Rohtang Tunnel is a 8.8 km long horsh shoe shaped tunnel being built under the Rohtang Pass in the eastern Pir Panjal range of the Himalayas on the Leh-Manali Highway by Border Road Organization (BRO). The tunnel is at 3,100 metres (10,171 ft) elevation whereas the Rohtang pass is at 3,978 metres (13,051 ft) elevation 51 km (32 mi) away from Manali. The pass receives heavy snowfall and blizzards during winter months and is open for road traffic for only four months in a year. The only other route through the Zoji La pass on the Srinagar-Drass-Kargil-Leh highway also gets blocked by snow for nearly four months in a year. These two routes are vital to feed military supplies into the sub-sector west (facing Aksai Chin) and the Siachen Glacier.
The project was conceived in 1983 and announced by Prime Minister Atal Bihari Vajpayee on 3 June 2000. The project was estimated to cost ₹ 5 billion and be completed in seven years.On 6 May 2002, the BRO was entrusted with the construction of the tunnel, and on 23 May 2002, the work was inaugurated by Mr. Vajpayee. The cost of the project was revised to ₹13.35 billion, with an expected completion by 2010.
However the work did not progress much, with the project not moving beyond the tree-felling stage by May 2003. By December 2004, the project cost estimate had escalated to ₹17 billion In May 2007, the contract was awarded to SMEC (Snowy Mountains Engineering Corporation) International Private Limited, an Australian company, and the completion date was revised to 2014. Despite multiple announcements that the work on the tunnel would begin in 2008,no progress had been made by November 2009.
The work was awarded to a joint venture of AFCONS Infrastructure Limited, an Indian construction company of Shapoorji Pallonji Group, and STRABAG AG, Austria in September 2009 after the Cabinet Committee on Security cleared the Rohtang Tunnel Project. The drilling of the Rohtang Tunnel through the Himalayan ranges began on 28 June 2010 at South Portal 30 km (19 mi) north of Manali.
When completed the tunnel is also set to become the world longest tunnel at an altitude above 3,000 m or 10,000 ft. The 85 km distance from Manali to Keylong on the other side of Rohtang Pass is usually covered by vehicles in about five to six hours, without counting the long hours of traffic jams on the hilly route. The same distance would now be covered in less than half-an-hour through the tunnel and without traffic snarls. Keylong would be just 25 km from the North Portal of the tunnel.
However, the construction of Rohtang tunnel will provide all-weather connectivity only to the Lahaul Valley of Himachal Pradesh up to Keylong. The all-weather road to Ladakh will require more tunnels.
Tourist rush in summer(Image: en.wikipedia.org)
The most challenging task is to continue the excavation during heavy snowfall in winter. Excavation for tunnelling is being done from both ends. However, as Rohtang pass closes during the winter, the north portal is not accessible during winter and the excavation is being done only from the south portal during the winter. Only about one-fourth of the entire tunnel will be excavated from the north end and three-fourths will be excavated from the south end.
The road is cleared by BRO by mid-May for public use and closed by October end(Image: www.homestaymanali.in)
Another challenge was water ingress on the south portal side in 2012. Detected to a source from Seri Nullah, a glacier-fed rivulet flowing through the 562 metres in the tunnel cavity, it took until early 2016 to fix it. At one time BRO which stopped all work on the tunnel to fix the problem even considered changing the alignment.
As of July 2016, 6.8 km of the tunnel digging had been completed.
In June 2016 Indian Express reported that the tunnel may be ready only by 2019-2020.
In August 2016 a bridge providing approach to the north face collapsed due to strong currents in the Chandra river while a truck was crossing it but the BRO assured that it would be restored in 4-5 days.