Project 75 Kalvari Class SSK: News & Discussion

[Rakesh]

Starting this thread, because we do not have a dedicated thread on the topic.

[Rakesh]

Indian Navy's first AIP-equipped submarine to be ready by year-end
https://www.business-standard.com/exter ... 080_1.html
06 March 2026

Between December 2017 and January 2025, six Kalvari-class conventional diesel-electric attack submarines were commissioned into service.

[Rakesh]

Three additional Kalvari Class (Project 75AS - Advanced Scorpene) boats still on the menu

https://x.com/sougat18/status/2031615318519583107?s=20 ---> Major Planned Shipbuilding Programs of the Indian Navy

[ashthor]

Once the german sub are contracted, 3 more french ones will come and P76 will get approved.
Just like the AF and Naval Rafale's. If you do this...i will do this. Ek haat le, Ek haat de.

[Rakesh]

Once the german sub are contracted, 3 more french ones will come and P76 will get approved.
Just like the AF and Naval Rafale's. If you do this...i will do this. Ek haat le, Ek haat de.

Bingo! Well said. That is the game plan now...

[Rakesh]

AIP System To Make Kalvari Class Subs Deadlier

By 2026, INS Khanderi will be retrofitted with India’s indigenously developed Air-Independent Propulsion (AIP) system, enhancing underwater endurance. All six Kalvari-class submarines will eventually receive the DRDO-developed fuel-cell-based AIP, which has passed extensive shore trials. Installation will occur during refits at Mazagon Dock, with sea trials slated for 2027 and completion by 2028. Using phosphoric acid fuel-cell technology, the system enables submarines to remain submerged for weeks, boosting stealth and sustainability, marking a milestone in India’s domestic defence innovation.

[Rakesh]

https://x.com/cezamne/status/2031694450154521054?s=20 ---> India’s DRDO (Defence Research & Development Organization) is reportedly poised to deliver its indigenously developed Air Independent Propulsion (AIP) plug-in time for integration with INS Khanderi during its scheduled refit in 2026–27. INS Khanderi is the second Kalvari Class (Project-75, Scorpene) submarine inducted into the Indian Navy (IN). It was commissioned on 28 September 2019. The Indian Navy inducted six Kalvari Class submarines under Project-75 between 2017 and 2024. Originally, it was planned to integrate DRDO-developed AIP plugs — designed to facilitate extended submerged endurance — into all Kalvari Class boats. However, the DRDO plug was not ready in time for installation on the first boat, INS Kalvari. The AIP modules, also called Energy Modules (EMs), are integrated into the AIP plug, which is then retrofitted into the submarine during refit. The refit will also include equipping the boat to launch DRDO-developed heavyweight torpedoes.

[Rakesh]

https://x.com/VinodDX9/status/2030508837007220923?s=20 ---> So INS Khanderi will get two major upgrades:

1) NMRL AIP (manufactured by L&T, ToT)

2) NSTL EWHT (Electric/Electronic Heavy Weight Torpedo)