The two Tunnel Boring Machines (TBMs) working on the underground section of the Pink Line for the Bengaluru Metro from Kalena Agrahara to Nagawara might not meet the tunnelling deadline of August 2024 because of rocky terrain.
Tunga and Bhadra, two tunnel boring machines (TBMs), are excavating the last section of the underground Pink Line. Tunga is making its final push from K.G. Halli to Nagavara, covering 935 meters. Meanwhile, Bhadra is also on its final task, digging a 939-meter tunnel northbound from K.G. Halli to Nagavara.
“Both Tunga and Bhadra, drilling side by side, have encountered rock under the ground. This could potentially prolong the completion timeline, and we may not meet the original deadline. We anticipate a few days of delay from the initially set deadline,” said a BMRCL official.
“Typically, the TBMs can advance by a minimum of 5 kilometres per day. However, due to encountering rock formations, they are currently only progressing at a rate of 3 kilometres per day,” the official added.
The Pink Line, stretching over 21.26 km and connecting Kalena Agrahara to Nagavara, features Bengaluru metro’s lengthiest underground section, spanning 13.76 km, in addition to a 7.5-km elevated segment. Within this underground portion, the ambitious endeavor of building 20.992 km of twin tunnels is under way. Progress is also being made on the construction of 18 stations, including 12 underground and six elevated stations, which are nearing completion.
Bangalore Metro Rail Corporation Limited (BMRCL) deployed nine TBMs for tunnel construction. Seven of them — Urja, Varada, Avni, Lavi, Vindhya, Vamika, and Rudra — have successfully completed their tasks. The eighth TBM is Tunga, and the ninth machine is Bhadra.
The progress on this stretch faced significant delays over the years due to multiple factors, such as the tender cancellation due to high bids, changes in alignment before final approval, land acquisition challenges, and other obstacles. The officials anticipate that the entire stretch may be opened in 2025.
Published - June 06, 2024 11:33 pm IST
