INS Aridhaman is the third indigenous submarine inducted into the Navy and follows the earlier induction of INS Arihant (2016) and INS Arighaat (August 2024).
In a major boost to India’s strategic deterrence capabilities, Defence Minister Rajnath Singh on Friday commissioned the indigenously built nuclear-powered ballistic missile submarine (SSBN) INS Aridhaman into the Indian Navy.
The submarine, also known as S4, is the third in India’s indigenous SSBN programme and follows the earlier induction of INS Arihant (2016) and INS Arighaat (August 2024). Its commissioning marks a significant step in strengthening the naval leg of India’s nuclear triad — the ability to launch nuclear weapons from land, air and sea.
INS Aridhaman has completed its final phase of sea trials and is expected to join the Strategic Forces Command, which oversees India’s nuclear arsenal. The programme remains one of the country’s most closely guarded defence projects.
BIGGER, QUIETER, MORE LETHAL
At around 7,000 tonnes, INS Aridhaman is slightly larger than its predecessors and features a more streamlined hull designed to improve stealth and acoustic performance — a critical factor for underwater survivability.
The submarine is powered by an upgraded 83 MW pressurised water reactor (PWR) developed by the Bhabha Atomic Research Centre (BARC), underscoring India’s growing indigenous technological capability in nuclear propulsion.
A key upgrade lies in its firepower. Unlike earlier boats, INS Aridhaman is equipped with eight vertical launch tubes, doubling the missile capacity of INS Arihant. This allows it to carry either:
STRENGTHENING NUCLEAR DETERRENCE
The induction of INS Aridhaman is expected to significantly enhance India’s ability to maintain a “continuous at-sea deterrence” — ensuring that at least one nuclear-armed submarine remains on patrol at all times, a key element of credible nuclear deterrence.
India is among a select group of countries — including the US, Russia, the UK, France and China — that operate nuclear-powered submarines.
While India has already demonstrated land- and air-based nuclear capabilities, the expansion of its submarine fleet signals a clear focus on strengthening its underwater nuclear posture.
