₹1,201 cr allocated for Kolkata Metro's blue line ventilation, air-conditioning upgrades

The Centre has allocated ₹585 crore for the modernization of the tunnel ventilation system and environmental control upgrades on Kolkata Metro’s Blue Line, Railway Minister Ashwini Vaishnaw informed Parliament. The total outlay for the comprehensive modernization project stands at ₹1,201 crore, he said in response to a written question.

Vaishnaw stated that work is currently underway to upgrade the Environmental Control System (ECS), including air-conditioning and tunnel ventilation, on the North-South corridor — Kolkata Metro’s oldest line. The modernization aims to enhance passenger comfort, safety and environmental protection across the underground stretch.

Out of the ₹1,201 crore total project cost, ₹585 crore has been specifically allocated for the advanced tunnel ventilation system and ECS upgrades. The remaining funds will be used for strengthening power supply systems and other related components. The minister said the upgraded ventilation system will incorporate an advanced smoke control mechanism, and the entire project is expected to take at least four years to complete.

At present, underground stations use water-cooled chillers that require significant groundwater. Under the new plan, these will be replaced with air-cooled chillers, eliminating the need for large volumes of water. Metro authorities estimate that the transition could save nearly 180 million litres of water annually, helping conserve groundwater and protect the environment.

The Blue Line runs underground from Mahanayak Uttam Kumar station to Belgachia, covering 15 underground stations before emerging above ground near Dum Dum. Officials noted that the original ventilation and environmental control systems were designed over four decades ago, when trains were non-AC and passenger numbers were far lower, necessitating a comprehensive upgrade now.