SMS Cöln (1916)

SMS Cöln was a light cruiser in the German Kaiserliche Marine, the second to bear this name, after her predecessor SMS Cöln had been lost in the Battle of Heligoland Bight. Cöln, first of her class, was launched on 5 October 1916 at Blohm & Voss in Hamburg and completed over a year later in January 1918. She and her sister SMS Dresden (1917) were the last two light cruisers built by the Kaiserliche Marine; eight of her sisters were scrapped before they could be completed. The ships were an incremental improvement over the preceding Königsberg class cruisers.

Cöln was commissioned into service with the High Seas Fleet ten months before the end of World War I; as a result, her service career was limited and she did not see action. She participated in a fleet operation to Norway to attack British convoys to Scandinavia, but they failed to locate any convoys and returned to port. Cöln was to have participated in a climactic sortie in the final days of the war, but a revolt in the fleet forced Admirals Reinhard Scheer and Franz von Hipper to cancel the operation. The ship was interned in Scapa Flow after the end of the war and scuttled with the fleet there on 21 June 1919, under orders from the fleet commander Rear Admiral Ludwig von Reuter. Unlike many of the other ships scuttled there, Cöln was never raised for scrapping.

Construction
Cöln was ordered under the contract name "Ersatz SMS Ariadne" and was laid down at the Blohm & Voss shipyard in Hamburg in 1915. She was launched on 5 October 1916, after which fitting-out work commenced. She was commissioned into the High Seas Fleet on 17 January 1918. The ship was 155.5 m long overall and had a beam of 14.2 m and a draft of 6.01 m forward. She displaced 7486 MT at full combat load. Her propulsion system consisted of two sets of steam turbines powered by eight coal-fired and six oil-fired Marine-type boilers. These provided a top speed of 27.5 kn and a range of approximately 6000 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. These guns fired a 45.3 kg shell at a muzzle velocity of 840 m/s. The guns had a maximum elevation of 30 degrees, which allowed them to engage targets out to 17600 m. They were supplied with 1,040 rounds of ammunition, for 130 shells per gun. Cöln also carried three 8.8 cm SK L/45 anti-aircraft guns mounted on the centerline astern of the funnels, though one was removed in 1918. 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
After their commissioning under the command of Erich Raeder (17 January 1918 – October 1918), Cöln and Dresden joined the High Seas Fleet. They were assigned to the II Scouting Group, alongside the cruisers SMS Königsberg (1915), SMS Pillau, SMS Graudenz, SMS Nürnberg (1916), and SMS Karlsruhe (1916). The ships were in service in time for the major fleet operation to Norway in 23–24 April 1918. The I Scouting Group and II Scouting Group, along with the Second Torpedo-Boat Flotilla were to attack a heavily-guarded British convoy to Norway, with the rest of the High Seas Fleet steaming in support. The Germans failed to locate the convoy, which had in fact sailed the day before the fleet left port. As a result, Admiral Reinhard Scheer broke off the operation and returned to port.

In October 1918, the two ships and the rest of the II Scouting Group were to lead a final attack on the British navy. Cöln, Dresden, Pillau, and Königsberg were to attack merchant shipping in the Thames estuary while the rest of the Group were to bombard targets in Flanders, to draw out the British Grand Fleet. Großadmiral Reinhard Scheer, the commander in chief of the fleet, intended to inflict as much damage as possible on the British navy, in order 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. When informed of the situation, the Kaiser stated, "I no longer have a navy."

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. Cöln was among the ships interned. On the voyage there, her captain radioed the fleet commander that one of the ship's steam turbines had a leaking condenser. Reuter dispatched another light cruiser to remain with the ship in the event that she needed to be towed. Despite the problematic turbine, Cöln managed to steam into port, the last ship in the German line.

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. Cöln sank at 13:50 and was never raised for scrapping.