India’s Kalvari-class submarines will be receiving an indigenously-developed air-independent propulsion system under a deal signed with French submarine builder Naval Group.
Developed by the Naval Materials Research Laboratory (NMRL) of the Indian Defence Research and Development Organisation (DRDO), the system will soon be fitted onboard INS Kalvari.
The agreement signed between senior officials of NMRL and Naval Group France in Mumbai on January 23 will take the project into the detailed design phase. As part of the agreement, Naval Group France will certify the AIP design for integration in the submarines.
The AIP has a force multiplier effect on lethality of a diesel electric submarine as it enhances the submerged endurance by several folds. It has merits in performance compared to other technologies and is unique as the hydrogen is generated onboard. This technology has been successfully developed by NMRL with the support of Indian industry partners. The technology has now reached the stage of maturity for industrialization.
It is worth mentioning that the land-based prototype of the NMRL’s AIP has been tested successfully. This new endeavor will be a significant step towards the detailed design certification of the energy module, which will be performed by NMRL along with Indian industry and design of the platforms impacted by the integration of the indigenous AIP inside the Indian submarine by Naval Group.
Speaking on the occasion, Chairman & CEO at Naval Group France Pierre Eric Pommellet said they are proud to cooperate with Indian stakeholders to safely integrate the AIP in the Kalvari class submarines, which have been built by Mazagon Dock Shipbuilders Limited.
Comissioning of fifth Kalvari-class submarine INS Vagir
The AIP deal was signed on the day of the commissioning of India’s fifth Kalvari-class submarine INS Vagir. The submarine entered service after being launched in Mumbai in November 2020.
Vagir is joining INS Kalvari, INS Khanderi, INS Karanj and INS Vela which had already been commissioned respectively in December 2017, September 2019, March 2021 and November 2021. The last submarine of the P75 series, the Vagsheer, is currently completing her sea trials in order to be delivered in 2024.
India is building the Kalvari-class submarines under a transfer of technology agreement with French shipbuilder Naval Group from 2005.
The diesel-electric attack submarines are 67.5 meters long and can deploy SUT heavyweight torpedoes or SM.39 Exocet anti-ship missiles. They have an endurance of 50 days and a range of 6,500 nautical miles. A total of six boats in the class are expected to be built.