India, July 6 -- The Mumbai-Ahmedabad Bullet Train project crossed a major construction milestone on Sunday with the country's largest railway Tunnel Boring Machine (TBM) commencing excavation from Vikhroli towards the Bandra Kurla Complex (BKC) station. The official inauguration by Union railway minister Ashwini Vaishnaw was cancelled due to the red alert and heavy rain in Mumbai.

The 13.6-metre diameter Mixshield TBM will construct a 6-km single-tube tunnel carrying both the up and down Bullet Train tracks. The tunnel forms part of the 21-km underground section of the Mumbai-Ahmedabad High Speed Rail corridor.

Of the 21-km underground stretch, 16 km between Ghansoli's Sawli and BKC will be excavated using TBMs, while the remaining 5 k...