Mumbai’s next big underground road is taking shape: TBM parts to arrive by December

Parts of the Tunnel Boring Machine (TBM) required for Mumbai's newest 3.9 km underground link between Malad's Mindspace and Charkop in Kandivali will be arriving in the city by December. This marks a significant milestone in the second phase of the Mumbai Coastal Road Project undertaken by the Brihanmumbai Municipal Corporation (BMC).

The project aims to create an alternate north-south corridor for motorists, linking Versova and Dahisar, spanning 22.93 km and divided into seven packages that include elevated roads, cable-stayed bridges, and over ten interchanges.

The twin tunnels, designated as part of Packages C and D, will be excavated using the TBM machinery, running beneath the densely populated area in North Mumbai. Each tunnel will be three lanes wide, with five cross-passage corridors on each side. Two TBM machines, approximately 15.70 metres in external diameter, will be deployed at a depth of around 40 metres below ground.

The project's chief engineers and the Additional Municipal Commissioner, Abhijit Bangar, recently inspected the site in Charkop, where construction of a 65 metres by 40 metres land parcel began. This is where the shaft for lowering the TBM machines will be built, serving as the launching point for the tunnel digging process. Once the spare parts of the first TBM arrive, work on assembly will commence, with the goal of launching and starting tunnel digging next month.

The completion of the tunnel assembly and digging is expected to be finished by June 2027, as per a senior BMC official's statement. Of the 3.9 km total length of the tunnels, the TBMs will excavate 3 km, while approximately 700 metres will follow a cut-and-cover rectangular box design.