BENGALURU: The eighth Tunnel Boring Machine (TBM) that will carry out drilling work in the Underground Corridor of Bengalore Metro’s Phase-II, between Nagawara and Dairy Circle, began operations on Thursday. It will be tunnelling a distance of 850 metres.
The 13.92-km Underground corridor with 12 Metro stations figures in the Pink Line or Reach 6 that will run for 21.25 kms from Nagawara to Kalena Agrahara (Gottigere). Two tunnels, each running into 10.37 kms, are being put in place for which nine TBMs will be used.
According to a senior Metro official, 'Bhadra' began operations below the upcoming Venkateshpura station at 12.30 pm. “It is drilling nearly 60 feet below the ground towards Tannery Road. As of now, the TBM which works in a circular fashion, has begun making temporary rings on the rock surface and it is expected to make a permanent ring inside the rock in two days. The actual excavation process begins only after that,” the official said.
The work is being carried by ITD Cementation India Limited which has got the Package-4 contract for the line. “Presently 70 workers are involved in the drilling work. This includes those below the ground and support staff working above the ground. All have been vaccinated and some have got the second dose too,” he said.
The TBM will work 24x7 all days barring alternate Sundays when the machine will be switched off during the change of shift of workers. 'Bhadra' was earlier deployed by Delhi Metro, brought to Chennai and refurbished fully before it was sent to Bengaluru.
“The biggest challenge we faced was the COVID second phase with labour as well as shortage of oxygen required in construction related work. It is an achievement that we managed to start work during this period,” the official added.
The other TBM in this direction 'Tunga' is yet to start operations and is likely to do so after the present one covers 70 metres (or 50 permanent rings).
Meanwhile, two other TBMs, Urja and Vindhya, have completed 510 metres and 445 metres tunnelling respectively (as of June 17 from Cantonment station to Shivaji Nagar. These two figure in the Package-3 contract, which has been awarded to Larsen & Tourbo Ltd.
The other TBMs employed by Bangalore Metro Rail Corporation Limited (BMRCL) are busy with their drilling work. Avni and Lavi are drilling from Shivaji Nagar towards MG Road while two TBMs 'Rudra' and 'Vamika' are drilling from South Ramp (Jayanagar Fire station) towards Langford and TBM 'Varada' is drilling from Rashtriya Military School.
BMRCL is yet to make public the latest distance completed by them.