Marine and defence work, Kolkata

Kolkata's shipbuilding is Garden Reach Shipbuilders and Engineers, a Navratna defence public sector undertaking that traces its work on the Hooghly back to 1884 and was nationalised on 22 April 1960. It was the first shipyard in independent India to build a warship, delivering the seaward defence boat INS Ajay in 1961, and has since delivered guided missile frigates, corvettes, fleet tankers, fast patrol vessels and landing craft to the Navy and Coast Guard, alongside ship repair work of its own from its Rajabagan and Taratala units. GRSE states its indigenous content on recent platforms at over 90 per cent, and has pursued naval export orders alongside its Navy and Coast Guard programme.

Syama Prasad Mookerjee Port, renamed from Kolkata Port Trust in January 2020, is India's oldest major port and its only riverine one, sitting roughly two hundred kilometres up the Hooghly from the sea. The Kolkata Dock System splits into two basins, Kidderpore Dock with eighteen berths and Netaji Subhas Dock with ten, plus six petroleum moorings at Budge Budge further downriver, and workshops at the docks cover diesel engine overhaul and structural repair alongside cargo handling. The Haldia Dock Complex, 104 kilometres further down the Hooghly by river, adds fourteen more berths and three oil jetties for the tonnage the river above it cannot take.