Atal Tunnel: PM Modi to inaugurate world's longest highway tunnel on Oct 3; check out its unique features

Prime Minister Narendra Modi will inaugurate the world's longest highway tunnel, named Atal Tunnel, at Rohtang Pass, Himachal Pradesh, at 10 AM on October 3. The 9.02-km long tunnel will now connect Manali to Lahaul-Spiti valley throughout the year. It's a big relief for travellers as earlier the valley was cut off for about 6 months each year owing to heavy snowfall at Rohtang Pass.

The tunnel is built with ultra-modern specifications in the Pir Panjal range of Himalayas at an altitude of 3,000 Mtrs (10,000 ft) from the sea level. It'll reduce the road distance between Manali and Leh by about 46km and the time by about 4 to 5 hours. The Atal Tunnel's south portal is located at a distance of 25km from Manali at an altitude of 3,060 mtrs, while the north portal near village Teling, Sissu, in Lahaul Valley (3,071 mtrs altitude).

It is horse shoe shaped, single-tube double lane tunnel with a roadway of 8 mtrs, and has an overhead clearance of 5.525 mtrs. Atal Tunnel is 10.5-metre wide and has a 3.6 x 2.25 mtrs fire proof emergency egress tunnel built into the main tunnel itself. The tunnel has been designed for traffic density of 3,000 cars per day and 1,500 trucks per day with max speed of 80 km/hr.

The tunnel has been made with the state of the art electromechanical system, including semi-transverse ventilation system, SCADA controlled firefighting, illumination and monitoring system.   

After attending the inauguration function of the Atal Tunnel at South Portal, Manali, on Sunday, Prime Minister Modi will take part in public functions at Sissu in Lahaul Spiti and at Solang Valley.

Some of the key safety features in the tunnel are:

•     Tunnel entry barriers at both portals
•     Telephone connections at every 150 mtrs for emergency communication
•     Fire hydrant mechanisms at every 60 mtrs
•     Auto incident detection system with CCTV cameras at every 250 mtrs
•     Air quality monitoring at every 1 km
•     Evacuation lighting/exit signs at every 25 mtrs
•     Broadcasting system throughout the tunnel
•     Fire rated dampers at every 50 mtrs
•     Cameras at every 60 mtrs

Foundation of strategic tunnel was laid 20 years back

The decision to construct a strategic tunnel below the Rohtang Pass was taken on June 3, 2000, when late Atal Bihari Vajpayee was India's prime minister. The Border Roads Organisation (BRO) worked relentlessly to overcome major geological, terrain and weather challenges that included the most difficult stretch of the 587-metre Seri Nalah Fault Zone.

The breakthrough from both ends was achieved on October 15, 2017. The Union Cabinet met under the chairmanship of Prime Minister Narendra Modi on December 24, 2019, and decided to name the Rohtang Tunnel as Atal Tunnel to honour the contribution made by Vajpayee.  

Also read: PM Modi launches Atal Bhujal Yojana, names Rohtang tunnel after former prime minister