India Approves Two Nuclear‑Powered Attack Submarines Under Project‑77 with 190 MW Reactors, BrahMos & Hypersonic Missiles

In a significant move to bolster India’s maritime defence capabilities, the Indian government has approved the construction of two state-of-the-art nuclear-powered attack submarines (SSNs) under the ambitious Project-77. This project, which ultimately aims to deliver a fleet of six such submarines, marks a major step forward in India's indigenous defence manufacturing and underwater warfare readiness.

These submarines will be powered by a next-generation 190 megawatt (MW) nuclear reactor, developed by the Bhabha Atomic Research Centre (BARC). The Compact Light Water Reactor (CLWR-B2), designed specifically for submarines, is a significant technological upgrade over the 83–100 MW reactors used in the Arihant-class ballistic missile submarines. This new power plant will allow the submarines to operate at higher speeds and remain submerged for longer durations, offering unmatched stealth and endurance in contested waters. The propulsion system is expected to be a pump-jet type, further enhancing quietness and survivability, essential traits for a hunter-killer submarine operating in hostile waters.

The submarines will be built at the Ship Building Centre (SBC) in Visakhapatnam, in collaboration with the Warship Design Bureau and private industry partners such as Larsen & Toubro (L&T). Construction is expected to begin soon, with the first submarine anticipated to be launched for sea trials around 2036–37 and the second by 2038–39. The project received final clearance from the Cabinet Committee on Security (CCS) in October 2024, with a projected cost of ₹40,000 crore (approximately USD 4.7 billion) for the first two boats.

Beyond propulsion and stealth, what makes these submarines particularly formidable is their cutting-edge weapons package. They will be armed with Vertical Launch Systems capable of firing the Indo-Russian BrahMos supersonic cruise missile. Even more significantly, they are being designed to carry India’s upcoming hypersonic cruise missiles, which are currently under development. These high-speed weapons will give India the capability to strike land and sea targets from long distances at speeds over Mach 5, greatly expanding the strategic reach of the Indian Navy.

In addition to these cruise missiles, the SSNs will also be equipped with advanced heavyweight torpedoes for anti-ship and anti-submarine roles. This diverse and powerful payload makes the Project-77 submarines ideal for deep-sea hunting missions, blockades, and precision strikes on enemy naval assets and coastal infrastructure. Their ability to carry out offensive operations deep in enemy waters makes them a vital complement to India’s nuclear ballistic missile submarines, which are focused on second-strike deterrence.

What sets these submarines apart from India’s existing underwater fleet is their attack role. Unlike nuclear-powered ballistic missile submarines (SSBNs) which are primarily used for strategic deterrence, SSNs are designed for fast, agile, and aggressive missions. They are tasked with hunting enemy submarines, escorting aircraft carrier groups, and gathering intelligence in hostile territory. The addition of these submarines will significantly enhance India’s presence and power projection in the Indian Ocean and beyond, especially amid the growing presence of Chinese naval forces in the region.

The decision to move ahead with Project-77 reflects India’s long-term strategic thinking in an increasingly competitive Indo-Pacific security environment. As global powers modernize their naval fleets with advanced submarines, India’s investment in indigenous nuclear-powered attack submarines ensures it won’t be left behind. These platforms will not only secure India's maritime interests but also signal its emergence as a technologically advanced and self-reliant naval power.

The approval of these two SSNs is only the beginning. The Indian Navy plans to build a total of six nuclear-powered attack submarines under Project-77, and the experience gained from these first two will lay the foundation for future vessels. The program also strengthens India's broader vision of “Aatmanirbhar Bharat” (Self-Reliant India) by pushing the boundaries of domestic defence technology, from nuclear propulsion to advanced missile integration.

With construction now moving toward execution and reactor testing already in progress, the Indian Navy is poised to enter a new era of underwater combat capability. Once operational, these submarines will serve as the silent sentinels of India’s maritime frontiers, capable of projecting power and protecting national interests across a vast stretch of ocean.