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.

Norwegian Navy's Type 212CD AIP Submarines to Revolutionize Underwater Capabilities

 

Norway's new Type 212CD diesel-electric submarines (SSKs) will introduce air-independent propulsion (AIP) to the Royal Norwegian Navy (RNoN), significantly enhancing its underwater capabilities. This advancement is expected to be a game-changer, as stated by the commanding officer (CO) of one of Norway's current in-service boats.

Currently, the RNoN operates six Type 210 Ula-class SSKs, which are set to be replaced by up to six Type 212CD submarines, with the first delivery slated for 2029 and subsequent deliveries extending into the mid-2030s. These new submarines are being developed through a strategic collaboration with Germany, initiated in 2017, marking the beginning of a broader defense partnership formalized in 2023.

Originally, the RNoN planned to replace the Ula-class boats with four Type 212CDs. However, rising regional security concerns and underwater challenges led Norway’s Chief of Defence, General Eirik Kristoffersen, to advocate for six new submarines. In April 2024, the Norwegian government proposed to parliament the acquisition of at least five new submarines as part of a long-term defense strategy extending to 2036.

The Type 212CD submarines will bring crucial new capabilities to the RNoN, particularly through AIP technology. The CO of the Ula-class boat HNoMS Utvaer emphasized that AIP is a significant game-changer. Unlike the current Ulas, the Type 212CD’s fuel-cell AIP will reduce the need for ‘snorting’ at periscope depth, a noisy and visible process that increases vulnerability to various threats.

This capability is demonstrated by the Royal Swedish Navy’s Gotland-class SSKs, which utilize a Stirling fuel-cell AIP system, allowing them to remain submerged without snorting for several weeks. The introduction of AIP aligns with the RNoN's focus on enhancing stealth and operational capability in its challenging regional waters.

In addition to AIP, the Type 212CDs will allow the RNoN to explore new capabilities such as strike capabilities with the Kongsberg Naval Strike Missile (NSM). The Ula-class boats, although not equipped with strike capabilities, remain formidable with up to 14 weapons and advanced torpedoes like the Atlas Elektronik DM2A3 Sea Hake.

Despite their age, the Ula-class submarines maintain high operational effectiveness through regular upgrades and maintenance. This includes new sonars, command and information control consoles, and advanced navigation equipment. The CO of Utvaer praised the robust maintenance process, which ensures high material readiness and prolongs the operational life of the submarines.

The continuous upgrade and maintenance efforts reflect the RNoN's commitment to maintaining a capable and ready submarine fleet, even as they age. This dedication ensures that the Ula-class boats remain potent platforms until the new Type 212CD submarines are fully integrated into the fleet.