INS Kalvari, the first Scorpene-class submarine built for the Indian Navy, will soon be fitted with an indigenous Air Independent Propulsion (AIP) system developed by the Defence Research and Development Organisation (DRDO), the Ministry of Defence (MoD) has said in a press statement.
The development comes on the day the fifth Scorpene-type submarine of the Kalvari- class, INS Vagir, was commissioned into the Indian Navy. “Fuel Cell-based AIP system of DRDO’s Naval Materials Research Laboratory will soon be fitted onboard INS Kalvari,” the MoD stated, adding, “An agreement was signed between senior officials of NMRL and Naval Group France in Mumbai on 23 January to extend cooperation to enter into the detailed design phase for integration of indigenous AIP in the Kalvari class.”
AIP system allows a submarine to remain submerged, significantly enhancing its endurance, being away from enemy sensors, for a longer time without surfacing. “As part of the agreement, Naval Group France will certify the AIP design for integration in the submarines,” the MoD said.
Speaking on the occasion, Pierre Eric Pommellet, Chairman and CEO at Naval Group France, said, “They are proud to cooperate with Indian stakeholders to safely integrate the AIP in the Kalvari class submarines, which Mazagon Dock Shipbuilders Limited has built. This is a natural extension of strategic bilateral cooperation shared between India and France in the field of underwater defence and deterrence and in line with Naval Group’s continued commitment towards the government’s ‘Atmanirbhar Bharat’ policy”.
According to DRDO, the land-based prototype of the NMRL’s AIP has been tested successfully. “This new endeavour will be a significant step towards the detailed design certification of the energy module, which NMRL will perform along with the Indian industry and design of the platforms impacted by the integration of the indigenous AIP inside the Indian submarine by Naval Group,” the DRDO said.
“These actions will seamlessly lead the way to the start of localisation and industrialisation of AIP, including the hull fabrication by the Indian industry for future fitment onboard the submarines,” it added.
The AIP has a force multiplier effect on the 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. NMRL has successfully developed this technology with the support of Indian industrial partners. The technology has now reached the stage of maturity for industrialisation, the DRDO said.
INS Kalvari, the lead boat of the Scorpene class, was inducted in 2017. Since then, INS Khanderi, INS Vela, INS Karanj and INS Vagir have also entered service. A sixth of the class, named ‘Vagsheer’ after a Vela-class diesel-electric submarine of the Indian Navy commissioned in 1973, is currently under construction and is expected to be ready in 2024.