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Engineering marvel: India’s highest tunnel to see light of day in October

The tunnel in Himachal Pradesh will bring down the distance between Manali and Leh by 46km.

india Updated: Sep 12, 2017 10:44 IST
Gaurav Bisht
Gaurav Bisht
Hindustan Times, Shimla
The horse-shoe shaped road tunnel will be functional for emergency vehicles through this winter but will get fully operational by August 15, 2019.
The horse-shoe shaped road tunnel will be functional for emergency vehicles through this winter but will get fully operational by August 15, 2019.(Aqil Khan/HT)

Running three years behind schedule, the strategic 8.8-km all-weather Rohtang Tunnel, the highest in the country, will open to emergency traffic in October. Being built under the Rohtang Pass at an altitude of 13,050 feet in the eastern Pir Panjal range of the Himalayas on the Leh-Manali highway, the horse-shoe shaped road tunnel will be functional for emergency vehicles through this winter but will get fully operational by August 15, 2019.

At 9.2km, the Chenani-Nashri Tunnel, also known as Patnitop Tunnel, that links the Kashmir Valley with Jammu on National Highway 44 is the country’s longest road tunnel built at a height of nearly 4,000 feet.

STRATEGIC LINK

The tunnel in Himachal Pradesh will bring down the distance between Manali and Leh by 46km. At present, the distance between the two towns is 474 km that takes six to eight hours to cover. The tunnel will reduce the travel time by two-and-a-half hours. The speed limit in the tunnel is 80km/h or 50mph.

This will help accelerate troop mobility to the strategic frontiers in Jammu and Kashmir besides providing a road link to Lahaul and Spiti in winter. At present, people in the tribal district are dependent on government-run helicopter services in winter. “If emergency vehicles start plying this winter, it will be a big relief. It will put an end to the harsh life people are forced to lead half the year round,” says Lahaul and Spiti legislator Ravi Thakur.

Engineers used the drill and blast technique for excavation as part of the New Austrian Tunneling Method (NATM). (Aqil Khan/HT)

HITTING ROADBLOCKS

Two portals of the tunnel, the south portal at Dhundhi and the north at Sissu Nullah, will be connected by October-end. “Only 250 metres of digging is left. We will work on electrical fittings and ventilation after that,” says chief engineer NM Chandrana. A defence ministry team, led by joint secretary Bharat Khera, took stock of the project in August. The project missed its 2015 deadline due to geological challenges since work started in 2010. The water ingress from Seri Nullah, a glacier-fed rivulet, above the tunnel was a challenge. In 2012, it took engineers almost a year to plug the seepage. The delay in permission for quarrying construction material slowed down work at the north portal. The ban on environmental clearances to mining also led to the shortage of construction material.

WORK IN PROGRESS

Engineers used the drill and blast technique for excavation as part of the New Austrian Tunneling Method (NATM). Defence road construction agency Border Roads Organisation (BRO) is excavating the tunnel with Strabag-Afcons, a joint venture between India’s Afcons Infrastructure Limited and Austria’s Strabag SE. The BRO will continue working on the north portal even after mid-November. Usually, work is halted in winter when the Rohtang Pass is cut off from the rest of the world due to snowfall.

COST AND DELAY

The estimated cost of the project in 2010 was Rs 1,700 crore. It was revised to Rs 2,000 crore in 2015 and now the projected cost by 2019 is Rs 4,000 crore. The project was to be completed in February 2015 but water ingress from Seri Nullah, ban on rock mining, delay in allotment of land needed for quarrying, and loose rock strata in the middle led to a slowdown.

MILESTONES

Conceived in 1998, the project was announced by then prime minister Atal Bihari Vajpayee on June 3, 2000. The work was entrusted to BRO on May 6, 2002. United Progressive Alliance chairperson Sonia Gandhi laid the foundation stone of the project on June 28, 2010.