Round-the-clock drilling down a hilltop enveloping the under-construction tunnel continued on Friday so that rescuers reach the three trapped workers. In all, a 40-m deep vertical shaft has to be created. Three workers are trapped inside the tunnel. While experts have contacted two workers, the fate of a third one is uncertain.
“We can only hope...it all depends on the kind of strata that we encounter atop the hill,” said tunneling expert from the SJVNL, Ramesh Chauhan. He is working alongside a geologist, Rakesh Sehgal who is also a design engineer, and Arun Dhiman, a construction expert. The BRO is guiding the rescue operation from day one.
The link road to the top of the tunnel was constructed to ferry a big drilling machine which started digging at 10.30 pm last night.
“The machine dug up 1.2-m diameter hole at the rate of about 2-m per hour till we reached the 28-m depth, but now it has slowed down and we could dig up 4-m depth in six hours till 8 pm and are at 31-m, say experts. “The tunnel site has silt rocks, clay stones and phylites, which are a weak strata and might have caved in”, says Chauhan. The machine has drilled about 31m till 8 pm and may take the whole day tomorrow as we have to put in a case to take the workers out safely”, adds Sehgal.
Another worry is that the drilling has encountered some rocky slush as the 1.2-km tunnel is beneath the Tihra nallah. “We go by the design parameters of the NHAI and the strata collapsed at 95-m deep inside the tunnel. and do not know the exact dimension of debris”, says SK Patial from the IL&FS company, a NHAI contractor firm. The rescue team is also digging horizontally another hole through the caved-in debris to keep all alternative routes open to rescue the workers. “We have bored a 30-m deep horizontal hole inside the tunnel, but we are not sure as to how much debris is left to be pierced”, adds Patial. NDRF team commander Santosh Kumar, who reached here today, says team members are ready with equipment.
They will lower the rescuer through the hole to take the workers out. They will hook them and pull them up one by one by the rope, the NDRF members add.
The 50-member two teams from the National Disaster Rapid Response Force (NDRF), one each from Una and Bathinda, reached the spot to rescue the trapped workers.
“We can only hope...it all depends on the kind of strata that we encounter atop the hill,” said tunneling expert from the SJVNL, Ramesh Chauhan. He is working alongside a geologist, Rakesh Sehgal who is also a design engineer, and Arun Dhiman, a construction expert. The BRO is guiding the rescue operation from day one.
The link road to the top of the tunnel was constructed to ferry a big drilling machine which started digging at 10.30 pm last night.
“The machine dug up 1.2-m diameter hole at the rate of about 2-m per hour till we reached the 28-m depth, but now it has slowed down and we could dig up 4-m depth in six hours till 8 pm and are at 31-m, say experts. “The tunnel site has silt rocks, clay stones and phylites, which are a weak strata and might have caved in”, says Chauhan. The machine has drilled about 31m till 8 pm and may take the whole day tomorrow as we have to put in a case to take the workers out safely”, adds Sehgal.
Another worry is that the drilling has encountered some rocky slush as the 1.2-km tunnel is beneath the Tihra nallah. “We go by the design parameters of the NHAI and the strata collapsed at 95-m deep inside the tunnel. and do not know the exact dimension of debris”, says SK Patial from the IL&FS company, a NHAI contractor firm. The rescue team is also digging horizontally another hole through the caved-in debris to keep all alternative routes open to rescue the workers. “We have bored a 30-m deep horizontal hole inside the tunnel, but we are not sure as to how much debris is left to be pierced”, adds Patial. NDRF team commander Santosh Kumar, who reached here today, says team members are ready with equipment.
They will lower the rescuer through the hole to take the workers out. They will hook them and pull them up one by one by the rope, the NDRF members add.
The 50-member two teams from the National Disaster Rapid Response Force (NDRF), one each from Una and Bathinda, reached the spot to rescue the trapped workers.
