India’s Submarine Fleet Boosted by MDL and Naval Group Propulsion Collaboration

In a significant step towards self-reliance, Naval Group of France and India’s state-owned Mazagon Dock Shipbuilders Limited (MDL) have entered into a landmark agreement to integrate a cutting-edge indigenous energy system developed by the Defence Research and Development Organisation (DRDO) into the Indian Navy’s Kalvari-class (Scorpène) submarines.

The collaboration marks a critical phase in the implementation of the contract awarded by the Indian Ministry of Defence to MDL on December 30, 2024, aimed at enhancing the underwater endurance and operational capability of the submarines.

The upgrade will involve a technically demanding process known as “Jumboisation”, which requires precision cutting of the submarine’s pressure hull to insert the new DRDO-developed propulsion plug. Once integrated, the hull will be reassembled to maintain structural integrity and ensure full operational safety.

Naval Group, as the original equipment manufacturer (OEM) of the Scorpène design, will offer technical supervision, proprietary materials, and advanced training to MDL engineers. This collaboration builds on the success of the Project 75 program, under which six Scorpène-class submarines were indigenously built by MDL using technology transferred by Naval Group.

Laurent Espinasse, Executive Vice President for Submarines at Naval Group, said, “This initiative represents a significant step forward in integrating indigenous innovations into a globally proven submarine platform. It reflects our shared commitment to technological excellence and the operational enhancement of the Indian Navy.”

MDL, India’s premier shipyard for submarine construction, views the integration as a continuation of its critical role in supporting India’s naval power.

“As the only defence PSU in India building submarines, we are proud to contribute to enhancing the operational strength of the Indian Navy,” said Commodore S B Jamgaonkar (Retd), Director of Submarines and Heavy Engineering at MDL. “Our longstanding partnership with Naval Group will be instrumental in delivering this complex modification, maintaining the highest standards of quality, and meeting project timelines.”

This joint effort underlines India’s focus on ‘Atmanirbhar Bharat’ (self-reliant India) in the defence sector. Incorporating DRDO’s propulsion system into operational submarines demonstrates the successful fusion of indigenous R&D capabilities with advanced foreign platforms, bolstering India’s status as a defence manufacturing hub.

Strengthening Indo-French Naval Ties

The move also represents another significant chapter in the Indo-French defence partnership, which has matured over the years through collaboration on advanced naval platforms. It showcases both countries’ mutual trust, strategic alignment, and commitment to a free and stable Indo-Pacific region.

Mazagon Dock: Building India’s Underwater Arsenal

Since its takeover by the Government of India in 1960, MDL has evolved from a small ship repair facility into the country’s leading builder of warships and submarines. With a legacy of building over 805 vessels, including 30 warships and eight submarines, MDL’s experience in delivering cutting-edge naval platforms is unrivalled. The successful execution of the six Scorpène-class submarines under Project 75 has positioned it as a central player in India’s underwater warfare capabilities.

With this new initiative, MDL and Naval Group are poised to further transform India’s submarine fleet into a force that combines international design excellence with homegrown propulsion innovation, marking a significant leap in India’s journey towards defence autonomy.

Team BharatShakti