Overview
- NHSRCL began lowering and assembling tunnel-boring components Thursday, starting with a 170-tonne main-shield segment lowered 56 metres at Vikhroli.
- The TBMs will dig a 16-km section of a 21-km tunnel between BKC and Shilphata that includes a 7-km undersea stretch, after 5 km built using the NATM blasting method.
- Three shafts are ready at BKC, Vikhroli and Sawli, with one machine set to bore from Vikhroli to BKC and the other from Sawli to Vikhroli using 13.6-metre mix-shield slurry TBMs about 95 metres long and over 3,000 tonnes each.
- A casting yard at Mahape is producing about 77,000 precast segments to line the single-tube, 13.1-metre-diameter tunnel, and crews are deploying settlement sensors and seismographs to protect nearby buildings.
- NHSRCL targets an initial TBM drive in July 2026 and a main drive in October 2026, with assembly expected to take about 97 days and remaining machine parts due to clear port by April 12.