Naval Group and Mazagon Dock Shipbuilders Ltd (MDL) extend their cooperation to support the integration of DRDO’s indigenous energy system into Kalvari-Class Submarines
Mumbai. On July 23rd 2025, Naval Group and Mazagon Dock Shipbuilders Limited (MDL) formally entered into a collaboration agreement for the integration of indigenous energy system plugs, developed by DRDO, onboard the Indian Navy’s Kalvari-class submarines, built entirely by MDL based on successful transfer of technology from Naval Group for its Scorpène® submarine. This agreement follows the contract signed on December 30 2024, between the Indian Ministry of Defence and MDL, for the construction and integration of this indigenous propulsion design.
Under this agreement, the submarines will undergo a complex process known as “Jumboisation,” involving precision cutting of the hull, safe insertion of the plug, and re-joining of the structure to have a fully operational and safe submarine. As the original equipment manufacturer (OEM) of the Scorpène® submarines, Naval Group will provide technical oversight, proprietary materials, and specialized training to experienced Indian engineers of MDL to ensure seamless integration.
This project, reflects the commitment of MDL and Naval Group in supporting India’s vision of self-reliance in defence manufacturing, contributing significantly to the ‘Aatmanirbhar Bharat’ initiative, with the incorporation of indigenous technologies developed by DRDO into the Kalvari class submarines. This cooperation between the major shipyards is epitome for further strengthening the long-standing defence partnership between France and India, built on mutual trust, technological collaboration, and shared strategic objectives.
Speaking on the occasion, Laurent Espinasse, Executive Vice President of Submarine Division at Naval Group, said “We are honored to deepen our partnership with MDL and DRDO. The integration of indigenous energy system into the Kalvari-class submarines is a major step forward in our shared journey toward technological and operational advancements. Naval Group is proud of its long-lasting collaboration with the Indian navy, industry and stakeholder, in “walking the talk” by working together in integrating key indigenous technologies into Scorpène® submarines, fully built in India”.
During the kick-off meeting for the project, Cmde S B Jamgaonkar, IN (Retd), Director Submarines and Heavy Engineering division at MDL, said, “As a ‘Shipbuilders to Nation’ and the only defence PSU to construct submarines in India, we are honoured to work towards enhancing the operational capability of the Indian Navy’s submarine fleet. We are pleased to extend our natural partnership with Naval Group and we shall jointly work towards successful integration of the DRDO developed propulsion system with the P75 Project Scorpene submarines. Mazagon Dock Shipbuilders Ltd remain fully committed to delivering this project with the highest standards of quality, precision and within the Project timelines”.
MDL, a Navratna DPSU of India
Mazagon Dock Shipbuilders Limited, Mumbai, is one of the leading shipbuilding yards in India. It was taken over by the Government in 1960, and grew rapidly to become the premier war-shipbuilding yard in India, producing warships for the Navy and offshore structures for the Bombay High. It has grown from a single unit, small ship repair company, into a multi-unit and multi-product company, with significant rise in production, use of modern technology and sophistication of products. The company’s current portfolio of designs spans a wide range of products for both domestic and overseas clients. Since 1960, MDL has built total 805 vessels including 30 warships, from advanced destroyers to missile boats and 8 submarines. MDL has successfully built 6 Scorpène® class submarines for the Indian Navy under P75 program.
Naval Group, a long-term partner of India
Naval Group is present in India through its 100% subsidiary Naval Group India. Established in September 2008, Naval Group India’s mission has been to support the indigenisation of equipment for Scorpene® submarine, to develop the Indian defence eco-system, as well as to develop design services in India with talented Indian engineers.
Naval Group India endeavours to implement the vision of Atmanirbhar Bharat and evolve as centre of excellence for support and maintenance of P75 submarines by further empowering Indian industries and creating a robust eco-system that can cater to the varied defence needs of the country.
