Boring of Rohtang tunnel complete

MC Thakur

Manali, October 12

The boring of the 8.8km-long Rohtang tunnel, being carried out at both ends, was completed today.

“The south portal of the tunnel in Kullu has been connected with its north portal in Lahaul,” project chief engineer NM Chandarana said.

The excavation of the tunnel had started from Dhundi, 25 km from here, on June 28, 2010. Later, the work was started from the opposite end in Lahaul near Sissu village. The work continued day in and day out and the breakthrough in the tunnel has finally been achieved. The air is now passing across the tunnel while men will walk across in the next few days.

Chandarana said: “We we have been able to reach the opening of the tunnel and connect the portals. Our next task will be to carry out a safety audit and installing support systems. A detailed survey to ensure a breakthrough as per the designed tunnel alignment within required norms of traffic geometry is under way.”

The tunnel faced many hurdles like water ingress and loose rock material that had slowed down the digging work. The project managed to negotiate the Seri Nala Fault Zone in January 2016 and progressed well. “We have achieved 3,500 metre progress in less than 20 months. We could complete 1,270 metre of heading excavation this season. Engineers are now checking structural stability and alignment,” Chandarana said.

He added that the sanctioned budget of the tunnel was Rs 4,035 crore and Rs 1,860 crore had been spent so far. “The tunnel will have an inbuilt fire safety system, telephone booths at every 150 m distance and an entrance to emergency escape point at every 500 m. We are working on the ventilation system and shall soon hold a meeting with the Lahaul-Spiti administration and locals to chalk out a strategy on how we can allow the people in emergency to cross the tunnel this winter,” he added.

The horse-shoe shaped tunnel is being built by the drill and blast method of tunnelling with the new Austrian Tunnelling Method.

The south portal of the tunnel is at Dhundi, 10,180ft, while the north portal is located close to Teling village of Lahaul at 10,226ft.

The tunnel, when completed, will reduce the distance between Manali and Leh by 46 km.

The tunnel will provide connectivity to residents of Lahaul throughout the year. Once completed, it will be the longest tunnel of the country at this altitude.