This German Cruiser With A Crazy Past Had These Even Wackier Torpedo Launchers

The torpedo launchers of the German heavy cruiser Prinz Eugen are really something to behold. At first glance, they look more like futuristic speedboats of sorts than torpedo launchers – something you’d see Roger Moore using in The Spy Who Loved Me to escape Karl Stromberg’s sinking Atlantis hideout. Yet the story of the vessel and its distinctive weaponry is just as fascinating, and improbable.

Originally designed to be operated in the open air, the torpedo launchers were an integral part of Prinz Eugen‘s armory during World War II. Both the ship and its torpedo launchers survived the war, eventually falling into American hands. In the post-war period, the vessel was put to use as a target in sea-base nuclear weapons testing – which, miraculously, it survived. In order to tell the remarkable story of the ship and its armory, we need to turn to events before World War II, amid the Nazis’ naval expansion efforts of the 1930s.

Prior to 1935, Germany was technically bound by the terms of the Versailles Treaty – which the country signed in June 1919 after months of negotiations with the allied powers. Alongside the provision that Germany had to accept responsibility for the outbreak of World War I, strict restrictions were placed on German military expansion under Part V of the treaty. In particular, Germany’s Navy was limited to six pre-dreadnought battleships, six light cruisers, 12 destroyers, and 12 torpedo boats. Submarines were forbidden, as was any form of naval aviation.

Hitler’s seizure of power in early 1933, ending Germany’s brief experiment in democracy during the Weimar Republic (1918-33), had significant implications for the country’s military and Navy. Yet even before this date, in November 1932, the Weimar Republic decided to launch a new naval rearmament program, flouting the conventions of the Versailles Treaty. The launching of the pocket battleship Deutschland in 1931 was an important step toward German naval rearmament, but, under the Nazis, this process would expand rapidly. Indeed, plans for the construction of large U-boats were put in place in late 1933.

The German “pocket battleship” Deutschland with her crew manning the rails, 1935. Heinrich Hoffman Collection, U.S. National Archives Collection of Foreign Records Seized, 1675-1958/Wikimedia Commons

In late 1934, Hitler began to suggest that his aim was to build a Navy around 35 percent the size of Britain’s Royal Navy. Recognizing that the Nazis would likely rearm the German Navy beyond this size, the British attempted to get ahead by forcing Hitler to commit to the figure, fearing the impact of German naval rearmament on the Royal Navy. By November 1934, Hitler informed the British of his desire to enter into a naval agreement, which resulted in the signing of the Anglo-German Naval Agreement in June 1935.

The agreement stipulated that the newly formed Kriegsmarine – the German Navy under the Nazis, formally established in May 1935 – would be restricted to 35 percent of the Royal Navy’s size. However, as part of the negotiations, the Germans were able to have submarines considered a separate issue, allowing German submarines to be restricted to 45 percent of the size of the Royal Navy’s submarine fleet.

Adolf Hitler receives Ambassador Joachim von Ribbentrop in Berlin (right), the head of the German delegation sent to London to negotiate the Anglo-German Naval Agreement, after the agreement’s signing, June 23, 1935. On the left, Admiral Erich Raeder. Photo by Heinrich Hoffmann/Ullstein Bild via Getty Images

The key point here is that, through the Anglo-German Naval Agreement, Germany was formally allowed to expand its Navy in ways that far exceeded the limitations of the Versailles Treaty. Minesweepers, submarines, and heavy cruisers were now permitted. Five, 10,000 ton heavy cruisers were also allowed to be constructed under the agreement. The vessels Admiral Hipper, Seydlitz, Lützow, Blücher, and Prinz Eugen were part of the Admiral Hipper class which constituted Germany’s new heavy cruiser fleet.   

Prinz Eugen was constructed by the Germaniawerft company, which was based at the harbor in the city of Kiel, north of Hamburg. The ship launched on August 22, 1938 – an event attended by Hitler himself – and was commissioned on August 1, 1940. In terms of its overall dimensions, as Gerhard Koop and Klaus-Peter Schmolke note in their book, Heavy Cruisers of the Admiral Class: Warships of the Kriegsmarine, Prinz Eugen’s length was just shy of 700 feet, its beam was just over 71 feet, and its draft was 24 feet.

With a displacement of around 19,000 tons (displacement figures for the vessel vary to a degree), Prinz Eugen ended up greatly exceeding the displacement limit imposed by the Anglo-German Naval Agreement on heavy cruisers. Powered by three steam turbines, the vessel sported an array of weapons standard on Admiral Hipper class vessels, including eight, 8-inch guns, twelve, 4.1-inch SK C/33 guns, twelve, 1.5-inch SK C/30 guns, and eight, 0.79-inch C/39 guns.

