Kolkata: Kolkata Metro’s oldest tunnel, which runs between Tollygunge and Dum Dum on the north-south corridor (Blue Line), will undergo a major revamp, four decades after it first became operational.
Metro Railway officials have confirmed that the 16.45-km underground stretch will receive a full-scale upgrade, including civil infrastructure and track improvements. A detailed study is currently being conducted by the consultancy agency RITES, which is expected to submit its report soon. “The tunnel is over 40 years old and needs repairs. RITES is preparing a report on how the overhaul should be carried out. Once we receive it, a Detailed Project Report (DPR) will be prepared and sent to the Railway Board for approval,” said Uday Kumar Reddy, general manager of Metro Railway. Authorities estimate that once the project begins, the revamp could take around three to four years to complete. Due to the scale of the work, train services may be suspended on parts of the stretch during certain phases.
A separate study by another agency is also underway to explore the addition of modern passenger amenities at older stations, including escalators and lifts. Meanwhile, a major signalling system upgrade is also planned for the north-south corridor. Officials said the signalling upgrade would be carried out alongside the overhaul. This will allow trains to run more frequently than the current six-minute intervals during peak hours, helping to reduce crowding, especially at key interchange stations like Esplanade.
Passenger numbers at Esplanade are expected to rise sharply once the long-awaited Sealdah-Esplanade stretch of the East-West (Green) corridor becomes operational. Metro officials believe that increased train frequency on the Blue Line will help manage the additional rush more efficiently.
Kolkata Metro, India’s first mass rapid transit system, marked 40 years of service in 2024. The network’s foundation stone was laid in December 1972, and its first commercial run between Esplanade and Bhowanipore (now Netaji Bhavan) took place on October 24, 1984.
The Tollygunge–Dum Dum stretch became fully operational on September 27, 1995.