India is significantly accelerating its nuclear-powered attack submarine (SSN) program under Project-77, marking a major step in strengthening its maritime capabilities, reported Financial Express.

The government has officially cleared the development of two SSNs, with plans to eventually build a fleet of six. These submarines, powered by nuclear reactors, can remain submerged for extended periods and operate at higher speeds than conventional diesel-electric submarines, providing a substantial tactical advantage.

These high-tech subs are designed for precision strikes and tracking enemy vessels, packing advanced missiles like upgraded BrahMos and future hypersonic weapons that can hit targets up to 2,000km away.

Nuclear-powered attack submarines (SSNs) are designed for offensive operations, including tracking enemy vessels, intelligence gathering, and launching precision strikes in high-risk scenarios. Unlike ballistic missile submarines (SSBNs) such as the Arihant class, which serve as platforms for strategic nuclear deterrence, SSNs focus on tactical roles and conventional warfare. They can stay underwater for months, with endurance limited primarily by crew needs rather than fuel, and do not need to surface for air, maintaining stealth and survivability.

A key feature of the Project-77 SSNs is their planned armament: they will carry an evolved version of the BrahMos supersonic cruise missile and future hypersonic missile systems currently under development by the Defence Research and Development Organisation (DRDO).

These advanced weapons are expected to have strike ranges of 1,500–2,000 kilometres, allowing the submarines to engage high-value targets from stand-off distances, well beyond the reach of enemy air defences and anti-submarine systems. The Indian Navy has strategically shifted away from traditional sub-sonic cruise missiles, which are seen as increasingly vulnerable to modern integrated air defence systems, in favour of these faster, harder-to-intercept weapons.

Larsen & Toubro (L&T) is playing a central role in this indigenous submarine development, leveraging its experience from the Arihant-class program. L&T is responsible for manufacturing critical components, including hulls and pressure compartments, at its Hazira facility in Gujarat. The Shipbuilding Centre in Visakhapatnam will handle assembly and sea trials, while the nuclear reactors will be built in Kalpakkam.

The first two submarines under Project-77 have received a budget allocation of ₹40,000 crore (approximately US$4.7 billion), with the first expected to be completed by 2036–37 and the second by 2038–39. These submarines will feature a displacement of nearly 10,000 tonnes, be powered by 190 MW pressurised light-water reactors, and achieve speeds exceeding 30 knots. Notably, they are expected to have an indigenous content of 95%, with foreign assistance limited to design consultancy.

This ambitious program is a direct response to the increasing presence of Chinese naval forces in the Indian Ocean, aiming to provide India with a credible undersea deterrent and the ability to conduct deep-strike missions across the Indo-Pacific. The integration of supersonic and hypersonic missiles, combined with the endurance and stealth of nuclear propulsion, is set to significantly enhance the Indian Navy’s undersea strike capabilities and its overall deterrence posture in a rapidly evolving regional security environment.

Agencies