The Kilo class is the NATO reporting name for a naval diesel-electric submarine that is made in Russia. The original version of the vessels were designated Project 877 Paltus (Turbot) in Russia. There is also a more advanced version, designated as Improved Kilo in the west, and Project 636 Varshavyanka in Russia. The Kilo will be succeeded by the Lada class submarine, which began sea trials in 2005.
The boats are mainly intended for anti-shipping and anti-submarine operations in relatively shallow waters. Original Project 877 boats are equipped with Rubikon MGK-400 sonar system (with NATO reporting name Shark Gill), which includes a mine detection and avoidance sonar MG-519 Arfa (with NATO reporting name Mouse Roar). Newer Project 636 boats are equipped with improved MGK-400EM, with MG-519 Afra also upgraded to MG-519EM. The improved sonar systems have reduced the number of operators needed by sharing the same console via automation.
Anechoic tiles are fitted on casings and fins to absorb the sonar sound waves of active sonar, which results in a reduction and distortion of the return signal. These tiles also help attenuate sounds that are emitted from the submarine, thus reducing the range by which the sub may be detected by passive sonar.
The first submarine entered service in the Soviet Navy in 1980, and the class remains in use with the Russian Navy. 17 vessels are believed to still be in active service with the Russian Navy, while 7 vessels are thought to be in reserve. So far, 33 vessels have been exported to several countries:
- Algeria – 2 Original Kilo, 2 Improved Kilo to be commissioned between 2009–2010.
- People's Republic of China – 2 Original Kilo, 10 Improved Kilo.
- India – designated as the Sindhughosh class; 10 active.
- Poland – 1 Kilo ORP Orzeł.
- Iran – 3 Kilo.
- Romania – 1 Kilo – (Delfinul II).
- Russia – 17 Kilo in active service (B-445; B-459 Vladikavkaz; B-464 Ust'-Kamchatsk; B-471 Magnitogorsk; B-494 Ust'-Bolsheretsk; B-800 Kaluga; B-871 Alrosa; B-808 Yaroslavl'; B-177 Lipetsk; B-806; B-340; B-190; B-227; B-260 Chita; B-345; B-394; B-402 Vologda).; 6 Improved Kilo ordered
- Vietnam – 6 Improved Kilo (Kilo-636 KMV) on order, contract signed in 2010, production of one per year.
- Egypt – likely to buy 4 Project 636 Kilo diesel subs for about $1.2 bln
- Indonesia – tender for 2 new diesel subs ongoing
- Venezuela – is interested in buying 3 Project 636 Kilo class submarines
- 2,300–2,350 tons surfaced
- 3,000–4,000 tons submerged
- Length: 70–74 meters
- Beam: 9.9 meters
- Draft: 6.2–6.5 meters
- Maximum speed
- 10–12 knots surfaced
- 17–25 knots submerged
- Propulsion: Diesel-electric 5,900 shp (4,400 kW)
- Maximum depth: 300 meters (240–250 meters operational)
- 400 nautical miles (700 km) at 3 knots (6 km/h) submerged
- 6,000 nautical miles (11,000 km) at 7 knots (13 km/h) snorkeling (7,500 miles for the Improved Kilo class)
- 45 days sea endurance
- Air defence: 8 SA-N-8 Gremlin or SA-N-10 Gimlet Surface-to-air missiles (export submarines may not be equipped with air defense weapons)
- Six 533 mm torpedo tubes with 18 53-65 ASuW or TEST 71/76 ASW torpedoes or VA-111 Shkval supercavitating "underwater missiles", or 24 DM-1 mines,
- Club S anti-ship missiles (only on some export versions)
- Crew: 52
- Price per unit is US$200–250 million (China paid approx. US$1.5-2 billion for 8 Project 636 Kilo class submarines)