Kolkata Metro Railway Opt for TBMs Over Cut-and-Cover Method
New Plan for Purple Line’s Esplanade-Eden Gardens Extension
Kolkata Metro Railway has altered its plan for the Purple Line’s 1.6-km extension between Esplanade and Eden Gardens. Instead of the cut-and-cover method, they will now use tunnel boring machines (TBMs) for construction.
Launching and Retrieval Shafts
- The TBM launching shaft will be located at the L20 bus stand.
- The retrieval shaft will be situated in the Maidan, opposite Eden Gardens.
Second Crossover and Underground Stations
A second crossover will be built using the cut-and-cover method at the Strand Road end, opposite Eden Gardens. This will allow rakes to switch tracks. The five underground stations – Kidderpore, Victoria, Park Street, Esplanade, and Eden Gardens – will also be constructed using this method.
TBM Path and Rail Vikas Nigam Ltd (RVNL)
The TBMs will start from the L20 bus stand, dig through Rani Rashmoni Road, pass by the underground East-West Metro station, go under Raj Bhavan, and finally cross over to the proposed Eden Gardens Metro station. Rail Vikas Nigam Ltd (RVNL) is responsible for implementing the Purple line and has acquired two TBMs, mostly made in India.
TBM Operations and Land Dispute
The TBMs will first dig 1.7 km from St Thomas’ to Victoria, and then cover 950 m from Victoria to Park Street. Despite the ongoing land dispute for the construction of the Purple line’s Kidderpore Metro station, the authorities will continue with the underground tunnelling from Kidderpore to Park Street.
