INS Kalvari of the Indian Navy.
As the Indian Navy seeks to modernize its underwater fleet to maintain regional maritime balance, strategic attention has focused on Project 75 India, commonly known as Project 75I. The ambitious program involves building six advanced conventional attack submarines equipped with Air Independent Propulsion in partnership with foreign original equipment manufacturers and domestic shipbuilders. Recent developments, including contract negotiations involving ThyssenKrupp Marine Systems, or TKMS, and Mazagon Dock Shipbuilders Limited, mark significant progress in the tender process. However, analyzing the broader global defense landscape raises important questions regarding international shipyard capacity, delivery schedules, and the procurement rationale for introducing an entirely new foreign submarine architecture.
Global Demand and Industrial Capacity Constraints
One of the primary areas of our discussion involves the operational bandwidth of international shipbuilders. In recent months, TKMS has secured major global commitments. Notably, the Government of Canada selected TKMS as the preferred supplier for the Canadian Patrol Submarine Project, an initiative that could encompass up to twelve Type 212CD submarines constructed directly in European shipyards. This major commitment joins existing obligations for the joint German and Norwegian Type 212CD program, creating an exceptionally heavy long-term build schedule in TKMS home facilities in Kiel.
This expanding backlog naturally prompts constructive questions for Indian defence circles. When a primary defense manufacturer manages multiple high-value programs simultaneously, how are technical resources allocated? Building submarines directly in owned home yards generally yields higher profit margins and simpler oversight compared to executing complex Transfer of Technology arrangements overseas. Furthermore, specialized human resources, particularly senior naval architects, propulsion specialists, and systems integration engineers, represent a finite pool across the global defense industry. Defense analysts must evaluate whether there is a risk that European-based builds could take precedence in resource allocation over long-distance technology transfers. As we can see with other programs as well, where a huge order book results in managerial issues.
Customization and Realistic Induction Timelines
Another critical dimension is the delivery timeline for Project 75I. The program calls for a tailored submarine configuration that combines specific Indian operational requirements, advanced sensor suites, and proven Air Independent Propulsion technology. Translating a customized paper design into an operational, sea-certified warship inherently requires extensive engineering validation.
Establishing a comprehensive Transfer of Technology process for a new submarine platform at Mazagon Dock Shipbuilders Limited involves significant preliminary work. Shipyard infrastructure must be re-tooled, quality assurance protocols aligned, local supply chains qualified, and workforce training conducted. Historical experience with complex naval platforms shows that setting up fresh production lines for unfamiliar hull designs often leads to extended lead times before the first unit reaches sea trials. Given the pressing operational needs of the Indian Navy, assessing whether these initial setup phases match required fleet induction timelines remains a vital exercise.
The Cost of a New Architecture
Mazagon Dock already has a working conventional-submarine production base, trained manpower, tooling and a domestic supplier network. Project 75I, however, is not a repeat of that line. It depends on a new TKMS design, fresh tooling and a full technology-transfer cycle.
That is the point that needs examination. A new foreign architecture can still be justified if the transfer is deep and the calendar holds. It is harder to justify if design freeze, yard setup and specialist support from Kiel slip because TKMS is also committed to a large home-yard programme for Canada, Germany and Norway. The question is not whether India can build submarines in Mumbai. The question is whether this particular TKMS programme can be staffed and delivered on the timeline now being discussed.
Air Independent Propulsion and National Self Reliance
The discussion around Air Independent Propulsion, or AIP, also warrants clarity regarding technology choices and sovereign capability. The tender requirements for Project 75I mandate a proven, operational foreign AIP system, which TKMS offers through its Siemens Polymer Electrolyte Membrane fuel cell technology. While this system has an established track record, adopting it means integrating another foreign proprietary technology into the navy surface and subsurface inventory.
Concurrently, India has made remarkable strides in developing indigenous fuel cell technology. The Naval Materials Research Laboratory under the Defence Research and Development Organisation, or DRDO, has developed a domestic Phosphoric Acid Fuel Cell AIP system. This indigenous AIP is designed to be integrated into existing boats during scheduled refits. That gives India a path to longer underwater endurance with greater sovereign control, rather than relying only on foreign proprietary sub-systems. How that Indian system is paced against a new TKMS AIP fitment is part of the same delivery question.
Balance for the Future
Raising these questions is not about doubting the engineering capability of foreign partners, but rather about exercising due diligence on strategic priorities. As regional maritime competition intensifies, the Indian Navy requires both capability and capacity. Choosing between establishing an entirely new foreign submarine architecture with complex technology transfer requirements and keeping the focus on timely induction involves balancing long-term technological aspirations against immediate force structure realities.
Ultimately, evaluating international order books, engineering bottlenecks, realistic setup timelines, and the maturity of domestic R&D allows India to make informed choices. By assessing these factors transparently, defense planners can ensure that capital investments deliver the maximum possible underwater capability in the shortest achievable timeframe.
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