Silkyara tunnel probe report soon, no need for a separate escape tunnel, say officials

While the detailed probe on the Silkyara tunnel is ongoing and the exact cause of the tunnel's collapse will be known soon, government officials have told Business Today TV that there is no Indian or international code mandating the construction of an escape tunnel in the ill-fated project at Uttarkashi.

Watch: Navayuga Engineering-The Company That Constructed The Silkyara Tunnel

Officials added there was no need for such a provision as the single tube is divided into two interconnected corridors by a partition wall. One part can function as an escape tunnel in case of an emergency, as the divider wall would have "egress openings" every 500 meters to move over to the other side. They added that the escape tunnel or escape passage, used for getting out of vehicles and passengers in case of fire or any other emergency, comes into play once the operation starts.

The official further added that as per the International Standard EU directive on road tunnels, there is no specific mention of a separate escape tunnel being mandatory. A separate escape passage to a safe area is considered to be sufficient.

The expert committee, led by R K Dhiman, Additional DG, Border Road Organisation, and its members, including Prof KS Rao from IIT Delhi, Prof AK Srivastava from Delhi Technological University, and an officer from Indian Railways, have concluded their visit to the site and will be submitting their final report soon, a government official said.

Even in response to a question from Congress leader Mallikarjun Kharge in Parliament on whether the government guidelines recommend emergency exits for tunnels longer than 1.5 km, the ministry of road transport and highways on Wednesday said there is no such recommendation.

Quoting the guidelines of the Indian Road Congress, union minister Nitin Gadkari said: "A separate service tunnel, adjacent to the traffic tunnels, could be considered at the design stage considering various factors like land availability, traffic volume, length of the tunnel, and additional cost. This additional tunnel provides access for maintenance without requiring tunnel closure. This service tunnel can be used as an escape passage during an emergency."

In the Silkyara bi-directional tunnel on Dharasu–Yamunotri highway, a provision of separation wall has been provided at the center of the carriageway along with egress openings at an average interval of 565 meters for vehicular crossover and at an average interval of 300 meters for pedestrian cross-passage for escape purposes during emergencies, the ministry said.

Responding to whether the rapid Environmental Impact Assessment (EIA) report had recommended or pointed to the need for an escape tunnel, officials said the structure and configuration of any project are technical issues, and EIA has nothing to do with this. "Construction of an additional tunnel would rather cause more damage to the environment," the official added.