Second 350-Tonne Cutterhead Installed for Bullet Train Tunnel

Construction of the ambitious Mumbai-Ahmedabad bullet train project reached another key benchmark this week when crews lowered the second enormous cutterhead into the Savli shaft. The 13.6-metre-diameter disc will power a 3,184-tonne tunnel boring machine on its journey beneath Mumbai's eastern suburbs toward Vikhroli. Designed exclusively for single-bore, double-track operation, the cutterhead combines 84 rolling disc cutters with scraper and bucket systems that simultaneously fracture rock and extract spoil. Its installation follows the placement of an identical unit at the Vikhroli end earlier in the week. Both machines are now undergoing final assembly and commissioning trials. Once operational, they will achieve a maximum cutterhead rotation of four revolutions per minute and an advance rate of 49 millimetres per minute, allowing steady progress through mixed geology. The milestone reinforces confidence that the project's underground package remains aligned with the 2026 target for initial tunnel drives, bringing India's first high-speed rail corridor closer to reality.