Germany, Spain ‘Battle’ For Indian Navy’s Massive API Submarine Deal; Madrid Eats Into Berlin’s Advantage

The Indian Navy’s quest for fuel cell-based Air Independent Propulsion (AIP)- equipped conventional submarines is progressing, albeit a bit slowly. The Navy is assessing two submarines for its requirement of advanced diesel-electric submarines, but only one has a proven and validated technology.

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The Indian Navy team is conducting field evaluation trials of the AIP technology developed by Spanish shipbuilder Navantia at Cartagena.

The technology is yet to be fitted into the S80 submarine offered to the Indian Navy. One of the submarines of the offered class has already been inducted into the Spanish Navy without AIP technology.

Navantia has been asserting that its submarine design meets ‘almost’ all the technical requirements of P-75I without any redesign.

“The AIP designed for S80 produces more than 300 kW of power and, therefore, can be directly used for P75(I) without any redesign or scaling up. This would substantially mitigate major risks of the Indian Navy with respect to the P75(I) project,” Spanish shipyard Navantia’s Chairman Ricardo Dominguez Garcia-Baquero was quoted by the Indian Media.

So far, Navantia has completed factory testing of its AIP technology for its S-80 program. During the tests, Navantia evaluated the system’s performance in a simulated environment that replicated the conditions the system would encounter during actual submarine missions. The facilities at Cartagena Shipyard allowed for this environment, with capabilities to simulate submarine operations and test entire sections of the submarine.

This is where the Indian Navy will be conducting its field evaluations.

The Navantia Chairman stated that the S80 offered to the Indian Navy has the most contemporary features and incorporates the latest technologies, such as Generation BEST AIP (Bio-ethanol stealth Technology) and an advanced sensor suite.

The proprietary technology Navantia uses in the AIP BEST system is based on fuel cells and is part of the so-called third-generation systems, i.e., those that use hydrogen produced on board from a fuel—bioethanol, in this case—instead of pure stored hydrogen for their operation. This evolution allows Spanish submarines to have a greater amount of onboard energy, being able to sail for up to three weeks in immersion with signatures comparable to those of pure electric navigation with batteries.

As the EurAsian Times understands, the Indian Navy requires efficient energy systems onboard.

Another requirement for the Indian Navy has been to have fuel cell AIP technology combined with a Lithium-ion battery, which will give them the capability to lurk in the ocean depths for a longer duration and, when required, race to their target at high speeds while not giving up their position.

Navantia and its Indian partner Larsen and Toubro (L&T) are not tying up with another partner to provide a proven Lithium-ion battery technology for the project, Navantia’s Chairman revealed.

The fuel-cell AIP gives the submarine long-range endurance at low speed, whereas the Lithium-ion battery allows it to cruise at high speed to reach its desired destination.

The first Navantia submarine equipped with the AIP BEST technology is expected to roll out by 2026.

Requesting anonymity, a source told the EurAsian Times that their AIP system is still at least three years from being exploited on an operational submarine. Until then, laboratory tests and simulations are the only means to make these claims. There can be a slip between the cup and the lip.

The other submarine on offer to India is already proven and is part of many frontline navies. Recently, the submarine created ripples by completing a rare voyage under the Arctic Ice. The Portuguese Navy’s first-of-its-kind mission was accomplished by the Arpão (S161), built by Howaldtswerke-Deutsche Werft (HDW) in Germany and based on the export-optimized Type 214 design.

The German shipbuilder ThyssenKrupp has offered its 214-class submarines. These combine the advanced technological aspects of 212 CD submarines with the latest developments in AIP technology. The 212 CD class submarines are built exclusively for the Norwegian Navy and are tailored to their operating requirements in the Baltic Sea.

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The 214 being offered to India will be tailored to the requirements of the Indian Navy. It will be a derivative of the 214 class of submarines, with the latest enhancements in AIP technology. It will be equipped with a Lithium-ion battery, have an advanced sensor and combat system, and not compromise on stealth features.

Also, the new 212 and 214-class submarines’ hydrogen-powered fuel cell-based AIP technology allows them to remain submerged for three weeks at a time.

The 212 or 214 submarine class can operate silently without emitting exhaust heat, increasing its stealth. Fuel cells offer the lowest noise levels because almost no sound is produced by an electro-chemical reaction. It can launch torpedoes stealthily with a water ram expulsion system. It also comes with countermeasures against torpedoes like underwater effector jammers and has minimized acoustic, thermal, and magnetic signatures to provide more stealth.

AIP-enabled submarines have increased mobility. They can “bottom” or sit on the ocean floor with only critical systems running to preserve energy and extend the operational time while using passive sonar to detect targets. Since fuel cells operate with greater efficiency at lower loads, bottoming could extend the endurance of a particular mission.

Indian Navy’s Quest For Undersea Deterrence

On March 25, the Indian Navy released stunning photographs of a pod of its submarines on the western seaboard. The eight submarines operated together in a recently concluded exercise in the Arabian Sea.

Before this, Indian Navy Chief Admiral Hari Kumar revealed that the Indian Navy had simultaneously deployed 11 conventional submarines for operations in different parts of the Indian Ocean Region.

This has been the highest number of operational submarines for the Indian Navy in the last two decades. The submarine arm has been facing dwindling strength, accidents, and write-offs. As against the required 24 conventional submarines, the Indian submarine fleet has only 16 submarines, and apart from the six recently-built submarines, the rest are over 30 years old and approaching their decommissioning date.

The Indian conventional submarine fleet includes five Scorpene class (French), four HDWs (German), and seven Kilo-class (Russian). An additional Scorpene class is still to be commissioned.

The Indian Navy has to be wary of the Chinese Navy, which is not only forging ahead with the induction of submarines into its fleet but also equipping India’s neighbor Pakistan with state-of-the-art technology.

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The Indian Navy’s adoption of AIP technology will put its fleet in a better position than Pakistan’s. All three of its French Agosta-90B (PNS Khalid, Saad, and Hamza) are powered by AIPs. Pakistan is also expected to receive eight 39 A Yuan-class AIP-powered submarines by the end of 2023 under a US$5 billion deal with China.

By next year, the Indian Navy will have 17 conventional submarines in its fleet. However, the older Kilo-class submarine’s availability ratio is low.

File Image: HDW Submarine

The Chinese undersea fleet has been growing exponentially in quantity and quality. For the first time, China has been able to deploy at least one nuclear-armed submarine constantly at sea.

Compared to this, the Indian submarine program has been growing steadily, albeit a tad bit slower, making it difficult to catch up with its giant assertive adversary in the East. The Indian Navy plans to construct six more conventional diesel submarines under Project-75 I.

Considering it took 11 years for the first Scorpene class submarine to enter the Indian Navy’s fleet after signing the deal, the subs to be built under Project 75I are at least a decade away from entering operations.

It remains to be seen if the Indian Navy will proceed with an operational technology or wait to see the AIP BEST technology deployed on an active submarine before awarding the contract.

  • Ritu Sharma has been a journalist for over a decade, writing on defense, foreign affairs, and nuclear technology.
  • The author can be reached at ritu.sharma (at)
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