Kolkata Metro completes tunneling of East-West Corridor

Kolkata, India (Urban Transport News): Ministry of Railways on May 16, 2021, informed that the tunneling work for the 16.6 km- long East-West Metro corridor, which hit several hurdles over the last two years, has finally been completed.

The tunneling work gets completed by Tunnel Boring Machine (TBM) in East-West Metro Corridor with the breakthrough of “Urvi“ at Bowbazar, Kolkata on May 15, 2021. With this breakthrough, the entire TBM tunneling for the Kolkata East-West Metro Project is completed. The stretch was difficult for tunneling work as it had century-old buildings. This challenging tunnel drive of 800m has been completed successfully amidst this pandemic situation following COVID-19 protocol.

The Tunnel Boring Machine ‘Urvi’ which had earlier completed the East Bound tunnel from Esplanade to Sealdah on October 9, 020 was relaunched from Sealdah after necessary refurbishment and inspection on January 9, 2021, to complete the balance 800 m tunneling work in the West Bound tunnel from Sealdah to Bowbazar. This drive of tunneling has been completed and the tunnel boring machine breakthrough at Retrieval Shaft at Bowbazar has been achieved on May 15, 2021.

This TBM (Urvi) has passed below Sealdah Flyover also for which vehicular movement on the Flyover was closed for 3 days for safety reasons. After completion of this TBM drive, the tunnel boring machine ‘Urvi’ along with the other stalled TBM ‘Chandi’ will be retrieved from this retrieval shaft at Bowbazar.

Excavation of shaft after ensuring the water-tightness of the shaft and the affected tunnel and retrieval of the TBMs are intricate activities that have to be done safely and hence will take time.

After completion of the entire excavation, both the TBMs will be retrieved in pieces from the shaft. The RCC flooring and roofing for the shaft area will be completed thereafter and the shaft top will be backfilled to prepare the ground for overground construction.

The Kolkata East-West Metro project has crossed several milestones along its journey. The most significant was on May 23, 2017, when TBM Rachna completed the tunnelling under the Hooghly in 36 days. Sibling TBM Prerna followed and finished the other river tunnel on June 21, 2017.

For more details, please explore the Kolkata Metro page of Urban Transport News.