from a pre-war complete of 68 million tons to a mere 26 million tons. Admiral Karl Dönitz, head of the U-boat arm, calculated that if he might inflict sustained losses of 700,000 tons per 30 days, he might starve Britain into submission.

However for all their menace, the U-boats had a key weak point. Like all submarines of the period, they have been powered by a mixture of diesel engines on the floor and electrical motors underwater. Nonetheless, submerged pace and maneuverability have been poor and battery capability restricted. Consequently, U-boats spent most of their time on the floor, utilizing their superior pace and the quilt of darkness to infiltrate Allied convoys at night time and solely submerging to flee enemy assault.

However such techniques quickly grew to become untenable because the introduction of radar and elevated Allied air cowl made the floor a harmful place for a U-boat to be caught. One stopgap resolution, launched in 1943, was the Schnorkel, a retractable air consumption and exhaust duct that allowed U-boats to run their diesel engines and recharge their batteries whereas working at periscope depth. However quickly even this grew to become insufficient, as advances in radar know-how allowed antisubmarine plane to detect even objects as small as a periscope protruding above the water. It quickly grew to become clear that a completely new kind of U-boat was wanted, one which might spend nearly all of its time underwater like a real submarine.

On this entrance, the Germans pursued two important strains of analysis. The primary, the Elektroboot idea, used a mixture of improved hydrodynamics and elevated battery capability to supply submarines which have been really sooner submerged than surfaced and which might stay submerged for days on finish. Two such designs reached manufacturing earlier than the conflict’s finish. The bigger of the 2, the Sort XXI, was 76 metres lengthy and had a displacement of 1,621 tons. It featured a radically streamlined hull and conning tower freed from the deck weapons, guard rails, and different drag-producing protuberances frequent to earlier designs, and a battery capability practically 3 times that of the Sort VII, the workhorse of the U-boat fleet. This allowed the sort XXI to achieve underwater speeds of as much as 17 knots or stay submerged for as much as 75 hours whereas cruising at 5 knots. The kind additionally sported different superior options, together with quieter electrical motors for silent working, an automated torpedo-loading system that allowed it to launch as much as 18 torpedoes in 20 minutes, and improved facilities for the 57-man crew together with a freezer for storing perishable meals.

The kind XXI’s smaller sibling was the Sort XXIII, designed for operations within the shallow coastal waters of the Mediterranean, Black, and North Seas. Measuring 35m lengthy and displacing 234 tons, the Sort XXIII might obtain 12.5 knots submerged or stay submerged for 48 hours cruising at 4 knots. Because the boat was designed to be transported cross-country by rail, its measurement was dictated by the scale of ordinary German railway tunnels. This in flip restricted the Sort XXIII’s armament to 2 torpedoes with no reloads, the tubes having to be reloaded from the surface whereas the boat was docked.

118 Sort XXI and 63 kind XXIII U-boats have been accomplished earlier than the conflict’s finish, although they entered service too late to have any main impression. Solely two Sort XXIs and 6 Sort XXIIIs have been deployed on conflict patrols, with the Sort XXIIIs managing to sink 14,601 tons of Allied transport. After the conflict, nonetheless, captured Elektroboote have been operated by the navies of a number of international locations, and the categories strongly influenced the design of post-war submarines like Soviet Whiskey-Class and American Tang-class. At the moment, just one Elektroboot survives: the sort XXI Wilhelm Bauer – previously U-2540 – preserved as a museum ship in Bremerhaven, Germany.

