9 days since Uttarkashi tunnel collapse, what is taking so long to rescue the 41 trapped workers?

Nine days have passed since Sunday, November 12, when 41 workers were trapped in an under-construction tunnel in Uttarkashi, Uttarakhand. A section of the Silkyara-Barkot Tunnel, part of the Char Dham (all-weather road) Project, collapsed while the workers were inside.

As time passes, the urgency mounts in the rescue operation aimed at freeing the trapped workers.

What happened

• On Sunday, November 12, a part of the tunnel from the Silkyara side, came crumbling down with the workers inside.
• The workers were fortunate enough as the overhead mountain did not collapse right where they were. It was some 200 meters from the entrance Silkyara side of the tunnel.
• The 4.5 km long tunnel between Uttarkashi and Yamunotri was being constructed by Andhra Pradesh-based Navyuga Construction for the National Highway Authority of India (NHAI).
• The 41 workers are trapped in a 400-meter dark buffer zone, with debris on both sides, where they are being supplied with food and medicines.

The situation spurred a collaborative effort from multiple agencies.

Rescue operations

• The first attempt was made through the Silkyara side where 60 meters of debris had to be drilled through to get to the 400-meter trapped zone.
• But the attempt did not succeed because as soon as the debris was removed more and more started to fall, making the operation tougher.
• By then, it was clear that it was going to be a long wait.
• To ease the trapped workers, the rescue personnel used pipes and pushed through debris to send them basic life support like medicines, water, food and a walkie-talkie to communicate with them.

• The next attempt was to insert a 600-millimetre pipe into the trap site for the workers to crawl out.
• This attempt also failed as the pipe did not go through big, strong boulders on the way.

• The next attempt was made by the powerful American Auger drills to put through a 900-meter pipe. After reaching some distance, the drill machine gave up as parts of it broke down.

What next?

• The next plan, i.e., the Five-Point Rescue Plan, employs a multi-pronged strategy, including vertical drilling, tunnel construction, reinforcing the existing structure and deploying drones for aerial monitoring.
• Elizabeth, an official, said, "The RVNL has placed a request for an electric connection, which the district administration is evaluating."
• "The vertical drilling is scheduled to be completed by November 26, Sunday," she added.
• Transport and Highways Minister Nitin Gadkari acknowledged the challenges, saying, "The rescue operation is challenging as the soil strata in the Himalayan region is not uniform."

• "We are working on six options simultaneously. The PMO is also closely monitoring the operation. Our biggest priority is to save all those who are trapped," Gadkari added.

Recognising the ordeal faced by the trapped workers, the Road, Transport and Highways Secretary,  Anurag Jain said, "The government is sending multivitamins, antidepressants and dry fruits to the 41 workers trapped for the past seven days."

Who is involved in the rescue?

• The rescue mission involves a coordinated effort from various agencies, including the Oil and Natural Gas Corporation (ONGC), Border Roads Organisation (BRO), Rail Vikas Nigam Limited (RVNL), THDC India Ltd, National Highways and Infrastructure Development Corporation Ltd. (NHIDCL), National Hydroelectric Power Corporation (NHPC), and Satluj Jal Vidyut Nigam Limited (SJVNL).
• The Indian Army is also actively monitoring the progress.