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.
Massive gantry lowered into shaft
An official statement said that a major component of the TBM, a gantry weighing around 190 metric tonnes, has been successfully lowered into the shaft. The structure measures approximately 18 metres in length, 10 metres in width and 9 metres in height.
In total, four gantries will be installed in each TBM. These will be attached to the main shield assembly and cutterhead.
Critical role of gantries in tunnel construction
The gantries will move along the entire excavated tunnel length along with the TBM. They play a crucial role in supporting operations such as excavation, waterproofing and the installation of tunnel lining segments.
Complex assembly due to space constraints
The assembly process at the Sawli shaft is particularly challenging due to limited space. Engineers are carrying out the work with careful planning and precision to ensure safety and efficiency.
The initial drive of the TBM is expected to commence in July 2026.
