Bangalore Metro’s TBM Tunga Records Breakthrough at K.G. Halli

Tunnel Boring Machine S-839B operated by ITD Cementation India on Wednesday recorded a breakthrough at Kadugondanahalli (K.G. Halli) Station of the 21.386 km Bangalore Metro Pink Line (Reach 6) project.

Nicknamed Tunga, this was TBM S-839B’s 3rd of 4 planned breakthroughs and ITD Cem’s 5th 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 originally launched in June 2021. For its latest assignment, it built a 1184m tunnel from Venkateshpura to KG Halli boring at an average rate of 2.95m/day through mixed face hard rock conditions.

Here’s a summary of all completed drives:

Photo by Bala Subramani

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.

Alignment of ITD Cem’s Package RT-04 – view Bangalore Metro Phase 2 info & route map
Photo by Rajib Paul
ITD Cem’s team – Photo by Rajib Paul
BMRCL’s team
Photo by Rajib Paul

Video (check it out for some cool visuals from all station sites in RT-04)

Per BMRCL’s recent newsletter, as of October 31 TBM Bhadra (S-840B) working on the parallel southbound tunnel had completed tunneling 63.89% of 1186m after being relaunched in February 2023. Assuming it follows a similar tunneling excavation rate, I see it arriving at K.G. Halli sometime in late February 2024.

With this development, Tunga will now be dragged across Kadugondanahalli Station’s box and be relaunched for its fourth and final drive of roughly 935m towards Nagawara Station.

Overall tunneling progress for Phase 2 stands at 18.83 / 20.9 km with 23/26 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 5/8 on RT-04 by ITD Cementation.

For more updates, check out the Bangalore section or my Home Page! Sign up for free instant email notifications on new posts over here. Like this post? Get early-access to updates and support the site over here.


written by

Global traveler who prefers mass rapid transit

13 Responses to "Bangalore Metro’s TBM Tunga Records Breakthrough at K.G. Halli"

  1. Raghu says:

    Hi TMRG
    What might be timeline for final breakthrough of entire tunneling of phase 2

    • TMRG says:

      Sometime in Q4 2024 (Oct – Dec)

      The KG Halli – Nagawara stretch is supposed to be relatively easier to tunnel through, but you never know.

  2. Aryan says:

    5 bidders for Mumbai Metro line 4 finishing work it includes only 7 stations

  3. Raghu says:

    When can we expect Pink line of Bangalore metro phase 2 to be completely operational

  4. Babuds says:

    Dear MRG,
    Is this UG metro line safe from flooding? Are there any drainage mechanisms planned for implementation and if so what are they? Thanks. – Babuds

  5. Akram sharif says:

    Sir I kindly request to have a look behind the venkatesh puram metro station how dirt water is coming from metro full f pollution mosquitoes because of drt I’ll health problem children’s suffering from fever u r only interested in completing noe interested in public health


Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published. Required fields are marked *