India Nears ₹70,000 Crore Deal With Germany To Build Six Project-75I Submarines

A 25-Year Procurement Finally Nears the Finish Line

India is closing in on final government approval for one of its largest-ever defence acquisitions: a submarine-construction programme with Germany worth roughly ₹70,000 crore (about $7.3 billion). The Cabinet Committee on Security (CCS) is expected to take up Project 75(I) — six advanced diesel-electric attack submarines to be built at Mazagon Dock Shipbuilders Limited (MDL) in Mumbai in partnership with Germany's ThyssenKrupp Marine Systems (TKMS) — with contract conclusion targeted for September 2026.

The Finance Ministry cleared the acquisition on May 28, 2026, leaving CCS authorisation as the last major government sign-off needed before a formal contract can be signed. If it goes through as expected, it will close out a procurement saga that has run for more than 25 years, tracing back to the Navy's original 30-year submarine-building plan approved in 1999.

What's Being Built

Project 75(I) calls for six 3,000-tonne diesel-electric submarines, fitted with German polymer-electrolyte-membrane (PEM) hydrogen fuel cells for air-independent propulsion (AIP). That technology lets a conventional submarine stay submerged continuously for around 21 days instead of surfacing or snorkelling every few days to recharge its batteries — a major boost to stealth and endurance for a boat patrolling contested waters.

The submarines are also expected to carry land-attack cruise missile capability and heavyweight torpedoes, bringing India's next-generation conventional submarines closer in capability to nuclear-powered boats on key metrics like underwater endurance, even though they remain diesel-electric.

Filling a Real Capability Gap

The Indian Navy currently operates a fleet of ageing Russian Kilo-class and German Type 209 submarines alongside six French-designed Scorpene-class boats (the Kalvari class) built domestically at MDL under the earlier Project 75, the last of which, INS Vagsheer, was delivered in 2024. Several of the older boats are well past their intended service lives, and naval planners have flagged a shortfall in conventional submarine numbers against expanding maritime activity from both Pakistan and China in the Indian Ocean region.

Project 75(I) was meant to close that gap years ago. The Request for Proposal for six AIP-equipped submarines was first issued in 2021 under the Strategic Partnership model, which requires the winning foreign shipbuilder to transfer technology to an Indian production partner rather than simply exporting finished submarines. MDL was named the Indian Strategic Partner, while TKMS and Spain's Navantia were shortlisted as the foreign contenders before commercial and technical negotiations ultimately centred on the German company.

Long Timelines, Even After Signing

Even a signed contract this year would not immediately translate into a bigger fleet. Under the terms being discussed, the first submarine is contractually due seven years after signature, with all six boats to follow in a staggered delivery schedule. Naval planners are currently projecting operational induction of the class only around 2034–35 — a reminder of how long submarine-building programmes take to bear fruit, even once the paperwork is finalised.

That long lead time is part of why the Navy has simultaneously pushed indigenous efforts, including the domestically designed Project 76 conventional submarine and continued construction of Kalvari-class boats, to avoid a capability gap while Project 75(I) moves from contract to steel.

Strategic Significance

Beyond the hardware, Project 75(I) is a test case for India's Strategic Partnership model, under which foreign primes are required to set up production lines and transfer submarine-building technology to an Indian yard rather than deliver ready-built boats. A successful execution would strengthen the case for using the same model in future naval and aerospace programmes, and would deepen an already growing defence-industrial relationship between India and Germany, which has separately discussed submarine-related technology cooperation in recent years.

For MDL, winning and executing this contract also means absorbing new AIP fuel-cell technology that it has not previously built domestically, adding a capability that could feed into future indigenous submarine designs long after the six Project 75(I) boats are delivered.

Sources

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