Project-75 Kalvari-class Submarines · P-75 Kalvari class — 6 diesel-electric attack submarines (Scorpène design, MDL + Naval Group)
India's six diesel-electric attack submarines (Scorpène design) built at MDL under Naval Group (DCNS) technical transfer; INS Kalvari lead 2017 through INS Vagsheer 2024; P-75 follow-on tranche and AIP integration under way.
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At a Glance
- Class
- Kalvari class (Scorpène design, P-75)
- Builder
- Mazagon Dock Shipbuilders Limited (MDL), Mumbai
- Displacement
- ~1,615 t surfaced / ~1,800 t submerged
- Length
- ~67.5 m
- Beam
- ~6.2 m
- Propulsion
- Diesel-electric — 4 Pielstick PA4V200 diesels + electric motor; AIP (DRDO) integration on follow-on
- Speed
- ~20 knots submerged
- Range
- ~6,500 nm surfaced; ~550 nm submerged (snorkel)
- Armament
- 6x 533mm torpedo tubes — heavy torpedoes + Exocet SM39 anti-ship missiles
- Sensors
- Thales/indigenous sonar; torpedo fire-control
- Crew
- ~31 (8 officers + 23 sailors)
- Class size
- 6 boats (Kalvari, Khanderi, Karanj, Vela, Vagir, Vagsheer)
- Status
- All 6 commissioned (2017-2024); P-75 follow-on + AIP under way
- indicators
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- key specs
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What It Is
The Project-75 Kalvari-class submarines are India's six diesel-electric attack submarines built at Mazagon Dock Shipbuilders Limited (MDL) in Mumbai to the French Scorpène design, developed under a technology-transfer agreement with Naval Group (formerly DCNS). The programme — approved in 2005 and signed in 2005 (build contract) — saw MDL fabricate the hulls with progressively rising indigenous content, integrating Indian-made and licenced subsystems around the Scorpène core. The lead boat INS Kalvari commissioned in December 2017 and the sixth boat INS Vagsheer commissioned in January 2024, completing the six-boat class (Kalvari, Khanderi, Karanj, Vela, Vagir, Vagsheer). The boats are fitted as multi-role attack submarines with six 533mm torpedo tubes firing heavyweight torpedoes and Exocet SM39 anti-ship missiles, a Thales-designed sonar suite (with Indian indigenisation), and a diesel-electric propulsion plant. The class operates under a deliberate under-strength submarine arm that badly needs rebuilding — India's submarine force is below its sanctioned strength. The P-75 hulls are now being upgraded with a DRDO-developed AIP (Air-Independent Propulsion) fuel-cell module on selected boats, and a P-75 follow-on tranche had been under negotiation as the Indian Navy seeks to rebuild submarine numbers toward the ~18-boat goal, alongside the separate P-75I programme for 6 new boats with AIP.
Deployments & Procurement
The six Kalvari-class boats all entered service (2017-2024). The class represents the French-licenced cornerstone of India's submarine force — complemented by the Russian-origin Sindhughosh class. Design weaknesses and the need to rebuild submarine numbers are driving the AIP upgrade and the separate P-75I (6 new AIP boats) programme, as well as a possible P-75 follow-on tranche from MDL/Naval Group.
| Agency | Context | Year | Quantity / Note | Sources |
|---|---|---|---|---|
| Indian Navy | P-75 Kalvari-class programme approved/build contract (6 boats) | 2005 | 6 Scorpène-design submarines at MDL | [1] |
| Indian Navy / MDL | INS Kalvari commissioned (lead boat) | 2017 | December 2017 — first P-75 submarine | [1] |
| Indian Navy / MDL | INS Vagsheer commissioned (sixth & final boat) | 2024 | January 2024 — completes six-boat class | [1] |
| Indian Navy | AIP integration on P-75 boats | 2026 | DRDO fuel-cell AIP being integrated on select boats; follow-on tranche under discussion | [1] |
Open Questions
- Exact status of the P-75 follow-on tranche (additional Kalvari-class boats) negotiation
- Which boats receive AIP first and when inducted
- Whether the class reaches the Navy's ~18-submarine target within the decade
Import Dependencies
The Kalvari class is a French-licenced design with substantial import content concentrated in the propulsion, sensors, torpedo tubes and torpedo/missile weapons.
| Component | Severity | Note | Pillar | Sources |
|---|---|---|---|---|
| Scorpène design / hull & subsystems licence | Critical | Naval Group (France) — the entire design is licenced; no fully indigenous submarine design in service (P-75I seeks to change this) | /research/pillars/defence/ | [1] |
| Torpedoes / SM39 Exocet missiles | High | Heavyweight torpedoes (sea mine lay, wire-guided family) and Exocet SM39 anti-ship missiles imported or licenced | /research/pillars/defence/ | |
| Sonar suite | Medium-High | Thales-built sonar with Indian indigenisation (BEL/NSTL); some arrays/transducers imported | /research/pillars/defence/ | |
| Propulsion diesels / electric motors | Medium | FR Pielstick/MAN-family diesels and motors partly imported; AIP is DRDO-indigenous | /research/pillars/defence/ |
Intelligence Assessment
Methodology: /research/methodology
French Scorpène design licenced; no fully indigenous design (P-75I target)
Sources: [1]
Design, torpedoes, sonar, propulsion heavily licenced/imported; AIP is the key indigenous lift
Sources: [1]
6 boats complete but submarine force remains below sanctioned strength
Sources: [1]
Scorpène design is Naval Group's; India gets no export benefit from a licenced build
Knowledge Graph
Maker — Other Systems
Related Pillars
Timeline
FAQ
How many Kalvari-class submarines does India have?
India has six Kalvari-class (Scorpène-design) diesel-electric attack submarines — Kalvari, Khanderi, Karanj, Vela, Vagir and Vagsheer — all built at MDL Mumbai and commissioned between 2017 and 2024.
Sources: [1]
What is the difference between P-75 and P-75I?
P-75 (Kalvari class) is the six-boat Scorpène-design series built at MDL that is now complete. P-75I is a separate, newer programme for six additional diesel-electric submarines with Air-Independent Propulsion (AIP), still in procurement.
Sources: [1]
Will the Kalvari class get AIP?
Yes — a DRDO-developed fuel-cell Air-Independent Propulsion (AIP) module is being integrated into selected Kalvari-class boats to extend submerged endurance, with the follow-on P-75I boats planned to have AIP from the start.
Sources: [1]
Why is India's submarine force considered under-strength?
India's submarine arm has historically operated below its sanctioned strength (~18+ boats) due to the slow decommissioning of older Russian-origin boats and the long build times of new programmes. The P-75, P-75I and follow-on tranches are all aimed at rebuilding submarine numbers.
Sources: [1]
Open Questions
- Status and timing of the P-75 follow-on (additional Kalvari-class) tranche
- Which boats receive AIP first and when
- Whether India reaches the ~18-boat submarine target within the decade
Sources
- src-1IndicativeKalvari-class submarine (P-75)
Class history, specifications and commissioning dates
- src-2OfficialINS Kalvari — Indian Navy
Indian Navy official submarine page
- src-3OfficialAIP for Indian submarines — DRDO
DRDO AIP development context
- src-4CredibleINS Vagsheer commissioned - last of six Project 75 Kalvari-class submarines
INS Vagsheer commissioning report
- src-atlas-listingIndicativeProject-75 Kalvari-class Submarines — Defence Atlas listing
Own register: indicative only, never official per standing evidence rules. All listing-derived figures in this dossier are attributed to this source.