The Sindhughosh-class, based on the Russian Project 877EKM “Kilo” design, are diesel-electric attack submarines that have formed a core part of the Indian Navy’s conventional submarine fleet since the late 1980s, providing torpedo and anti-ship-missile-armed underwater strike capability well before the arrival of the newer Kalvari-class (Scorpene) boats.[1]
The class displaces around 3,000 tonnes submerged, with a maximum diving depth of about 300 m. As a classic Kilo-class design, the boats are optimised for quiet operation in littoral and coastal waters, using a diesel-electric propulsion system for underwater endurance, and are armed with heavyweight torpedoes and, in upgraded units, the Klub anti-ship cruise missile.[1]
Several Sindhughosh-class boats have undergone mid-life refits and modernisation in India and Russia, upgrading sonar, combat-management and missile systems to extend their operational relevance alongside the Indian Navy’s newer Kalvari-class submarines, pending the eventual arrival of the Project-75I follow-on class.[1]
| Type | Diesel-electric attack submarine (Project 877EKM / Kilo-class) |
| Origin | Soviet Union/Russia |
| Displacement | ~3,000 tonnes (submerged) |
| Max diving depth | ~300 m |
| Armament | Heavyweight torpedoes; Klub anti-ship cruise missile (upgraded units) |
| User | Indian Navy |