Forging Supplier for India Shipbuilding: Mazagon Dock, GRSE, and Cochin Shipyard

August 12, 2026


India’s naval and commercial shipbuilding sector — Mazagon Dock Shipbuilders (MDL, Mumbai), Garden Reach Shipbuilders and Engineers (GRSE, Kolkata), Cochin Shipyard Limited (CSL), and Hindustan Shipyard Limited (HSL, Visakhapatnam) is experiencing unprecedented growth driven by the Indian Navy’s 200+ warship construction programme and the government’s Sagarmala initiative. Propulsion shaft forgings, rudder stock forgings, and structural hull fitting forgings for Indian Navy destroyers, frigates, submarines, and commercial vessels require ABS, Bureau Veritas, or Lloyd’s Register marine classification survey credentials that Vinir holds as an ABS-approved manufacturer.

ShipyardProgrammeKey ForgingClassification
Mazagon Dock (Mumbai)INS Visakhapatnam class (P15B destroyer), Kalvari class submarinePropulsion shaft, pressure hull fittingsIRS / BV Naval
GRSE (Kolkata)INS Nilgiri class (P17A stealth frigate), LCU Mark IVPropulsion shaft, structural fittingsIRS / Lloyd’s Register
Cochin Shipyard (Kochi)INS Vikrant (aircraft carrier), commercial vesselsPropulsion shaft, rudder stock, hull fittingsIRS, Lloyd’s Register, ABS
HSL (Visakhapatnam)Fleet support vessels, Indian Coast GuardPropulsion shaft, structural fittingsIRS, ABS
L&T Shipbuilding (Hazira)Commercial vessels, Coast GuardPropulsion shaft, structural fittingsABS / Lloyd’s Register

Mazagon Dock Shipbuilders Limited (MDL) — India’s premier warship builder is constructing the P15B Visakhapatnam-class destroyers (four ships, 7,400 tonnes displacement) and the Kalvari-class Scorpene submarines (six submarines, under technology transfer from Naval Group France). Each P15B destroyer uses two propulsion shaft systems with alloy steel propulsion shaft forgings of 2,000–5,000 kg each. Each Kalvari submarine requires a single propulsion shaft forging and pressure hull fitting forgings in high-strength steel equivalent to HY-80. MDL procures these forgings through IRS (India’s national classification society) and Bureau Veritas Naval.

GRSE — constructing the P17A Nilgiri-class stealth frigates (seven ships, 6,670 tonnes) uses a CODAD propulsion system with alloy steel shaft forgings of 1,500–3,000 kg each. GRSE has historically sourced propulsion shaft forgings from European and Korean sources India’s Atmanirbhar Bharat naval programme explicitly targets domestic sourcing of these structural and propulsion forgings as part of the 70%+ domestic content requirement for naval construction.

Cochin Shipyard Limited — which built INS Vikrant (India’s first domestically built aircraft carrier, 45,000 tonnes, delivered 2022) is India’s largest shipyard by dry-dock capacity. INS Vikrant’s propulsion uses four LM2500 gas turbines and four shaft propulsion systems each shaft requiring large-diameter alloy steel propulsion shaft forgings (3,000–8,000 kg per shaft) with IRS classification survey. CSL is now building the next IAC-2 at 65,000 tonnes an even larger programme with higher forging content.

The Indian Register of Shipping (IRS) — headquartered in Mumbai is India’s national classification society and an IACS associate member. IRS classification survey for Indian naval and commercial vessels is equivalent in technical rigor to ABS, DNV, and Lloyd’s Register classification. Vinir’s ABS marine approval covers the same technical requirements as IRS survey and can be applied to IRS-classed vessel supply.

