On the 15/05/2021 the Joint Venture ITD-ITD Cementation India Ltd celebrated the TBM Urvi breakthrough at a retrieval shaft in Bowbazar (click here for the video), completing the entire TBM tunnelling for the 16.6 km Kolkata East West Metro Corridor project -  between Howrah Maidan on the West bank of River Hooghly with Salt Lake Sector-V on the East bank. The elevated section was inaugurated on February 2020.  

The TBM Urvi - which had earlier completed East Bound tunnel from Esplanade to Sealdah on the 09/10/2020 - was relaunched on 09/01/2021 from Sealdah after refurbishment and inspection to complete the 800 m tunnelling work in the West Bound tunnel from Sealdah to Bowbazar. This last 800 m stretch was exceedingly difficult for tunnelling work as it had century old buildings.   

The two TBMs EPB S615 and S616, christened Chandi and Urvi, with a 6.65 m diameter, had first built the tunnels section Subhash Sarovar Ramp - Phoolbagan Station - Sealdah in 2012-2013. A realignment of the line in central Kolkata forced ITD-ITD Cementation India Ltd. JV to stop further tunnelling for over 5 years,  during which both TBMs were sent to drive Delhi Metro’s Magenta Line tunnels. In March 2017 the machines were brought back to Kolkata and they were lowered 28m below the ground at the Esplanade site in July 2018 for driving the Esplanade -  Sealdah section. TBM Chandi started the west-bound tunnel on 25/01/2019, while TBM Urvi started the east-bound tunnel on 18/02/2019.  

After completion of this last TBM Urvi drive, both the TBMs will be retrieved in pieces from this retrieval shaft at Bowbazar.  

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 over ground construction.  

In October 2020 the Indian Government approved the Ministry of Railways’ proposal for a revised cost estimate for construction of the Kolkata East West Metro Corridor Project at an estimated cost of EUR 958.92  million (INR85.75 bn/Crore 8574.98). Fof further information please click here and in/64 for the tunnelbuilder archive. Also visit https://pib.gov.in/PressReleseDetailm.aspx?PRID=1719055 and http://www.kmrc.in/index.php. 20/21.