KOLKATA: The proposed 1.6 km underground extension of Kolkata Metro’s Purple Line from Esplanade to Eden Gardens has received the green signal from Raj Bhavan, enabling Rail Vikas Nigam Ltd (RVNL) to complete the necessary topographical survey. The new stretch will pass along the edge of the Governor House lawns before crossing to the opposite flank, where the line’s fifth underground station is being planned.
It is uncommon for Metro agencies to require the governor’s clearance for a survey, but in this case, a portion of the route runs close to the Raj Bhavan estate, necessitating formal approval.
The survey marks a significant step forward in the alignment finalization process for this key segment of the Purple Line, which is being extended northward by 1.6 km from Esplanade and southward by 1.2 km towards IIM-Calcutta.
“Such surveys help assess terrain, underground utilities, soil conditions, and other vital factors to determine alignment, construction techniques, and project cost,” a senior RVNL engineer explained.
The planned tunnel will see Tunnel Boring Machines (TBMs) curve past the East-West Metro’s Esplanade station, follow along approximately 250 meters of Raj Bhavan’s garden edge, and then veer across the road to the proposed Eden Gardens station, likely located opposite Gate No. 1.
A Railways official said the final alignment will aim for the shortest and most efficient path based on the survey data.
To execute the construction, RVNL plans to redeploy the TBMs ‘Durga’ and ‘Divya’, currently being used for the 1.7 km stretch between Kidderpore and Victoria Memorial. The machines will soon begin their second drive of 950 meters between Victoria Memorial and Park Street. The next section, 640 meters from Park Street to Esplanade, will be constructed using the cut-and-cover method, as it faces minimal encroachment.
The final leg, from Esplanade to Eden Gardens (1.6 km), will require the third TBM launch. This segment is also free from major overhead structures, making tunneling relatively straightforward.
The Times of India first reported on January 12 that the Metro Railway was planning this extension to Eden Gardens. The addition aims to serve commuters from BBD Bag, Strand Road, Babughat, and the Calcutta High Court area, while providing seamless access for sports fans heading to Eden Gardens stadium. The new station will also enhance connectivity by allowing easy interchange with the North-South (Blue) Line at Esplanade.
Originally, officials considered linking Eden Gardens to Esplanade via a long pedestrian subway, but the revised plan prioritizes direct Metro access through this underground extension.
