Ashwini Vaishnaw witnesses breakthrough of India’s longest rail tunnel in Uttarakhand

Railway Minister Ashwini Vaishnaw witnessed the breakthrough of India's longest rail tunnel at Janasu in Uttarakhand on Wednesday.

Accompanied by Chief Minister Pushkar Singh Dhami, Vaishnaw went about 3.5 km inside the tunnel when a boring machine achieved the breakthrough from the other side breaking last layer of rock.

The 14.57-km-long tunnel no 8 between Devprayag and Janasu is part of the ambitious 125-km Rishikesh-“Karnaprayag Broad Gauge Rail Link Project in Uttarakhand.

Vaishnaw called it a historic moment as the breakthrough coincided with the day rail service was started in India on April 16, 1853.

Rail Vikas Nigam Limited (RVNL), a public sector undertaking under the Ministry of Railways, which is looking after the whole project, achieved this breakthrough using a German-made tunnel boring machine (TBM) named 'Shakti'.

Since Tunnel 8 is a twin tunnel, the work on another parallel one is going on with the help of the second TBM and it is expected to achieve breakthrough by July. The work contractor for this tunnel is L&T.

"The remarkable feat was achieved in the presence of Hon'ble Railway Minister Ashwini Vaishnaw, who visited the site to mark this momentous milestone in Himalayan rail connectivity," a statement from RVNL said.

Earlier, RVNL CMD Pradeep Gaur had told PTI that this is the first time TBM technology has been deployed for rail tunnelling in mountainous regions of the country, and the progress sets a new global benchmark with a 9.11-m diameter single-shield rock TBM.

Gaur has mentioned that the 9.69-m diameter Cabrera tunnel in Spain was built by a double shield TBM at an average rate of 423 m per month while the 14.58-km tunnel between Devprayag and Janasu has just been completed by Single Shield TBM at an average rate of 413 metres per month, becoming the second fastest in the world.

"This breakthrough marks a significant step in the government's mission to enhance connectivity across India's hill states," Gaur said after the event.

"The Rishikesh-Karnaprayag project, executed from concept to commissioning by RVNL, aims to transform regional connectivity by linking key towns such as Devprayag, Srinagar, Rudraprayag, Gauchar, and Karnaprayag across five Himalayan districts," the RVNL statement said.

"More than 83% of the 125-km alignment passes through tunnels, involving over 213 km of tunnelling across main and escape routes," it added.

Officials present at the tunnel site stated that the TBM has faced extraordinary logistical and geological challenges, including transporting 165 MT components from Mundra port to site across narrow Himalayan roads and old bridges.

The tunnel also lies in tectonically active Seismic Zone IV, requiring sophisticated design and continuous advance geological probing, they added.

RVNL is of the view that once completed, the project will drastically reduce travel time, improve all-weather access to remote regions, and boost tourism and economic development across Uttarakhand.

"It is also a critical step in realizing the Char Dham rail connectivity initiative," the statement said.