Platform profile · India · Diesel-electric attack submarine · Indian Navy
Kalvari-class (Project 75) submarines
OngoingAll six boats are commissioned, and INS Vaghsheer completed an operational dived sortie from Karwar on 2025-12-28 while class upgrades remain in progress.
President Droupadi Murmu undertook a more than two-hour dived sortie from Karwar aboard INS Vaghsheer on 28 December 2025, demonstrating the sixth boat in active service. In August 2025, Indian media reported that INS Kalvari would finish its refit without the planned DRDO air-independent-propulsion plug because the system was not yet operationally ready, shifting hopes to INS Khanderi's later refit. INS Vaghsheer had completed the six-boat Project 75 series when it was commissioned in Mumbai on 15 January 2025. Separate December 2024 contracts worth about Rs 2,867 crore cover an indigenous AIP plug and integration of an electronic heavyweight torpedo across the class. The class matters because it provides India's newest complete conventional-submarine line while preserving domestic construction skills for follow-on programmes.
Updated 28 Dec 2025
Verified figures
Specifications
| Specification | Value |
|---|---|
| Type and propulsion | Diesel-electric conventional attack submarine ↗ |
| Project 75 class size | 6 submarines ↗ |
| Length | 67.5 m ↗ |
| Breadth | 6.2 m ↗ |
| Surfaced displacement | 1,600 tonnes ↗ |
| Submerged displacement | 1,775 tonnes ↗ |
| Maximum speed | 20 knots ↗ |
| Endurance | 50 days ↗ |
| Complement | 8 officers and 35 sailors ↗ |
| Torpedo tubes | 6 x 533 mm tubes ↗ |
| Weapon load | 18 torpedoes and anti-ship missiles, or up to 30 mines ↗ |
| Combat and survivability systems | Integrated platform and combat-management systems, surveillance radar, periscopes, acoustic silencing, torpedoes, anti-ship missiles and torpedo decoys ↗ |
Spec sources: mazagondock.in ↗ · pib.gov.in ↗ · mazagondock.in ↗
Changelog
Program timeline
-
President Droupadi Murmu completed a more than two-hour dived sortie aboard INS Vaghsheer from Karwar Naval Harbour, Karnataka.
-
The Times of India reported that INS Kalvari would complete its current refit without the delayed DRDO AIP plug and that officials hoped the system would be ready for INS Khanderi's scheduled mid-2026 refit.
-
INS Vaghsheer was commissioned at Naval Dockyard, Mumbai, completing the six-submarine Project 75 series.
-
The Ministry of Defence signed a Rs 1,990 crore AIP-plug contract with MDL and an approximately Rs 877 crore electronic-heavyweight-torpedo integration contract with Naval Group.
-
INS Vagir, the fifth Project 75 submarine, was commissioned into the Indian Navy.
-
MDL launched Vaghsheer, the sixth and final Project 75 submarine, in Mumbai.
-
INS Vela, the fourth Kalvari-class submarine, was commissioned into the Indian Navy.
-
INS Karanj, the third Kalvari-class submarine, was commissioned into the Indian Navy.
-
INS Khanderi, the second Kalvari-class submarine, was commissioned into the Indian Navy.
-
INS Kalvari, the first submarine built under Project 75, was commissioned into the Indian Navy.
-
India and France signed contracts worth about $3.5 billion to construct six Scorpene submarines at MDL under Project 75 with French technology transfer.
0 tagged stories
Coverage
No tagged stories yet — coverage lands here automatically.