The Sela Tunnel is expected to be completed by June next year

The Sela Tunnel being constructed at an altitude of 13,500 feet on a strategic road in Arunachal Pradesh will provide all-weather connectivity to Tawang and ensure better movement of troops and weaponry to various forward locations along the Line of Actual Control (LAC), military officials said Thursday.

Once its construction is completed, the ₹ 700 crore tunnel on the Balipara-Charduar-Tawang (BCT) road will be the longest bi-lane road tunnel in the world at an altitude of over 13,000 feet, said project director Colonel Parikshit Mehra.

The movement of troops and military equipment is severely hit when the Nuranang area, where the tunnel is being constructed, receives heavy snowfall during the harsh winter months of December, January, and February.

The need for quick mobilisation of troops and weapon systems gained renewed focus in the wake of the lingering border standoff between India and China in eastern Ladakh.

The construction of the tunnel on the 317 km-long BCT road is expected to be completed by June next year ahead of its scheduled deadline of August 2022.

The 1.55 km tunnel in Nuranang between the Tawang and West Kameng districts will cut down the distance to Tawang by six kilometres and the travel time by at least an hour, Colonel Mehra said.

Another senior official said that the tunnel will help in the quicker movement of troops and weapons and it has strategic significance.

The main tunnel is a bi-lane tube with an overhead clearance of 5.5 metres and a total of 3,000-4,000 vehicles are expected to use the tunnel every day. An escape tunnel with an equal length of 1.55 km is being constructed parallel to the main tunnel in case of any emergency.

The twin tunnel is connected by an approach road with another tunnel 980 metres long.

"Between tunnel one (1.55 km) and tunnel two (980 metres), there is another 1.2 km stretch of road," said Colonel Mehra.

"The work on both the tunnels is going on rapidly. In tunnel two, we have completed excavation of 780 metres of the 980 metres. We just have 200 metres to complete and we are trying our best to finish it by Army Day (January 15)," he said.

While the first blast on tunnel one took place on October 31, 2019, the work on the second tunnel began on January 15 this year.

"The existing BCT road climbs up the Sela pass and goes towards Tawang and the road is on the snow line. When there is snowfall from December to February, the roads get closed and it requires massive efforts to clear the snow," said Colonel Mehra.

"Even if the road is kept open, we need massive efforts to clear the snow and only heavy vehicles are able to go across. It becomes very difficult for people who are living in Tawang and for the convoys to cross over in those three months," he said.

When asked which is the longest bi-lane road tunnel at present, Colonel Mehra said it is in the Tibet region.

Colonel Mehra oversaw the construction of the Rohtang tunnel in Himachal Pradesh.

"The Rohtang tunnel has gone through one of the worst geologies in the world. It is those lessons of geology which helped me here where I can foresee what all measures we can take before going ahead in excavation," he said.

The Sela tunnel project is being implemented by a battery of about 50 engineers and 500-600 labourers.

Colonel Mehra said the tunnel is being constructed using the latest Austrian technology.