India and Germany are close to finalising the ₹90,000‑crore Project‑75I submarine deal, but no contract has yet been signed.

The program will deliver six advanced Type‑214 submarines with Air Independent Propulsion (AIP), built in India by Mazagon Dock Shipbuilders Limited (MDL) in partnership with ThyssenKrupp Marine Systems (TKMS). The real prize is the ability to remain submerged for weeks, a decisive tactical advantage in the Indian Ocean.

India and Germany are negotiating one of the largest defence acquisitions in Indian naval history. The proposed €8‑billion Project‑75I program would see six submarines constructed domestically, combining German design expertise with MDL’s growing shipbuilding capacity.

German Ambassador Philipp Ackermann has repeatedly expressed optimism that the deal could be signed soon, though similar timelines have slipped before. Statements in March and April suggested imminent agreement, yet the July 30 update again emphasised advanced negotiations rather than a completed acquisition.

The submarines are expected to be based on TKMS’s Type‑214 family. This design integrates fuel‑cell AIP technology, which allows submarines to generate electricity without atmospheric oxygen. Conventional diesel‑electric submarines must periodically snorkel to recharge batteries, exposing themselves to detection.

AIP reduces this vulnerability by enabling weeks of submerged endurance, particularly valuable for silent patrols and ambush missions. TKMS claims its latest Type‑214 design combines low acoustic signatures with extended underwater operation, though exact endurance will depend on India’s chosen configuration and mission profile.

AIP does not equate to nuclear propulsion. Nuclear submarines can sustain higher speeds and remain deployed for months, while AIP is most effective for quiet, low‑speed patrols. Yet in contested waters where stealth is paramount, the ability to remain hidden for extended periods is tactically decisive.

India’s current Kalvari‑class Scorpene submarines lack AIP, though the Defence Research and Development Organisation (DRDO) is developing an indigenous fuel‑cell AIP system for retrofitting during refits. Thus, India is pursuing both foreign acquisition and domestic innovation simultaneously.

TKMS and MDL formally entered contract negotiations in September 2025. Binding offers included engineering services, advanced submarine components, AIP modules, and combat‑system options. The final value of the deal will depend on the scope of technology transfer and long‑term support arrangements.

For MDL, the contract would secure a multi‑year construction pipeline, preserving specialised submarine‑building skills and expanding indigenous capability. Until signed, however, the project remains a prospective order rather than a confirmed addition to MDL’s portfolio.

Technical details of the Type‑214 design highlight its advanced capabilities. The submarine measures 65 metres in length, displaces 1,860 tonnes submerged, and uses HY‑100 ferromagnetic steel to reduce magnetic signature.

Propulsion combines MTU diesel engines, a Siemens Permasyn electric motor, and hydrogen fuel cells. It achieves speeds of 20 knots submerged, endurance of up to 84 days, and continuous submerged operation for three weeks using AIP.

Armament includes eight 533 mm torpedo tubes capable of launching heavyweight torpedoes and anti‑ship missiles. Combat systems such as the ORCCA suite and ISUS 90 sonar enhance situational awareness and strike capability.

Strategically, the deal reflects India’s push for military self‑reliance and Germany’s growing Indo‑Pacific engagement. With China expanding its naval presence and Pakistan strengthening ties with Beijing, India’s acquisition of advanced AIP‑equipped submarines is critical for deterrence and sea‑lane security.

The partnership also diversifies India’s defence imports away from traditional reliance on Russia, while boosting MDL’s long‑term industrial pipeline. Technology transfer terms are expected to scale indigenous content to 60% by the final vessel, embedding capability within India’s defence ecosystem.

The most important measure of success will not be the number of submarines delivered, but the number of days they can remain hidden beneath the waves. Project‑75I’s strategic value lies in extending India’s underwater endurance and ensuring that capability can be built, maintained, and eventually improved domestically.

Agencies