Tunnelling work for Bangalore’s longest underground Metro corridor, between Dairy Circle and Nagawara (14km), commenced today (Thursday, 30th July 2020). Chief minister BS Yediyurappa flagged off tunneling work between Cantonment and Shivajinagar stations at 10.30am.
The much-delayed section saw several hurdles, including land acquisition issues, alignment changes, Covid-19 pandemic, lockdown and India-China standoff even before the complicated process of tunnelling through congested CBD areas could begin. In fact, BMRCL had changed the corridor’s colour from red to pink.
“Tunnel Boring Machine Urja will tunnel from Cantonment (Bamboo Bazar) towards Shivajinagar. Testing has been completed. Three more TBMs will be deployed along the section in a phased manner,” said a BMRCL source.
Four giant TBMs, including Avni (earth), Urja (energy), Lavi (lion) and Vindhya (knowledge), will drill and cut through CBD areas between Vellara Junction and Pottery Town (5.5km). In February 2019, Larsen & Toubro received bids for the underground section from Vellara Junction to Shivajinagar (2.7km) and Shivajinagar to Pottery Town (2.8km).
L&T had procured four TBMs from China Railway Construction Heavy Industry Corporation Limited (CRCHI). Tunnel shafts, which will be used to lower the machines, were created at Shivajinagar and Cantonment stations.
“The tunnelling process is finally kicking off after several obstacles. First, it was land acquisition and then delay in the arrival of TBMs from China because of Covid-19. This was followed by visa restrictions for Chinese engineers to assemble these machines and shortage of workers due to lockdown. In fact, tunnelling was supposed to start in March 2020 but was delayed due to the pandemic,” said a senior BMRCL official.
The TBMs are expected to tunnel 2.5-5 metres per day, depending on the geographical condition they encounter. BMRCL has set 2024 as the deadline for commissioning of the underground section. It took about five years to complete the 10 km tunnelling work during Phase I. ITD Cementation India Ltd is responsible for construction of the 4.6 km underground section between Tannery Road and Nagawara. Similarly, Afcons Infrastructure will build the 3.7 km underground corridor from Dairy Circle to Langford Town. BMRCL said nine TBMs will be deployed along the 14-km section.