Construction work on the Mumbai-Ahmedabad Bullet Train project achieved another milestone after the cutterhead for the second Tunnel Boring Machine (TBM) was successfully lowered at Sawli in Ghansoli. The machine will be used for the 21-kilometre underground section of the high-speed rail corridor near Mumbai.
The latest development comes shortly after the first TBM cutterhead was lowered at Vikhroli earlier this week. Following the installation process, both machines will undergo assembly and commissioning trials before tunnelling operations are scheduled to begin in the first week of July 2026.
The second TBM is expected to excavate the tunnel stretch from Sawli towards Vikhroli, operating in the opposite direction of the first machine. Together, the two machines will construct the underground alignment of the bullet train corridor, which is among India’s largest transport infrastructure projects.
According to project details, the cutterhead has a diameter of 13.6 metres and weighs nearly 350 tonnes. It forms a key part of the TBM’s shield assembly and is specifically designed to create a single tunnel accommodating both the up and down rail lines of the high-speed network.
The underground section will be constructed using two slurry-based Mix Shield TBMs. TBM 1 weighs 3,080 tonnes, while TBM 2 weighs 3,184 tonnes. Both machines share identical cutterhead diameters and have a total length of 95.32 metres.
Each TBM includes major components such as the cutter wheel, main bearing, jaw crusher, erector, main shield, tail shield and four support gantries. The machines are capable of operating at a maximum cutterhead speed of four revolutions per minute and can excavate at a rate of up to 49 millimetres per minute.
Source: Swarajya
