Mazagon Dock Shipbuilders Explained

Mazagon Dock Shipbuilders Limited (MDL) is a Government of India defence public sector shipyard in Mumbai that builds warships and submarines for the Indian Navy, including the Kalvari-class (Scorpene) submarines and the Kolkata-class, Visakhapatnam-class and Shivalik-class surface combatants. Its roots go back to the eighteenth century, and it has been under government ownership for more than six decades.

Mazagon Dock Shipbuilders has built a large share of India’s major surface warships and most of its modern submarines, making it one of the most important shipyards in the country’s naval self-reliance effort. This explainer covers the shipyard’s history, the vessels it has delivered, its ownership and facilities, and how it fits into India’s plans for future submarines and destroyers. Numbers are given in broad terms, and the content was last reviewed on 17 October 2026.

Key Takeaways

• Mazagon Dock Shipbuilders is a Mumbai-based defence public sector shipyard under the Ministry of Defence, with a heritage that is traced to 1774 and government ownership since 1960.
• Mazagon Dock Shipbuilders built India’s Kalvari-class submarines, the six Scorpene boats of Project 75 designed by France’s Naval Group and delivered between 2017 and 2025.
• Mazagon Dock Shipbuilders has built several classes of major surface warships, including the Delhi, Shivalik, Kolkata and Visakhapatnam classes, as well as ships of the Nilgiri class under Project 17A.
• Mazagon Dock Shipbuilders also built the Shishumar-class submarines, Shalki and Shankul, under a technology transfer arrangement with a German firm in the 1980s and 1990s.
• Mazagon Dock Shipbuilders is a lead contender for future submarine projects, including Project 75 India, which plans six air-independent-propulsion submarines built through a strategic partnership model.
• Mazagon Dock Shipbuilders was listed on the stock exchanges in 2020, while the Government of India continues to hold a large majority stake.

What is Mazagon Dock Shipbuilders?

Mazagon Dock Shipbuilders is one of India’s oldest and largest shipyards and the main builder of warships and submarines for the Indian Navy. It is a state-owned company located in the Mazagon area of Mumbai, on the city’s eastern waterfront facing Mumbai Harbour.

The shipyard is organised to build complex naval vessels that contain propulsion plants, weapons, sensors and electronics supplied by many different firms. Mazagon Dock Shipbuilders acts as the lead integrator: it constructs the hull, installs machinery and systems, conducts harbour and sea trials and delivers the finished ship to the Navy.

The company is commonly shortened to MDL, and it is often grouped with Garden Reach Shipbuilders and Engineers (GRSE) in Kolkata, Goa Shipyard Limited and Hindustan Shipyard Limited as defence shipyards, with Cochin Shipyard Limited being another major public sector builder of large ships.

What is the history of Mazagon Dock Shipbuilders?

The history of Mazagon Dock Shipbuilders is generally traced to 1774, when dock facilities were established at Mazagon during the East India Company’s period in Bombay, as the area was then called. A modern company named Mazagon Dock Limited was formed in 1934, with British shipping interests involved in its early decades.

After Independence the shipyard took on increasing importance for the Indian Navy and for merchant shipping. The Government of India took over the company in 1960, and it was placed under the Ministry of Defence. From then on the yard began undertaking naval construction in a larger way, starting with frigates built under licence from British designs.

INS Nilgiri, commissioned in 1972, was the first Leander-class frigate built in India and a landmark for local warship building. Later projects increased in complexity, culminating in guided-missile destroyers and submarines. The company later became Mazagon Dock Shipbuilders Limited and was publicly listed on the stock exchanges in October 2020.

Timeline of major milestones

Who owns and runs Mazagon Dock Shipbuilders?

Mazagon Dock Shipbuilders is owned mostly by the Government of India, which holds a large majority of the shares, and it is administered by the Department of Defence Production in the Ministry of Defence. A minority of the shares is held by public investors following the initial public offering in 2020.

The shipyard is led by a Chairman and Managing Director, along with functional directors responsible for shipbuilding, submarines and finance. Government nominee directors and independent directors sit on the board. The company has been described in government announcements as a Miniratna enterprise and later reported to have been upgraded to the higher Navratna category, which allows greater autonomy in investment and joint venture decisions, although the current category should be verified against official lists.

