Atal Tunnel, also called the Rohtang Tunnel, is a highway tunnel on National Highway 3 in Himachal Pradesh, India.
Located beneath the Atal Tunnel Rohtang Pass in the eastern Pir Panjal range of the Himalayas. Initially, they named it after the former Indian Prime Minister, Atal Bihari Vajpayee.
It is the world’s tallest roadway single-tube tunnel above 10,000 feet (3,048 m) at 9.02 kilometers. The planned building of the Shinku La Tunnel, scheduled for completion by 2025.
Along with the current Atal Tunnel, will make the new Leh-Manali Highway via the Nimmu–Padum–Darcha road an all-weather route.
Wonders of Engineering Behind Atal Tunnel
1. History
Named for former Indian Prime Minister Atal Bihari Vajpayee, the Atal Tunnel (also called the Rohtang Tunnel) is a highway tunnel on National Highway 3 in Himachal Pradesh, India.
Atal Tunnel runs beneath the Rohtang Pass in the eastern Pir Panjal range of the Himalayas. It is the world’s tallest roadway single-tube tunnel above 10,000 feet (3,048 m) at 9.02 kilometers.
As a significant achievement in engineering and a notable addition to the Heritage Sites in Himachal Pradesh, the tunnel exemplifies the region’s commitment to advancing infrastructure while preserving its natural beauty.
The planned building of the Shinku La Tunnel, scheduled for completion by 2025, along with the current Atal Tunnel, will make the new Leh-Manali Highway via the Nimmu–Padum–Darcha road an all-weather route.
On the route to Leh, the tunnel shortens the total distance and travel time between Manali and Keylong.
A. In 19th Century
In 1860, the Moravian Mission first mentioned the prospect of building a tunnel that would cross Rohtang Pass and go to Lahaul.
B. In 20th Century
The idea to build a tunnel across Rohtang Pass originated in 1942 during a visit by Dr. John Bicknell Auden of the Geological Survey of India (GSI) to redirect the Chandra River’s water to Beas.
Locals advised boyhood buddy Arjun Gopal to visit Atal Bihari Vajpayee and discuss the Rohtang Tunnel when he was to become prime minister.
Gopal relocated to Delhi with two friends, Chhering Dorje and Abhay Chand. Following a year of deliberations, Vajpayee visited Lahaul in June 2000 and announced that the Rohtang Tunnel would be built.
RITES did a feasibility study. The project was scheduled to be finished in seven years and cost ₹500 crore in 2000.
With new infrastructure like Airports in Himachal Pradesh, the region’s connectivity and development were further enhanced.
Construction began on May 26, 2002, with the Border Roads Organization (BRO), a tri-service Defence Ministry organization led by Lt. Gen. Prakash Suri, PVSM, taking responsibility for the project.
BRO specializes in building roads and bridges in challenging terrain. Atal Bihari Vajpayee opened the approach road to the tunnel entrance.
But by May 2003, the project had yet to progress past the point of felling trees. The cost estimate increased to ₹900 crore by December 2004.
The Australian company SMEC (Snowy Mountains Engineering Corporation) International Private Limited was given the contract by the Dr. Manmohan Singh administration in May 2007.
The original completion date was changed to 2014. But for the following three years, until May 2010, nothing changed.
C. Rohtang Tunnel Project
The Rohtang Tunnel Project was finally approved by the UPA government’s Cabinet Committee on Security.
In September 2009, STRABAG AG, Austria, and AFCONS Infrastructure Limited, an Indian construction company of the Shapoorji Pallonji Group, entered into a joint venture to win the work.
On June 28, 2010, work on the Rohtang Tunnel began at the South Portal, located 25 km (16 mi) north of Manali, through the Himalayan peaks. Spar Geo Infra Pvt Ltd was given a portion of the anchoring and slope stabilization work under subcontract.
Manav Energy Pvt. Ltd. was subcontracted to design, supply, and install a permanent maintenance-free earthing system.
On December 25, 2019, the day of Vajpayee’s birth, Prime Minister Narendra Modi renamed the tunnel the Atal Tunnel in honor of Shree Atal Bihari Vajpayee.
2. Challenges
The hardest part of the dig was keeping going, although there was a lot of snowfall in the winter. Workers excavated the tunnel from both ends.
However, as Rohtang Pass closes in the Atal Tunnel during winter, workers could only excavate from the south entrance because the north portal remained inaccessible.
Workers excavated about 1/4 of the tunnel from the north end and 3/4 from the south end. Around 46 avalanche locations were located on the tunnel’s approaches.
