Chenani-Nashri tunnel: Prime Minister Narendra Modi will be unveiling South Asia’s longest road tunnel which will run from Chenani to Nashri in Jammu and Kashmir. When it comes to technology, it will be one of the most advanced road tunnels built in India as the challenges of terrain and distance has been very difficult to overcome. The tunnel is at an altitude of 1,200 meters (almost 4,000 feet) and is a part of NHAI’s project between Srinagar and Jammu along the National Highway 44.
The tunnel has been built at the cost of Rs 3,720 and it took only 5 and a half years to build the 9.2-kilometre long road amidst the Himalayan terrain. It has been built by Infrastructure Leasing & Financial Services (IL&FS) Ltd. The tunnel is will be reducing the time required to travel on National Highway 44 between Jammu and Srinagar by around 2 hours as it has shortened the distance by 30 km, and will also bypass areas like Kud, Patnitop and Batote, which are prone to landslides and heavy snow.
Here are 5 cool technologies used in the Chenani-Nashri road tunnel:
1. The Chenani-Nashri road tunnel is the country’s first and globally the sixth road tunnel which uses a transverse ventilation system. It has been enabled by ABB drives and controlled by ABB software. Such ventilation systems, for such long tunnels, are crucial to maintain clean air, permissible carbon dioxide levels and expel harmful vehicle emissions. The ventilation system in the Chenani-Nashri tunnel, the longest highway tunnel in Asia, will ensure that passengers have access to fresh air as they drive through it.
2. The tunnel has two tubes running parallel. While the main traffic tunnel is 13 metres in diameter, a separate safety or escape tunnel of diameter 6 metres alongside. These two tubes, each around 9 km in length, are connected by 29 cross passages at regular intervals along the entire length of the tunnel. These passages add up to about 1 km of tunnel length, and the main and escape tubes, plus the cross passages make up about 19 km of tunnel length, IE reported.
3. Low harmonics variable speed drive (VSD) system for tunnel ventilation has been designed, engineered and supplied, in a bid to make sure the travel of commuters will be safe. The VSDs and motors are installed at the North (Nashri) and South (Chenani) portals for air supply and exhaust. The VSDs are also equipped with inbuilt redundancy to ensure minimum downtime.
4. People will be able to use their phones while travelling inside the tunnel. According to an IE report, network providers have reportedly set up facilities inside the tunnel to carry signals. Also, lighting inside the tunnel has been adjusted at a gradient luminous capacity in order to prevent diminution of vision because of the sudden change in light that happens while inside and outside the tunnel.
5. New Austrian Tunnelling method (NATM) also known as Sequential Excavation Method (SEM). It is a technique used in many famous tunnels.
(with agency inputs)