The assembly of the second Tunnel Boring Machine (TBM) for the Mumbai-Ahmedabad Bullet Train project has begun at Sawli near Ghansoli, marking a key milestone in the construction of the high-speed rail corridor, officials said on Saturday.

They said that the TBM is being assembled at a depth of 39 metres below ground level. Once completed, the machine will begin tunnelling from Sawli towards Vikhroli, forming an important underground stretch of the project.