Mazagon Dock Shipbuilders Limited (MDL) is India's premier warship-building yard, located on the Mazagaon waterfront in Mumbai, Maharashtra. A Navratna Defence Public Sector Undertaking under the Ministry of Defence, MDL is the country's principal builder of destroyers, frigates and conventional submarines for the Indian Navy, and traces its origins to a small dry dock established on the site in the eighteenth century. Majority-owned by the Government of India, the shipyard has delivered the bulk of the Navy's major surface combatants and submarines built domestically since Independence, and is now central to the country's next generation of submarine construction under Project-75(I).

Key facts

  • Full name: Mazagon Dock Shipbuilders Limited
  • Location: Mazagaon, Mumbai, Maharashtra
  • Founded: 1774 as a small dry dock; incorporated as a private limited company in 1934; taken over by the Government of India in 1960
  • Status: Navratna Defence PSU, Ministry of Defence, majority Government-owned
  • Core products: guided-missile destroyers, frigates, conventional submarines, offshore platforms and support vessels
  • Key programmes: Kolkata-class and Visakhapatnam-class destroyers, Nilgiri-class frigates, Kalvari-class (Scorpene) submarines, Project-75(I) submarines

History

A dry dock first operated at Mazagaon from 1774, and the enterprise passed through various British trading and shipping interests before being registered as a private limited company in 1934. The Government of India took over management in 1960, after which the yard grew rapidly into the country's foremost naval shipbuilder, delivering its first indigenously built warship, the frigate INS Nilgiri, in 1972. Since then MDL has built the great majority of the Navy's major surface combatants and all of its conventionally powered, technology-transferred submarines, alongside commercial vessels and offshore oil-and-gas platforms for the Bombay High fields.

Destroyers and frigates

MDL built the Delhi-class and, subsequently, the Kolkata-class (Project 15A) guided-missile destroyers, the first of which, INS Kolkata, was delivered in 2014, followed by two further ships of the class. It is now completing the larger, more heavily stealth-shaped Visakhapatnam-class (Project 15B) destroyers, the lead ship of which was launched in 2018 and commissioned in 2021, with further vessels following. On the frigate side, MDL is one of two yards, alongside GRSE, building the Nilgiri-class (Project 17A) stealth frigates, an improved successor to the earlier Shivalik class, with the lead ship launched in 2019.

Submarines

MDL is the Navy's principal submarine builder, having assembled the Shishumar-class (Type 209) submarines under licence from Germany from the 1980s, and more recently the Kalvari-class submarines under Project-75, based on the French Scorpene design and built in partnership with Naval Group under a technology-transfer arrangement. The first of six Kalvari-class boats, INS Kalvari, was commissioned in December 2017, with the remaining submarines delivered progressively in the following years. Building on this experience, MDL has been selected to construct the next generation of submarines under Project-75(I), a larger programme for advanced conventional submarines fitted with air-independent propulsion, being pursued in partnership with a foreign original equipment manufacturer.

Recent developments

Through the mid-2020s MDL has expanded its order book and modernised its infrastructure, including new dry docks and a wet basin allowing simultaneous construction of multiple large warships and submarines. In 2025 the company entered contract negotiations with Germany's ThyssenKrupp Marine Systems (TKMS) for the Project-75(I) submarine programme, valued at tens of thousands of crores of rupees, following government clearance for the project. Alongside its warship and submarine work, MDL continues to build support vessels and offshore platforms, and its rising order book, profitability and Navratna status have made it one of the most closely watched companies in India's defence-industrial base.