Larsen & Toubro last week rotated tunnel boring machine (TBM) Mavala’s shields using a special turntable at Girgaum’s Chowpatty Ramp for Mumbai’s 29.2 km Coastal Road (Western Freeway) project.
The 80m long CRCHI slurry machine (DZ636) recorded its first breakthrough in early January 2022 after tunneling 2,070m between Priyadarshini Park Launch Ramp and Chowpatty for the south-bound tunnel.
It’s the largest TBM ever to be deployed in India and will commence its second drive, for the northbound tunnel, back to Priyadarshini Park by the end of March to build MCRP project’s 3.93 Package-4.
Along the way, it’ll excavate 75 meters below Malabar Hill and bore through complex geological conditions that include basalt, breccia and shale – more details can be viewed here.
Each tunnel will be 12 meters wide consisting of two lanes and one emergency lane.
Prior to this, TBMs in India have been rotated in Delhi and Bangalore, so while this is a cool little feat, it isn’t unique.