From Our Special Correspondent
Daijiworld Media Network - Bengaluru
Bengaluru, Jul 30: The long-delayed work on the underground section of Bengaluru’s Namma Metro Phase 2 line linking the two stations at Cantonment and Tannery Road junctions was flagged off by chief minister B S Yediyurappa in Bengaluru on Thursday.
Yediyurappa flagged off the work on the tunnel boring machines (TBMs) Urja and Vindhya.
Urban Development Minister Byarathi Basavaraj, Revenue Minister R Ashok and BMRCL Managing Director Ajay Sait were among the dignitaries who participated in the function.
Larsen & Toubro (L&T) Construction had received the two tunnel boring machines (TBMs) for the construction of underground (UG) tunnels on February 20.
Both the TBMs will be deployed for excavating and building tunnels as part of the 73.92 km long network of Bangalore Metro Phase 2 project.
The TBM Urja will be deployed from Cantonment Station for constructing the tunnels on the 2.884 km section of package RT-03 (Shivaji Nagar Station–Tannery Road).
After this, TBM Lavi will follow the TBM Avni and TBM Vindhya will follow TBM Urja.
In January 2018, Bangalore Metro Rail Corporation had decided to place the Cantonment Station at Bamboo Bazaar instead of the original location which was closer to the Railway Station.
The underground section of the phase-2 of the project consists of 13.9 km underground corridor from the south ramp near Jayanagar fire station to the north ramp near Nagawara underground station, consisting of 12 underground stations and 10.37 km of twin tunnels.
The construction of the entire underground work has been divided into four packages namely RT01, RT02, RTO3 and RT04.
Four packages of underground work
Under RT03 package, the work involves, tunnelling from Cantonment station to Shivaji Nagar station and from Cantonment station up to launching/retrieval shaft at Shadi Mahal near Tannery Road underground station for a length of 2.88 km with two underground stations of Cantonment and Pottery Town.
The contractor M/s Larsen and Toubro Ltd have procured two slurry based Tunnel Boring Machines (TBM) to complete the above tunnelling works.
TBMs have been procured from M/s CRCHI and consignments reached the Chennai port by sea route and were transported to Bengaluru in March 2020. The names of the two TBMs are Urja and Vindhya.
Chief minister set in motion one tunnel boring machine Urja on Thursday.
The TBM named Urja will be tunnelling (northbound tunnel) between Cantonment and Shivaji Nagar stations.
The expected geology in this tunnel section is about 250m in hard rock, 350m in mixed ground conditions and about 255m in soil.
The second TBM Vindhya will be commissioned shortly after the required advancement of the first TBM Urja.
Completion timeline of phase-2 extension lines:
R4 from Yelachenahalli to Anjanapura is likely to be commissioned in November.
Extension line R2 from Mysore Road to Kengeri in February 2021.
Extension line R1 from Baiyappanahalli to Whitefield in June 2022.
Extension line R3 from Nagasandra to BIEC in January 2022.
New line R5 from RV Road to Bommasandra in March 2022.
New line R6 from Kalena Agrahara to Nanawere in June 2024.