Soviet submarine K-1

K-1 was the lead boat of her class of a dozen double-hulled cruiser submarines built for the Soviet Navy during the late 1930s. Although given a heavy torpedo armament, the boats could also lay mines. Commissioned in 1940, the boat was assigned to the Northern Fleet. During the Second World War, she made sixteen war patrols, including eight minelaying missions. K-1 never returned from her last patrol in September 1943, probably sunk by a mine laid by a German heavy cruiser.

Profile drawing of the class
History
Soviet Union
Name	K-1
Builder	Zavod No. 194, Leningrad
Laid down	27 December 1936
Launched	28 April 1938
Completed	16 December 1940
Commissioned	26 June 1940
Fate	Missing after 5 September 1943
General characteristics
Class and type	Soviet K-class submarine
Displacement	1,490 t (1,470 long tons) (surfaced) 2,104 t (2,071 long tons) (submerged)
Length	97.7 m (320 ft 6 in) (o/a)
Beam	7.4 m (24 ft 3 in)
Draught	4.5 m (14 ft 9 in) (full load)
Installed power	8,400 PS (6,200 kW) (diesel) 2,400 PS (1,800 kW) (electric)
Propulsion	2-shaft diesel electric
Speed	21 knots (39 km/h; 24 mph) (surfaced) 10.3 knots (19.1 km/h; 11.9 mph) (submerged)
Range	7,500 nmi (13,900 km; 8,600 mi) at 10.3 knots (19.1 km/h; 11.9 mph) (surfaced) 176 nmi (326 km; 203 mi) at 3.1 knots (5.7 km/h; 3.6 mph) (submerged)
Test depth	80 m (260 ft)
Complement	66
Sensors and processing systems	Tamir-51 sonar
Armament	6 × bow 533 mm (21 in) torpedo tubes 4 × stern 533 mm (21 in) torpedo tubes (2 internal, 2 external) 2 × 100 mm (3.9 in) deck guns 2 × 45 mm (1.8 in) deck guns 20 × mines

Design and description

Despite the unsuccessful Pravda class built in the early 1930s, the Soviet Navy still dreamed of cruiser submarines capable of attacking enemy ships far from Soviet territory. In 1936 it received approval to build them with the addition of minelaying capability. The boats displaced 1,490 metric tons (1,470 long tons) surfaced and 2,104 t (2,071 long tons) submerged. They had an overall length of 97.7 meters (321 ft), a beam of 7.4 meters (24 ft 3 in), and a draft of 4.5 meters (15 ft) at full load. The boats had a diving depth of 80 m (260 ft). Their crew numbered 66 officers and crewmen.^[1]

For surface running, the K-class boats were powered by a pair of 9DKR diesel engines, one per propeller shaft. The engines produced a total of 8,400 metric horsepower (6,178 kW), enough to give them a speed of 21 knots (39 km/h; 24 mph). When submerged each shaft was driven by a PG11 1,200-metric-horsepower (883 kW) electric motor for 10.3 knots (19.1 km/h; 11.9 mph). The boats had a surface endurance of 7,500 nautical miles (13,900 km; 8,600 mi) at 10.3 knots (19.1 km/h; 11.9 mph) and 176 nmi (326 km; 203 mi) at 3.1 knots (5.7 km/h; 3.6 mph) submerged.^[1]

They were armed with six 533-millimeter (21 in) torpedo tubes in the bow and four were in the stern, two internal and two external. They carried a dozen reloads. A dual-purpose minelaying/ballast tank was located under the conning tower that housed 20 chutes for EP-36 mines which also served as outlets for the ballast tank's Kingston valves. This arrangement proved problematic as this was the location of the greatest structural loads in the hull and the mines were sometimes pinched in the chutes as the hull flexed. Another issue was that the chutes would sometimes jam when debris was drawn in with ballast water. The boats were also equipped with a pair of 100-millimeter (3.9 in) B-24PL deck guns fore and aft on the conning tower and a pair of 45-millimeter (2 in) 21-K guns above them.^[2][1]

Construction and career

K-1 was commissioned into the Baltic Fleet on 26 May 1940 and departed Leningrad for Polyarny via the White Sea–Baltic Canal on 23 June. She was commissioned into the Northern Fleet on 6 August. During the Great Patriotic War, the boat made 16 patrols, half of which were minelaying missions. K-1 was damaged by a mine on 11 August 1942, but managed to make port three days later. The submarine departed base on 5 September 1943 and was never heard or seen again, probably sunk by a mine laid by the Admiral Hipper.^[3][4][5]

Claims

Ships sunk by K-1^[4]

Date	Ship	Flag	Tonnage	Notes
8 November 1941	Flottbeck		1,930 GRT	Freighter (mine)
26 December 1941	Kong Ring		1,994 GRT	Freighter (mine)
8 April 1942	Kurzsee		734 GRT	Freighter (mine)
23 May 1942	Asuncion		2,454 GRT	Freighter (mine)
12 September 1942	Robert Bornhofen		6,643 GRT	Freighter (mine)
6 December 1942	V-6116/Ubier		350 GRT	Patrol vessel (mine)
6 December 1942	V-6117/Cherusker		304 GRT	Patrol vessel (mine)
Total:			14,409 GRT