Mazagon Dock Shipbuilders Ltd (MDL), a public sector shipyard, has signed a formal agreement with French defence firm Naval Group to integrate an indigenous energy system into the Indian Navy’s Kalvari-class submarines. The agreement involves the transfer of technology for installing energy modules developed by India’s Defence Research and Development Organisation (DRDO).
These modules will be added to the submarines through a process known as jumboisation—which includes cutting the submarine’s hull, inserting the new energy system, and reassembling the structure with precision to maintain full operational readiness. Naval Group, which originally designed the Scorpene-class submarines on which the Kalvari class is based, will provide technical support, proprietary components, and hands-on training to Mazagon Dock engineers to ensure the system is properly integrated.
“This partnership with Naval Group strengthens our ongoing collaboration. Together, we aim to successfully install the DRDO-developed propulsion system into the P75 submarines,” said SB Jamgaonkar, Director of Submarines at MDL.
The move is part of a larger effort by the Ministry of Defence to modernize and enhance the performance of the Navy’s submarine fleet. In December 2024, the ministry signed two major contracts totaling ₹2,867 crore. The first, worth ₹1,990 crore, was awarded to Mazagon Dock for building and installing the air-independent propulsion (AIP) plug.
The second, worth ₹877 crore, was signed with Naval Group for the integration of an advanced heavy-weight torpedo system, co-developed with DRDO. These upgrades are expected to extend the underwater endurance of the submarines and significantly improve their combat capabilities.
Mazagon Dock Shipbuilders Ltd (MDL) is a leading state-owned shipyard in India, known for constructing warships and submarines for the Indian Navy and other clients. Located in Mumbai, MDL has played a pivotal role in strengthening India’s maritime defense capabilities.
The company specializes in building a wide range of vessels, including destroyers, frigates, and submarines, and is also involved in commercial shipbuilding and offshore platforms. With a strong legacy dating back to 1774, Mazagon Dock has earned a reputation for its technical expertise, innovation, and commitment to quality, making it a critical asset in India’s shipbuilding industry.
