History of Bangalore Metro Green Line’s Underground Section

With just one day to go for the inauguration of Bangalore Metro’s final 12 km Sampige Road – Yelachenahalli section of the Green Line, here’s a post with some brief, high-level information on its 4 km underground section between Sampige Road & National College.

This section of the 42.30 km Phase 1 project is officially referred to as UG-1 and was originally envisioned to be ready by the end of 2011. Delays arose in the tendering stage even before ground-work started, somewhat similar to what’s transpiring right now in Phase 2. When tunneling-work finally began in late-2012, the TBMs deployed by Coastal-TTS JV encountered difficult geology conditions comprising of soft soil, high groundwater levels, hard granite and large boulders due to which some machines took as many as 35 months (1st drive of TBM Godavari) and 22 months (2nd drive of TBM Krishna) to complete tunneling.

Workers on this challenging section witnessed everything from a broken cutterhead (TBM Godavari) to the Bangalore Metro Rail Corporation Ltd pleading with (1) the east-west line’s contractor, CEC-SOMA-CICI JV, to deploy a TBM and build one tunnel from Majestic to the North Ramp, and (2) The Robbins Company to take control of their competitor Herrenknecht’s TBMs Kaveri & Krishna to finish the last 2 tunnels between Chickpet and Majestic. Even after those corrective measures, the TBM operators had to move cautiously due to the precariously weak & shallow foundations of old structures and illegal borewells dug by residents along the route.

Underground section of the Green Line – view Bangalore Metro map & info

Pre-Tunneling Period (2008-2012)

Bids for the UG-1 section were invited in February 2008. The scope originally included part-design & construction of 2 ramps, 8 tunnel sections and 3 stations at Majestic, Chickpet and KR Market, but due to the exceptionally high bids received  (Rs 600 cr more than the estimate), the BMRCL in late-2009 hived off Majestic Station’s construction into a separate package of its own which later got awarded to the Coastal-GYT JV in November 2011.

Here’s how things played out with UG-1:

February 2008 – BMRCL invites global bids for its design & construction
December 2009 – BMRCL re-invites separate bids for UG-1 and Majestic Station’s construction
June 2010 – BMRCL opens bids to reveal Coastal-TTS JV as its lowest bidder
• March 2011 – JICA approves & BMRCL awards UG-1’s contract to Coastal-TTS JV for a value of Rs. 707.09 crore

Tunneling Period (2012-2016)

The Coastal-TTS JV team carried out tunneling works using 3 TBMs. TBMs Krishna & Kaveri completed factory acceptance tests at Herrenknecht’s Chinese facility in February 2012 and arrived in Bangalore in May & August 2012.

TBM Kaveri (S-726) – a Ø6.45m Herrenknecht EPB machine tunneled from South Ramp → KR Market → Chickpete → Majestic. This was the 1st TBM to be commissioned in November 2012 on a short 393m first drive towards KR Market Station

TBM Krishna (S-725) – a Ø6.45m Herrenknecht EPB machine tunneled from South Ramp → KR Market → Chickpete → Majestic. In December 2012, it became the 2nd TBM to be commissioned to build a parallel tunnel towards KR Market Station.

TBM Krishna – Photo Copyright: MD Bangalore Metro

TBM Godavari – a SELI-Kawasaki EPB machine built the north-bound tunnel from the North Ramp → Majestic. This was commissioned on May 15 2013 in what turned out to be its only tunneling drive as it broke its cutterhead midway and got knocked out of service for a year.

