Mazagon Dock Shipbuilders Limited

Mazagon Dock Shipbuilders is India's principal builder of submarines and large surface combatants. The yard on Mumbai's eastern waterfront traces back to a small dry dock opened in the eighteenth century, became a limited company in 1934, and was taken over by the government in 1960. Since then it has delivered more than eight hundred vessels of every description, of which around three dozen are warships and eight are submarines. A 2020 public offering listed the shares on the NSE and BSE while leaving the Government of India with roughly four fifths of the stock, so the company is state controlled and publicly traded at the same time.

Submarines are the hardest thing MDL does and the reason it matters strategically. Two Shishumar-class boats were built under German licence in the 1980s and 1990s. Project 75 then produced six Kalvari-class boats to a Scorpene design, closing with INS Vagsheer, and the follow-on Project 75(I) for six air-independent-propulsion boats in partnership with ThyssenKrupp Marine Systems would be the largest contract the yard has ever signed. Surface work covers the Delhi, Kolkata and Visakhapatnam classes of guided missile destroyers, the Godavari, Shivalik and Nilgiri classes of frigates, Khukri-class corvettes, Vibhuti-class missile boats, Vikram-class offshore patrol vessels for the Coast Guard, next generation offshore patrol vessels, fast patrol craft and floating border outposts.

Away from warships the company builds naval auxiliaries, littoral combat ships, tugs, barges, dredgers, ferries, cargo vessels and support craft, and it lists fuel-cell electric vessels and remotely operated underwater vehicles among newer products. Offshore engineering is a separate line running back decades, covering platforms, jackets and wellhead structures for the Indian oil and gas sector. Services carry real weight alongside new construction. MDL takes on repair and refit of warships and submarines, ship design, technology transfer as a know-how provider, training, tug support, supply chain management and heavy module movement on self-propelled modular transporters. In 2026 it acquired a controlling stake in Colombo Dockyard, its first significant move outside India and a step toward regional submarine and warship maintenance work. Capacity rather than order intake has been the binding constraint, which is why the yard has spent heavily on a new wet basin, a goliath crane, a module workshop and additional covered building space. Around six thousand people are on the payroll, supported by a large contract workforce and a supplier network that the Navy's indigenous content targets have pushed steadily toward Indian firms. The submarine line is the part that cannot be rebuilt quickly. Welding, pressure hull work and integration skills built on the Shishumar boats and carried through Kalvari sit with a workforce that took decades to assemble, and they decay when there is no boat on the slipway. That is the argument the yard makes every time a follow-on order looks like slipping.