India is set to strengthen its maritime security through the Project-75I (P-75I) submarine programme, one of the country’s largest defence acquisition projects.
India’s ₹90000 Crore Project-75I Submarine Deal with Germany
The proposed deal, valued at around ₹90,000 crore (approximately €8 billion), involves the construction of six next-generation conventional submarines in India in collaboration with Germany’s ThyssenKrupp Marine Systems (TKMS) and Mazagon Dock Shipbuilders Limited (MDL). The project is expected to significantly enhance the Indian Navy’s underwater combat capabilities while promoting indigenous defence manufacturing.
Background
The Indian Navy is modernising its submarine fleet to address evolving maritime security challenges in the Indian Ocean Region (IOR). With increasing underwater activities by regional powers, India requires advanced submarines capable of conducting long-duration stealth operations.
Project-75I forms an important part of this modernisation programme and supports the Government’s Aatmanirbhar Bharat and Make in India initiatives by ensuring that the submarines are built within the country with substantial technology transfer.
Key Highlights
- The agreement is estimated to be worth ₹90,000 crore (€8 billion).
- Six advanced diesel-electric submarines will be constructed in India.
- The project will be executed through a partnership between Mazagon Dock Shipbuilders Limited (MDL) and ThyssenKrupp Marine Systems (TKMS) of Germany.
- The submarines will be based on Germany’s advanced Type 214 design.
- They will be equipped with Air Independent Propulsion (AIP) technology, enabling them to remain submerged for extended periods without surfacing.
- The programme includes significant technology transfer, helping India strengthen its indigenous submarine design, manufacturing, and maintenance capabilities.
- Officials have indicated that the agreement is nearing finalisation following technical evaluations and government approvals.
Air Independent Propulsion (AIP) Technology
One of the most significant features of the Project-75I submarines is the incorporation of Air Independent Propulsion (AIP) technology.
Unlike conventional submarines that must frequently surface or use a snorkel to recharge batteries, AIP-equipped submarines can remain underwater for much longer periods. This increases:
- Operational endurance
- Stealth during missions
- Survivability in hostile environments
- Effectiveness in intelligence gathering and anti-submarine operations
The enhanced underwater endurance makes these submarines particularly valuable for modern naval warfare.
Strategic Importance
The Project-75I programme will substantially strengthen India’s underwater warfare capability at a time when maritime competition in the Indo-Pacific continues to grow. Besides enhancing naval preparedness, the project is expected to:
- Strengthen India’s conventional submarine fleet.
- Expand indigenous defence manufacturing capabilities.
- Promote technology transfer and skill development.
- Generate employment in India’s shipbuilding sector.
- Deepen strategic defence cooperation between India and Germany.
The programme also supports India’s long-term objective of achieving greater self-reliance in defence production while improving the operational readiness of the Indian Navy.
Key Points
- Project: Project-75I (P-75I)
- Estimated Cost: ₹90,000 crore (Approx. €8 billion)
- Number of Submarines: Six
- Indian Partner: Mazagon Dock Shipbuilders Limited (MDL)
- German Partner: ThyssenKrupp Marine Systems (TKMS)
- Submarine Design: Type 214
- Key Technology: Air Independent Propulsion (AIP)
- Objective: Enhance India’s underwater combat capability and promote indigenous defence manufacturing.
Indian Navy Submarine Fleet (2026)
| Submarine Class | Type | Submarines | Origin | Status |
|---|---|---|---|---|
| Arihant Class (SSBN) | Nuclear-Powered Ballistic Missile Submarine | INS Arihant (S2), INS Arighaat (S3) | India | In Service |
| Kalvari Class (Scorpene) | Diesel-Electric Attack Submarine (SSK) | INS Kalvari (S21), INS Khanderi (S22), INS Karanj (S23), INS Vela (S24), INS Vagir (S25), INS Vagsheer (S26) | France/India | In Service |
| Sindhughosh Class (Kilo Class) | Diesel-Electric Attack Submarine (SSK) | INS Sindhughosh (S55), INS Sindhuraj (S57), INS Sindhuratna (S59), INS Sindhukesari (S60), INS Sindhukirti (S61), INS Sindhuvijay (S62), INS Sindhurashtra (S65) | Russia (Former USSR) | In Service |
| Shishumar Class (Type 209/1500) | Diesel-Electric Attack Submarine (SSK) | INS Shishumar (S44), INS Shankush (S45), INS Shalki (S46), INS Shankul (S47) | Germany/India | In Service |
Nuclear-Powered Ballistic Missile Submarines (SSBN)
| Submarine | Pennant No. | Class |
|---|---|---|
| INS Arihant | S2 | Arihant Class |
| INS Arighaat | S3 | Arihant Class |
Role: Nuclear Deterrence (Strategic Forces)
Kalvari-Class (Project-75 Scorpene)
| Submarine | Pennant No. | Commissioned |
|---|---|---|
| INS Kalvari | S21 | 2017 |
| INS Khanderi | S22 | 2019 |
| INS Karanj | S23 | 2021 |
| INS Vela | S24 | 2021 |
| INS Vagir | S25 | 2023 |
| INS Vagsheer | S26 | 2025 |
Built by: Mazagon Dock Shipbuilders Limited (MDL), Mumbai
Sindhughosh-Class (Kilo Class)
| Submarine | Pennant No. |
|---|---|
| INS Sindhughosh | S55 |
| INS Sindhuraj | S57 |
| INS Sindhuratna | S59 |
| INS Sindhukesari | S60 |
| INS Sindhukirti | S61 |
| INS Sindhuvijay | S62 |
| INS Sindhurashtra | S65 |
Origin: Russia (Former Soviet Union)
Shishumar-Class (Type 209/1500)
| Submarine | Pennant No. |
|---|---|
| INS Shishumar | S44 |
| INS Shankush | S45 |
| INS Shalki | S46 |
| INS Shankul | S47 |
Origin: Germany (HDW Type-209)
Upcoming Indian Navy Submarine Projects
| Project | Details | Status |
|---|---|---|
| Project-75I | Six next-generation conventional submarines with Air Independent Propulsion (AIP) technology | Proposed; expected to be built by Mazagon Dock Shipbuilders with Germany’s TKMS |
| Project-75 Alpha | Indigenous Nuclear-Powered Attack Submarines (SSN) | Under development |
Quick Revision Facts
- Total Submarine Classes in Service: 4
- Nuclear Ballistic Missile Submarines (SSBN): Arihant Class
- Diesel-Electric Submarine Classes: Kalvari, Sindhughosh, Shishumar
- Newest Conventional Submarine: INS Vagsheer (Kalvari Class)
- Project-75 Builder: Mazagon Dock Shipbuilders Limited (MDL)
- Project-75 Design Partner: Naval Group (France)
- Project-75I Technology: Air Independent Propulsion (AIP)
- German Partner for Project-75I: ThyssenKrupp Marine Systems (TKMS)
