New Delhi: There is more good news about the much-awaited Mumbai-Ahmedabad bullet train project. The ambitious mission has achieved its first important milestone as a 21-km-long tunnel between Mumbais Bandra-Kurla Complex (BKC) and Thanes Shilphata has been constructed.
Which method has been used?
A 2.7-km-long continuous tunnel section has been successfully completed using the New Austrian Tunneling Method (NATM). The National High Speed Rail Corporation Limited (NSSRCL) has given this information. This achievement is a significant leap in Indias first bullet train project which aims to connect Mumbai and Ahmedabad through a high-speed rail corridor.

This will significantly reduce travel time and increase transport efficiency between the two financial centers. The 21-km long tunnel will be a crucial part of the high-speed rail corridor of which 16 km will be constructed using tunnel boring machines (TBMs) and the remaining five km using the New Austrian Tunnelling Method (NATM) including the section between Shilphata and Ghansoli.
What else does the tunnel include?
The tunnel also includes a seven-km undersea section under the Thane creek. To expedite the tunnelling work in the NATM section an additional operated intermediate tunnel (ADIT) was constructed enabling simultaneous excavation from both Ghansoli and Shilphata ends. Out of the total NATM section about 1.62 km has been excavated from the Shilphata side and the total progress is 4.3 km.
What is the cost of this project?
The NHSRCL said that extensive safety measures have been implemented at the site including installation of ground settlement markers piezometers inclinometers strain gauges and biometric access control systems. These are designed to ensure safe and controlled tunnelling work without affecting nearby infrastructure or habitations.

However sources said that TBM machines have not yet been received from the companies for the construction of the 16-km-long tunnel while the shafts and other equipment for these machines are in place.

The total cost of the Mumbai-Ahmedabad High Speed Rail Corridor project has been estimated at Rs 1.08 lakh crore. As per the shareholding pattern the central government will pay Rs 10000 crore to NHSRCL while Gujarat and Maharashtra have to pay Rs 5000 crore each.