INS Aridhaman, nuclear-powered submarine, enters India’s naval fleet

Defence Minister Rajnath Singh presided over a brief ceremony to formally commission the country’s third nuclear submarine, INS Aridhaman (S4), which is the third in the Arihant-class of SSBNs (Submersible Ship Ballistic Nuclear), on Friday (April 3) at Visakhapatnam.

The boat, being part of the strategic weapons programme, falls under the domain of the Strategic Forces and is part of the country’s nuclear triad. As per sources in the Navy, the commissioning was not made public and was carried out quietly, but Mr. Singh dropped enough hints to acknowledge the commissioning of the vessel.

While the event was kept under wraps, Defence Minister Rajnath Singh, taking to social media, posted a cryptic message on ‘X’, describing the submarine as: “It’s not words but power, ‘Aridhaman’!”

Sources in the Navy said that the commissioning of INS Aridhaman was on the cards, as the submarine had already undergone extensive sea trials, and it coincided with Mr. Singh’s visit to Visakhapatnam for the commissioning of the stealth guided-missile frigate INS Taragiri on April 3.

The closely guarded SSBN project, initially launched as the Advanced Technology Vessel (ATV) project, is being executed by the Ship Building Centre (SBC) in Visakhapatnam. The first boat was launched in July 2009 and was quietly commissioned in 2016. The second indigenously built SSBN, INS Arighaat, was commissioned in August 2024.

While Arihant and Arighaat are smaller vessels of about 6,000 tonnes, Aridhaman (S4) and S4* are bigger boats of about 7,000 tonnes. The S4* (which may be named Arisudan) is currently undergoing sea trials.

It may be recalled that Navy Chief Admiral Dinesh Tripathi, in last December, had said that INS Aridhaman was in the final stages of trials and would be commissioned soon.

Compared to its predecessors, Aridhaman and its successor S4* will have more firepower and can carry up to 24 K-15 Sagarika missiles, eight K-4 missiles, or K-5 missiles, which can be nuclear-tipped.

Arihant and Arighaat can carry about twelve K-15 Sagarika missiles or four K-4 missiles.

The K-4 missiles have a range of about 3,500 km and are developed as nuclear-capable submarine-launched ballistic missiles (SLBMs).

India is already one of the nations, along with the U.S., Russia, China, and France, to possess a nuclear triad capability, which means it has the ability to launch nuclear-tipped missiles from air, land, and sea.

Apart from SSBNs, India is also planning to indigenously build a few SSNs (nuclear-powered attack submarines), of which at least two are expected to be commissioned by 2036–39.