Atal Tunnel pass
Atal tunnel pass is a newly built highway tunnal built in eastern Pir Pranjal range of himalyas. The tunnel is constructed under Rohyang pass mountain structure. The highway over which tunnel is constructed is Leh – Manali highway.
The tunnel is significant, as this is the world’s longest tunnel ( 10,000 feet or3,048m), to ever be constructed.
As the name suggest, the tunnel is named after former Prime Minister of India, Shri Atal Bihari Vajpayi. This tunnel changes the time and distance patterns between Manali and Keylomg. The tunnel is902 km long and reduces the route,which was previously 116 km in length to 71 km. As far as time is conserned, it chops off 3 to 4 hours of time from former duration. Another benefit of this tunnel is that it goes past landslide and avalanche prone areas thus sparing the unnecessary hactic for travellers and tourists furthermore this is the first tunnel was inaugurated by Prime Minister Narendra Modi on 3rd October 2020 after years of construction and an astonishing cost of 438 million US dollers(200 crore).
The tunnelhave rockbolt and fiber reinforced concrete as its main support mechanism which is further supported by steel bars and ribs.
Construction of Atal tunnel was one of the most challenging work project in the modern era because of extreme environmental factors and raw landscape. The excavation work or tunnelling was usually done from both sides of the tunnel, but during winters north end of the tunnel gets closed as a result of heavy snowfall. This lead to around three-fourth of tunnel excavation material to be excavated from north end and thus delaying the work. Also while excavating seeping water posed a major hurdle for progress of tunnelling constant dewatering was required each day. Other than this on 8th august 2003 a flash flood due to a cloud burst caused 42 labourers to lose their life.