Overview
- The cutterhead for the second TBM was lowered at Sawli near Ghansoli on Saturday, completing primary assembly of the machine’s main shield; the cutterhead is the rotating front section that cuts soil and rock.
- Each cutterhead is 13.6 metres in diameter, weighs about 350 tonnes, and is fitted with 84 cutter discs, 124 scrapers and 16 bucket lips to cut material and remove muck during excavation.
- Two slurry/mix‑shield TBMs—about 95.32 metres long and weighing roughly 3,080 and 3,184 tonnes—are being finalised and will undergo commissioning trials through June before starting tunnelling in the first week of July.
- The machines are set to bore a roughly 21‑km underground tunnel between Ghansoli and Vikhroli that includes an approximately 7‑km undersea crossing beneath Thane Creek; idealised rates mention up to 70.56 metres per day but actual progress is expected to be slower and take about a year for the underground section once pauses and maintenance are factored in.
- This tunnelling work is part of the wider 508‑km Mumbai–Ahmedabad high‑speed corridor that aims to cut travel time to around two hours and is targeted for an August 15, 2027 launch.