Kilo-class submarine

	Russian Black Sea Fleet Improved Kilo–class submarine B-265 Krasnodar in 2015
Class overview
Builders	Rubin Design Bureau; Krasnoye Sormovo Shipyard; Amur Shipbuilding Plant; Admiralty Shipyard; Sevmash;
Operators	See Operators
Preceded by	Tango class
Succeeded by	Lada class
Subclasses	Sindhughosh class
Built	1980–present
In service	1980–present
In commission	December 1980–present
Completed	75
Active	56
Lost	1
Retired	17
Preserved	1
General characteristics
Type	Attack submarine
Displacement	Surfaced: 2,325 (Project 877) – 2,350 (Project 636.3) tons; Submerged: 3,075 tons full load (Project 877); 3,950 tons full load (Project 636.3);
Length	72.6 m (238 ft 2 in) (Project 877); 73.8 m (242 ft 2 in) (Project 636.3)
Beam	9.9 m (32 ft 6 in)
Draft	6.2 m (20 ft 4 in)
Installed power	Diesel-electric
Propulsion	Diesel-electric propulsion; 2 × 1000 kW diesel generators; 1 × 5,500–6,800 shp (4,100–5,100 kW) propulsion motor; 1 × fixed-pitch 6-bladed (Project 877) or 7-bladed (Project 636) propeller;
Speed	Surfaced: 17 knots (31 km/h; 20 mph); Submerged: 20 knots (37 km/h; 23 mph);
Range	With snorkel: 6,000–7,500 nmi (11,100–13,900 km; 6,900–8,600 mi) at 7 kn (13 km/h; 8.1 mph); Submerged: 400 nmi (740 km; 460 mi) at 3 kn (5.6 km/h; 3.5 mph); Full run: 12.7 nmi (23.5 km; 14.6 mi) at 21 kn (39 km/h; 24 mph);
Endurance	45 days
Test depth	Operational: 240 m (790 ft); Maximum: 300 m (980 ft);
Complement	52
Armament	6 × 533 mm (21 in) torpedo tubes; 18 torpedoes; 4 Kalibr/Club land-attack cruise missile, anti-ship missile and anti-submarine missile (some versions); 24 mines; 8 9K34 Strela-3 (SA-N-8 Gremlin) or 8 9K310 Igla-1 (SA-N-10 Gimlet) surface-to-air missiles (export submarines may not be equipped with air defense weapons);

The Kilo-class submarines are a group of diesel-electric attack submarines designed by the Rubin Design Bureau in the Soviet Union in the 1970s and built originally for the Soviet Navy. Since it was introduced, more than 70 Kilo class boats have been built, and around 60 were in active service as of 2023, not only in Russia but also in Algeria, Vietnam, India, Iran, Myanmar, and Poland.

The first version had the Soviet designation Project 877 Paltus (Russian: Па́лтус, meaning "halibut"), NATO reporting name Kilo. They entered operational service in 1980 and continued being built until the mid-1990s, when production switched to the more advanced Project 636 Varshavyanka variant, also known in the West as the Improved Kilo class. The design was updated again by the Russian Navy in the mid-2010s, to a variant called Project 636.3, also known as Improved Kilo II. Due to the delays and other problems with the successor Lada-class submarine, the Improved Kilo II has been built in larger numbers, with several more units under construction as of 2023.