02 June,2026 12:51 PM IST | Mumbai | Rajendra B. Aklekar
According to project officials, the second TBM will begin its tunnelling journey from Sawli (Ghansoli) towards Vikhroli. Pic/Special Arrangement
The Mumbai-Ahmedabad Bullet Train Project has reached another significant milestone with the lowering of the cutterhead for the second Tunnel Boring Machine (TBM) at Sawli (Ghansoli) near Mumbai.
The massive cutterhead, measuring 13.6 metres in diameter and weighing around 350 tonnes, marks the completion of the main shield assembly for the second TBM that will be used to excavate part of the project's underground tunnel section.
According to project officials, the second TBM will begin its tunnelling journey from Sawli (Ghansoli) towards Vikhroli.
Earlier this week, the cutterhead for the first TBM was lowered at Vikhroli. Both machines will now undergo final assembly, testing and commissioning before beginning excavation work in the first week of July 2026.
The giant cutterhead has been specially designed to excavate a single tunnel large enough to accommodate both the up and down tracks of the high-speed rail corridor.
The cutterhead is equipped with:
- 84 cutter discs
- 124 scrapers
- 16 bucket lips
These components help cut through soil and rock while efficiently removing excavated material during tunnelling operations.
The two TBMs are among the largest machines being used in India's high-speed rail infrastructure programme.
Key specifications include:
- Number of TBMs: 2
- Weight of TBM 1: 3,080 tonnes
- Weight of TBM 2: 3,184 tonnes
- Cutterhead diameter: 13.6 metres
- TBM type: Mix Shield/Slurry-based
Each machine measures 95.32 metres in length and consists of several specialised components, including the cutter wheel, main bearing, jaw crusher, erector, main shield, tail shield and four support gantries.
The TBMs are capable of operating at a maximum cutterhead speed of four revolutions per minute (RPM).
They can achieve an excavation rate of up to 49 millimetres per minute, allowing engineers to carry out tunnelling work safely and efficiently while maintaining strict quality and safety standards.
The Mumbai-Ahmedabad High-Speed Rail Corridor is one of India's most ambitious infrastructure projects. The deployment of the two giant TBMs is expected to play a crucial role in constructing the 21-kilometre underground tunnel section near Mumbai, helping advance work on the country's first bullet train network.
