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.
Design and description
Despite the unsuccessful 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 surfaced and submerged. They had an overall length of, a beam of, and a draft of at full load. The boats had a maximum operating depth of. Their crew numbered 66 officers and crewmen.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, enough to give them a speed of. When submerged each shaft was driven by a PG11 electric motor for. The boats had a surface endurance of at and at submerged.
They were armed with six 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 B-24PL deck guns fore and aft on the conning tower and a pair of 21-K guns above them.