Overview
- The cutterhead, lowered Sunday at Mumbai’s Vikhroli site, finishes the TBM’s primary shield assembly for the high‑speed rail tunnel.
- Two TBMs weighing more than 3,000 tonnes each, the largest used for rail tunnels in India, will excavate 16 km of the 21 km Mumbai tunnel that includes a 7 km undersea section beneath Thane Creek.
- The first drive will run about 6 km from Vikhroli toward the Bandra‑Kurla Complex station, passing under dense neighborhoods and the Mithi River before retrieval at BKC.
- The 13.6‑metre cutterhead arrived in five loads and used about 1,600 kg of precision welding, and it is built to cut one large bore that can house both directions of track.
- Engineers have installed surface settlement points, optical displacement sensors, 3D targets, strain gauges and seismographs to track ground movement and safeguard nearby structures during tunnelling.