Additional obstacles to the tunnel’s development included the need to dispose of over 8 lakh m³ of dirt and rock excavated during construction.
The significant water infiltration (up to 30 lakh liters per day in June 2012) that necessitated continuous dewatering, more expensive treatment, and unstable rocks that hindered blasting and digging.
On August 8, 2003, a cloud burst, and a flash flood killed forty-two laborers who were constructing the temporary access road.
Concerns were also expressed over the effects of taking down over 700 trees on the ecosystem and the potential impacts on the nearby Lakes in Himachal Pradesh.
3. Specifications
The Atal Tunnel is designed to provide an all-weather route to Leh and the Lahaul and Spiti valleys in Himachal Pradesh.
This impressive structure stretches 9.02 kilometers (5.6 miles) in atal tunnel length and features a horseshoe-shaped cross-section.
The tunnel’s finished width is 10 meters (32.8 feet) at road level, with 8 meters dedicated to the pavement and 1 meter allocated for a footpath on each side.
Located at approximately 3,000 to 3,100 meters (9,840 to 10,170 feet), the tunnel accommodates vehicles at a designated speed of 80 kilometers per hour (50 miles per hour).
A. Geology of Atal Tunnel
The geology of the tunneling media includes a sequence of quartzites, quartzitic schists, and quartz-diorite-schist with thin bands.
Rather than using tunnel boring machines, which were impractical due to visibility issues inside the mountain, the tunnel was constructed using blasting and digging methods.
Atal tunnel temperature variations in the area range from 25 to 30 °C (77 to 86 °F) during May and June and from −30 to −20 °C (−22 to −4 °F) during December and January.
The maximum overburden is 1,900 meters (6,230 feet), with an average of over 600 meters (1,970 feet).
B. Construction Techniques Atal Tunnel
Construction employed the Drill & Blast technique with NATM, utilizing a support system of fiber-reinforced concrete (100–300 mm or 0–10 inches thick) combined with rock bolts (26.50 mm diameter, 5,000–9,000 mm or 200–350 inches long).
The tunnel features a semi-transverse ventilation system and includes a 2.25-meter-high by 3.6-meter-wide emergency tunnel integrated into the cross-section beneath the main carriageway.
Design parameters for the tunnel include an upper tolerance limit for a concentration of 150 ppm, a visibility factor of 0.009 per meter, and provisions for 3,000 cars and 1,500 trucks.
The peak hour traffic is designed to handle 337.50 PCUs, with a maximum speed of 80 km/h (50 mph) and a minimum speed of 30 km/h (19 mph) set for vehicles within the tunnel.
4. Safety measures
Large fans individually move air around the tunnel as part of a semi-transverse ventilation system that engineers installed using the New Austrian tunneling method.
For emergency evacuation, the design incorporates a 2.250 m tall and 3.6 m wide emergency tunnel within the tunnel cross-section under the main highway.
Firefighters will contain fires inside the tunnel within a 200-meter radius, and workers will position fire hydrants at key points throughout.
Additionally, the tunnel has a public announcement system that uses regularly spaced loudspeakers to broadcast critical information in an emergency.
Significant snowfall in the Rohtang Pass region is a severe hazard, particularly on the roads leading up to the main tunnel.
Avalanche control systems guard the roads and ensure everyone’s safety when using the tunnels and roads.
Considering the likelihood of high traffic in the Atal Tunnel, authorities positioned CCTV cameras regularly throughout the tunnel and linked them to two monitoring rooms at either end to manage traffic and monitor pollution.
Pollution sensors continuously monitor the tunnel’s air quality, and if it falls below the appropriate threshold, two powerful fans on either side of the tunnel introduce fresh air.
For those exploring Places for Honeymoon in Himachal Pradesh, the safety measures in such tunnels ensure a secure and enjoyable travel experience through this beautiful region.
5. Nearby Tourist Spots At Atal Tunnel
A. Lahaul
When passing through the Atal Tunnel Manali, be sure to include a visit to Lahaul if you’re searching for the experience of a lifetime!
Nestled between towering mountains and rivers, this charming valley in the Himachal Pradesh state of India is a place you really should go.
The breathtaking natural splendor of Lahaul will astound you despite the region’s often bitterly cold winters and copious amounts of snowfall. Go via the Himalayan Lahaul Valley to this Atal Tunnel tourist location.
B. Ladakh
A road trip from Manali to Leh Ladakh via the Atal Tunnel is ideal if you’re searching for an exciting adventure into the heart of the Himalayas.
