Kolkata Rail Metro Network: Big progress for East West Kolkata Metro Corridor Project! The tunneling work was recently completed in the East West Metro Corridor by Tunnel Boring Machine (TBM) with the breakthrough of “Urvi“ at Bowbazar, Kolkata. With this achievement, now the entire TBM tunneling work for the Kolkata Metro’s East – West Corridor Project is completed. According to the Railway Ministry, the metro stretch was difficult for tunneling work as it had century old buildings. However, the challenging tunnel drive of 800 metres was successfully completed amidst the ongoing pandemic situation following the COVID-19 protocols, the ministry said.
The TBM called ‘Urvi’ which had earlier completed the east bound tunnel from Esplanade to Sealdah in Kolkata on 9 October 2020 was relaunched from Sealdah after necessary refurbishment as well as inspection on 9 January 2021 in order to complete the balance 800 metres tunneling work in west bound tunnel from Sealdah to Bowbazar.
According to the ministry, this TBM has passed below the Sealdah flyover for which movement of vehicles was closed on the flyover for three days for safety reasons. Following the completion of this TBM drive, ‘Urvi’ along with the other stalled Tunnel Boring Machine ‘Chandi’ will be retrieved from this retrieval shaft at Kolkata’s Bowbazar area.
The Railway Ministry further stated that shaft excavation after ensuring the water tightness of the shaft and the affected tunnel, as well as retrieval of the Tunnel Boring Machines, are intricate activities that have to be safely done. Hence, the work will take time. Once the entire excavation is completed, both the Tunnel Boring Machines will be retrieved in pieces from the shaft. Thereafter, the RCC flooring, as well as roofing for the shaft area, will be completed and the shaft top will be backfilled in order to prepare the ground for overground construction, the ministry added.