India is building its submarine strength step by step through three big projects - Project-75, Project-75I, and Project-76. Each project shows how India is moving from buying and assembling submarines with foreign help to designing and building its own advanced submarines at home. The main improvements focus on longer underwater endurance, better stealth, modern weapons, and higher self-reliance.
India has been steadily building up its submarine force through three major projects: Project-75, Project-75I, and Project-76. Each step shows how India is moving from depending on foreign designs to building fully indigenous submarines. The main focus areas across these projects are Propulsion technology (use of air-independent propulsion: AIP, batteries, and engines) Level of indigenisation (how much of the submarine is designed and built in India) Strategic role (what purpose the submarines will serve in future wars) What it is: The most ambitious submarine project so far. It aims to design and build 12 submarines fully in India. Key technologies: Air Independent Propulsion (AIP) made by DRDO Lithium-ion batteries for longer underwater endurance Indigenous weapon control systems Advanced stealth features Displacement: Around 3,000–4,000 tons. Indigenisation: Almost 80–90%, a big leap compared to earlier projects. Timeline: Design by 2027, construction around 2028–2030, and operational in the 2037–2040 period. Strategic role: Will replace the old Kilo-class submarines and form the backbone of India’s submarine fleet. It aims for self-reliance and future-proofing, ensuring India doesn’t depend on foreign suppliers. What it is: The current active project where India plans to build six submarines with foreign collaboration. Foreign partner: Based mainly on German Type-214 submarines, though other designs were also considered. Key technologies: AIP fuel-cell systems (allowing them to stay underwater for 2–3 weeks) Modular design for future upgrades Advanced stealth and sensor systems Displacement: About 3,000 tons. Indigenisation: Around 45–60%, with higher local content in later submarines. Timeline: Expected deliveries from the late 2020s into the 2030s. Strategic role: Acts as a bridge project, provides immediate capability with modern foreign technology while preparing the ground for India’s fully indigenous P-76 submarines. What it is: The first major modern submarine-building program in India. Built with French help, it delivered six Scorpene-class submarines. Foreign partner: Naval Group (France). Key technologies: Modern torpedoes and anti-ship missiles Improved stealth features Advanced sensors Displacement: About 1,500–1,700 tons. Indigenisation: About 30–45% (assembly in India, but design was French). Limitations: No AIP in the first batch. Submarines need to surface every 48 hours for battery recharging. Strategic role: Served as the foundation project. It gave India the know-how for submarine assembly and operations but is now considered outdated against Chinese and Pakistani fleets. Project-75 (Scorpene): First step, built with foreign design and tech transfer, but limited endurance (no AIP). Project-75I: The second step adds AIP and advanced systems and more indigenisation but is still foreign design-dependent. Project-76: Final step, fully indigenous design, high self-reliance, advanced propulsion, stealth, and weapons. India’s submarine program shows a clear journey from dependence to independence: P-75 (Scorpene) gave India its submarine-building foundation. P-75I provides modern AIP subs for immediate needs, with more local production.Project-76 Marks India’s Leap to Indigenous Submarines
Project-76: India’s Next-Generation Indigenous Submarines
Project-75I: Advanced AIP Submarines with Foreign Help
Project-751 (Project-75): The Scorpene-Class Submarines
Evolution Across the Three Projects
Comparison Table
P-76 is the big leap, aiming for fully homegrown submarines with advanced endurance, stealth, and combat capabilities, ensuring strategic autonomy and self-reliance in undersea warfare.