TBM Godavari – Photo Copyright: MD Namma Metro

The CEC-Soma-CICI JV was roped in mid-2014 to redeploy 1 TBM used previously in building the east-west Purple Line:

TBM Margarita – a Hitachi Zosen slurry shield machine built the south-bound tunnel from Majestic → North Ramp

TBM Margarita - Photo Copyright: Tunnel Talk

TBM Margarita – Photo Copyright: Tunnel Talk

Here’s a look at all 8 breakthroughs on the line –

1. May 6 2013 – 1st breakthrough by TBM Krishna at KR Market from South Ramp (393m)

Photo Copyright: The Hindu

2. May 11 2013 – 1st breakthrough by TBM Kaveri at KR Market from South Ramp (393m)

Photo Copyright: MD Namma Metro

3. October 17 2014 – 2nd breakthrough by TBM Kaveri at Chickpet from KR Market (432m)

Photo Copyright: Aditya Kapoor

Photo Copyright: Sankar Rao

4. August 31 2015 – 2nd breakthrough by TBM Krishna at Chickpet from KR Market (432m) – view details/images

Pass the beer! - Photo Copyright: Karnataka Photo News

Photo Copyright: Karnataka Photo News

5. November 7 2015 – 1st breakthrough (4th incl. EW line) by Margarita at the North Ramp from Majestic (970m) – view details/images

Photo Copyright: Adarsh Ratan

Photo Copyright: Adarsh Ratan

6. April 19 2016 – 1st breakthrough by TBM Godavari at Majestic’s North Shaft (973m) – view details/images

Photo Copyright: Deepak Maddy

Photo Copyright: Deepak Maddy

Photo Copyright: Deepak Maddy

Photo Copyright: Deepak Maddy

Photo Copyright: GOK Updates

Photo Copyright: GOK Updates

7. June 8 2016 – 3rd breakthrough by TBM Kaveri at Majestic’s South Shaft from Chickpet (432m) – view details/images

Photo Copyright: Sharath Kumara

Photo Copyright: Sharath Kumara


Photo Copyright: Bangalore Connect

8. September 23 2016 – 3rd and final TBM breakthrough by TBM Krishna (747m) – view details/images


Photo Copyright: Naveen Menezes


Photo Copyright: Pushkar

Post-Tunneling Period (2016-2017)

This stage, from the final breakthrough to commissioning, typically takes anywhere from 12-18 months but the BMRCL, under massive pressure from the state government, is all set to open the line for public use in just 9 months with plans to complete all pending finishing works at Chickpet & KR Market stations over the next few months.

July 2016 – Tracks arrive at KR Market Station
November 19 2016 – BMRCL pulls a train through the tunnels towards Reach 4
March 31 2017 – BMRCL begins trial runs through on this stretch
May 5 2017 – RDSO launches 3-day speed trials
May 29 2017 – CMRS begins a 4-day safety inspection
June 13 2017 – Alstom hands-over the signalling system to BMRCL
June 17 2017 – Inauguration by the President scheduled at Vidhana Soudha at 6 pm
June 18 2017 – Public launch scheduled to take place in the afternoon 🙂

For more updates, check out the Bangalore section of The Metro Rail Guy!


written by

Global traveler who prefers mass rapid transit

18 Responses to "History of Bangalore Metro Green Line’s Underground Section"

  1. Ashok Kumar says:

    Phew! It took 8 years for the 4km UG line to go from tendering to inugration.

    With the tenders for the new Gottigere-Nagawara line yet to be invited, I think we can safely assume the opening of that line to be only after 2025.

  2. Naveen S Arur says:

    Hope BMRCL learn from their mistakes and ….WHOM AM I KIDDING?!!!

  3. Anoop says:

    Phase 2 would not be driven like this they have the experience, what i know is they are yet to get the financial closure for the UG sector lets hope we scale up like Delhi Metro asap

  4. Santhosh says:

    So actual tunneling happened from Nov 2012 to Sep 2016, 47 months for 4 kms of tunneling which probably can be improved in Phase 2 by improving engineering practices….. The delay in the remaining 6 years is where the major prob still lies. They have to improve time taken for tendering and handing over. Like you said, they are repeating the same in Nagavara to Gottigere line. Sad 🙁

  5. Madhushekar says:

    Guys let’s put our hand on our heart and say that we have been part of any project in life which is never delayed. We are unusually harsh in my opinion. I have worked in the famed IT industry and I can tell you only 20% projects are on time and in budget. Mind you there are no litigations, traffic,terrain or enviromental issues. Many projects get abandoned Alon t he way. It’s commendable for BMRCL to have finished this. Comparisons with Delhi are not fair as its capital and gets funds from centre and preferential treatment from centre as it’s the capital. As a blorian iam really proud. Phase 2 is where it’s really connects the peripheries and the IT zone which will be eagerly waited.

