India’s Largest TBM Arrives for Mumbai’s Coastal Road Project

India’s largest tunnel boring machine (TBM) with diameter of 12.19m arrived in Mumbai’s Priyadarshini Park neighborhood this Sunday morning after a 5000+ nautical mile journey from Shanghai Port to Mumbai’s Jawaharlal Nehru Port to build twin 1,920m road tunnels for Mumbai’s 29.2 km Coastal Road (Western Freeway) project.

This China Railway Construction Heavy Industry Co., Ltd. slurry machine passed factory acceptance tests (FAT) at the manufacturer’s Changsha plant in December 2019 in the presence of officials from Larsen & Toubro and AECOM (General Consultant).

Larsen & Toubro will deploy the machine on the project’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.

Alignment of the tunnel in navy blue

Per CRCHI’s website, the TBM is 80m long, weighs 2,300 tons, has an installed capacity of 7,280 kW, gradeability of 5% and can achieve a 350m horizontal turning radius.

The tunnel construction faces complicated geological conditions that require excavation in deep overburden and will see the TBM pass through a compound stratum of basalt, breccia and shale. To solve these challenges, the TBM has been designed designed with a mixed cutter head with eight spokes and eight panels which will enable it to bore in the complicated strata for a long distance.

The TBM is fitted with a big-diameter slurry feeding port and several slurry flushing lines to increase the flow rate of slurry. In addition, this TBM has adopted many innovative systems, such as dual-chamber indirect slurry control system, dual-circuit automatic pressure system, high-torque and retractable main drive as well as high-power slurry circulation system.

Spotted on Bhulabhai Desai Road in Breach Candy – Photo Copyright: Rushikesh Jadhav
Trailers with the TBM’s parts at the project site near the launch shaft in Priyadarshini Park (PDP) – Photo Copyright: Save Our Coast Mumbai


Images, project walkthrough video and a cool timelapse of the TBM shot during factory acceptance tests can be viewed here.

Besides this machine, CRCHI is supplying 4 smaller Ø6.67m slurry machines to Larsen & Toubro for Bangalore Metro’s Phase 2 project. The first of them, nicknamed Urja, was lowered into Cantonment Station’s shaft in March.

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Global traveler who prefers mass rapid transit

5 Responses to "India’s Largest TBM Arrives for Mumbai’s Coastal Road Project"

  1. Fahad says:

    Has the project owner named it? If not, then I hope they do! Giving a name makes the project instantly recognizable and fun to track. Cities around the world hold naming contests prior to boring by such mega machines.

    • TMRG says:

      They haven’t announced a name for it yet. That might happen on the day tunneling works are officially launched.

  2. Mrigen Adhikari says:

    The project name is as its said: Mumbai Coastal Road Project.
    The barricades set up in different parts of the city also have this name. Lets hope unlike the Sealink which took 10 years to build, this takes less time.

    Moreover, I thought the worlds largest TBM Bertha was supposed to come to Mumbai!

  3. Mrigen Adhikari says:

    Oops! My bad!


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