L&T Lowers TBM Mavala (India’s Largest) for Mumbai’s Coastal Road

Larsen & Toubro and Freight Wings on Thursday lowered the shields of TBM Mavala – the largest tunnel boring machine (TBM) to ever be deployed in India – at the Priyadarshini Park launch ramp for building twin 1,920m tunnels of Mumbai’s 29.2 km Coastal Road (Western Freeway) project.

This slurry TBM with a diameter of 12.19m was manufactured by China Railway Construction Heavy Industry Co. Ltd. (CRCHI) and arrived in Mumbai’s Priyadarshini Park neighborhood in April 2020.

Assembly works on it commenced in September on reclaimed land just 250 meters away from the launch ramp. Last week, Freight Wings transported three backup gantry parts (weighing 350 MT) and its newly assembled shields (weighing 1500 MT) over to the launch ramp using a 200 wheel self-propelled modular transporter.

Larsen & Toubro will deploy Mavala on the MCRP’s 3.93 km Package-4 for constructing 12m wide twin (3 + 3 lane) tunnels under Malabar Hill (75m deep) and Girgaum Chowpatty (25m deep) between Priyadarshini Park and Marine Drive in South Mumbai. Details on the expected geology can be viewed here.

Alignment of the tunnel in navy blue
Shot on Wednesday night
This gives an excellent idea about how massive it is! (shot earlier this week)

Over the past week, Brihanmumbai Municipal Corporation (BMC) and Larsen & Toubro christened the TBM as Mavala (note the new stickers on the side) after the troops of Chhatrapati Shivaji who excelled in mountain warfare.

This is a break from giving female names in a long-standing tradition, dating back to the 1500s, in the mining/tunneling world to bring good luck to the project team. The last time a male name was used (TBM Chandi in Kolkata) didn’t end too well when the TBM hit an aquifer leading to heavy soil displacement which triggered the collapse of several residential buildings over a month’s period.

On Thursday, the 10 meter long assembled shields were lowered by Freight Wings into the launch ramp using a 2500 MT capacity customized Strand Jack system for this project. This system is similar, but way larger, than the one deployed by them to retrieve and lower Dogus-Soma JV’s TBMs 1238 and 1239 for Mumbai Metro’s Line-3.

An image and video of how the TBM will eventually look like with its Indian flag themed cutterhead can be viewed here.

Here’s a snap of L&T’s precast segment casting yard, shot in October, which has been setup close to the assembly site:

According to BMC, L&T will use Mavala to excavate around 3 meters/day, with a total excavation time of 276 days to complete both tunnels. Per a comment left below by Sandeep, who claims to be associated with the project, the expected excavation rate will be higher at 9 meters/day.

Stay tuned for a post on when Mavala gets commissioned!

For more updates, check out my Home Page!

– TMRG

written by

Global traveler who prefers mass rapid transit

16 Responses to "L&T Lowers TBM Mavala (India’s Largest) for Mumbai’s Coastal Road"

  1. Rishi Raj says:

    Congrats to project manager Sandeep Singh sir and package 4 team. You all rock!

    Reply
  2. Kanishka says:

    …when so much tunneling is happening around, why isn’t there a single TBM manufacturer in India? Why does India have to rely on imported TBMs?
    Can’t solve this riddle…manufacturing a TBM is no rocket science…
    …just need to unleash the right entrepreneurial spirit

    btw, howz the progress on this coastal road project? ..will the phase-1 be completed by 15th Aug ’22 (the 75yr jubilee package)??

    Reply
    • TMRG says:

      Tunneling should easily be completed by then, but I don’t see the tunnels + new bridge opening up prior to Q4 2023.

      Reply
    • Hemanth Kumar says:

      If indian Infrastructure companies are ready to accept, the Indian high quality products compared to Chinese low quality products than tons of quality based indian manufacturers will come forward for manufacturing in INDIA. Unfortunate Indian Infrastructure companies are interested in low price products irrespective of quality and life of product.

      Reply
  3. Swapnil Ambekar says:

    I do not get the math on the tunneling speed. With the speed of 3 meters/day, how is it possible to tunnel out 1920 meters in 276 days? Am I missing something?

    Reply
    • TMRG says:

      Good question. That 1920m figure includes cut and cover sections on either end:

      Southbound tunnel: 660m (both ends)
      Northbound tunnel: 410m (Girgaum-end) and 660m (Priyadarshni Park-end)

      This graphic shows all parts: https://i.imgur.com/RXV7dbU.jpg

      Reply
      • Sandeep says:

        It seems you don’t have the right information. I am part of this project as Consultant design Engineer. 1.9km is the length of the TBM tunnel only excluding the Cut and Cover and Ramp portion. And rate of excavation is approximately 9m/day.

        Reply
        • TMRG says:

          Thanks – that’s interesting. The figures are straight from BMC and widely reported. I will add an update in the post.

          Reply
        • Ravi says:

          Hi Sandeep,
          Good to connect with you. How does L&T propose to complete the tunnel with the present tunneling speed of 3m/day as against the target of 9m/day?

          Reply
  4. Ravinder says:

    This is a very good innovative in india by this company. It will pick up slowly and move to work best in the world. Congratulations to all engineers and staff of the company.
    Good luck

    Reply
  5. sankar says:

    Please find this TBM was designed & Manufactured by Chinese Company.
    What is there to congratulate L&T.
    Any Freight Contractor in Namakkal, in Tamil Nadu would be able to transport from Mumbai harbour.
    Out if ignorance we are giving bouquet to Chinese Companies. Please quote how much money was paid to Chinese for this
    TBM. There is long way to go and it is time our companies should strive to manufacture not simply importing from china like toys. Be Indian Buy Indian.

    Reply
  6. Jaishankar says:

    It’s good to say ‘make in india’, but unless we bring down all the relevant factors of production,we cannot match not only the Chinese, but also Bangladesh or Vietnam. Land,labour, capital are all much above any of the standard competitive rates. Even Bombay Dyeing imports polyester blankets from China and sells them in their showrooms in India.

    Reply
  7. Subash BV says:

    What’s there to enjoy.
    You are using a Chinese machine.
    Why can’t you develop it vyourself.
    You are serving for isro and automic plants.
    Why not this.
    Have to feel shame.
    Put the nation first.

    Reply
  8. Subash BV says:

    What’s there to enjoy.
    You are using a Chinese machine.
    Why can’t you develop it vyourself.
    You are serving for isro and automic plants.
    Why not this.
    Have to feel shame.
    Not a rocket science.
    Put the nation first.

    Reply
  9. Laxman B. Landge says:

    Congratulations to L&Tites, such techmically trend setting inovative jobs, is only L&T can carry out. All the best to complete the job in time.

    Reply

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