Mavla, the largest tunnel boring machine ever to be installed in India, achieved its maiden success for 29.2 kms of Mumbai at Chowpatty in Girgaum today. Coastal Road (Western Freeway) Project,
Larsen And Toubro was commissioned In January 2021, it will construct the 80-metre-long CRCHI Slurry Machine (DZ 636), the first of two 2,070-metre tunnels between the Priyadarshini Park launch ramp and Chowpatty. The machine has a nice Indian flag themed cutterhead With a diameter of 12.19 m which was clearly damaged during the excavation.
TBM operates 75 meters below Malabar Hill and is bored by complex geological conditions including basalt, brescia and shale – more details could be had seen here,
The first southbound tunnel (3.93 km package-4 of MCRP) on this section is 12 meters wide and has two lanes and one emergency lane.
Back in 2021, L&T was hoping to excavate 9 m/day and complete both tunnels by its internal deadline of June 2022 – but that would not be possible. The machine will now be dismantled and taken back to the PDP launch ramp for its second assignment, and I think this is being recomended before the end of March.