It is an important step that will significantly enhance the endurance of the Scorpene-class conventional submarines of the Indian Navy

In an important step that will significantly enhance the endurance of the Scorpene-class conventional submarines of the Indian Navy, the Defence Research and Development Organisation (DRDO) and Naval Group have reached an agreement to fit the indigenous fuel cell-based Air Independent Propulsion (AIP) system on INS Kalvari soon.

The AIP has been developed by DRDO’s Naval Materials Research Laboratory (NMRL), and the land-based prototype has been tested.

Chief of the Naval Staff Admiral R Hari Kumar with other dignitaries at the commissioning ceremony of Indian Navy’s fifth stealth Scorpene class Submarine INS Vagir into the Indian Navy

“This new endeavour between the DRDO and Naval Group France will be a very significant step towards the detailed design certification of the energy module, which will be performed by the 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,” the DRDO said in a statement. “These actions will seamlessly lead the way to start of localisation and industrialisation of AIP, including the hull fabrication by the Indian industry for future fitment on board the submarines.”

The Cabinet Committee on Security approved the project in March 2022, according to defence sources. Following the sanction and a Detailed Design Phase, the DRDO has started tendering for various equipment, officials said. The AIP is planned to be installed on the first Scorpene class submarine INS Kalvari when it goes for first refit in 2024, as reported by The Hindu earlier.

An AIP module acts as a force multiplier as it enables conventional submarines to remain submerged for longer duration thereby increasing their endurance and reducing chances of detection.

While there are different types of AIP systems being pursued internationally, the DRDO said earlier that the fuel cell-based AIP being developed is unique as the hydrogen is generated onboard and has merits in performance compared to other technologies. “This technology has been successfully developed by the NMRL with the support of Indian industry partners. The technology has now reached the stage of maturity for industrialisation,” the DRDO stated.

Speaking at the event in Mumbai, Pierre Eric Pommellet, Chairman & CEO of Naval Group, said, “We are very proud to cooperate with Indian stakeholders to safely integrate the DRDO AIP in the Kalvari class submarines built by the MDL. This is a natural extension of strategic bilateral cooperation shared between France and India in the field of underwater defence and deterrence and in spirit of Naval Group’s continued commitment towards Aatmanirbhar Bharat policy.”

Six Scorpene submarines are being built under Project-75 by the MDL under technology transfer from Naval Group of France under a $3.75 billion deal signed in October 2005. The project is about four years behind schedule. The first submarine INS Kalvari was commissioned in December 2017, the second one INS Khanderi in September 2019, third INS Karanj in March 2021 and the fourth INS Vela joined service in November 2021.