The “K class”, Reichsmarine’s innovative ships
After the launch of Emden (1925), light ‘K’ class cruisers were immediately started on the basis of a modernized armament, three triple turrets, of which the last two were offset from the axis, one further to starboard and the other to port. This strange configuration, never used again, was intended to improve stability as the turret No.2 was barely higher than the N°3. In addition, their open fire traverse area was improved. The engines themselves were also slightly shifted on the other sides to compensate. Moreover they innovated by adopting a square stern, which was extremely rare in time for large ships, again a condition dictated by weight saving considerations.
The Köln, Königsberg and Karlsruhe keels were laid in Whilhelmshaven in 1925-1926 on behalf of the Reichsmarine (for a 36 million Reichsmarks contract order each). They were launched from 1927 to 1928, and completed for testing in 1929-30. Their construction necessitated welding instead of riveting, also in order to save weight: Due to the 6000 tonnes limit imposed by the Treaty of Versailles for cruisers, it was the only assembly method fitting the bill. Furthermore protection was reduced, and it appear later in service that the superstructure twisted much in the rough northern seas and the weldings were deemed fragile, requiring additional internal supports. Designed for long distances, they had been fitted with turbines and diesels.
Other particulars and early career
All three ships participated in the peaceful cruise of the German fleet in 1931, carrying besides many cadets. The Karlsruhe showed such structural weaknesses that she had to be refitted in 1936 in San Diego, the hull being strengthened and widened, and as a result displacement jumped to 8350 tonnes fully loaded. At the origin they had a catapult installed between the second chimney and rear firing post, for two Arado 196 observation seaplanes. The Köln had it removed in 1942, as well as its torpedo tubes. Their tripod mast judged too fragile in bad weather was replaced by a “military mast” for observation. Their career was active, but short: The Köln was indeed the only one to survive the Norwegian campaign, and was confined in the Baltic for the remainder of the conflict.
The Königsberg in action
In 1939, the Königsberg served as a minelayer in the North Sea when she was sent to Norway in order to support the landings (operation Weserübung). She was finally severely damaged in a fjord by Norwegian shore batteries. She was then stationed in Bergen, while the rest of the fleet returning to Kiel. Attacked in April 1940 by a squadron of Royal navy’s Blackburn Skua torpedo planes, she was so badly damaged that she capsized in shallow water and remained there until 1943. Unlisted, she was never salvaged or repaired but dismantled in situ after the war.
The Karlsruhe in action
The Karlsruhe had an even shorter career: Having laid mines and embarked troops to Norway whe was torpedoed at Kristiansand in April 1940 by HMS Truant, being scuttled to avoid capture and achieved by the Torpedo Boat Greif.
The Köln in action
The Köln also served as a minelayer in the North Sea between September and October 1939, and was also sent in Norway, but emerged without major damage. She then participated in various operations in the Baltic until 1942, receiving a modernization of her AA artillery and much needed hull reinforcements. She sailed again to Norway to remain at anchor in a fjord, waiting orders to help attack convoys to Russia, teaming with the Hipper. In February 1943, she was damaged in operation and had to return for repairs in Germany. She then was confined in the Baltic, converted into a cadet training ship. She also doubled as an escort, to protect in particular against the threat of Soviet destroyers and submarines. She was bombed December 12, 1944 by the RAF, and joined Whilsmehaven for extensive repairs. In March 1945, several Lancasters night raids destroyed all port facilities, city and ships present. The Köln sank in shallow water, its artillery still emerging, playing a role in delaying US troops advancing towards the town. The Köln was scrapped in 1946.
KMS Emden specifications
|Dimensions||174 x 15.30 x 6.30 m|
|Displacement||6200 t, 5830 t FL|
|Propulsion||2 screws, 2 Brown-Boveri turbines, 69 800 hp|
|Speed||32 knots (xx km/h, xx mph)|
|Range||7,300 nmi (xx km; xx mi) at 15 knots (28 km/h, 17 mph)|
|Armament||9 x152mm SK C/25 (3×3), 6 x88 mm AA, 8 x37 mm AA SK C/30, 8 x20 mm AA, 12 x533 mm TT (4×3), 120 mines, 2 Arado 196 Floatplanes.|
|Armor||Belt: 30mm, Deck: 25mm, Conning tower: 30mm|
The Köln in 1941. The only K class cruiser to survive the Norwegian campaign.