BENGALURU (Metro Rail & Steel): The Bengaluru Metro’s ambitious Pink Line, boasting the longest underground section, is poised for yet another significant breakthrough as the Tunnel Boring Machine (TBM) Tunga is set to emerge triumphantly on Wednesday. This milestone marks the 21st successful tunnelling endeavor out of the 24 assignments planned for the 21.26-kilometer stretch, connecting Kalena Agrahara to Nagavara via key locations like MG Road and Tannery Road. The German-engineered Herrenknecht TBM, christened Tunga, embarked on its mission in the city on July 23, 2021. Over a span of 13 months, it tirelessly carved through the underground, tunneling 1,260 meters between Venkatespura and Tannery Road. Commencing its second assignment on October 31, 2022, the TBM commenced its journey through a mix of rock, soil, and a combination of both, this time between Venaktespura and KG Halli.
A source within the Bangalore Metro Rail Corporation Limited (BMRCL) shared, “The TBM has completed its tunneling task and is currently engaged in core cutting, drilling holes, and other finishing works. Its grand emergence from the KG Halli shaft is anticipated on Wednesday.” BL Yashavanth Chavan, Chief Public Relations Officer at BMRCL, confirmed the much-anticipated breakthrough scheduled for Wednesday, which will be commemorated with a celebratory event at 10.30 am. The TBM’s journey comprised traversing 1,184.4 meters over 401 days, achieving an average of 2.99 meters per day. The path encountered consisted of 40% rock, 40% soil, and 20% a blend of both, according to insiders familiar with the project.
In total, BMRCL has deployed nine machines to tunnel through the 20.99 km stretch of the Pink Line. While seven of these machines have successfully completed their tasks, Tunga has concluded two drives, and Bhadra, another TBM, has completed one. The second drive for Bhadra, covering 1,186 meters between Venkateshpura and KG Halli, is anticipated to be finalized by January. Looking ahead, Tunga is set for its final drill in January 2024, slated to bore through 935 meters from KG Halli to Nagavara. Bhadra’s final drive is scheduled to commence in March 2024 and conclude by July, marking another significant step forward for the Pink Line’s ambitious construction.