India has marked a significant milestone in transport infrastructure with the inauguration of Tunnel No. 8 of the Rishikesh-Karnaprayag Railway Project, which is now the longest transport tunnel in the country. With a length of 14.58 kilometers, this tunnel surpasses all previous records in both rail and road tunneling in India.
Historic Inauguration Ceremony
The tunnel was officially inaugurated in the presence of Railways, IT & Electronics Minister Ashwini Vaishnaw, Uttarakhand Chief Minister Pushkar Singh Dhami, and Member of Parliament Anil Baluni. The event marked a monumental achievement in India’s railway development in the Himalayan region.
Key Highlights of the Rishikesh-Karnaprayag Rail Project
- Total Project Length: 125.20 km
- Total Tunnel Length: 213.57 km
- 16 Main Tunnels: 104 km
- 12 Escape Tunnels: 97.72 km
- Cross Passages: 7.05 km
- Longest Tunnel: Tunnel No. 8 (14.58 km)
- Total Stations: 12
- Major Bridges: 19
- Minor Bridges: 38
- Longest Bridge: Devprayag Bridge (125 meters)
- Tallest Bridge: Gauchar Bridge (46.9 meters)
Advanced Engineering & Tunnel Boring Technologies
This project is the first in Indian Railways history to successfully use Tunnel Boring Machine (TBM) technology in the Himalayan terrain. The Single Shield TBM with a diameter of 9.11 meters has excavated 10.4 km of the tunnel, while New Austrian Tunneling Method (NATM) has been used for an additional 4.11 km.
Challenging Geological Conditions
The tunnel route passes through the Chandpur formation of the Jaunsar Group, composed of phyllites, quartzites, and schists. The Himalayan terrain posed numerous geological and logistical challenges such as:
- Steep and rugged terrain with difficult site access
- High overburden of up to 800 meters
- Varying rock mass quality and squeezing zones
- Groundwater ingress at multiple tunnel points (up to 2000 LPM)
- Complex logistics due to monsoons and pilgrimage traffic
Strategic Importance of Tunnel No. 8
Tunnel No. 8 not only holds the title of India’s longest transport tunnel but also reflects the integration of modern engineering with tough Himalayan geology. The tunnel significantly reduces travel time and enhances rail connectivity to Karnaprayag, improving access to remote regions of Uttarakhand.
Conclusion
The successful execution of Tunnel No. 8 in the Rishikesh-Karnaprayag Rail Line is a testament to India’s growing capabilities in infrastructure development, tunneling technology, and sustainable connectivity in mountainous regions. It paves the way for faster, safer, and more efficient travel in the Himalayan belt—connecting communities, promoting tourism, and boosting economic growth.