The 9 km long tunnel bypasses the Rohtang Pass on the Manali-Leh Highway. It provides all-weather connectivity to the Lahaul Spiti Valley and northern India, reducing travel distance by 47 km and travel times by up to four hours. Facilitating two-way traffic, it is designed to cater to up to 3,000 vehicles per day in any weather conditions at a maximum vehicular speed of 80 km per hour. The tunnel is now the world’s longest at an altitude of over 10,000 feet.
Located in the Himalayas, the tunnel site featured complex topography and geologies including peaks of 5200m. The remoteness, accessibility and extreme altitude of the project presented enormous challenges to geological works, tunnelling and mechanical and electrical installations.
After nearly a decade under construction, the tunnel opened to traffic in October 2020. Previously, access over the mountain pass was restricted to only six to eight months each year, due to heavy snowfall, avalanches and landslides. Providing safe, year-round access through the Rohtang Pass will assist economic development in the region, allowing almost 20,000 people in previously isolated communities of the Lahaul and Spiti Valleys to travel and sell agricultural produce in towns. The tunnel will also boost tourism by providing all-year access to Leh and Lahau.
SMEC was engaged by India’s Border Roads Organisation and the Ministry of Defence in 2006 to provide design, engineering and advisory services on the Atal Tunnel, formerly known as the Rohtang Tunnel. SMEC was subsequently engaged as the Independent Engineer, carrying out supervision, project management and contract management for all electrical and mechanical installations. A team of more than 25 specialists from different countries came together to contribute our global expertise to helping our client make this huge undertaking a reality.
- Technical Area:
- Border Roads Organisation