India is considering the acquisition of three additional conventional submarines to bolster the Indian Navy’s underwater capabilities and address potential force-level gaps until the indigenous Project-76 submarine programme becomes operational. However, authorities have yet to determine whether these vessels will be based on the upcoming Project-751 design or an enhanced version of the existing Kalvari-class submarines.
One of the leading options is a submarine derived from the Project-751 programme, for which the long-awaited contract is expected to be awarded to the partnership between Germany’s TKMS and Mazagon Dock Shipbuilders Limited (MDL). Their proposed U-214NG design represents an advanced evolution of the Type-214 submarine family and is expected to feature modern air-independent propulsion (AIP), improved stealth characteristics, and greater underwater endurance for extended missions.
An alternative approach would involve constructing the additional boats using an upgraded Kalvari-class design. This option would leverage the industrial infrastructure, skilled workforce, and supply chain network already established through the successful execution of Project-75. Based on the French Scorpene design, the Kalvari-class has been built domestically by MDL, resulting in substantial localisation and valuable manufacturing expertise.
Opting for an Advanced Kalvari variant could allow India to take advantage of an existing production ecosystem, reducing development risks, shortening build schedules, and potentially lowering programme costs. The design could also integrate lessons learned from the six submarines already delivered, along with improvements in sensors, combat management systems, battery technologies, and indigenous subsystems.
Conversely, selecting the U-214NG-based Project-751 route would provide the Navy with a more advanced platform incorporating next-generation technologies and capabilities. It would also align with planned technology transfer provisions and create greater operational commonality with the future Project-751 fleet. However, this option would require the establishment of a new production, training, and support framework.
No final decision has yet been announced regarding the preferred design. The Indian Navy and the Ministry of Defence are expected to assess factors including acquisition costs, delivery timelines, indigenous content levels, operational effectiveness, and long-term sustainment requirements before making a selection.
