Forty tunnel workers who have been trapped some 200m from the portal since a collapse occurred at 5am on Sunday morning remain stranded inside the 4.5km, 13m diameter Silkyara Tunnel in the northern Indian state of Uttarakhand as attempts to auger an 800mm evacuation tunnel have so far failed.
ITA President, Arnold Dix gave this update, “The ground is a mixture of soft ground and hard boulders. The boulders have blocked the auger. A larger diameter pipe jack solution is not an option as the materials and equipment are not available in the urgent time frame. Mobilizing high technology mechanised solutions is not an option either – too slow to mobilise. A much more powerful auger has just now been deployed – of the same type that was deployed in the Chilean mining emergency of 2010.
“Right now there is a 200mm mini tunnel that emergency crews have driven into the mountain tunnel where the men are trapped. The “mini” emergency tunnel is providing compressed air, food water and medicine. The 40 trapped tunnel builders are in good health. “I am coordinating ITA’s international emergency response team – comprising SME and industry experts in emergency tunnelling. Collectively we have designed an “option C” which is a mini high speed mining operation using advanced ground stabilisation and traditional mining support to create an emergency escape tunnel. “Option C draws on high technology ground improvement technologies currently manufactured in India, existing mining equipment and local experts. Other options are also being developed.
“There is no guaranteed solution – the conditions are extremely bad – geologically speaking. The experts on site, are known personally to many of our international team. Without any doubt the local experts are best qualified and competent to deal with this emergency. We and myself personally have complete faith in the on site emergency team.
“Please spare a thought and a prayer for our colleagues trapped deep underground – their noble mission to bring connectivity to some of the most sacred Hindu places on earth.”To those trapped – and those performing the rescue – we say just this: “We as the worlds tunnellers – countries, practitioners and industry are United. Our mission is clear – to bring you home safe”.God speed rescue teams – may all be safely reunited soon.
Even in the safest conditions the risk of a tunnel collapse is always there, My thougths and prayers to the trapped miners and to the team that will deliver them safely to open air.
Problem of tunneling in Himalaya has been lack of appreciation of risk involved and advance planning with suitable provision in contract. So tunneling even in not so high risk also get affected.
This culture is all pervasive.