Even as the fifth submarine of the Project – 75, Kalvari Class submarines, `Vagir’ (Yard 11879) is set to be commissioned into the Indian Navy early next year as `INS Vagir’, the indigenous Fuel Cell based Air Independent Propulsion (AIP) System of the Defence Research and Development Organisation (DRDO) is still not ready.

For the Kalvari Class Submarines, Financial Express Online has reported earlier this year that AIP is a critical technology needed to make the diesel electric submarine more lethal. “This is possible by enabling these submarines to stay under water for an extended period of time, around two weeks without having to surfacing to recharge their batteries. The traditional diesel-electric submarines have to surface every few days,” explained a senior officer.

Sources have confirmed to Financial Express Online that “The Indian Navy has urged DRDO to ensure that the Fuel Cell based AIP is ready soon and that it undergoes trials before they can be accepted to be fitted onboard the first boat which will come for retrofit in 2025.”

DRDO AIP is not ready

And earlier this year in June the then Secretary, Department of Defence R&D and Chairman DRDO Dr G Satheesh Reddy had told Financial Express Online that by 2025 DRDO made AIP will be ready to be fitted on INS Kalvari which is scheduled to come up for retrofit in 2025.

DRDO had in 2021 claimed – as compared to other technologies, the Fuel cell-based AIP has merits in performance as compared to other technologies. And all these submarines are expected to be retrofitted with AIP – whether they are from DRDO, Germany, South Korea or France.

So far four submarines built under Project-75 — INS Kalvari, INS Khanderi and INS Karanj and INS Vela are already commissioned in the Indian Navy. And `Vagir’ is the fifth in the series to be commissioned soon.

More about `Vagir’

India has reaffirmed its membership in the exclusive group of submarine building nations.

Sea trials of `Vagir’  commenced from early February 2022 and in comparison to the earlier submarines, she has completed all major trials including weapons and sensor trials in the shortest time. Once commissioned this will further enhance the navy’s capability.

`Vagir,’ the fifth submarine under the Project 75, Kalvari Class Submarines which has been constructed at the Mazagon Dock Limited (MDL), Mumbai was delivered to the Indian Navy today (December 20, 2022).  This submarine has been built under collaboration with M/s Naval Group of France and is based on `Scorpene’ design. This was launched on November 12, 2022 and it had commenced its sea trials earlier this year.

Speaking on the signing of the Acceptance Document with the India Navy, VAdm Narayan Prasad, (Retd), Chairman & Managing Director MDL, said that with the delivery of the fifth submarine to the Indian Navy, the shipyard has lived up to its reputation as one of the leading shipyards in the country with its capacity and its capability to meet requirements of the Indian Navy.

RAdm C Raghuram, VSM, Chief Staff Officer (Tech), Western Naval Command in the presence of Commanding Officer (desig) CdrS Divakar, MDL Directors and Navy personnel at MDL were all present at the ceremony of signing the document.

CMD, according to an official statement released by the MDL has mentioned that the building of Scorpene has been challenging. As all the work was being done in most congested spaces and dovetailed by stringent clearances and tolerances –required to be maintained throughout the process of the construction.

The state-of-the-art technology has been used to ensure that the boat has superior stealth features and these include low radiated noise levels, hydro-dynamically optimized shape, advanced acoustic absorption techniques, and more.

It has the ability to attack the enemy using precision guided weapons. An attack can be launched underwater or on surface using torpedoes and tube launched anti-ship missiles. Its stealth has been enhanced by providing her characteristic underwater signature.