The submarine, constructed at Mazagon Dock Shipbuilders Limited (MDL) in Mumbai, is undergoing final trials, the officials said.

The Kalvari-class (Scorpene) diesel-electric attack submarines have been constructed at the yard, with technology transfer from French firm Naval Group. The boats can carry out various missions like anti-surface warfare, anti-submarine warfare, long-range strikes, special operations, and intelligence.

India is in talks with France to build three more such submarines at MDL to strengthen its maritime posture in the vast Indian Ocean region, where the challenges include China’s carefully calculated power play for influence and defending the rules-based international order.

On August 29, India commissioned its second indigenous nuclear-powered ballistic missile submarine, INS Arighaat, at Visakhapatnam, with defence minister Rajnath Singh then asserting that it will further strengthen India’s nuclear triad, enhance nuclear deterrence and help establish strategic balance in the region.

Arighaat or S-3 is the second Arihant-class submarine and more advanced than INS Arihant (S-2). The country’s third nuclear-powered ballistic missile submarine, Aridaman or S-4, is also set to be commissioned next year, followed by a fourth SSBN codenamed S-4*, as previously reported by Hindustan Times. The last two Arihant-class submarines are expected to be bigger and capable of launching longer range missiles.

The navy is also looking at building two nuclear-powered conventionally armed submarines to deter the country’s adversaries in the Indo-Pacific.

Earlier this month, the navy commissioned a submarine escape training facility, called Vinetra, at INS Satavahana in Visakhapatnam to prepare crews to respond swiftly if a Kalvari-class boat is in distress. The navy has similar facilities to train crews for its Kilo-class and Shishumar-class submarines at INS Satavahana, India’s premier submarine training establishment commissioned in December 1974.

L&T Defence has built the new facility in line with the Atmanirbhar Bharat initiative to boost self-reliance in the defence manufacturing sector. It is equipped with a five-metre escape tower integrated with a diving basin and will be utilised for imparting both basic and refresher escape training to submarine crews.