India has kicked off formal talks for Project 75I, a ₹70,000 crore program set to reshape its undersea power. This deal will bring cutting-edge diesel-electric boats with Air Independent Propulsion (AIP) and cement India’s place as a submarine builder.
Project 75I : August 2025 Update
On August 23, 2025, New Delhi cleared negotiations. Years of red-tape ended. Mazagon Dock Shipbuilders and Germany’s ThyssenKrupp Marine Systems (TKMS) now sit at the table.
From Six to Nine Boats
Officials hint at nine submarines in two phases meaning that after acquisition of first 6 additional follow on order will be given expected to be in battlegroup with IAC2 likely with INS Vishal.:
- Phase 1: Six AIP-equipped boats (₹90,000 crore).
- Phase 2: Three follow-on vessels, taking the total close to ₹1 trillion.
Nine boats offer scale. They’ll patrol both the Arabian Sea and Bay of Bengal.
Why TKMS Won the Race
TKMS beat Spain’s Navantia thanks to:
- Proven AIP systems in NATO service
- Stealthy Type 214 design
- “Sea-proven” performance clause met
- Full tech-transfer pledge
Navantia’s bioethanol AIP remains untested at sea until 2026—too late for India’s timeline.
Project 75I Increase in Cost due to delay
Project 75I jumped from ₹43,000 crore (2021) to ₹70,000 crore (2025). Key drivers:
- Global inflation and rupee swings
- Advanced AIP integration
- Upgraded combat and sensor suites
- Single bidder leverage
Each sub now costs about $1.3 billion, up from $800 million.
Regional Context: Challenges at Sea
Adversaries like China is growing its fleet with rapid speed ,this should be concern for India. the number of Subs being deployed by china in the Indian Ocean increasing day by day.
Pakistan is also building eight Chinese AIP boats under a $5 billion deal in that one is already deliver, In any other way there is no match between Indian Navy and Pakistan Navy..
India needs tackle both issues to stay ahead for that Project 75I is needs to be completed as soon as possible.
Timeline for Project 75I : Long Haul Ahead
- Aug 2025–Feb 2026: Negotiations
- Mar 2026: Cabinet nod and contract
- Mid 2026: Steel cutting begins
- 2032–33: First boat joins fleet
- Late 2030s: Full nine-boat flotilla
Building advanced subs takes time—and patience.
Make in India: Building Homegrown Muscle
- 45% indigenization in Boat 1, rising to 60% by Boat 6
- TKMS to transfer full design know-how
- MSMEs to supply parts and systems
- MDL’s Mumbai yard becomes a submarine hub
This isn’t just buying subs; it’s building an industry Project 75I is going tot pave road for Make in India initiative.
AIP’s Game-Changer Edge
With fuel-cell AIP, these boats can stay submerged for up to three weeks. Compare that to 2–3 days on battery power. More time underwater means more stealth, more patrols, and more deterrence.
Risks and Pitfalls
- Tech transfer must go beyond assembly
- Keeping German quality in Indian yards
- Sticking to a one-boat-per-year delivery pace
- Avoiding fresh delays in talks
What It Means for India’s Navy
- AIP subs boost endurance and stealth
- They form a shield around aircraft carriers
- They can strike land targets with cruise missiles
- They give India a stronger hand against China and Pakistan
Beyond Defense: Economic Upside
- Thousands of jobs across shipyards and suppliers
- High-tech spillover to civilian marine industries
- Potential exports to friendly navies
The Bottom Line
Project 75I is more than a weapons deal. It’s a strategic bet on India’s maritime future. Success hinges on swift contracts, real tech transfer, tight cost control, and steady political backing. Get it right, and India will command the underwater domain for decades to come.
Missiles in Submarines: Types and Operational Ranges
Indian Navy submarines employ a Different types of missile systems. For Project 75I If I compare it to previous submarines it will have better missile systems within it. From anti-ship warfare to land attack missions I have listed all the capabilities .
Primary Missile Systems of Project 75I Subs:
BrahMos Supersonic Cruise Missile
Type: Anti-ship and land-attack cruise missile, Range: 290-650 km (export variants limited to 290 km, extended versions up to 800 km), Speed: Mach 2.8-3.5 ,Warhead: 200-300 kg, Features: Ramjet-powered, fire-and-forget capability, vertical launch capability
Club/Klub Anti-Ship Missiles (3M-54)
Type: Anti-ship cruise missile (Russian origin), Range: 220 km, Platform: Currently operational on Kilo-class submarines, Features: Submarine-launched, terminal supersonic phase
SM-39 Exocet Anti-Ship Missiles
Type: Anti-ship missile, Range: 50+ km, Platform: Scorpene/Kalvari-class submarines, Features: Sea-skimming trajectory, active radar homing
Heavy Weight Torpedoes
Type: Anti-submarine and anti-ship torpedoes, Range: 20-50 km depending on variant, Guidance: Wire-guided and autonomous homing, Platform: All submarine classes
Future Integration Possibilities:
Nirbhay Cruise Missile: Subsonic cruise missile with 1,000+ km range (under development)
Extended Range BrahMos: Variants with 800-1,500 km range capability
Vertical Launch Systems: Potential integration for rapid multi-angle missile deployment
The Project 75I submarines are expected to integrate both indigenous and proven foreign missile systems, with emphasis on BrahMos variants and advanced torpedo systems developed by Indian defense laboratories.
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