The Atal tunnel, which cuts the travel time between Manali and Leh from four to five hours, will be inaugurated by Prime Minister Narendra Modi on Saturday. The longest highway tunnel in the world by altitude will connect Manali with the Lahaul-Spiti Valley throughout the year. The valley was isolated for about six months each year due to heavy snowfall. The decision to build the tunnel was made by the government led by Atal Bihari Vajpayee in June 2000. It was previously known as the Rohtang Tunnel. The government led by Narendra Modi later decided to call it the Atal Tunnel in memory of former Prime Minister Atal Bihari Vajpayee.
Take a look at the longest high-altitude tunnel in the world
The 9.02-kilometer-long tunnel is built to ultra-modern specifications in the Pir Panjal mountain range of the Himalayas at an altitude of 3,000 meters from mean sea level (MSL).
The south portal (SP) of the Atal tunnel is located at a distance of 25 km from Manali at an altitude of 3060 meters, while the north portal (NP) of the tunnel is located near the Teling village, Sissu, in the Lahaul valley at an altitude of 3,071 meters.
It is a double-lane, single-tube, horseshoe-shaped tunnel with an 8-meter carriageway and a clearance height of 5,525 meters, the PMO said. It has been designed for a traffic density of 3000 cars per day and 1500 trucks per day with a maximum speed of 80 km / h.
It has the latest generation electromechanical system that includes semi-transversal ventilation system, fire control system, lighting and SCADA monitoring.
The tunnel, built at a cost of approximately ₹Rs 3,300 crore is extremely significant from a country’s defense standpoint, officials said. The most difficult stretch was the 587-meter Seri Nalah fault zone. The advance of both extremes was achieved on October 15, 2017.
Most of the construction was done by the Border Roads Organization (BRO). They had to overcome a series of climatic, terrain and geological challenges to build the tunnel.
Speaking of the tunnel, an official from the BRO said that it provides a telephone installation in every 150 meters of its section, a fire hydrant every 60 meters, emergency exits every 500 meters, a turning cavern every 2.2 kilometers, quality monitors of the air every 1 km, transmission system. and automatic incident detection system with CCTV cameras every 250 meters.
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