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Once operational, it will fundamentally transform connectivity between Kashmir and Ladakh
The tunnel was constructed using the New Austrian Tunneling Method.
On June 9, India will achieve a milestone for which engineers, planners and policy makers have been working for years.
Beneath the snowy mountains of the Western Himalayas, workers will complete the final breakthrough of the 13.153 kilometer long Zojila Tunnel, ending the excavation phase of one of the country’s most ambitious infrastructure projects.
The tunnel, being built at an altitude of about 11,578 feet above sea level, is set to become the world’s longest single-tube bi-directional road tunnel at the highest altitude. Once operational, it will fundamentally transform connectivity between Kashmir and Ladakh, a route that has historically been vulnerable to some of the harshest weather conditions in the country.
for generations, Zojila Pass This has been both a lifeline and a challenge. The mountain pass located on the Srinagar-Kargil-Leh highway is often closed during winter due to heavy snowfall, blizzards and avalanches. The entire expanse remains inaccessible for long periods, disrupting civilian movement, supply chains and strategic logistics.
The goal of the tunnel is to eliminate that vulnerability.
Stretching from Baltal near Sonamarg in Jammu and Kashmir to Meenamarg in Dras sector of Ladakh, the project is designed to ensure seamless, all-weather connectivity between the Kashmir Valley and the Union Territory of Ladakh. Once completed, it will allow travel in one of India’s most difficult mountain corridors throughout the year, regardless of the weather conditions outside.
The sheer scale of the project is evident from its numbers.
numberspeak
While the main tunnel itself is 13.153 kilometers long, the total project length including access roads, bridges and associated infrastructure extends to 30.894 kilometers. The corridor also includes the Nilgiri twin tunnels of 457.35 meters and 1,953.63 meters respectively, seven cut-and-cover structures spanning 2.35 kilometres, an ice gallery of 450 meters and three major bridges with a combined length of 460 metres.
One of the most notable engineering features of the project is its ventilation and security systems. Since the tunnel does not have a separate escape tunnel, engineers built three huge vertical shafts to provide ventilation and emergency access.
The largest of these, located on the western side, extends 474.3 meters into the mountain, making it the longest vertical shaft in India. The length of the second shaft is 367.38 meters, while the third extends 213.5 meters below the surface.
The project is being executed by Megha Engineering and Infrastructure Limited (MEIL) for National Highways and Infrastructure Development Corporation Limited (NHIDCL), the specialized agency of the Central Government for highway development in difficult terrain.
However, the engineering challenge extended far beyond simply digging a tunnel through a mountain.
battling extreme weather
The Zojila region is notorious for its extreme weather. Temperatures regularly drop below minus 20 degrees Celsius and can drop as low as minus 30 degrees Celsius during winter. For approximately 100 days each year, construction teams have to work in sub-zero conditions.
Over the past five years, the project site has suffered at least five major avalanche events.
One of the most serious was the avalanche of January 12, 2023, near the Sarbal area close to the Nilgiri tunnels. A few days later, a secondary avalanche trapped workers in the area, prompting a major rescue effort. The Indian Army evacuated more than 172 stranded personnel. Further avalanche incidents were recorded in February 2024 and March 2025, causing disruption and damage to machinery and project infrastructure.
Despite these challenges, construction activity continued.
Heavy snow accumulations often require dedicated snow-clearing operations, involving specialized snow blowers and earth-moving equipment, not only to maintain access to the project but also to help keep portions of the highway operational.
Geology
Geology proved equally demanding.
Unlike tunneling projects in more predictable rock formations, the Zojila alignment passed through highly variable Himalayan geology. According to project engineers, the classification of rocks over a distance of 13 kilometers was changed 67 times, leading to frequent amendments to excavation and support strategies.
To deal with these situations, tunnel It was constructed using the New Austrian Tunneling Method (NATM), widely considered one of the most suitable methods for delicate mountain geology.
Rather than relying on rigid construction sequences, NATM allows engineers to continuously adapt to changing rock conditions through staged excavation, immediate reinforcement using shotcrete and rock bolts, and real-time geological monitoring. This method is increasingly being adopted in complex Himalayan tunnel projects but has rarely been tested at this scale and altitude.
difficult task
The human effort behind the project is equally impressive.
More than 1,200 personnel are engaged in construction activities, with approximately 80 percent of the workforce drawn from local communities. To maintain operations in one of the country’s most remote environments, a self-contained base camp was established to accommodate over 1,100 people. The facility includes medical support, transportation systems, food services adapted to extreme weather conditions, and a round-the-clock logistics infrastructure.
The project has also registered an important safety milestone by completing more than 10 million safe man-hours by April 2026.
Several important successes have already been achieved during construction.
The first blast in the Nilgiri Tunnel took place on October 14, 2020, just days after the project began. The breakthrough was achieved for both tubes of the Nilgiri Tunnels between November 2021 and April 2022. The eastern ventilation shaft was completed in November 2023, while the country’s longest vertical shaft was successfully excavated in July 2025.
In March 2025, the project completed its first major package, consisting of approach roads, bridges, ice galleries and associated infrastructure works.
The final breakthrough of the main Zojila tunnel now represents the most important milestone of the excavation phase of the project.
For the government, the tunnel is expected to deliver significant economic benefits by improving access to Ladakh, reducing travel disruptions, boosting tourism and ensuring more reliable movement of goods and essential supplies.
For the residents of Kargil, Dras and Leh, it promises something even more concrete: freedom from the annual isolation imposed by winter.
The strategic dimension is also impossible to ignore.
The Srinagar-Leh corridor serves as a vital logistics route for India’s military presence in Ladakh and along the northern border. Year-round reliable connectivity is expected to strengthen operational mobility and reduce reliance on weather windows for movement of personnel, equipment and supplies.
Overall, the Zojila Tunnel is much more than a transportation project. It represents India’s growing ability to execute complex infrastructure works in some of the world’s toughest terrains.
The final breakthrough on June 9 will not mark the end of the project. Significant work remains in the tunnel lining, ventilation system, electrical installation, safety infrastructure and finishing activities before the tunnel can be opened to traffic.
But for engineers who have battled avalanches, freezing temperatures, unpredictable geology and high-altitude working conditions over the past several years, the moment when the two ends of the tunnel finally meet will be a defining chapter in India’s infrastructure story.
This is a breakthrough that has been years in the making and brings the long-held promise of all-weather connectivity between Kashmir and Ladakh closer than ever.
About the author
Aman Sharma, Executive Editor – National Affairs at CNN-News18, and Bureau Chief of News18 in Delhi, has over two decades of experience covering a wide spectrum of politics and Prime Minister…read more
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