India’s submarine construction capabilities are undergoing a significant transformation, marked by a landmark memorandum of understanding (MoU) between Mazagon Dock Shipbuilders Limited (MDL) and Hindustan Shipyard Limited (HSL), the country’s two premier defence shipyards. This partnership is designed to accelerate India’s self-reliance in submarine construction and bolster its strategic maritime posture amid rising tensions in the Indo-Pacific region.

Under the agreement, MDL, based in Mumbai, and HSL, headquartered in Visakhapatnam, will jointly undertake submarine projects, leveraging their respective strengths and geographical locations to cover both the eastern and western coasts.

Historically, India’s submarine production has been constrained by reliance on a single shipyard—MDL, which has spearheaded the construction of both German-designed SSK-class and French-designed Scorpene-class submarines. This limited capacity has hindered the pace and scalability of India’s submarine program, making it difficult to meet the Indian Navy’s long-standing requirement of approximately 24 submarines.

The strategic integration of HSL into India’s submarine construction ecosystem addresses this critical limitation. HSL, initially established for naval ship repairs, has steadily evolved its expertise through decades of experience in submarine refits and upgrades

The shipyard’s journey began in the early 1970s with the repair of Egyptian submarines, followed by the refit of India’s ageing Foxtrot-class submarines in the late 1990s. A major turning point came with HSL’s work on Russian-origin EKM-class submarines, which provided invaluable experience in handling complex modern submarine technologies. HSL’s reputation was further solidified in 2015 with the successful completion of the only domestically executed mid-life upgrade for INS Sindhukirti, and again in 2020 with the ahead-of-schedule refit of INS Sindhuvir.

HSL’s infrastructure is a key enabler of its new role. The shipyard boasts specialised facilities, including advanced electrical and weapons system workshops, sophisticated pipe-fitting stations, chemical cleaning bays, and a deep-water waterfront capable of accommodating complex submarine operations. These assets, combined with a skilled workforce and robust local supply chains, position HSL as an ideal partner for large-scale submarine construction programs such as Project-75(I) and the future Project-76.

The dual-yard approach, championed by the MDL–HSL partnership, mirrors international best practices adopted by leading maritime powers such as the United States and Russia. By dividing responsibilities between MDL’s submarine assembly expertise and HSL’s outfitting capabilities, the partnership promises significant efficiency gains, reduced production timelines, and optimal utilisation of national resources. This model not only accelerates submarine delivery but also enhances India’s ability to sustain operational readiness and strategic flexibility in the face of evolving regional threats.

Government policy has played a pivotal role in this transformation. The Cabinet Committee on Security (CCS) envisioned the development of an alternate submarine construction facility on the East Coast as far back as 1999. This vision was reaffirmed in 2010 when the Defence Acquisition Council (DAC) officially approved HSL as the alternate yard for conventional submarine construction. The administrative transfer of HSL to the Ministry of Defence in 2010 further underscored its strategic importance.

Recent military operations, such as Operation Sindoor, have highlighted the critical need for an expanded and modern submarine fleet. While the operation primarily involved air and missile capabilities, it underscored the importance of maritime surveillance and deterrence, particularly in the Arabian Sea and Bay of Bengal, where naval assets from countries friendly to Pakistan are present. A robust submarine fleet is indispensable for fulfilling the Indian Navy’s Blue Water ambitions and safeguarding national interests across the Indian Ocean region.

The MDL–HSL partnership not only addresses India’s immediate submarine construction needs but also positions the country for future growth in the global submarine servicing market. HSL is actively pursuing discussions with international navies, such as the Vietnam People’s Navy, for submarine refits and lifecycle maintenance. Capturing such contracts could mark a significant step toward exporting India’s defence expertise and equipment.

The collaboration between MDL and HSL marks a new era in India’s submarine construction capabilities. By leveraging the strengths of both shipyards and aligning with long-standing government policy, India is poised to overcome historical capacity limitations, accelerate production, and achieve its strategic maritime goals. The dual-yard model ensures sustained naval readiness, operational flexibility, and a strong foundation for future expansion in both domestic and international submarine markets.

IDN