Rohtang Tunnel: All you need to know about the world’s longest highway tunnel

Rohtang Tunnel: All you need to know about the world’s longest highway tunnel

A 3,000-member team of contractual workers and 650 regular employees of the Border Roads Organisation (BRO) have been working in shifts through 24 hours on the Rohtang Tunnel project.

The Rohtang Tunnel, when complete, will cut through the mighty Pir Panjal range and become the world’s longest highway tunnel above 10,000 feet. For now, the tunnel provides a temporary winter link to the outside world not only to residents of Lahaul and Spiti but also to those living in Zanskar Valley of Ladakh. Without this link, opened on humanitarian grounds for Himachal Roadways bus service and some emergency vehicles, these villagers would have remained cut off for the next six months.

One of the most prestigious tunnel projects in the country, the work is monitored by the Prime Minister’s Office. PM Narendra Modi will inaugurate the project once complete. The tunnel is expected to be named after former PM Atal Bihari Vajpayee, who took a keen interest in the project during his tenure, and was also a regular visitor to Manali.

A 3,000-member team of contractual workers and 650 regular employees of the Border Roads Organisation (BRO) have been working in shifts through 24 hours on the project. It would have been completed at least four years earlier, but for a massive torrent of water encountered inside the tunnel. The Seri Nullah, which flows on top of the tunnel, almost threatened to derail the project and it took several years to devise ways to tackle the massive flow of water that often went up to 140 litres per second.

The project also has significant strategic implications for the military as it will allow access beyond Rohtang Pass even in peak winters. All-winter connectivity to Ladakh, however, is still some time away as more tunnels will have to be built to tackle the high passes which fall beyond Rohtang.

While Rohtang Pass is at a height of 13,050 feet, the pass on the road to Leh is Baralacha La at 16,040 feet. A 13.2-km long tunnel would be required to bypass this pass and a Detailed Project Report for the same is ready to be presented to the government.

Further down the highway comes Lachung La Pass at 16,800 feet requiring a 14.78 km long tunnel to provide all-weather connectivity. Thereafter falls the Tanglang La pass at 17,480 feet, which will need a 7.32-km long tunnel.

An alternate road link to Ladakh has also been developed by BRO on the Darcha-Padam-Nimu axis, but here again a 4.15-km long tunnel at Sinka La Pass (16,703 feet) would be required for all-weather access. The National Highways and Infrastructure Development Corporation Limited (NHIDCL) is making a DPR for this tunnel which will give a new road link to Leh.

Services inside Rohtang Tunnel:

*Telephone at every 150 metres

*Fire hydrant at every 60 metres

*Emergency exit at every 500 metres

*Turning cavern at every 2.2. km

*Air Quality monitoring every 1 km

*Broadcasting system

*Automatic incident detection system with CCTV every 250 metres

*Width of carriageway: 10.50 metres including one metres footpath on both sides

*Maximum speed limit: 80 km per hour
*Max Traffic expected: 3,000 petrol cars a day and 1,500 trucks a day

Tunnel sequence of events

*Cost: Rs 4083 crore sanctioned (eventual cost will be less by approx. Rs 300 crore)

*Feasibility study: May 1990

*Geological report submitted: June 1994

*Design and specification report submitted: Dec 1996

*Final technical approval: 2003

*CCS approval: 2005

*Consultant appointed: 2006

*Tenders floated: 2007

*Letter of acceptance for tender: 2009

*Foundation stone laid: July 28, 2010

*Original date of completion: Feb 1, 2015

*Expected date of completion: September 2020.

Source : BRO