On April 9, 1940, the cruiser “Karlsruhe” led the German Navy attack on the Norwegian city of Kristiansand. The ship was torpedoed and sunk – where, however, was not yet clear. Now recordings from a remote-controlled diving robot have identified the wreck: it stands upright at a depth of 490 meters on the bottom of the Skagerrak, around 13 nautical miles from the southern Norwegian coast.
The cruiser “Karlsruhe” was put into service during the Weimar Republic in 1927 and, after being rebuilt, was part of the German Navy during World War II. The ship was 174 meters long, had nine cannons and, with its steam-powered turbines, reached a top speed of around 30 knots. On April 9, 1940, the cruiser took part in the “Weser Exercise” operation, during which the ship was supposed to support the landing of German troops in Kristiansand, Norway.
Chance find on the submarine cable
But when the Karlsruhe entered the fjord upstream of the city of Kristiansand, it came under fire. Initially by flak from the Norwegian fortress Odderøy, which however could not prevent the capture of Kristiansand by the German troops. Then, however, the Karlsruhe was hit by a torpedo from a British submarine and so badly damaged that her captain ordered the ship to be sunk. “The fate of the Karlsruhe is described in the history books, but nobody knew exactly where the ship sank,” explains the archaeologist Frode Kvalø from the Norwegian Naval Museum. “She is the only large German warship that was lost in an attack on Norway in an unknown position.”
But three years ago employees of the Norwegian electricity company Stattnet happened upon an unknown shipwreck while inspecting a submarine cable between Norway and Denmark. It was only about 15 meters from the submarine cable at a depth of 490 meters on the bottom of the Skagerrak. However, it was initially unclear which ship it was. In the summer of 2020, a trip on a reconnaissance ship offered the Stattnet engineer Ole Petter Hobberstad, together with the archaeologists, the chance to find out more about the wreck. With multibeam echo sounders and a remote-controlled diving robot, they took a closer look at the sunken ship for the first time.
Upright and still threatening
Even the first recordings of the diving robot were spectacular: “When the recordings showed us that the ship had been torpedoed, we knew that it must have come from the war,” says Hobberstad. “And when the cannons became visible on the screen, we knew it had to be a very large warship.” Closer investigations then confirmed that they had found the wreck of the Karlsruhe. “After all these years, we finally know where the final resting place of this once so important warship is,” says Kvalø. In the recordings of the diving robot, their superstructures and cannons are clearly visible and enable clear identification.
This was made easier by the fact that the shipwreck lies upright on the seabed. As Kvalø explains, this is rather unusual for large warships. Because of their high center of gravity, they usually tip over when they sink and then land on their side on the seabed. “But the Karlsruhe still stands upright and firm even at a depth of 490 meters and points its cannons threateningly out into the sea,” says the archaeologist. “With its main battery of nine cannons in three three-turrets, this was the largest and most dangerous ship in the attack on Kristiansand.”
Source: Stattnet