India’s submarine modernisation is entering a decisive phase with the twin indigenous programs — Project 76 for conventional diesel-electric submarines (SSKs) and Project 77 for nuclear-powered attack submarines (SSNs). These initiatives will determine the trajectory of India’s maritime power in the 21st century, filling long-standing gaps in its undersea warfare capabilities.
Project 76 represents India’s first attempt to design and build its own conventional submarines. Six large diesel-electric boats of around 3,000 tons are planned, with the design expected to be completed by 2028.
This is a historic step, as India has operated submarines for nearly six decades but has never designed one indigenously. The Advanced Technology Vessel Project, which built the Arihant-class SSBNs, will lead the effort alongside the Navy’s Submarine Design Group.
However, the program faces delays and funding challenges, particularly as India is also set to sign a ₹100,000 crore contract with Germany’s TKMS for six imported AIP-equipped submarines under Project 75(I). Naval officials suggest Project 76 will only be ordered after the German deal is finalised, raising concerns about timelines and budgetary strain.
Project 77, cleared by the Cabinet Committee on Security in 2024, is even more significant. These SSNs will be nuclear-powered, giving them unlimited range and endurance limited only by crew and supplies.
They will travel at twice the speed of SSKs and carry heavy loads of missiles and torpedoes, enabling them to operate in defended waters, hunt large enemy platforms, and strike land targets.
The first SSN is expected to enter service in the mid-2030s. India’s designers have scaled the displacement up to 10,000 tonnes, comparable to the Russian Akula-class SSNs leased by India, and will equip them with vertically launched tubes for hypersonic missiles, effectively making them SSGNs.
The design will share commonality with the S-5 SSBN, including the 190 MW reactor, leveraging India’s SSBN industrial ecosystem.
The strategic importance of SSNs cannot be overstated. All five permanent members of the UN Security Council operate SSNs, with the US fleet dwarfing the rest of the world combined. India has leased SSNs from Russia in the past, but reliance on borrowed military power is increasingly untenable in a world where dependencies can be weaponised.
Submarines remain uniquely survivable platforms in an era of satellite surveillance, drones, and long-range missiles that threaten surface fleets. For India, attack submarines — both conventional and nuclear — are the trump card to counter China’s expanding maritime power. China already fields the world’s largest navy with 370 vessels, projected to exceed 400.
India’s submarine gap is stark. Despite building aircraft carriers, destroyers, and frigates indigenously, it has struggled to acquire conventional and nuclear attack submarines. The Arihant-class SSBNs represent India’s greatest technological achievements, with 80 per cent indigenous content sourced from 500 local industries.
Yet this ecosystem was not leveraged for conventional submarine building, despite studies showing 60–70 per cent equipment commonality between conventional and nuclear boats. India developed indigenous combat systems, sonars, pumps, periscopes, and submarine-grade steel, but continued to rely on imports for SSKs from France, Germany, and Russia.
Delays and competing priorities have compounded the problem. India’s 30-year submarine plan of 1999 envisaged 24 SSKs and 6 SSNs by 2030. To date, only 6 SSKs and no SSNs have been built. The SSN project was treated as low priority for years, with approvals for six boats in 2015 but orders placed only in 2024. Cost is a factor, with each SSN estimated at ₹20,000 crore.
Meanwhile, South Korea absorbed German technology and pursued spiral development, offering India advanced submarines in 2019, while India remained caught in the mirage of transfer-of-technology deals with European partners.
The challenge now is to reconcile finite defence budgets with the need to fund two parallel conventional submarine projects — the imported P-75(I) and the indigenous P-76 — alongside the ambitious SSN program.
India’s wait for a truly indigenous conventional submarine may stretch further, but the stakes are high. Without these capabilities, India risks ceding undersea dominance in the Indian Ocean Region to China and other adversaries.
Agencies