Because the Navy is its primary customer, shipbuilding contracts are typically awarded by the Ministry of Defence after the Defence Acquisition Council approves a project. The Indian Navy’s Directorate of Naval Design designs many of the surface ships, while submarines have been built on foreign designs under technology transfer.

What submarines has Mazagon Dock Shipbuilders built?

Mazagon Dock Shipbuilders has built two classes of conventional submarines for the Indian Navy: the Shishumar-class (German Type 209/1500 design) and the Kalvari-class (French Scorpene design). It is the only Indian yard that has built diesel-electric submarines at scale for the Navy.

Shishumar-class

The Shishumar-class consists of four submarines based on the German HDW Type 209/1500 design. Two were built in Germany and two at Mazagon Dock, INS Shalki (commissioned in 1992) and INS Shankul (commissioned in 1994), under a transfer-of-technology arrangement. These boats gave Indian engineers valuable experience in submarine construction and, though they have been in service for decades, they were important in building the Navy’s local submarine capability.

Kalvari-class

The Kalvari-class is the Indian version of the Scorpene-class submarine designed by France’s Naval Group (formerly DCNS). It is the subject of Project 75, under which Mazagon Dock Shipbuilders built six submarines through a technology transfer agreement signed in the mid-2000s. The six are named Kalvari, Khanderi, Karanj, Vela, Vagir and Vagsheer.

How were the Kalvari-class Scorpene submarines built at Mazagon Dock Shipbuilders?

The Kalvari-class Scorpene submarines were built at Mazagon Dock Shipbuilders under Project 75, using a design and technology transfer agreement with Naval Group of France. Hull sections, combat systems and other parts were produced or integrated in Mumbai with a mix of French and Indian-sourced equipment, and the first boat was commissioned in December 2017.

A contract for six boats was signed in 2005, and construction began some years later. The project experienced considerable delays, with the first submarine delivered several years later than originally planned. Later boats came faster as the yard gained experience, and the sixth, INS Vagsheer, was commissioned in January 2025.

The Scorpene is a diesel-electric attack submarine of roughly 1,500 to 1,700 tonnes, designed for anti-ship, anti-submarine, intelligence gathering and mine-laying roles. It carries torpedoes and anti-ship missiles launched from torpedo tubes, and it is known for relatively low acoustic signature. Indian-built boats include local content in several areas, though key systems remain imported.

Discussions about building additional Scorpene-type submarines have been reported over several years, but readers should check official statements for the current status of any follow-on order.

What surface warships has Mazagon Dock Shipbuilders built?

Mazagon Dock Shipbuilders has built a long series of frigates and destroyers for the Indian Navy, from licence-built frigates in the 1970s to modern stealth destroyers. The table below lists the main surface warship classes associated with the yard.

Destroyers such as the Kolkata and Visakhapatnam classes displace around 7,000 tonnes or more and carry long-range surface-to-air missiles, anti-ship missiles, anti-submarine weapons and helicopters. They are among the most capable warships to have been built in India.

What are the Visakhapatnam-class and Nilgiri-class ships?

The Visakhapatnam-class (Project 15B) and Nilgiri-class (Project 17A) are the Navy’s latest indigenous destroyer and frigate classes, with Mazagon Dock Shipbuilders building all of the former and four of the latter. Both classes emphasise stealth features, improved sensors and a high proportion of Indian-made equipment.

The Visakhapatnam-class includes four ships, named Visakhapatnam, Mormugao, Imphal and Surat, which were delivered between 2021 and 2025. They are follow-ons to the Kolkata-class and carry advanced radars and missiles, with much of the weapons and sensor equipment sourced domestically or through partnerships.

The Nilgiri-class under Project 17A is an upgrade of the Shivalik-class design with improved stealth and combat systems. Seven ships were ordered, split between Mazagon Dock Shipbuilders and Garden Reach Shipbuilders and Engineers. The lead ship, INS Nilgiri, was launched in 2019, and the class has begun entering service in the mid-2020s, subject to the progress of remaining hulls.

What are Mazagon Dock Shipbuilders’ facilities and non-naval business?

Mazagon Dock Shipbuilders operates a main shipyard at Mazagon in Mumbai together with additional facilities, including an assembly and outfitting yard at Nhava in the Mumbai metropolitan region. The yard includes dry docks, slipways, covered construction halls for submarines and heavy fabrication shops.

