India’s maritime defence planning, the Indian Navy is reportedly reconsidering its ongoing submarine acquisition strategy, opting to move away from purchasing three additional French-designed Scorpene-class submarines. Instead, a more ambitious project—centered around building six advanced German-designed stealth submarines—is gaining momentum to strengthen the country’s underwater warfare capabilities.
The proposed shift involves scrapping the follow-on order for Scorpenes from Mazagon Dock Shipbuilders Limited (MDL) and fast-tracking the long-delayed Project 75-India (P-75I). The ₹70,000-crore initiative aims to construct six next-generation diesel-electric submarines at MDL’s Mumbai shipyard, marking one of India’s largest indigenous naval projects to date.
At the heart of this strategic pivot lies Germany’s cutting-edge Air-Independent Propulsion (AIP) technology. Offered by ThyssenKrupp Marine Systems (TKMS), the system enables conventional submarines to remain submerged for extended durations—up to three weeks—without surfacing to recharge batteries. This not only enhances stealth but also significantly improves operational range and survivability.
In comparison, the current Scorpene-class submarines, though modern and reliable, rely on conventional diesel-electric systems that require periodic surfacing, exposing them to detection. The German platform—likely based on the proven Type 212 or 214 design—offers a mature and field-tested AIP solution, giving it a decisive edge in endurance and stealth.
Under the P-75I deal, TKMS has emerged as the frontrunner. The agreement, cleared by the Cabinet Committee on Security (CCS) in August 2025, is structured as a strategic partnership model. It ensures full transfer of technology, use of locally produced high-grade steel, and a phased indigenisation plan spanning 15 years. MDL will serve as the prime integrator, with defence major Larsen & Toubro (L&T) providing critical private-sector support.
The planned submarines are expected to displace between 1,800 and 2,000 tons and boast stealth characteristics approaching those of nuclear-powered attack submarines (SSNs). Each vessel will carry an advanced weapons suite, including heavyweight torpedoes, anti-ship missiles, and land-attack cruise missiles capable of striking deep inland targets.
The construction phase is expected to begin in 2026–27, with the first submarine entering service by 2032–33. Subsequent boats will follow at regular intervals, ensuring continuous capability enhancement. This phased induction will allow the Indian Navy to maintain combat readiness as older platforms—like the Sindhughosh-class (Kilo) submarines—retire from active service.
India’s renewed urgency stems from a shifting maritime balance in the Indian Ocean Region (IOR). China’s growing presence, including frequent patrols by advanced Type 039A (Yuan-class) submarines, and Pakistan’s parallel induction of eight AIP-equipped Chinese vessels, have raised alarm in New Delhi.
These developments have underscored the importance of extending underwater endurance and surveillance coverage across key maritime corridors—from the Andaman and Nicobar Islands to the Strait of Malacca. With AIP-equipped submarines, the Indian Navy would gain the ability to conduct long-duration covert operations, monitor critical sea lanes, and reinforce deterrence in a contested environment.
The P-75I project also represents a major boost to India’s defence manufacturing ecosystem under the Atmanirbhar Bharat (Self-Reliant India) initiative. The partnership is expected to create over 10,000 direct and indirect jobs, while developing critical technological know-how in submarine design, propulsion, and systems integration.
The transfer of fuel-cell technology from Germany would mark a milestone, giving Indian engineers the expertise to develop and sustain next-generation submarine propulsion systems domestically—an area in which India has long depended on foreign suppliers.
However, defence experts caution that the ambitious plan faces potential pitfalls. India’s past submarine projects have been marred by lengthy delays and cost overruns—the Scorpene programme, for example, exceeded its original schedule by nearly eight years. Additionally, foreign defence contracts often draw scrutiny over pricing, offsets, and transparency.
To mitigate these risks, the government is reportedly considering tighter oversight mechanisms, streamlined approval processes, and performance-linked payment milestones to ensure accountability and adherence to timelines.
If executed effectively, the P-75I submarines will complement India’s indigenous nuclear-powered attack submarine (SSN) programme, Project 75 Alpha. Together, these efforts would provide the Navy with a dual-layered underwater defence capability—combining the endurance and strategic reach of nuclear submarines with the stealth and operational flexibility of AIP-equipped diesel-electric boats.
This integrated approach could reshape India’s maritime posture, ensuring that the Navy remains capable of deterring and countering any adversarial presence in the IOR.
