India is preparing to commission INS Aridhaman, its third nuclear-powered ballistic missile submarine (SSBN), between April and May 2026, significantly strengthening the country’s nuclear triad and second-strike capability.
Built under the Advanced Technology Vessel (ATV) programme at the Ship Building Centre, Visakhapatnam, the 7,000-tonne submarine has completed final stages of sea trials and is now ready for induction. The Chief of the Naval Staff has indicated that commissioning will take place soon, following successful trials concluded in late 2025.
INS Aridhaman marks a major upgrade over earlier boats of the class. Unlike INS Arihant and INS Arighaat, which are equipped with four missile tubes, Aridhaman features eight vertical launch tubes. This allows it to carry up to 24 K-15 Sagarika missiles (750 km range) or a mix of longer-range K-4 (3,500 km) and future K-5 missiles (up to 6,000 km), effectively doubling the firepower of its predecessors.
Powered by an 83 MW compact light-water pressurised nuclear reactor derived from the Kalpakkam prototype, the submarine offers greater endurance, lower acoustic signature and improved stealth. With submerged speeds of around 24 knots, its operational range is limited primarily by crew endurance and logistics rather than fuel, enhancing survivability in deterrence patrols.
With the induction of INS Aridhaman, the Indian Navy will, for the first time, operate three Arihant-class SSBNs simultaneously. This significantly improves India’s ability to maintain a continuous at-sea nuclear deterrent, a cornerstone of its no-first-use doctrine. A fourth SSBN of the class is already undergoing sea trials and is expected to join the fleet by early 2027, further consolidating India’s underwater nuclear force.
