SMS Karlsruhe (1916)

SMS Karlsruhe was a light cruiser of the Königsberg class, built for the Kaiserliche Marine (Imperial Navy) during World War I. She was named after the earlier Karlsruhe, which had sunk in November 1914, from an accidental explosion. The new cruiser was laid down in 1914 at the Kaiserliche Werft shipyard in Kiel, launched in January 1916, and commissioned into the High Seas Fleet in November 1916. Armed with eight 15 cm SK L/45 guns, the ship had a top speed of 27.5 kn.

She saw relatively limited service during the war, due to her commissioning late in the conflict. She was present during a brief engagement with British light forces in August 1917, though she did not actively participate in the battle. She joined the large task force assigned to Operation Albion in October 1917, but did not see significant action during that operation either. She was assigned to what was to have been the final sortie of the High Seas Fleet in the closing days of the war, but a large-scale mutiny in significant parts of the fleet forced the cancellation of the plan. Karlsruhe was interned in Scapa Flow after the end of the war, and scuttled there on 21 June 1919. Unlike most of the other ships sunk there, her wreck was never raised.

Construction
Karlsruhe was ordered under the contract name "Ersatz SMS Niobe (1899)" and was laid down at the Kaiserliche Werft shipyard in Kiel in 1915. She was launched on 31 January 1916, after which fitting-out work commenced. She was commissioned into the High Seas Fleet on 15 November 1916. The ship was 151.4 m long overall and had a beam of 14.2 m and a draft of 5.96 m forward. She displaced 7125 MT at full combat load. Her propulsion system consisted of two sets of steam turbines powered by ten coal-fired and two oil-fired Marine-type water-tube boilers. These provided a top speed of 27.5 kn and a range of 4850 nmi at 12 kn.

The ship was armed with eight 15 cm SK L/45 guns in single pedestal mounts. Two were placed side by side forward on the forecastle, four were located amidships, two on either side, and two were arranged in a super-firing pair aft. They were supplied with 1,040 rounds of ammunition, for 130 shells per gun. Karlsruhe also carried two 8.8 cm L/45 anti-aircraft guns mounted on the centerline astern of the funnels. She was also equipped with a pair of 60 cm torpedo tubes with eight torpedoes in deck-mounted swivel launchers amidships. She also carried 200 mines. The ship was protected by a waterline armored belt that was 60 mm thick amidships. The conning tower had 100 mm thick sides, and the deck was covered with 60 mm thick armor plate.

Service history
On 16 August 1917, Karlsruhe participated in a mine-sweeping operation in the North Sea. The minesweepers were clearing Route Yellow, one of the channels in the minefields used by U-boats to leave and return to port. Karlsruhe was joined by the cruiser SMS Frankfurt and three torpedo boats. At 12:55, lookouts on one of the minesweepers spotted a British squadron of three light cruisers and sixteen destroyers approaching. The minesweepers fled south under cover of smoke screens, after which the British broke off the attack. Karlsruhe and the rest of the escort failed to come to their aid, however, and the commander of the operation was subsequently relieved of command.

In early September 1917, following the German conquest of the Russian port of Riga, the German navy decided to eliminate the Russian naval forces that still held the Gulf of Riga. The Admiralstab (Navy High Command) planned Operation Albion to seize the Baltic island of Ösel, and specifically the Russian gun batteries on the Sworbe Peninsula. On 18 September, the order was issued for a joint operation with the army to capture Ösel and Moon Islands; the primary naval component comprised the flagship, the battlecruiser SMS Moltke, along with the III and IV Battle Squadrons of the High Seas Fleet. The invasion force amounted to approximately 24,600 officers and enlisted men. Karlsruhe and the rest of the II Scouting Group provided the cruiser screen for the task force.

The operation began on the morning of 12 October, when Moltke and the III Squadron ships engaged Russian positions in Tagga Bay while the IV Squadron shelled Russian gun batteries on the Sworbe Peninsula on Ösel. On 18–19 October, Karlsruhe and the rest of the II Scouting Group covered minesweepers operating off the island of Dagö, but due to an insufficient number of minesweepers and bad weather, the operation was postponed. By 20 October, the islands were under German control and the Russian naval forces had either been destroyed or forced to withdraw. The Admiralstab then ordered the naval component to return to the North Sea.

In October 1918, Karlsruhe and the rest of the II Scouting Group were to lead a final attack on the British navy. Karlsruhe, SMS Nürnberg (1916), and SMS Graudenz were to bombard targets in Flanders while SMS Pillau, SMS Cöln (1916), SMS Dresden (1917), and SMS Königsberg (1915) were to attack merchant shipping in the Thames estuary, to draw out the British Grand Fleet. Admirals Reinhard Scheer and Franz von Hipper intended to inflict as much damage as possible on the British navy, to secure a better bargaining position for Germany, whatever the cost to the fleet. On the morning of 29 October 1918, the order was given to sail from Wilhelmshaven the following day. Starting on the night of 29 October, sailors on SMS Thüringen and then on several other battleships mutinied. The unrest ultimately forced Hipper and Scheer to cancel the operation.

Following the capitulation of Germany in November 1918, most of the High Seas Fleet's ships, under the command of Rear Admiral Ludwig von Reuter, were interned in the British naval base in Scapa Flow. Karlsruhe was among the ships interned. The fleet remained in captivity during the negotiations that ultimately produced the Versailles Treaty. Von Reuter believed that the British intended to seize the German ships on 21 June 1919, which was the deadline for Germany to have signed the peace treaty. Unaware that the deadline had been extended to the 23rd, Reuter ordered the ships to be sunk at the next opportunity. On the morning of 21 June, the British fleet left Scapa Flow to conduct training maneuvers, and at 11:20 Reuter transmitted the order to his ships; Karlsruhe sank at 15:50. She was never raised for scrapping. The rights to her wreck were sold in 1962.