Launching of the German heavy cruiser Prinz Eugen, August 22, 1938. Ullstein Bild via Getty Images

The Admiral Hipper class of heavy cruisers all featured twelve, 21-inch torpedo tubes, as Koop and Schmolke indicate. These were arranged in four triplet sets on the main deck level.

Prinz Eugen schematics according to the Division of Naval Intelligence, U.S. Navy, August 1942. The placement of the vessel’s torpedo tubes, seen from the side and above, are circled in red. Note that they do not feature their distinctive enclosures. U.S. Navy

The torpedo tubes themselves featured a barbette – protective, circulator armor – and a turntable with a firing station and aiming optic, and could be manned by a team of two.

Admiral Hipper class torpedo configuration. © Koop and Schmolke, Heavy Cruisers of the Admiral Class
Crewmen aboard the flagship Admiral Hipper working on the open control position of the triple torpedo mount in 1940, during the invasion of Norway. © Steve Backer, Admiral Hipper Class Cruisers

In terms of the torpedoes, Prinz Eugen, and the other vessels of the Admiral Hipper class, was capable of firing Type G7a (T1) torpedoes. The standard-issue torpedo of the Kriegsmarine, Type G7a (T1) torpedoes were introduced into service in 1934 and were used aboard surface vessels as well as U-boats. Featuring a steam-powered design, the torpedoes boasted a maximum speed of around 50 miles per hour (44 knots) for a range of up to 3.6 miles (5.8 kilometers). Each Type G7a (T1) torpedo weighed over 1.74 tons (1.538 tonnes), with an explosive charge of over 617 pounds (280 kilograms) of TNT.

The use of torpedoes was an important part of naval warfare during World War II. Torpedoes were frequently used to sink, or severely damage, enemy vessels – a single hit from a G7a (T1) was enough to sink most merchant vessels, for example. During the Battle of the Denmark Straight in late May 1941, it was planned that Prinz Eugen – which was defending the Kriegsmarine battleship Bismarck against attack by the Royal Navy battlecruiser HMS Hood and the battleship HMS Prince of Wales – should launch a torpedo attack on the British vessels if they were to come into range. At one stage, Prinz Eugen was in range to strike Hood with its torpedoes, but did not fire. Of course, the warships of the period frequently boasted thick armor and anti-torpedo bulkheads to protect against torpedo strikes, meaning that torpedoes needed to detonate their explosive charge underneath enemy vessels to be effective. You can read more about this time honored tactic here.

As the illustrations above suggest, the firing stations on Prinz Eugen’s torpedo launchers were originally designed with no protection from the elements for the men operating them. Given the frigid conditions in the open air at sea, having some form of enclosure would no doubt help sailors shelter from the cold for prolonged periods of time. During its service in the Kriegsmarine, Prinz Eugen sailed in the Atlantic Ocean (Operation Rheinübung, for example, in May 1941), the English Channel (notably during the ‘Channel Dash’ of February 1942), as well as in the Baltic. The enclosures would also likely have provided a semblance of psychological protection to sailors during combat, too.

Prinz Eugen seen during Baltic trials in January, 1941. One of the vessel’s torpedo launchers, circled in red, does not feature the enclosed firing station. © Backer, Admiral Hipper Class Cruisers

Pinpointing the exact time period the enclosures were added is challenging due to a lack of photographs with verifiable dates. The firing stations remained open during 1940 and most likely in 1941, too. In 1942, at some stage, it would appear the torpedo firing stations were enclosed. The War Zone reached out to Vincent O’Hara, naval historian and author of Heavy Cruiser Prinz Eugen: Naval History Special Edition for more on when Prinz Eugen’s torpedo launchers may have been enclosed. O’Hara suggests that these were most likely added either shortly before, or shortly after, Prinz Eugen left for Norway in March 1942.

Prinz Eugen pictured in Brest, France, early 1941. One of the torpedo launchers, circled in red, appears to sport some form of covering, although this doesn’t seem to resemble the permanent enclosures seen in later images. Historical Photo Archive
Prinz Eugen pictured in 1942, supposedly in Copenhagen. The back hatch of one of the distinctive torpedo enclosures can be seen circled in red. Historical Photo Archive
One of Prinz Eugen’s torpedo launchers pictured in the Baltic in 1944 (month unknown). Here, the distinctive enclosure can be seen. © Backer, Admiral Hipper Class Cruisers

Many of the clearest images of Prinz Eugen and its torpedo launchers were actually taken at the end of the war, and in the immediate post-war period, as the vessel fell into British, and subsequently American hands. 

After moving to Copenhagen in Denmark on April 20, 1945, Prinz Eugen was surrendered to the British Royal Navy on May 8. As one of two German naval vessels to survive the war in serviceable condition – the other being the light cruiser NürnbergPrinz Eugen was part of the captured German bounty the Allies divided up between themselves after the war. Although neither the U.S. nor the U.K. particularly wanted Prinz Eugen, they were equally unwilling for her to end up in the hands of the Soviet Union. As fate would have it, the ship was awarded to the U.S. in December 1945 via a lottery. Representatives from the three countries drew lots from the hat of U.S. Navy Captain Arthur H. Graubart, with one of the lots including Prinz Eugen. The vessel was subsequently commissioned into the U.S. Navy as USS Prinz Eugen, and arrived in Boston on January 22, 1946.

