Bengaluru Metro’s longest underground section is set to achieve another construction milestone as the Tunnel Boring Machine Tunga will make its second breakthrough on Wednesday.
This will be the 21st out of 24 tunnelling assignments to be completed on the 21.26-km Pink Line, which will connect Kalena Agrahara to Nagavara via MG Road and Tannery Road.
The German-made Herrenknecht machine was first launched in the city on July 23, 2021, and took 13 months to tunnel 1,260 metres between Venkatespura and Tannery Road. Its second assignment began on October 31, 2022, to bore through rock, soil and a mixture of both between Venaktespura and KG Halli.
“The TBM has tunnelled its specified length and is currently engaged in core cutting, drilling holes and other works. It will emerge out of the KG Halli shaft on Wednesday,” a well-placed source in Bangalore Metro Rail Corporation Limited (BMRCL) told DH.
The BMRCL’s Chief Public Relations Officer, B L Yashavanth Chavan, confirmed that the breakthrough was scheduled for Wednesday.
A small ceremony will take place at 10.30 am to celebrate the momentous occasion.
The machine bored 1,184.4 metres in 401 days or, an average of 2.99 metres per day. Its path was composed of 40% rock, 40% soil and 20% of both, according to the source.
The BMRCL deployed nine machines to bore through 20.99 km on the Pink Line. Seven of these machines (Urja, Varada, Avni, Lavi, Vindhya, Vamika and Rudra) have finished their job. Tunga has completed two drives and Bhadra one. Bhadra’s second drive — 1,186 metres between Venkateshpura and KG Halli — will be completed by January, according to the source.
Thereafter, Tunga will be relaunched for its final drive in January 2024 to bore through 935 metres from KG Halli to Nagavara. Bhadra’s final drive will begin in March 2024 and complete by July, the source said.
Work is also going on at a brisk pace on the Pink Line’s 12 underground stations.
The stations between Dairy Circle and Shivajinagar are nearly 70-90% complete. Cantonment-Tannery Road stations are 85% complete while Venkateshpura, KG Halli and Nagavara are 65% complete. The BMRCL is also preparing to lay tracks between Cantonment and Venkateshpura, the sources said.
The Pink Line’s deadline is March 2025.
Published 05 December 2023, 23:36 IST