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Vinir Capability

  1. ABS approved manufacturer recognised by IRS, Bureau Veritas, and Lloyd’s Register as equivalent IACS classification society approval.
  2. Open die alloy steel propulsion shaft forgings to 15,000 kg on 3,000T hydraulic press.
  3. HY-80 equivalent high-strength alloy steel for pressure hull structural fittings.
  4.  ABS Grade 3 and Grade 4 alloy steel per ABS Rules for Survey at Sea.
  5.  IRS survey coordination through IRS-recognised surveyors.
  6. 100% UT before and after heat treatment per ASTM A388.
  7. Wet fluorescent MT in two perpendicular directions.
  8. Atmanirbhar Bharat domestic defence content documentation.
  9. Close proximity to Cochin (6 hours road from Hosur).

Frequently Asked Questions

1. What is IRS (Indian Register of Shipping) and how does it relate to international classification societies for Indian naval vessel construction?+–
IRS (Indian Register of Shipping) is India’s national classification society, founded in 1975 and headquartered in Mumbai. IRS is an IACS associate member its technical rules meet IACS unified requirements. IRS classifies both Indian-flagged commercial vessels and Indian Navy vessels built at Indian shipyards. For Indian Naval warships, IRS classification provides the technical assurance equivalent to Lloyd’s Register Naval or Bureau Veritas Naval for foreign-built vessels. For Indian forging manufacturers, IRS survey approval obtained through IRS-recognised surveyors is the primary classification requirement for Indian naval shipbuilding supply.
2.What is the INS Vikrant aircraft carrier programme and what propulsion forging content does it contain?+–
INS Vikrant (IAC-1) is India’s first domestically designed and built aircraft carrier delivered by Cochin Shipyard in 2022 after 13 years of construction. At 45,000 tonnes full displacement, Vikrant is propelled by four GE LM2500 gas turbines driving four shaft systems. Each of the four propulsion shafts requires a large-diameter forging (approximately 3,000–6,000 kg per shaft, 600–800mm diameter) in alloy steel with ABS or IRS classification. India’s next aircraft carrier (IAC-2, planned at 65,000 tonnes) will have even larger propulsion shaft forging requirements creating the most significant single-site domestic forging opportunity in Indian naval history.
3. What Atmanirbhar Bharat requirements apply to Indian naval shipbuilding and how do they affect forging procurement?+–
The Ministry of Defence’s Atmanirbhar Bharat defence procurement policy requires minimum domestic content percentages for defence acquisition categories. For the P17A stealth frigates (Buy Indian IDDM), GRSE is required to source at least 50% of the total vessel value from Indian manufacturers. Propulsion shaft forgings, structural hull fittings, and non-classified pressure hull structural components are all categories where Indian private sector manufacturers can supply contributing to the domestic content percentage. The naval Atmanirbhar Bharat programme creates a government-mandated market for domestic forging supply.
4.What is the Kalvari-class submarine programme and what pressure hull forging requirements does it have?+–
The Kalvari-class submarines (P75 programme) are Scorpene-class diesel-electric submarines built by Mazagon Dock under technology transfer from Naval Group France. Six submarines have been ordered; all are now commissioned or in advanced fitting-out. Pressure hull structural fittings (through-hull penetrations for periscope masts, torpedo tubes, and sensor housings) are forged in high-strength steel equivalent to HY-80 (yield strength minimum 551 MPa). The subsequent P75I programme (six additional submarines) explicitly targets domestic Indian sourcing of these structural forgings.
5.What commercial shipbuilding opportunity exists in India beyond naval vessels?+–
India’s commercial shipbuilding industry at Cochin Shipyard, ABG Shipyard, Chowgule Shipyard, and L&T Shipbuilding (Hazira) builds dredgers, coastal tankers, container feeder vessels, and offshore support vessels. Each commercial vessel requires propulsion shaft forgings (500–3,000 kg) with commercial classification survey (ABS, Lloyd’s Register, or Bureau Veritas). The government’s target of making India a top 5 global shipbuilder by 2047 implies significant capacity expansion that will generate increasing commercial vessel forging demand for domestic manufacturers.