Beyond warships, the company has built commercial vessels and offshore structures. Its past work includes cargo ships, tankers, dredgers, tugs and platforms for the offshore oil and gas sector, particularly for fields off the western coast of India. The company also provides ship repair and refit services, including for naval vessels.

The firm has also looked at expanding abroad and into related businesses, with media reports in 2025 indicating plans to take a controlling stake in Colombo Dockyard in Sri Lanka; readers should consult company announcements for the current status.

What is Project 75 India and what is next for Mazagon Dock Shipbuilders?

Project 75 India (P-75I) is a planned programme to build six conventional submarines with air-independent propulsion (AIP) in India under the strategic partnership model, and Mazagon Dock Shipbuilders has been prominently associated with it, with Germany’s TKMS reported as its foreign partner. AIP technology allows a diesel-electric submarine to stay submerged for longer without surfacing.

The programme is estimated to cost tens of thousands of crore rupees, according to media and government statements, and it has gone through multiple stages of evaluation and negotiation, so the timeline and final configuration should be verified through official sources. Success would help India add more conventional submarines to its fleet and build further domestic capability.

Other prospects for the yard include additional destroyers or frigates, follow-on Scorpene-type boats and potential work on next-generation naval vessels. The Navy’s long-term plans also envisage more indigenous warships as part of its goal of building a larger fleet.

How does Mazagon Dock Shipbuilders contribute to naval self-reliance?

Mazagon Dock Shipbuilders contributes to naval self-reliance by constructing the Navy’s most complex ships and submarines in India, retaining design, engineering and construction skills domestically. Almost every major warship class the yard has built has increased the share of Indian-made equipment compared with its predecessor.

The effect is wide. A large warship project can involve hundreds of suppliers, including steel plants, electronics firms and engine makers, and many of these are Indian micro, small and medium enterprises. Companies such as Bharat Electronics Limited supply sensors and combat systems, while Bharat Dynamics Limited and other firms supply weapons, making the shipyard a central node in the defence manufacturing ecosystem.

Challenges persist, including cost and time overruns on some programmes, dependence on foreign suppliers for certain propulsion and weapons subsystems, and the need to modernise shipyard infrastructure. The Navy has a stated policy of preferring Indian-built ships, and indigenisation targets have been pursued through the Ministry of Defence’s procurement guidelines.

Bottom Line

Mazagon Dock Shipbuilders is the Mumbai defence shipyard at the heart of India’s naval construction, having built the Kalvari-class submarines and a series of frigates and destroyers, including the Visakhapatnam and Nilgiri classes. Its future depends on follow-on submarine and surface-ship programmes and on the continuing deepening of domestic content in India’s warships.

Frequently Asked Questions

What does Mazagon Dock Shipbuilders build?

Mazagon Dock Shipbuilders builds warships and submarines for the Indian Navy, including Scorpene-based Kalvari-class submarines and destroyers and frigates such as the Kolkata, Visakhapatnam, Shivalik and Nilgiri classes. It also builds some commercial vessels and offshore structures and provides ship repair and refit services.

Where is Mazagon Dock Shipbuilders located?

Mazagon Dock Shipbuilders is located in the Mazagon area of Mumbai, Maharashtra, on the city’s eastern harbour. It also has an assembly and outfitting yard at Nhava in the Mumbai region.

Is Mazagon Dock Shipbuilders a government company?

Yes, Mazagon Dock Shipbuilders is a government company, with the Government of India holding a large majority of its shares and the Ministry of Defence providing administrative control. The company was listed on the stock exchanges in 2020, so a minority of its shares is held by public investors.

Which submarines did Mazagon Dock build?

Mazagon Dock built two Shishumar-class submarines, INS Shalki and INS Shankul, and six Scorpene-based Kalvari-class submarines under Project 75. The Kalvari-class boats were commissioned between December 2017 and January 2025.

What is Project 75 India?

Project 75 India is a planned programme to build six air-independent-propulsion conventional submarines in India for the Indian Navy under the strategic partnership model. Mazagon Dock Shipbuilders has been associated with it, with a German partner reported for the design, and the project terms should be checked in official sources as they evolve.

How old is Mazagon Dock?

Mazagon Dock’s heritage is traced to 1774, which makes the shipyard more than 250 years old. The present company was formed in 1934 and has been owned by the Government of India since 1960.

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