In a major step towards self-reliance in defense production, Mazagon Dock Shipbuilders Limited (MDL) has commenced manufacturing the first indigenous Air Independent Propulsion (AIP) system for the Indian Navy's Scorpene-class submarines.
A formal production ceremony was held yesterday at MDL's Mumbai facility, attended by MDL Chairman and Managing Director, Mr. Biju George, along with representatives from the Indian Navy and other senior officials.
This AIP system is a crucial upgrade designed to significantly extend the underwater endurance of the Scorpene submarines, part of the ongoing Project 75 (P-75).
The system, developed domestically by the Defence Research and Development Organisation (DRDO) in collaboration with Indian industry partners, will be added to the submarines during their regular maintenance periods. The first submarine to receive the upgrade, INS Kalvari, is scheduled for its refit in September 2025.
The AIP technology being built at MDL represents a significant achievement in India's defense technology capabilities. The system, created by DRDO's Naval Materials Research Laboratory (NMRL), utilizes a phosphoric acid fuel cell (PAFC) to generate electricity. This provides a dependable and effective power source, positioning it as a strong alternative to imported AIP systems.
The Indian Navy's decision to adopt this domestically-produced technology demonstrates its confidence in the system's capabilities. According to the DRDO, a Phosphoric Acid Fuel Cell based AIP offers better performance compared to other technologies.
The construction involves creating an 8- to 10-meter-long "plug," weighing about 300 tons, which will be integrated into the existing submarine hull. This involves a complex process of cutting the submarine and inserting the new section. MDL, supported by the Naval Group (France), is prepared for this intricate task.
The integration on INS Kalvari will act as a trial, with the technology subsequently being installed on the remaining five Scorpene submarines: INS Khanderi, INS Karanj, INS Vela, INS Vagir, and INS Vagsheer.
The addition of AIP to the Scorpene fleet will substantially improve the Indian Navy's operational capabilities in a region facing evolving security challenges. The Indian Ocean has seen increased activity from other naval forces. An AIP system allows submarines to remain submerged for extended periods, enhancing their stealth capabilities.
This allows for longer surveillance and deterrence operations in key areas like the Bay of Bengal, the Arabian Sea, and the eastern Indian Ocean, strengthening India's maritime security. Non-AIP equipped submarines need to surface or use a snorkel to recharge the batteries that power the propulsion. This leaves them visible, and thus easy targets.
This project reinforces MDL's reputation as a leading submarine builder. Having successfully delivered all six Scorpene submarines under Project 75, the shipyard has demonstrated its ability to manage and complete complex shipbuilding projects.
The construction of the AIP plug utilizes MDL's advanced infrastructure, including its recently opened AIP Integration and Testing Facility. This ensures the AIP system will adhere to the Navy's strict operational requirements. The Ministry of Defence has stated that self-reliance in defence production is a key priority for the government.
