Indian Navy’s Indigenous AIP System Enters Setting-to-Work Phase-2

The Indian Navy’s indigenous Air Independent Propulsion (AIP) system reached a development milestone on 24 October 2026 with the inauguration of the Setting to Work Phase-2 (STW-2) activity for its Energy Module. The ceremony took place at Larsen and Toubro’s AM Naik Heavy Engineering Complex in Hazira, Gujarat.

Development and Testing of the Energy Module

The Defence Research and Development Organisation’s Naval Materials Research Laboratory developed the AIP system. During STW-2, the Energy Module will undergo testing for power production under Indian Navy protocols. Defence Secretary and DRDO Chairman Rajesh Kumar Singh attended the inauguration virtually. Vice Admiral B Sivakumar, Indian Navy Chief of Materiel, and Dr R Balamuralikrishnan, DRDO Director General (Naval Systems and Materials), attended at the Hazira facility.

After successful testing, the module is scheduled for handover to Mazagon Dock Shipbuilders Limited for integration into a Kalvari-class submarine in early 2027.

Air Independent Propulsion in Conventional Submarines

Air Independent Propulsion is a set of technologies that enables a submarine to operate underwater without drawing atmospheric oxygen for its propulsion system. Diesel-electric submarines normally need to surface or use a snorkel to run diesel engines, recharge batteries and obtain air. An AIP system reduces this dependence and can extend the period a conventional submarine remains submerged; the Navy’s system is designed to support underwater endurance for weeks.

AIP systems are distinct from nuclear propulsion, which uses a nuclear reactor to generate power. AIP does not make a conventional submarine nuclear-powered, and the submarine still relies on its batteries and diesel-electric systems for operations.

Kalvari-Class Submarines

The Kalvari class is a series of diesel-electric attack submarines built in India under Project 75. Mazagon Dock Shipbuilders Limited builds the submarines, which are based on the Scorpène design. The class is operated by the Indian Navy.

Important Facts for Exams

:

• DRDO is the research and development agency under India’s Ministry of Defence.
• The Naval Materials Research Laboratory is a DRDO laboratory based in Ambernath, Maharashtra.
• Project 75 concerns the construction of six Kalvari-class submarines for the Indian Navy.
• A submarine snorkel allows a submerged conventional submarine to draw in atmospheric air for diesel-engine operation.

The AIP Energy Module is scheduled for testing under Indian Navy protocols before its planned handover in early 2027. Its intended integration is with a Kalvari-class submarine.