It is easy to understand why Leh Ladakh is regarded as one of India’s most picturesque areas. The untamed peaks, profound gorges, and glistening lakes will captivate you.
Take a memorable road trip through the Atal Tunnel to Leh Ladakh and discover something new.
C. Spiti
The Atal Tunnel has significantly altered travel on the Lahaul-Spiti road. Lahaul Spiti was a dream before the Atal Tunnel because it used to take two days to get there.
Today, using the Atal Tunnel to Lahaul-Spiti and exploring the breathtaking locations in the Spiti Valley is a relatively simple process.
For adventure seekers and backpackers looking for a genuine experience, it’s the ideal place to go.
It’s simple to fall in love with this Land of Himalayan adventure because of its soul-satisfying weather, delicious cuisine, and warm welcome.
Spiti features some of the world’s tallest landmarks, including the highest motorable road. The region also boasts some of the most thrilling rides and passes that will raise your heart rate.
D. Gondhla Fort
You can use the Atal Tunnel, Rohtang, to reach the Gondhla Fort. Situated in the Kangra Valley of Himachal Pradesh, the fort boasts an impressive architectural design and a rich historical background.
However, perched atop a hill, it offers stunning views over the surrounding terrain.
E. Hampta Pass
Hampta Pass is a fantastic location via the Atal Tunnel, Rohtang. The Pir Panjal Pass, situated in the Himalayan mountain range, connects the Indian states of Himachal Pradesh’s Kullu Valley and Lahaul’s Chandra Valley.
The Pass is an exciting trekking location in Manali for those seeking adventure. The Hampta Pass hike provides an exceptional chance to experience the breathtaking scenery on the Manali side of Himachal Pradesh.
F. Hikkim Village
The Atal Tunnel offers another stunning escape point: Hikkim Village. It is a serene and lovely spot in Himachal Pradesh’s Lahaul Valley.
This isolated community has the world’s highest post office, which is its most intriguing feature.
The conventional postal services have maintained the village’s connection to the outside world despite the area’s low network connectivity. Hikkim village also offers thrilling activities.
G. Sissu
Sissu Valley is one of the best sites to visit in Manali in a single day. What’s the best thing, then? The 9-kilometer Atal Tunnel connects you to this enchanted hamlet.
Moreover, prepare to enjoy the stunning vistas and unspoiled paths that await you as you travel to Sissu.
A helipad located on Sissu serves as the region’s transit hub. It is also a portal to discover Lahaul’s hidden gems and is essential for emergency services.
FAQ
Q. What is the Atal Tunnel?
A. The Atal Tunnel, also known as the Rohtang Tunnel, is a highway tunnel on National Highway 3 in Himachal Pradesh, India. It runs beneath the Rohtang Pass in the eastern Pir Panjal range of the Himalayas and is the world’s highest roadway single-tube tunnel above 10,000 feet (3,048 meters).
Q. How long is the Atal Tunnel?
A. The Atal Tunnel stretches 9.02 kilometers (5.6 miles) in length.
Q. What are the key features of the Atal Tunnel?
A. The tunnel features a horseshoe-shaped cross-section, a finished width of 10 meters (32.8 feet) at road level, and accommodates vehicles at a designated speed of 80 km/h (50 mph). It also includes a semi-transverse ventilation system and an emergency tunnel integrated into the main structure.
Q. What is the altitude of the Atal Tunnel?
A. The tunnel is approximately 3,000 to 3,100 meters (9,840 to 10,170 feet) above sea level.
Q. Why was the Atal Tunnel constructed?
A. The tunnel provides an all-weather route to Leh and the Lahaul and Spiti valleys in Himachal Pradesh, reducing travel time and enhancing connectivity through the challenging Rohtang Pass.
Q. What were the significant challenges faced during the construction of the tunnel?
A. Construction challenges included severe weather conditions, significant snowfall, unstable rock formations, water infiltration, and the need to dispose of large amounts of excavated material. Additionally, there were concerns over environmental impact and safety issues, including a tragic cloud burst that resulted in the loss of lives.
Conclusion
In conclusion, the Atal Tunnel, named after former Indian Prime Minister Atal Bihari Vajpayee, represents a monumental achievement in infrastructure.
It provides a crucial all-weather route through the challenging terrain of the Rohtang Pass.
As the world’s highest single-tube tunnel above 10,000 feet, it shortens the journey between Manali and Keylong and enhances connectivity to Leh and the Lahaul and Spiti valleys.
Despite numerous challenges, including severe weather, geological complexities, and construction delays, the tunnel is a testament to innovative engineering and perseverance.
