The Centre has sanctioned ₹895.3 crore for metro and rail infrastructure upgrades in Kolkata, with ₹671.7 crore directed at a comprehensive overhaul of the Blue Line and ₹223.5 crore earmarked to rebuild the railway bridge over the Damodar river under South Eastern Railway.
The Blue Line upgrade targets a reduction in service headway from the current five-minute intervals to 2.5 minutes, serving the approximately six lakh daily commuters on the 41-year-old corridor. The overhaul encompasses seven new traction substations worth ₹291 crore, a power system upgrade from 11 kV to 33 kV across key stretches, replacement of the existing steel third rail with aluminium for improved conductivity and reduced voltage drop, and a signalling upgrade from the current Train Protection and Warning System to the more advanced Communication-Based Train Control system. Maximum train speed, currently capped at 55 kmph across most of the corridor, is also set to increase.
The Blue Line has been operating at reduced capacity since July 2025, following the closure of its southern terminal, Kavi Subhas station, after platform cracks were detected. Reconstruction of the terminal is set to begin shortly.
