India’s longest railway tunnel is currently being constructed deep in the Himalayan mountains. Dubbed Tunnel No. 8 or T-8, it will be a 14.57km tunnel between Rishikesh and Karnaprayag, and connect Devprayag and Janasu in Uttarakhand. While the length of the tunnel in itself is a major engineering achievement, the technology that went into the excavation and construction of the structure in such challenging terrains also deserves recognition.
