DRDO's Indigenous AIP System for Navy Submarines Reaches Phase-2 Milestone at Hazira

The Ministry of Defence announced on October 24 that the 'Setting to Work Phase-2' activity for the indigenous Air Independent Propulsion (AIP) system's Energy Module was inaugurated at L&T's Hazira complex. Developed by DRDO's Naval Materials Research Laboratory, the fuel-cell system will let diesel-electric submarines stay submerged far longer without atmospheric oxygen. After energising and Navy-protocol testing, it is scheduled for handover to Mazagon Dock Shipbuilders in early 2027 for integration on Kalvari-class submarines.

Awaaz Punjab Investigations Desk24 October 20263 min readRead in all 3 languages

India's indigenous submarine propulsion programme crossed a new milestone on Saturday, October 24, with the inauguration of the 'Setting to Work Phase-2' (STW-2) activity for the Air Independent Propulsion (AIP) system's Energy Module, the Ministry of Defence announced.

Source: Ministry of Defence announcement, reported by Tulsian News

The ceremony took place at Larsen and Toubro's AM Naik Heavy Engineering Complex in Hazira, Gujarat. Defence Secretary Rajesh Kumar Singh attended virtually as chief guest, while the Indian Navy's Chief of Materials, Vice Admiral B Sivakumar, and DRDO's Director General (Naval Systems and Materials), Dr R Balamuralikrishnan, attended at the facility.

The AIP system has been developed by the Naval Materials Research Laboratory (NMRL) of the Defence Research and Development Organisation (DRDO). AIP allows a diesel-electric submarine to generate power and stay submerged for much longer without needing atmospheric oxygen, reducing how often it must surface or snorkel — the moments when a submarine is easiest to detect.

The DRDO Chairman congratulated DRDO and its industry partners and acknowledged the Indian Navy's cooperation in testing and validation at every trial stage, according to the announcement. Emphasis was placed on maintaining exacting safety standards for the hydrogen and fuel-cell systems as the programme moves towards the Navy's induction timelines.

What happens next

The next phase involves energising the AIP Energy Module for power production, followed by rigorous testing under Indian Navy protocols. The system is scheduled for handover to Mazagon Dock Shipbuilders Limited for integration on Kalvari-class submarines in early 2027, the report said.

Sources: Ministry of Defence (PIB) announcement of October 24, 2026; Tulsian News report of the MoD announcement.