Germany and Spain Compete for Indian Navy Submarine Deal with Advanced AIP Technology

 

The Indian Navy's pursuit of fuel cell-based Air Independent Propulsion (AIP)-equipped conventional submarines is moving forward, albeit slowly. Currently, the Navy is evaluating two submarines for its advanced diesel-electric submarine needs, but only one has proven and validated technology. The Indian Navy is conducting field evaluation trials of the AIP technology developed by Spanish shipbuilder Navantia at Cartagena.

This technology has yet to be integrated into the S80 submarine offered to the Indian Navy, although a submarine of this class has already been inducted into the Spanish Navy without AIP technology. Navantia claims that its submarine design meets 'almost' all technical requirements of the P-75I without needing redesign.

Navantia's AIP system for the S80 produces over 300 kW of power, which can be directly applied to P75(I) without scaling up, thus reducing major risks for the Indian Navy. Factory testing of the AIP technology has been completed, simulating actual submarine mission conditions at the Cartagena Shipyard.

Navantia states that the S80 offered to the Indian Navy incorporates the latest technologies, such as Generation BEST AIP (Bio-ethanol Stealth Technology) and an advanced sensor suite. This third-generation AIP system uses hydrogen produced on board from bioethanol instead of stored hydrogen, allowing submarines to sail for up to three weeks submerged with minimal detectable signatures.

The Indian Navy also requires AIP technology combined with Lithium-ion batteries, enabling submarines to operate at high speeds without compromising their position. Navantia and its Indian partner, Larsen and Toubro (L&T), are not collaborating with another partner for proven Lithium-ion battery technology for this project.

Navantia's first submarine equipped with AIP BEST technology is expected to be operational by 2026. However, experts estimate that the AIP system will be ready for operational deployment in about three years, pending further laboratory tests and simulations.

Another submarine under consideration by India is already proven and used by several frontline navies. Recently, a submarine from this class completed a rare voyage under the Arctic ice. This submarine, the Arpão (S161), built by Howaldtswerke-Deutsche Werft (HDW) in Germany, is based on the export-optimized Type 214 design.

ThyssenKrupp has offered India its 214-class submarines, which combine advanced technologies from the 212 CD submarines with the latest AIP developments. These submarines, tailored to the Indian Navy's requirements, will feature Lithium-ion batteries, advanced sensor and combat systems, and enhanced stealth capabilities.

The 212 and 214-class submarines' AIP technology, powered by hydrogen fuel cells, allows for extended submerged operations and silent running, enhancing stealth. These submarines can operate silently, launch torpedoes stealthily, and have countermeasures against torpedoes, providing increased operational flexibility.

The Indian Navy is currently strengthening its undersea fleet, as evidenced by a recent exercise in the Arabian Sea involving eight submarines. Despite challenges such as dwindling fleet numbers and aging submarines, the Navy is pushing forward with plans to build six more conventional diesel submarines under Project-75 I.

However, the Chinese Navy's rapid expansion poses a significant challenge. China has been continuously deploying at least one nuclear-armed submarine at sea and is providing advanced submarine technology to Pakistan. In response, the Indian Navy is enhancing its capabilities to maintain strategic balance in the region.

The Indian Navy's adoption of AIP technology will enhance its fleet's capabilities, putting it in a better position against regional threats. While the Navy considers whether to proceed with proven technology or wait for the deployment of Navantia's AIP BEST technology on an operational submarine, the decision will significantly impact India's undersea defense strategy.

Project-75I: German Shipbuilder to Provide Stealthy AIP Submarines with Lithium-Ion Batteries to Indian Navy

 

The Indian Navy is pursuing the acquisition of six submarines under its Project-75I, which aims to integrate Fuel Cell Air-Independent Propulsion (AIP) technology with Lithium-ion batteries. This combination will enable the submarines to remain submerged for extended periods and move swiftly without compromising their stealth.

The focus of the Indian Navy is not on having the largest or fastest submarines but rather on achieving superior stealth and lethality. German shipbuilder ThyssenKrupp, a leading contender for the contract, has proposed its 214-class submarines, which incorporate advanced AIP technology and are tailored to Indian requirements. These submarines will be an enhanced version of the 214 class, featuring advanced sensors, combat systems, and Lithium-ion batteries, all while maintaining stealth capabilities.

Dr. Christian Frühling, Program Head for Project-75I at ThyssenKrupp Marine Systems (tkMS), emphasized that their unique AIP solution and proven submarine design would be game-changing for the Indian Navy. The AIP system provides long-range endurance at low speeds, while the Lithium-ion battery enables high-speed cruising, allowing the submarines to cover extensive areas like the Bay of Bengal while remaining submerged.

The hydrogen-powered AIP technology allows the submarines to stay submerged for up to three weeks, significantly reducing the need to surface and enhancing stealth. The 212 and 214 class submarines operate silently, launching torpedoes stealthily and featuring countermeasures against enemy torpedoes. These submarines can also "bottom" on the ocean floor, conserving energy and extending mission duration while using passive sonar to detect targets.

Efficient energy systems are crucial for the Indian Navy, which currently has only 16 conventional submarines against a requirement for 24. Most of these submarines are over 30 years old, making Project-75I a high priority.

AIP-based submarines are more cost-effective and easier to maintain than nuclear-powered ones. They have modular fuel cell systems and smaller crews. The German government, which initially hesitated when the tender was issued three years ago, now supports the project. In March 2024, the German Navy provided its submarine for the Indian Navy's evaluation.

TkMS, confident in its technology, remains the only company with sea-proven fuel-cell-based AIP systems. The 214-class submarines are already in service with Greece, Portugal, Turkey, and South Korea. The Indian Navy, which operates 209-class submarines, has partnered with Mazagon Dockyard Limited (MDL) for repairs and refurbishments. TkMS and MDL jointly produced four submarines for the Indian Navy and are now bidding together for Project-75I.

In Project-75I, the submarines will be built in India from the first unit onward, with TkMS providing design and critical components. MDL will lead the project, with the first submarine expected to be completed seven years from the contract date, followed by one submarine annually.

The field evaluations for Project-75I are set to conclude by June. Spain's Navantia is also competing for the contract but lacks operational AIP technology. Given India's urgent need for advanced submarines to counter China's growing maritime presence, a government-to-government contract to build these submarines in India is a possibility.