In a significant development, Larsen & Toubro (L&T) and the Defence Research and Development Organisation (DRDO) have forged a strategic contract to re-fit two Air Independent Propulsion (AIP) System modules for the esteemed Kalvari class of submarines in the Indian Navy.
At the heart of this collaboration lie the cutting-edge fuel cell-based AIP System modules, meticulously developed by the Naval Materials Research Laboratory (NMRL) of the DRDO, with L&T serving as the prime industry partner. The deal was officially inked, signifying a momentous occasion for the nation’s defence, as these modules play a critical role in enhancing the endurance of conventional submarines.
One of the hallmarks of this indigenous AIP system is its energy modules (EMs), equipped with fuel cells capable of generating the necessary power, along with onboard hydrogen generation. What sets this technology apart is its unique ability to produce hydrogen on demand, thus eliminating the need to carry hydrogen on board, a significant safety concern for submarines.
The contract exchange ceremony was attended by eminent personalities, including Arun T Ramchandani, Executive Vice President and Head-L&T Defence, and PT Rojatkar, Director of the Naval Materials Research Laboratory (NMRL) of the DRDO. The presence of JD Patil, Member of the Executive Committee of Management and Advisor (Defence & Smart Technologies) to CEO and MD of Larsen & Toubro Ltd, along with senior officials from NMRL, added to the significance of the event.
Notably, this groundbreaking collaboration between DRDO and L&T has elevated India to a prestigious league of countries that possess their own AIP system modules. Joining the ranks of Germany and South Korea, India now stands as a nation that has successfully developed this vital technology. Arun Ramchandani expressed his pride in being the longest-serving development partner to DRDO across multiple domains, emphasizing L&T’s privileged association with the realization of an indigenous AIP system, a dream nurtured over 12 years of dedicated R&D by the DRDO. In 2021, the technology was successfully transferred to L&T, marking a new chapter in India’s defence capabilities.
Delving into the specifics of the agreement, JD Patil shed light on the project’s timeline, aiming to deliver two AIPs in less than two years. One of these AIPs will be refitted on a Kalvari class submarine built by Mazagon Dock Shipbuilders Limited (MDL) for the Navy, while the other will be navalised for future R&D purposes by the DRDO, following successful ground testing of the existing module. So far, MDL has delivered five Kalvari class diesel-electric submarines—INS Kalvari, INS Khanderi, INS Karanj, INS Vela, and INS Vagsheer—with the sixth one, under Project 75, currently in progress.
The first refit cycle of a submarine currently in service with the Navy is expected to conclude by early 2026, allowing ample time for the integration of the EMs into the AIP Plug on the maritime platform.
Aiming to set new benchmarks, the manufacturing, integration, and factory acceptance trials of the EMs will take place at L&T’s AM Naik Heavy Engineering Complex in Surat. Moreover, the success of this project is anticipated to pave the way for orders of AIP Systems for the remaining five Kalvari Class submarines in the near future. The potential export opportunities to other nations that operate Scorpene class submarines add an international dimension to this remarkable endeavour.