Mumbai-Ahmedabad bullet train: NHSRCL completes first mountain tunnel in Gujarat's Valsad

The corporation constructing India's first high-speed rail corridor between Mumbai and Ahmedabad on Thursday announced the completion of its first 350-metre-long mountain tunnel near Zaroli village in Valsad district of Gujarat.

National High Speed Rail Corporation Limited (NHSRCL) celebrated the moment by carrying out a final blast to remove the last layers of rock close to the entrance of the tunnel.

"The biggest challenge for us was how to keep the alignment of the tunnel absolutely straight because the bullet train will run at 320 kmph speed and a minor alignment flaw can play a spoilsport. So, every specification has to be followed precisely and you will not find a deviation of even a single millimetre," S P Mittal, Chief Project Manager of the Valsad section, told PTI.

"We have just dug the skeleton structure of the complete tunnel and the finishing work will start now," he added.

According to him, it took more than a year and a large workforce to complete the tunnelling work.

Mittal also expressed great satisfaction as it happened to be the first mountain tunnel under his direct supervision.

Total seven tunnels are proposed to be made on the entire 508-km route between Mumbai and Ahmedabad and the work for the second tunnel will start very soon, he said.

NHSRCL has awarded the contract to L&T and the technique which has been used to make the tunnel is the well-established New Austrian Tunnelling Method (NATM), which has already been used in India for rail and road projects in several mountain areas.

"What makes us celebrate it is that it is the first tunnel in India through which a train with a speed of 320 kmph will pass," Mittal said, adding that in the entire construction period his team did not face a single untoward incident.

According to him, when blasts are carried out for such tunnels, the safety of workers and people residing in the vicinity are paramount.

"We took every precaution so that stones, boulders or any other such material did not spread in the nearby area and hurt villagers or our workers,” Mittal said.

After coming into existence in 2016, NHSRCL laid the foundation stone of the bullet train project in 2017 and it was proposed to be ready by December 2023. However, land acquisition issues delayed the ambitious project.

Though the construction work is going on in full swing, the new deadline for the project's operationalisation has not been announced yet.

"A commuter using this bullet train can finish the 508-km journey in 2 hours and 7 minutes. At present, the train journey takes about 5 hours," the official spokesperson of NHSRCL told PTI.