The second and extra radical line of submarine improvement was the Sort XVII Walterboot. This submarine was powered by a novel air-independent propulsion system designed by Dr. Hellmuth Walter, maybe most well-known for designing the HWK 109-509 engine used within the Messerschmitt Me-163 Komet rocket-powered interceptor – and for extra on this, please checkout our earlier video The German Rocket Fighter That Dissolved its Pilots Alive. Like these engines, Walter’s submarine propulsion system was based mostly on the decomposition of Excessive-Take a look at Hydrogen Peroxide, or HTP, recognized in German parlance as T-Stoff. When introduced into contact with an appropriate catalyst, hydrogen peroxide decomposes violently into high-temperature oxygen and steam. In Walter’s submarine propulsion system, the peroxide was decomposed utilizing a sodium permanganate catalyst, with the oxygen-rich exhaust being blended with gas oil to extend its power earlier than being handed by a turbine linked to the propeller shaft. This method produced an amazing quantity of energy whereas not requiring exterior oxygen to function, theoretically permitting a submarine to achieve unheard-of underwater speeds in extra of 20 knots.

In an effort to show the idea, Walter obtained funding from the Kriegsmarine to construct the V-80, a small 22-metre, 80-ton submarine with a 4-man crew. The V80 was modern not just for its propulsion system but in addition its hull form, which was optimized for underwater efficiency quite than floor cruising. This “teardrop hull” would turn out to be the de facto commonplace for submarines beginning within the Sixties. Accomplished in 1940, the V80 would perform greater than 100 trial dives within the Schlei inlet and off Hela within the Baltic, reaching a record-breaking underwater pace of 28 knots. Nonetheless, this blistering efficiency got here at a price. The Walter propulsion system was exceptionally thirsty, consuming gas at a fee 30 instances better than a diesel engine and giving the V80 a spread of solely 80 kilometres. It was additionally costly to function, with a single 6.5-hour trial run costing the trendy equal of $200,000 in Excessive-Take a look at Peroxide alone.

The trials of V-80 have been witnessed by Admirals Erich Raeder and Werner Fuchs, who, whereas impressed, have been gradual to approve additional improvement. Lastly, in 1942 Walter satisfied Admiral Dönitz to approve the development of a bigger combat-capable Walterboot, the sort XVII. Just like the Sort XXIII elektroboot, the 36-metre lengthy, 300-ton Sort XVII was a small coastal boat with a teardrop-shaped hull largely freed from exterior projections. It was powered by two 4,900 horsepower Walter generators with an auxiliary 210 horsepower diesel engine and a 76 horsepower electrical motor for silent maneuvering. Using aircraft-like controls diminished the variety of crew required, whereas armament was two bow torpedo tubes with one reload every.

4 prototype Sort XVIIAs have been ordered, the primary two, U-792 and U-793, being accomplished by Hamburg shipbuilder and plane producer Blohm und Voss in October 1943. Throughout trials in March 1944, U-793 attained an underwater pace of twenty-two knots with Admiral Dönitz aboard, whereas in June U-792 it reached 25 knots. Nonetheless, the Sort XVVIAs have been tormented by quite a few issues. The already thirsty Walter generators have been rendered even much less environment friendly at depth by again stress on the exhausts, whereas the boat’s lack of dive planes made it troublesome to manage at excessive speeds. Even worse, the length-to-beam ratio of the hull was discovered to be too small, leading to excessively excessive drag. However maybe the largest flaw lay the center of the system itself: hydrogen peroxide. Not solely was HTP extremely corrosive, dissolving human flesh on contact, however even the smallest speck of natural matter might trigger it to decompose violently. This meant that even small leaks might – and did – trigger extreme accidents, fires, and explosions.

By the point the trials of the sort A’s ended, the conflict was going badly for Germany, and Admiral Fuchs argued that the continued improvement of a brand new U-boat kind would divert scarce assets from extra confirmed varieties. However he was overruled by Dönitz, who accepted the development of 24 Sort XVIIBs, which in bid to enhance gas effectivity have been fitted with solely a single 2,500 hp Walter turbine. This diminished the highest pace to 21 knots however elevated vary to 113 nautical miles. A Okay Sort submarine was additionally projected utilizing a closed-cycle Diesel engines fed from cylinders of pure oxygen.

