Indian Navy To Acquire Advanced AIP Technology Submarines Under Project-75I

The Indian Navy plans to buy six new submarines with Air Independent Propulsion (AIP) technology under Project-75I. The 'I' stands for India. These submarines will use Fuel Cell AIP technology, allowing them to stay submerged longer and be harder to detect by enemy sonars.

The AIP technology uses Lithium-ion batteries, enabling the submarines to remain hidden deep underwater for extended periods and providing a burst of speed when needed. The Navy seeks submarines that can stay submerged and undetected for longer durations, enhancing their lethality.

India has issued a tender for this project. German shipbuilder ThyssenKrupp is leading the race with its 214-class submarines. These submarines combine advanced technology from the 212 CD class with the latest AIP developments, making them effective underwater platforms.

The 212 CD class submarines were designed for the Norwegian Navy's needs in the Baltic Sea. The 214-class submarines offered to India will be tailored to Indian requirements, featuring an advanced version of AIP technology, Lithium-ion batteries, advanced sensors, and combat systems without compromising stealth capabilities.

Dr Christian Fruhling, Head of Programme tkMS for Project-75I, stated that their design is proven and state-of-the-art, specifically tailored to India. He highlighted the AIP technology as their biggest advantage for this project.

The AIP system combines fuel-cell and Lithium-ion batteries, which will be crucial for the Indian Navy's vast maritime territory from the Gulf of Aden to the Strait of Malacca. With China's expanding oceanic capabilities, a strong submarine force is essential for India.

The fuel-cell AIP allows the submarine to run at low speed for longer periods, while Lithium-ion batteries enable high-speed sprints to reach targets. This combination is not used by Europeans but by the Japanese. If ThyssenKrupp gets the contract, it will integrate these technologies for India.

Dr Fruhling explained that this technology would allow the Indian Navy to cover the entire Bay of Bengal while remaining underwater. Submarines are most vulnerable when they come up to periscope depth to take in oxygen for diesel-electric batteries.

The new 212 and 214 class submarines will have hydrogen-powered fuel-cell-based AIP technology, allowing them to stay submerged for three weeks at a time. ThyssenKrupp Marine Systems (tkMS) owns Howaldtswerke-Deutsche Werft (HDW), which built the world's first operational submarine.

The Indian Navy needs 24 submarines but currently operates only 16. Of these, only six are new; the rest are over three decades old and nearing retirement. The Navy already operates 209-class submarines, two of which — INS Shishumar and INS Shankush — are being upgraded by tkMS and Mazagon Dockyard Limited (MDL).

tkMS has been working with MDL since the 1980s. The first two boats of the 209-class were built in Germany, while the next two were built in India at MDL shipyard. All repairs and refits have been done by MDL without sending them back to Germany.

Now, tkMS and MDL have come together again to bid for Project-75I. Dr Fruhling mentioned that tkMS is unique in enabling other nations to create an autonomous submarine industry. Under Project-75I, complete submarines will be built in India from the first boat onwards.

tkMS will supply the design and critical equipment while MDL will be the prime contractor. The first submarine is expected within seven years of finalising the contract, with subsequent submarines delivered yearly.

India is also considering Spain's Navantia for the contract, but Navantia does not yet have operational AIP technology. It remains uncertain whether India will choose ThyssenKrupp or wait for Spain's AIP technology to mature.

A government-to-government deal is also possible now that Modi's government has been re-elected. However, India needs this capability as China continues making progress with its silent and long-endurance submarines appearing in the Indian Ocean Region.