India has revived a proposal to build three more advanced Scorpene-derived submarines at Mazagon Dock Shipbuilders Limited in Mumbai as it tries to prevent a decline in its conventional underwater fleet. The modi government is moving a modified proposal estimated at around ₹33,000 crore towards the Cabinet Committee on Security, according to the latest reporting. The three boats would extend the existing Project-75 production line and add another kalvari class submarine batch to the six already commissioned into service.

The move comes as older Sindhughosh- and Shishumar-class boats move deeper into their service lives and India's longer-term Project-75(I) programme for six air-independent-propulsion-equipped submarines works through its own procurement process.

Modi Government Kalvari Class Submarine Plan: What Has Changed?

The latest development is best understood as a revival rather than a completely new procurement. In July 2023, the Defence Acquisition Council formally granted Acceptance of Necessity for three additional Scorpene submarines under the Buy (Indian) category. The Ministry of Defence said they would be constructed at MDL and would incorporate greater indigenous content than the original Project-75 boats.

The proposal subsequently remained pending while the Navy and government focused heavily on Project-75(I), which seeks six more advanced conventional submarines equipped with fuel-cell-based AIP systems. Defence Secretary-level comments in early October confirmed that the three additional Scorpenes remained under consideration, but were at an earlier stage than Project-75(I). Hindustan Times now reports that Narendra Modi has put the three-submarine proposal back on the priority list and that a modified case is being prepared for CCS consideration.

The crucial distinction is that an AoN allows a procurement case to move forward; it is not the same as a signed acquisition contract.

Why the Indian Navy Wants Three More Submarines

The immediate problem is force availability. The Indian Navy needs to maintain sufficient numbers of conventional diesel-electric attack submarines while older boats retire and next-generation projects take years to enter service. India currently operates six Project-75 Scorpenes: INS Kalvari, INS Khanderi, INS Karanj, INS Vela, INS Vagir and INS Vaghsheer. The final vessel, Vaghsheer, was commissioned in January 2025, completing the original programme.

Building three more would allow MDL to use expertise and industrial infrastructure already developed through Project-75 instead of beginning an entirely unfamiliar design. That is one reason the modi government appears to see the additional boats as a relatively faster bridge between today's fleet and future submarine programmes. The wider Navy currently operates 20 submarines when nuclear-powered boats are included, according to reporting around the October 2026 commissioning of INS Mangrol. But headline fleet totals do not show the more important issue: how many conventional attack submarines are available at a given time after maintenance, refits and ageing are considered.

What Is a Kalvari-Class Submarine?

India's Kalvari class is based on the French Scorpene design developed by Naval Group. The original six were constructed in India by MDL under Project-75, with French technological collaboration. The first, INS Kalvari, entered service in December 2017; the sixth, INS Vaghsheer, followed in January 2025. A Scorpene submarine is a diesel-electric attack platform designed for missions including anti-surface warfare, anti-submarine operations, intelligence gathering, surveillance and special operations.

The Ministry of Defence has previously highlighted the class's acoustic-silencing measures, low radiated noise, hydrodynamically optimised hull and ability to use precision-guided weapons. For the Indian Navy submarines fleet, the advantage of ordering a follow-on batch is familiarity. Crews, dockyards and maintenance organisations already have years of experience with the design. The additional kalvari class submarine programme could therefore involve less industrial risk than introducing an entirely new platform.

How Will the New Boats Differ From the Existing Six?

The three proposed vessels are expected to be evolved versions rather than exact replicas of the current class. Hindustan Times reports that the revised boats are being considered with newer torpedoes, additional indigenous weapons and a longer-range land-attack capability. The report also says the initial propulsion arrangement would retain lead-acid batteries while leaving room for a future move to lithium-ion technology.

Some caution is necessary around the exact missile configuration. The report refers to an approximately 800-km submarine-launched SCALP-family weapon. MBDA, however, officially distinguishes the air-launched SCALP from its naval cruise missile family, known as NCM or MdCN. Its latest NCM/LCM Mk2 is advertised with a range exceeding 1,000 km. The Ministry of Defence has not publicly released a final weapons package for the three proposed Indian boats.

Separately, the Navy issued a requirement in 2026 for submarine-launched land-attack cruise missiles capable of fitting standard 533-mm torpedo tubes, while DRDO is also pursuing indigenous submarine-launched cruise-missile technology. So the safer conclusion is that enhanced land-attack capability is under active consideration, but the final missile type should not yet be treated as confirmed.

Will the New Scorpenes Have AIP?

This is another important distinction. The latest report suggests the additional Scorpenes would initially use conventional battery-based propulsion rather than arriving with the same type of proven AIP requirement central to Project-75(I). India is separately developing an indigenous Air Independent Propulsion system through DRDO's Naval Materials Research Laboratory for integration with Project-75 boats during refits.

AIP allows a conventional submarine to remain submerged for longer periods without regularly exposing itself by running diesel engines to recharge batteries. Project-75(I), meanwhile, was explicitly structured around six new conventional submarines fitted with fuel-cell AIP, advanced torpedoes, missiles and modern countermeasure systems.

That means the extra Scorpenes and Project-75(I) are not necessarily substitutes. They address the same broad fleet shortage but through different timelines and technical approaches.

Project-75(I) Remains a Separate ₹80,000-Crore Programme

India is simultaneously advancing the much larger Project-75(I). Recent reporting places that six-submarine programme at more than ₹80,000 crore, with Germany's TKMS and MDL central to the negotiations. It is intended to deliver modern diesel-electric submarines with AIP and substantial Indian manufacturing participation.

Project-75(I) has taken considerably longer than initially envisaged.

That delay helps explain the renewed interest in more Scorpenes. Ordering three familiar boats could keep MDL's submarine-building workforce active while next-generation construction ramps up. For the Indian Navy submarines programme, continuity of specialist welders, engineers, designers, integration teams and supply chains is strategically important because submarine-building skills can be difficult and expensive to regenerate after production stops.

Pakistan and China Add to the Strategic Pressure

Regional underwater developments are another part of the calculation. Pakistan is acquiring eight Hangor-class submarines developed with Chinese assistance. The type is related to China's Type-039 family and is intended to provide Pakistan with a substantially larger modern conventional submarine force. China, meanwhile, operates one of the world's largest submarine fleets and maintains a growing naval presence across the wider Indo-Pacific.

Hindustan Times presents these developments as part of the rationale for accelerating India's underwater modernisation. That does not mean the additional three boats alone would determine the regional naval balance. India's strategy spans conventional attack submarines, nuclear-powered ballistic-missile submarines, planned nuclear attack submarines, anti-submarine warfare ships, aircraft and seabed-surveillance capabilities. The extra Scorpenes are one component of that larger architecture.

Narendra Modi Has Previously Commissioned the Final Project-75 Boat

The proposed follow-on programme would build on a submarine project already closely associated with India's domestic naval-industrial push. Narendra Modi commissioned INS Vaghsheer alongside INS Surat and INS Nilgiri at Mumbai's Naval Dockyard on January 15, 2025. The government described Vaghsheer as the sixth and final submarine of Project-75 and highlighted MDL's experience in building the Scorpene design in collaboration with France's Naval Group.

That experience is now one of the strongest arguments for the follow-on order. A second Scorpene submarine batch could preserve the production ecosystem built over the original programme while potentially incorporating more Indian equipment. The modi government has also used naval procurement to push higher domestic manufacturing content, and the original 2023 approval explicitly required the three additional submarines to have greater indigenisation than their predecessors.