Bengaluru Metro’s TBM Tunga has its breakthrough, UG corridor set to be completed by June 2024
BENGALURU: After tunneling for 401 days from the Venkateshpura Metro station, Bengaluru Metro’s Tunnel Boring Machine (TBM) `Tunga’ had its breakthrough on Wednesday at Kaadugondanahalli (KG Halli) Metro station on Wednesday around 11.15 am. It completed tunnelling a distance of 1184.4 meters. With just two out of the nine TBMs yet to complete their job, tunnelling for the entire underground network is likely to be completed by June 2024.
An official release said, “With this breakthrough, a total of 89.7% of the Underground corridor has been completed - 18832.3 metres out of 20992 metres.”
The TBMs are building the 13.76-km underground corridor from Diary Circle to Nagwara, which is part of the Reach-6 line from Kalena Agrahara to Nagawara.
Giving details, a senior BMRCL official told TNIE, “This is the second drive of Thunga. In its first drive, it had tunnelled 1066.88 metres from Venkateshpura station (South) to Shaadi Mahal. It was lifted from the shaft and brought to the North end. For its third drive, it will tunnel 939 metres from K G Halli to Nagawara. It is expected to complete the tunnelling by May end.”
Asked about the challenges it faced, the official said that the twin challenges were the mixed ground and the tunnelling below the railway line near K G Halli.
The last TBM on its journey,`Bhadra’ is tunnelling parallel to it. “It has completed its first leg and is drilling its second leg on the same stretch just completed by Tunga. It will complete its third leg by June next year. The geology of Bengaluru is making it tough for Bhadra too.”