
Prime Minister Narendra Modi has placed a proposal to build three additional Kalvari-class submarines at the forefront of India's maritime modernisation plans, with construction set to take place at Mazagon Dock Shipbuilders Limited (MDL) in collaboration with France's Naval Group, Hindustan Times reported.
The project is estimated to cost around ₹33,000 crore, with a revised proposal expected to be considered by the Cabinet Committee on Security (CCS). The move is aimed at preserving the Indian Navy's conventional submarine strength as several ageing platforms approach retirement.
India currently operates six Kalvari-class submarines, the latest being INS Vaghsheer, which was launched in April 2022. However, concerns over declining submarine numbers by the end of the decade have prompted a renewed focus on expanding the fleet.
The strategic urgency has increased due to Pakistan's expected induction of eight Chinese-origin Type-039 Yuan-class submarines between 2028 and 2030. Equipped with Air Independent Propulsion (AIP) systems, these submarines are expected to significantly enhance Pakistan's underwater warfare capabilities and pose a greater challenge in the Indian Ocean Region alongside China's growing naval presence.
India's older Shishumar-class and Sindhughosh-class submarines are nearing the end of their operational service lives, creating the need for replacements to maintain credible conventional deterrence and operational readiness.
Although the additional Kalvari-class submarines were previously placed on the back burner, national security planners had initially prioritised Project 75(I), which focuses on next-generation submarines equipped with advanced AIP technology as part of India's long-term submarine acquisition strategy.
The proposed new submarines will incorporate several upgrades over the existing Kalvari fleet. These include NATO-standard torpedoes, DRDO-developed heavyweight torpedoes and submarine-launched SCALP cruise missiles with a strike range of approximately 800 kilometres.
The program is also expected to sustain and further develop India's submarine-building ecosystem at MDL, while enhancing the technical expertise of engineers, designers and skilled workers involved in complex naval construction projects.
Initially, the three new submarines are expected to operate with lead-acid batteries. However, they are being designed with the potential for future upgrades to lithium-ion battery technology, which offers higher energy density, improved endurance, greater underwater speed and enhanced stealth characteristics.
The adoption of lithium-ion batteries could provide a substantial operational advantage and improve overall underwater performance compared with conventional battery systems used by many existing diesel-electric submarines.
Another significant benefit of the expanded Kalvari programme is the potential for India to emerge as a regional submarine manufacturing hub. With extensive technology transfer from France's Naval Group, India may eventually be able to construct submarines for friendly nations such as Indonesia or offer customised export variants.
The revival of the proposal also reflects continuing delays in Project 75(I). One of the factors affecting progress has been the validation process for the indigenous AIP system being developed by DRDO, despite Germany's TKMS having indicated its readiness to provide proven AIP technology for the programme.
The renewed push comes amid growing strategic competition across the Indo-Pacific and persistent instability in the Middle East. Defence planners view a strong conventional submarine fleet as essential for safeguarding sea lanes, protecting national interests and maintaining maritime deterrence.
Alongside conventional submarine expansion, India's nuclear submarine programme continues to advance. The country's ballistic missile submarine fleet is expected to grow further, strengthening its sea-based nuclear deterrent capability.
The Modi government has already approved the construction of two conventionally armed nuclear-powered attack submarines (SSNs). In addition, the Indian Navy is expected to induct another Russian nuclear-powered attack submarine on lease by 2028, further enhancing its underwater warfare capabilities and long-range operational reach.
Agencies













