India Takes a Giant Leap in Submarine Modernisation with Indigenous AIP Technology

India Takes a Giant Leap in Submarine Modernisation with Indigenous AIP Technology

India's Defence Secretary, Rajesh Kumar Singh, has confirmed that the country's first indigenous Air Independent Propulsion (AIP) submarine is set to begin sea trials in 2027. This significant development marks a major milestone in India's submarine modernisation efforts and is expected to enhance the Indian Navy's underwater capabilities.

The AIP system, developed by the Defence Research and Development Organisation (DRDO), uses a fuel-cell-based architecture that enables a submarine to generate electrical power while submerged without running its diesel engines and exposing a snorkel. This reduces the number of times a conventional submarine needs to come close to the surface of the water to recharge its batteries, thereby enhancing underwater endurance and reducing exposure to detection.

The submarine, slated for completion in 2028, will be the first to field India's fuel-cell based AIP technology on a frontline submarine. The system is being integrated into the submarine during its refit, which is expected to take place in mid-2027. The refit is being carried out at Mazagon Dock Shipbuilders Limited (MDL), with the submarine needing structural modification to accommodate the AIP module.

The Ministry of Defence had signed a contract valued around ₹1,990 crore with MDL in December 2024 for the construction of the AIP plug and its integration into Indian submarines. The development of the AIP system has been a long-term effort, with India originally planning to fit it on the lead Kalvari-class submarine. However, delays in the development programme have resulted in the technology being shifted to a later boat and refit cycle.

The sea trials of the AIP-fitted submarine are expected to begin around July-August 2027, following integration and harbour-related testing. The trials will be crucial in translating shore-based qualification of the AIP system into operation within an actual submarine. The successful integration and testing of the AIP system will enable the Indian Navy to take another step towards fielding its own fuel-cell based AIP technology on a frontline submarine.

The development of indigenous AIP technology is a significant step towards enhancing India's submarine capabilities and reducing its dependence on foreign technology. The successful deployment of the AIP system will also enable the Indian Navy to operate its submarines for longer periods without surfacing, thereby reducing its vulnerability to detection.

In conclusion, the development of India's indigenous AIP submarine is a significant milestone in the country's submarine modernisation efforts. The successful integration and testing of the AIP system will enable the Indian Navy to take another step towards fielding its own fuel-cell based AIP technology on a frontline submarine, thereby enhancing its underwater capabilities and reducing its dependence on foreign technology.