From UPSC perspective, the following things are important :
Prelims level : Rohang Tunnel
Mains level : Significance of the tunnel
The Rohtang Tunnel will become the world’s longest highway tunnel above 10,000 feet, after its inauguration in Sept 2020.
- Rohtang Tunnel is a highway tunnel being built under the Rohtang Pass in the eastern Pir Panjal range of the Himalayas on the Leh-Manali Highway.
- At 8.8 km length, the tunnel will be one of the longest road tunnels in India and is expected to reduce the distance between Manali and Keylong by about 46 km.
- For now, the tunnel provides a temporary winter link to the outside world not only to residents of Lahaul and Spiti but also to those living in Zanskar Valley of Ladakh.
- While Rohtang Pass is at a height of 13,050 feet, the pass on the road to Leh is Baralacha La at 16,040 feet.
- An alternate road link to Ladakh has also been developed by BRO on the Darcha-Padam-Nimu axis, but here again a 4.15-km long tunnel at Sinka La Pass (16,703 feet) would be required for all-weather access.
- It would have been completed at least four years earlier, but for a massive torrent of water encountered inside the tunnel.
- The Seri Nullah, which flows on top of the tunnel, almost threatened to derail the project and it took several years to devise ways to tackle the massive flow of water that often went up to 140 litres per second.
- The project also has significant strategic implications for the military as it will allow access beyond Rohtang Pass even in peak winters.
- All-winter connectivity to Ladakh, however, is still some time away as more tunnels will have to be built to tackle the high passes which fall beyond Rohtang.