Bangalore Metro’s TBM Bhadra Records Breakthrough at K.G. Halli
Tunnel Boring Machine S-840B operated by ITD Cementation India today recorded a breakthrough at Kadugondanahalli (K.G. Halli) Station of the 21.386 km Bangalore Metro Pink Line (Reach 6) project.
Nicknamed Bhadra, this was TBM S-840B’s 3rd of 4 planned breakthroughs and ITD Cem’s 6th of 8 breakthroughs planned for the 73.92 km Bangalore Metro Phase 2 project’s 4.591 km Package RT-04 (Tannery Road – North Ramp).
This Herrenknecht mixed-shield EPB machine was first commissioned from Venkateshpura Station southward to Tannery Road in June 2021. For its latest assignment, it built a 1184m tunnel northward from Venkateshpura to KG Halli boring at an average rate of 3.3m/day through mixed face hard rock conditions.
Here’s a summary of all completed drives:
- Venkateshpura to Tannery Road (822m): June 2021 – July 2022
- Tannery Road to Shadi Mahal TBM Retrieval Shaft (222m): July 2022 – December 2022
- Venkateshpura to Kadugondanahalli (1184m): February 2023 – February 2024
ITD Cem’s scope of work involves building a combined total of 6.34 km twin tunnels, roughly 360 meter ramp at Nagawara, and four stations at Tannery Road, Venkateshpura, Kadugundanahalli (formerly Arabic College) and Nagawara.
With this development, Bhadra will now be dragged across Kadugondanahalli Station’s box, which can take 20-45 days, and be relaunched for its fourth and final drive of roughly 935m towards Nagawara Station’s southern cut & cover section-1.
Its sister machine, TBM Tunga (S-639B), working on the parallel down-line tunnel had arrived at Kadugondanahalli Station in December 2023 and was re-commissioned earlier this week towards Nagawara. The soil profile of this final section comprises of a mix of weathered rock and sandy silt/clayey sand at shallow depths – making it relatively easier to tunnel through.
Per BMRCL overall tunneling progress for Phase 2 stands at 19.12 / 20.9 km with 24/26 tunnel breakthroughs recorded so far: 8/8 on Package RT-01 by Afcons, 4/4 on RT-02 by L&T, 6/6 on RT-03 by L&T, and 6/8 on RT-04 by ITD Cementation.
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– TMRG
Hi TMRG
When to expect final breakthrough of both the TBM.
Hi, BMRCL’s January newsletter says they’re aiming for May 31 (Tunga) and June 30 (Bhadra), so sometime in Q3 (July – Sept)? Let’s see how things progress
Well what is the position on the trains for this section. Have the orders been placed and do we have a time frame when its expected. It should not be a yellow line situation where we are waiting for over 1 years for the trains to arrive.
Trains have been “ordered”: https://themetrorailguy.com/2023/08/08/beml-awarded-bangalore-metros-318-coach-rolling-stock-contract-5rs-dm/
Expect prototype in Q2 2025.
So, “knock on wood”, line is functional in Q3-4 of 2025, maybe even early 2026.
Hi TMRG
I reckon the tunnelling for the entire pink line should finish by the end of this year? How long would the station work take in your opinion? When do you expect pink line to be operational?
40 %. Is a curse on Bangaloreans irrespective of who governs. Let’s hope we will have a fully functional metro system by 20 ! 40 (%).