Bengaluru: The Bangalore Metro Rail Corporation Ltd (BMRCL) Thursday announced the commencement of tunnelling work between Cantonment station and Shivajinagar for the city's longest underground metro corridor after chief minister Yediyurappa set a tunnel boring machine in motion.

"The CM has set in motion one Tunnel Boring Machine on July 30. The TBM named Urja will be tunnelling (north-bound tunnel) between Cantonment and Shivajinagar stations. The expected geology in this tunnel section is about 250 m in hard rock, 350 m in mixed ground conditions, and about 255 m in soil," the statement read.

BMRCL officials further confirmed that the second TBM (Vindhya) is likely to be commissioned soon after the first TBM completes required advancement.

The city's longest underground metro corridor is planned between Dairy Circle and Nagawara, spanning across a distance of 14 kilometres.

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.

BMRCL has set 2024 as the deadline for commissioning of the underground section. It took about five years to complete the 10km tunnelling work during Phase I.

ITD Cementation India Ltd is responsible for construction of the 4.6km underground section between Tannery Road and Nagawara. Similarly, Afcons Infrastructure will build the 3.7km underground corridor from Dairy Circle to Langford Town. BMRCL said nine TBMs will be deployed along the 14-km section.

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