With the wartime state of affairs quickly deteriorating and Blohm und Voss struggling to finish orders of the Sort XXI Elektroboot, the Kriegsmarine diminished the order from 24 to 6 boats. Of those, three have been accomplished – U-1405, U-1406, and U-1407 – and three have been nonetheless below building when the conflict ended. Not one of the accomplished Sort XVIIs noticed motion and all three – together with the prototype V-80 – have been scuttled by their crews. On the Potsdam Convention in July 1945, the place the key Allied leaders met to debate the destiny of postwar Europe, varied German experimental submarines have been allotted to the USA and Nice Britain for analysis, with the usNavy elevating U-1406 and the Royal Navy elevating U-1407 and capturing the partially-completed U-1408 and U-1410. Whereas U-1406 was transported to the U.S. naval base at Portsmouth, New Hampshire, the Navy noticed the Peroxide know-how as too harmful and costly and by no means tried to revive the submarine to working situation. The Walter turbine was eliminated and evaluated for a number of years earlier than it and the hull have been finally scrapped.

The Royal Navy, against this, was significantly extra keen about Peroxide propulsion, and arrange an Admiralty Improvement Institution at Barrow-in-Furness to additional develop the know-how. The analysis staff included Dr. Hellmuth Walter himself and members of his authentic analysis group. Beneath Walter’s path, the captured U-1407 was rebuilt because the analysis vessel HMS Meteorite, which was commissioned into the Royal Navy on September 25, 1945. All through 1946 Meteorite carried out various experimental trials, permitting the Admiralty to guage the efficiency and practicality of the Walter system. Nonetheless, as throughout her authentic 1944 trials, Meteorite’s crew discovered her unstable, temperamental, and troublesome to manage, drolly describing her as being “75% protected.” Nonetheless the Admiralty was sufficiently impressed to approve the development of two bigger Peroxide-powered analysis vessels: HMS Explorer, commissioned in 1956; and HMS Excalibur, commissioned in 1958. Having served her objective, HMS Meteorite was scrapped in 1949.

Whereas ostensibly extra superior and streamlined than the previous Sort XVII U-boats, with retractable fittings like mooring bollards and sonar domes for increased underwater pace, HMS Explorer and Excalibur – recognized jokingly because the “Blonde Boats” since hydrogen peroxide can be used to bleach hair – proved no much less troublesome to function. The turbine compartment – left unmanned whereas underway – would typically spew vivid white flames, whereas on a number of events the boats immediately stuffed with noxious fumes, forcing the crew to evacuate onto the deck. Even worse, the peroxide, saved in particular plastic luggage mounted outdoors the stress hull, had an unnerving behavior of spontanously exploding. Consequently, crews nicknamed the boats“HMS Exploder” and “HMS Excruciator.” Although the boats have been able to spectacular underwater speeds of 25 knots, by the late Fifties it grew to become clear that Peroxide-based propulsion was a dead-end know-how, and the Blonde Boats served primarily as high-speed targets for extra superior submarine designs. The 1954 launch of U.S.S. Nautilus, the world’s first nuclear-powered submarine, finally sealed their destiny. HMS Explorer was scrapped in 1965 and HMS Excalibur in 1968.

Whereas Peroxide propulsion was short-lived in manned submarines, it discovered a way more profitable software in torpedoes, a know-how additionally pioneered by the Germans throughout WWII. In 1952, the UK launched the Mk.12 “Fancy”, a 21-inch Peroxide-fuelled torpedo based mostly on the wartime German Steinbut prototype. Although able to speeds of as much as 52 km/h, improvement was halted when, on June 16, 1955, a peroxide explosion led to the sinking of the S-Class submarine HMS Sidon and the loss of life of 13 of her crew. Different navies have had better success with HTP torpedoes, together with Sweden and Russia. Nonetheless even these aren’t with out their issues, with the unintended explosion of an HTP-fuelled Sort 65-76A torpedo being chargeable for the lack of the Russian Oscar II-class submarine Kursk and all 118 of her crew on August 12, 2000. With most international locations at the moment phasing out their HTP torpedoes, these will hopefully be the final victims of the century-long naval flirtation with the unstable energy of hydrogen peroxide.

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