Four laining of Chenani Nashri section oh NH1A from 89 Km to 130 Km (New Alignment) of NH-1A including 09 Km long Tunnel(2 Lane): Tunnel Excavation from north portal, Tunnel Concrete Lining from north portal & other allied works.
Its India’s longest road tunnel and Asia’s longest bi-directional highway tunnel, it traverses a distance of 9.2 km connecting Chenani in Udhampur district with Nashri in Ramban district.
The tunnel is a part of the 286 km long 4-laning of Jammu-Srinagar National Highway.
The Chenani-Nashri tunnel, located at an altitude of nearly 4,000 feet, is built in a record time of 5 and a half years.
The Chenani-Nashri tunnel is India’s first and the world’s sixth road tunnel with a transverse ventilation system, which basically means it has inlets every 8 m bringing fresh air into the main tube along with exhaust outlets every 100 m opening into the escape tube. Tranverse ventilation is significant as it prevents suffocation and allows for acceptable levels of visibility.
The tunnel comprises of two tubes which are connected by 29 cross passages at regular intervals along the entire length of the tunnel. the main tunnel tube has a diameter of 13m. The escape tunnel has a diameter of 6 m.
The tunnel is specially significant as it would reduce travel time on National Highway 44 between Jammu and Srinagar by almost 2 hours. By bypassing Kud, Patnitop and Batote, the tunnel not only reduces the distance between the two cities by 30 km, but also averts the danger of snow and landslide blockades.
From the movement of vehicles to the inflow and outflow of air, and even the evacuation of passengers or vehicles in distress, the tunnel controls everything externally thanks to the India’s first fully integrated mechanism engineering.