Major Milestone Achieved in Mumbai-Ahmedabad Bullet Train Project with Second TBM Cutterhead Launched

May 23, 2026

Mumbai, May 23: A significant achievement has been reached in India’s ambitious Mumbai-Ahmedabad bullet train project. The second tunnel boring machine (TBM) cutterhead has been successfully launched for the construction of a 21-kilometer tunnel at the Savli (Ghansoli) shaft near Mumbai.

Weighing approximately 350 tons and measuring about 13.6 meters in diameter, this cutterhead is considered the final and most crucial part of the TBM’s main shield assembly. Its launch is expected to accelerate tunnel construction work.

This second TBM will commence its excavation journey from Savli (Ghansoli) and will progress towards Vikroli. Earlier this week, the cutterhead of the first TBM was also launched in Vikroli. The final assembly and commissioning trials for both machines will now take place, with plans to initiate their preliminary drive in the first week of July 2026.

Designed specifically for single tunnel excavation, the 13.6-meter diameter cutterhead will allow both up and down lines of the high-speed rail corridor to operate simultaneously.

This state-of-the-art unit is equipped with 84 cutter discs, 124 scrapers, and 16 bucket lips, enabling it to cut through rocks and remove debris with high efficiency.

So far, two advanced TBMs have been received for the project, with TBM-1 weighing 3080 tons and TBM-2 weighing 3184 tons. Both machines feature cutterheads with a diameter of 13.6 meters and operate on mix shield and slurry-based technology.

Each TBM has a total length of 95.32 meters and includes advanced equipment such as cutter wheels, main bearings, jaw crushers, erectors, main shields, tail shields, and four specialized gantries for tunnel construction.

These machines can operate at a maximum cutterhead speed of 4 RPM and an excavation capacity of up to 49 mm per minute, ensuring that tunnel construction is completed safely, in a controlled manner, and at a continuous pace.

The Mumbai-Ahmedabad bullet train project is regarded as one of the largest high-speed rail infrastructure projects in the country, and this new achievement is seen as a significant milestone for the initiative.