Moving ahead with the next phase, RRTS tunnelling work for India’s first Regional Rail begins with the construction of around 1.5 km long tunnel by Tunnel Boring Machine (TBM) from Anand Vihar to New Ashok Nagar.

The 90 meters long machine (TBM) named as Sudarshan 4.1 has completed tunnel boring of half the total distance of around 3 km long tunnel.

The Delhi-Ghaziabad-Meerut RRTS corridor is 82 km long, of which 14 km is in Delhi. The Delhi section has four stations, Jangpura, Sarai Kale Khan, New Ashok Nagar, and Anand Vihar, with only Anand Vihar station being underground.

Two Sudarshans (TBMs) are in operation to construct two 3 km long parallel tunnels from Anand Vihar station towards New Ashok Nagar.

Out of this, the first Sudarshan, 4.1 has already bored 1.5 km of tunnel to date, while the second Sudarshan, 4.2 has also constructed about 1 km of tunnel so far.

To retrieve these Sudarshans, after the completion of the construction of the tunnels, a retrieving shaft has been built near the New Ashok Nagar station, from where the corridor gets elevated.

On the other hand, about 2 km long parallel tunnels will be constructed from Anand Vihar towards Sahibabad, Uttar Pradesh, which will terminate in front of Vaishali metro station.

At present, one Sudarshan, 4.3 is boring a tunnel, and the other Sudarshan, 4.4 is in the final stages of assembling which will soon be launched to construct the tunnel.

Tunnel rings are made underground by TBM with the help of tunnel segments. Seven  tunnel segments are generally used to form a tunnel ring. The tunnel segments are being manufactured at NCRTC's Casting Yard with assured quality control.

Due to the large rolling stock and a high design speed of 180 mph, the width of RRTS tunnels is being constructed as 6.5m diameter. Compared to the metro systems, this is for the first time that a tunnel of such a large size is being constructed in the country.

For the movement of trains in the underground parts of RRTS, two parallel tunnels are being built. Along with this, provision has also been made for various security measures to ensure the safety of the passengers.

There will be a cross-passage approximately every 250 meters in the underground sections for the safety of passengers in case of any emergency.

In addition, the tunnel will also have a side walkway of 60 cm-90 cm wide which will assist in maintenance activities as well as in case of emergency. Ventilation ducts will also be provided to ensure the movement of air in the tunnel.

Also Read: Chennai Metro: First Tunnelling Work Of Phase II Project To Begin In Mid-October In Madhavaram