Set in the Pir Panjal range of the Great Himalayas, the Atul tunnel has been constructed at an altitude of more than 10,000 feet (3000 m). It is a perennial all-weather tunnel of 9.02 km in length, and is the longest tunnel in the world at that altitude.
The single tube, two laned, bi-directional horseshoe shaped tunnel will provide all-year connectivity between Manali in the South to the Lahaul & Spiti valley in the North on the NH connecting Leh. It is also the country’s first tunnel to have an escape tunnel within the main tunnel.
The South Portal of the tunnel is located at an altitude of 3060 m above sea level which is 25 km North of Manali, on the left bank of Seri Nala, which is a tributary of Beas-Kund River. The North Portal is located across the Rohtang Pass on the South West bank of Chandra River at an altitude of 3071 m above sea level, at an approximate distance of 79 km from Manali on the Manali-Sarchu road (NH 21) via Rohtang Pass. The tunnel has been excavated using the Drill and Blast technique with the application of the New Austrian Tunnelling Methodology (NATM ) philosophy.
The tunnel built by the Border Roads Organisation, reduces the distance between Manali and Leh by 46 km. it is designed for a traffic density of 3000 cars and 1500 trucks per day with a max speed of 80 km per hour. The tunnel was dedicated to the nation by the Hon’ble Prime Minister Shri Narendra Modi, on 03 Oct 2020.