    • Sham says:

      I concur. Large & complex infra projects usually have delays because it is almost impossible to foresee & have plan-Bs for every kind of eventuality. Despite the many major obstacles it faced, BMRC has actually done quite well. The only criticism I have is that the state govt kept making promises they couldn’t keep & spoiled BMRC’s name.

      The comparison with Delhi metro is actually most inappropriate as it enjoys far too excessive attention & funding, despite several blunders they made like the airport express line.

  6. Madhushekar says:

    Amazing work from the TMRG hats off or you guys. Hope you have funds to carry on your work. Iam sure we all can contribute in a small way. Let us know

  7. Arvind says:

    Hi, can u please share launch date of magenta line in Noida- Delhi.It is also witnessing similar delays.


  8. Vinay Chaitanya D says:

    Timings for the public services on Sunday?

  9. Nirmal says:

    Excuses and more excuses,sheer inefficient workforce and Management. While we are struggling,just take a look at China and the quality of their infrastructure. Take a closer look at the amount of water leaks in the underground tunnels if namma metro to understand the shoddy work carried out at inflated budgets

    • Sham says:

      Sorry, but China has been doing things fast but construction quality is much poorer. There have been tunnel caveins & roof collapses. Kindly google & read about them.

  10. Nirmal says:

    There is nothing much to feel proud about of namma metro.in comparison to our south east Asian neighbors, it must be surely somewhere last in terms of quality as well as timelines. What is stopping bmrcl from targeting to be the best in Asia if not the world ? At best our metro is adequate and acceptable, nothing more.there is lack of foresight and planning at most of the stations.

    • Sham says:

      Other than bus bays at stations, what are the issues that lack foresight and planning?

      • Akshay Mathur says:

        Planning. At every step. They had correct geography values from soil testing, but created a project spec where they copied the soil values from Delhi Metro DPR (the only operation metro at the time). This caused TBMs to breakdown midway and cause massive budgetary inflation and time delays.

        They started work BEFORE clearing up technical and legal issues. So they ran into technical troubles where the grade is too much for the train and then they ran into issues where work had to be stopped because legal issues had not been stopped. This caused budget overruns and time delays.

        And to top it off, they started off the wrong foot. They made massive mistakes in launching tenders (and in the wrong order) and then took more than three times the time to process each bid because of the massive screw ups.

        Unfortunately one of these mistakes is still being made today (but I hope they have learnt their lessons and are careful).

  11. Nirmal says:

    No need to Google, have visited personally and seen the quality.it is just a myth that Chinese cannot deliver quality and on time. As much as being a proud Bangalorean having been born and brought up in this lovely city, the metro project as a whole could have been so much better. The half hearted approach and attitude is shown all over the stations and reflects in the project.

    • Sham says:

      Again, you don’t specify what the problem areas are. What exactly do you mean by half hearted approach and attitude shown all over the stations?

  12. Madhushekar says:

    It’s wrong to compare with China. China is not a democracy. People don’t own land and acquisition of land for building projects are non existent cause the Govt owns everything. You need permits to move from rural to city. Govt controls everything. But I also agree with the quality aspect the stations particularly looks bad from outside. I have seen at nayandhalli Jayanagar Banashankari the civil work is shoddy. Quality can hardly be increased but overall the mistake for to delay start of the project till 2007. The talk of metro started in 90s. That delay costed us more than anything else.


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