German cruiser Prinz Eugen at Philadelphia Navy Yard, February 1946. Note the torpedo launchers circled in red. U.S. Navy photo/Wikimedia Commons

Upon arrival in the U.S., USS Prinz Eugen was thoroughly searched for anything of intelligence value. Parts of the vessel were also removed, including its large GHG passive sonar array, which was installed for testing on the submarine USS Flying Fish (SS-229), as well as the two, forward-facing 8-inch guns of turret ‘Anton’, the foremost turret of the ship. Interestingly, however, USS Prinz Eugen’s torpedo launchers appear to have been retained, as the photo below indicates.

USS Prinz Eugen transiting the Panama Canal, March 1946. Note the torpedo launchers circled in red, and the removed guns from turret ‘Anton’ circle in green. U.S. Navy photo/Wikimedia Commons  

Under the command of Captain Graubart, USS Prinz Eugen boasted a mixed American-German crew, at least for a time. The majority of the ship’s crew, 574 men, were Kriegsmarine prisoners of war (POW). Eight U.S. Navy officers and 85 enlisted men supervised the crew up to May 1, 1946, on which date the POW crew was ordered to return to Germany. However, with the vessel experiencing issues with its propulsion system, and after complaints from its U.S. Navy crew that it was difficult to operate, it was decided that USS Prinz Eugen should be put to use in another way. The vessel was assigned to a fleet of target ships for Operation Crossroads – a naval nuclear weapons test conducted by the U.S. Navy running in July 1946 at the Bikini Lagoon, a coastal reef in the Marshall Islands.

At this point, only three atomic blasts had ever been successfully conducted in history. The first, code-named ‘Trinity,’ which took place on July 16, 1945, in the Jornada del Muerto desert, New Mexico, was designed to test the U.S.’s nuclear capability. The subsequent blasts were inflicted by the U.S. on the Japanese cities of Hiroshima and Nagasaki on August 6 and 9, 1945. Little was known about the impact an atomic detonation would have on ships at sea, and so a large fleet consisting of 95 target ships was assembled by Joint Army/Navy Task Force One for tests. 

Some three weeks prior to Operation Crossroads, USS Prinz Eugen was thoroughly photo-documented by the U.S. Navy. The resulting images, including several of the vessel’s torpedo launchers, provide a detailed look at how the torpedoes themselves were maneuvered. According to Mark Mortensen at Ship Archive, torpedoes would be moved in and out of Prinz Eugen’s torpedo room, located on the top deck, via an overhead rail. From there, in the case of torpedo mount number four (port side, aft) a transfer rail attached to the underside of the top deck allowed torpedoes to be maneuvered and lowered to the main deck level.

Front-facing view of number four mount. Just to the left of the mount, the shell and torpedo transfer rail system is located. U.S. Navy photo
A rear view of number three mount. The operator entry hatch can be seen towards the back of the enclosed firing station. U.S. Navy photo
The ship’s torpedo workshop. The overhead rail was used to move torpedoes in and out of the workshop. U.S. Navy photo

Miraculously, USS Prinz Eugen survived the Navy’s nuclear weapons tests at Bikini Lagoon. In all, two nuclear bombs were detonated during what would be termed the ‘Able’ and ‘Baker’ tests – both were ‘Fat Man’ MKIIIs, the same type used over Nagasaki in 1945, which boasted explosive yields of 23 kilotons.

On July 1, 1946, a B-29 Superfortress named ‘Dave’s Dream,’ which was previously called ‘Bing Stink’ and served as the camera aircraft for the Nagasaki bombing, dropped the MKIII codenamed ‘Gilda’ during test Able, which missed its target by some 2,130 feet (710 yards). Only five vessels sank as a result – as USS Prinz Eugen was moored roughly 1,200 yards from the target zone, the ship survived with minor damage but was contaminated with radiation. The second bomb test which occurred on July 25, codenamed Baker, saw the detonation of another MKII, ‘Helen of Bikini,’ only this time below the water. Although the explosion the bomb unleashed was enormous, USS Prinz Eugen only suffered a small leak as a result.    

Due to radiation contamination, the leak sustained could not be patched and USS Prinz Eugen began to list – eventually capsizing at Kwajalein Atoll in the central Pacific on December 22, 1946, where the vessel was towed after Operation Crossroads. 

And there you have it – the fascinating, and unlikely, history of Prinz Eugen with its wacky torpedo launchers, which survived both World War II and two nuclear blasts.

Contact the author: