UPGRADATION WORK OF TUNNEL VENTILATION SYSTEM AND ENVIRONMENT CONTROL SYSTEM OF BLUE LINE STATIONS BEGINS
Kolkata, Date: 04.02.2026
The upgradation work of Tunnel Ventilation System (TVS) and Environment Control System (ECS) of Blue Line stations has begun from today i.e. on 04.02.2026 in presence of Shri Subhransu S. Mishra, General Manager, other senior officers of Metro Railway, President and other members of MRWWO at a function held at Noapara Carshed. Once completed this work will add a new dimension in passenger comfort and safety in Blue Line of Metro Railway, Kolkata.
This work being executed at a cost of Rs.585 crores would be completed in 4 years. This is an updated energy efficient and improved system. This covers the cooling system of 15 underground stations of Blue Line. This will bring in changes from traditional water cool chiller to air cool chiller thereby saving of watter and ultimately environment.The familiar scene of cooling towers outside Metro stations is going to change. Once this is implemented, Metro Railway will be able to save 18 crore litters of ground water consumption annually. In the present system, this amount of ground water is required to run the water cool chillers for making Metro stations cool every year. Once air cool chillers replace the water cool chillers then this huge amount of water will be saved which in turn help to protect environment and ground water resources.
In addition, Tunnel Ventilation System is also being upgraded. In the 41-year old existing system, tunnels were cooled as the rakes were non-air-conditioned. But as Metro Railway, Kolkata is now using AC rakes discarding all non AC rakes, it provides the opportunity to shift to state-of-the-art TVS (Tunnel Ventilation System) to have state-of-the-art smoke extraction system as well. In existing system, forced ventilation using centrifugal fans of 110 kW at fourteen midpoints are being used. These fans rotate 24X7 hrs and consume total energy of 3 crores unit annually at a cost of Rs 21 Cr annually. By installing Variable Frequency Drive in midpoint in 2021-2022 this consumption was reduced to half. These fans can rotate in one direction to work as exhaust fans. All these fans shall now be replaced by axial fans which are suitable for two-hour operation even if the air temperature it handles reaches 250 °C. These fans will rotate automatically when fire / smoke in tunnel occur or ambient temperature of the tunnel crosses the set limit or concentration of CO2 or sub-soil temperature inside the tunnels crosses the set limit.
This work will be executed by an Indian subsidiary of a Japanese company. This holding company has already commissioned ECS and TVS systems in more than one hundred underground Metro stations in Singapore Metro.
This will ensure improved fire safety and save Rs.21 Cr annual electricity bill as well as reduce carbon footprint by 23,000 Metric Tonnes annually.
