Kolkata: The country’s oldest Metro is now set for a complete overhaul of its electricity supply system.Metro Railway, which operates the city’s rapid transit system, is often hit by power snags along the New Garia–Dakshineswar corridor that runs along the city’s north–south axis. To address issues with the third rail, which supplies electricity for train movement, it has floated a Rs 345.7 crore tender for a comprehensive modernisation of its third rail and 33 KV electric substations.The comprehensive modernisation project will be a milestone for Kolkata Metro. It will involve replacement of the ageing electrical infrastructure with modern 33 KV systems, which will enhance power supply reliability, operational efficiency, and safety across the network.“One can expect fewer power snags and other issues plaguing the old electrical system, for which services and operations are disrupted every now and then,” explained an official.A third-rail metro system powers underground trains via a continuous, electrified conductor rail located alongside or between the running rails. Using collector shoes, trains typically receive 750 V DC to operate, making it a common, cost-effective, and low-profile choice for underground or elevated urban transit. The mechanism involves the metal “shoes” on the train bogies contacting the third rail, which is energised with direct current (DC).Earlier this month, Metro general manager Subhransu Sekhar Mishra flagged off a Rs 585 crore project to modernise the air-conditioning and tunnel ventilation system across the Blue Line’s 15 underground stations, spanning 16 km from Belgachhia to Rabindra Sarobar. Now, Metro’s electricity infrastructure upgrade will allow the carrier to replace equipment at the 750 V DC traction substations, including the third rail and power cables, along with the upgrade of 11 KV auxiliary substations to 33 KV auxiliary substations. The tender, issued last Friday, follows an open bidding system under a two-packet system. The work must be completed in three years from the date of commencement. Bids must be submitted between March 6 and 20, with a validity of 90 days from the bid closing date. The pre-tender meeting is this Friday.
