Kolkata Metro crosses new frontiers beneath Hooghly
Kolkata: A Metro journey beneath the Hooghly River marks a major milestone in Kolkata’s urban transport transformation, expanding from India’s first 3.4-km stretch in 1984 to 73.42 km across five colour-coded lines. Begun in 1972, commercial services started on October 24, 1984, between Esplanade and Bhowanipore, now Netaji Bhavan, growing to 58 stations by 2025 across northern, southern, eastern, and central areas.
The Green Line under-river section features twin 520-metre tunnels constructed 13 metres below the river bed using Earth Pressure Balancing Tunnel Boring Machines through stiff clayey silt in a record 66 days. Commercial operations on the 4.8-km Howrah Maidan to Esplanade section, built at Rs 4,965 crore, began on March 15, 2024. Howrah station, located 30 metres underground, is among India’s deepest. Complete operations on the 16.55-km Green Line concluded with the Esplanade to Sealdah link in August 2025, slashing travel time from 40–45 minutes by road to 11 minutes by Metro and boosting daily ridership from 78,000 to 2.04 lakh passengers.
Metro expansion accelerated significantly, adding 45 km between 2014 and 2025 compared to 28 km between 1972 and 2014. Current operations include the Blue Line’s 28-km Kavi Subash to Noapara route and 4.14-km Dakshineswar extension, the Yellow Line’s 6.77-km airport link, the Purple Line’s 7.74-km Joka to Majerhat section, and the Orange Line’s 9.8-km New Garia to Belaghata stretch. Construction continues across four major corridors, including extensions to Barasat, Esplanade, Dum Dum Airport, and Barrackpore.
In July, TBM Durga achieved a breakthrough at Victoria station on the Purple Line, completing the Khidderpore drive started in July 2025. Traffic diversions at Chingrighata crossing will facilitate Orange Line viaduct work towards the airport. Metro Railway General Manager Prem Sagar Gupta confirmed Kolkata Metro carried 23.60 crore passengers during 2025-26, while digital ticketing expands Aamar Kolkata Metro application.