Mumbai-Ahmedabad Bullet Train: First Mountain Tunnel Shaped In Just 10 Months

The completion of the mountain tunnel for the Mumbai-Ahmedabad High-Speed Rail corridor project on October 5, marked a significant milestone for National High Speed Rail Corporation Limited (NHSRCL). This is the first mountain tunnel of the route and its breakthrough was made in under 10 months.

"This single tube horseshoe-shaped tunnel, with a length of 350 meters and a diameter of 12.6 meters, is intended to accommodate both tracks (up and down) of the projected Mumbai-Ahmedabad Bullet train corridor. Its height is approx 10.25 meters," according to an NHSRCL official.

This tunnel, which is about 1 km distant from Zaroli Village in Gujarat's Valsad district's Umbergaon Taluka, serves as an example of contemporary tunnelling methods. The tunnel structure consists of the tunnel, a tunnel portal, and other auxiliary buildings, such as the hood above the tunnel entrance.

According to NHSRCL, the cutting-edge New Austrian Tunnelling Method (NATM), a method renowned for its accuracy and effectiveness, was used to build this tunnel. The NATM approach entails a series of meticulous steps, starting with marking drill holes on the tunnel face and continuing with drilling, explosive charging, controlled blasting, removal of muck (blasted rock pieces), and installation of primary support elements like steel ribs, lattice girder, shotcrete, and rock bolts. According to an official, these actions are catered to the particular geological circumstances that each blast brings about.

The NATM Method will be used to build the seven mountain tunnels that make up the Mumbai-Ahmedabad High-Speed Rail Corridor. The Mumbai-Ahmedabad High-Speed Rail Corridor (MAHSR) project, which includes numerous mountain tunnels built utilizing the NATM technique, is expected to revolutionize transportation in the area. As this ground-breaking project moves forward, it portends a promising future for high-speed rail connectivity in India, boosting connectivity and travel effectiveness between two important cities.

On October 1, NHSRCL at Gujarat’s Anand opened a track slab manufacturing facility. The development of the ballastless track works for the MAHSR will require track slabs, which will be produced by this new TSMF.

Modern equipment is housed in the factory, which has a 1 lakh square meter footprint, to produce track slabs for the 116 km double line High-Speed Rail track for the MAHSR Corridor.

The TSFM will produce 45,000 precast track slabs required for the project. In this facility, 60 high-precision moulds have been procured and installed. These moulds can produce 60 track slabs per day. Per kilometer of track requires about 200 track slabs. To make track installation easier and more seamless, it has storage space for up to 9000 track slabs. 

TSMF is completely automated with a Concrete Distribution System. Various ancillary facilities have been used by NHSRCL to support the production of track slabs.