A powerful new drilling machine is slowly making progress to rescue 40 workers trapped in a tunnel in Uttarakhand, India for over 100 hours.
A new and more powerful drilling machine was finally pushed into service in the third attempt by rescue officials to create a passage large enough to evacuate 40 workers who have been trapped behind a 70-metre-thick wall of debris inside a 4.5km-long tunnel in Uttarkashi district of Uttarakhand for more than 100 hours as of late Thursday night.
The new “state-of-the-art” auger machine was able to drill through nine metres in the first six hours of its operation which started at 10.30am on Thursday morning, National Highways and Infrastructure Development Corporation Limited (NHIDCL) officials said.
At this pace, it will take at least another two days to reach the workers, they said — at a time when concerns over the safety and health of the workers trapped with low oxygen and scant nourishment is mounting.
As of midnight on Thursday, the workers were trapped in the tunnel behind a cave-in for 114 hours, even as NHIDCL officials assured the families of those trapped that all were alive and were being provided supplies through a water pipe.
Meanwhile, the size of the debris has increased from 50-55m initially to 65-70m after repeated cave-ins, said a Railways official who is involved in the rescue operation and did not wish to be identified.
A portion of the under-construction tunnel from Silkyara to Dandalgaon on the Yamunotri National Highway (NH) collapsed at around 5.30am on Sunday, trapping 40 workers around 260m from the tunnel entrance at the Silkyara end. After four days of wait, the families and other workers staged a protest outside the tunnel, alleging that the construction company Navayuga Engineering Company Limited (NECL), and rescue teams were not working fast enough to rescue the trapped men.
The rescue operation is being managed by the National Disaster Relief Force (NDRF) and Uttarakhand Disaster Management Authority, while the drilling is being done by NHIDCL. NDRF officials at the spot said they are awaiting the completion of the drilling after which they can enter and bring back the workers.
In the first four days of operations, two rescue attempts to cut through the wall of rock blocking the tunnel had failed — to the despair of the families and colleagues of the workers.
In the first attempt, rescue workers tried to dig through the rubble using heavy excavator machines and sought to prevent more debris from falling using the “shotcrete method” (shotcrete is a construction technique that involves spraying concrete onto surfaces using air). However, loose rock and sand kept collapsing, rendering the strategy unsuccessful. In the second attempt, they tried to create a hole using an auger machine and fitting in large pipes inside which workers can crawl out of. This plan failed as the drilling machine was rendered useless as it was damaged after the drill hit a boulder on Tuesday night.
Now, a state-of-the-art American-made auger machine, which officials said is more capable and powerful than the one used previously was requisitioned in three parts that were flown in from Delhi on Wednesday evening. The machine started drilling early on Thursday. While the previous 35HP (horse power) auger machine had a capacity to penetrate at the rate of 1m per hour, the new 175-200HP machine can cut through rock at 5m per hour, officials said.
Col Deepak Patil, an official of NHIDCL and in charge of the drilling operation, said, “We have started the drilling process using the high performance auger machine to rescue the trapped workers.”
On the possibility of failure of the current plan, he said: “The equipment and machines for an alternative plan is already on wheels. But there are high chances that the current plan will succeed. We are going ahead more cautiously so that we shouldn’t damage the equipment… there could be twisted metal lattice girders and ribs in the rubble and impediments inside. However, there chances of boulders in the debris are less.”
Aakash Negi (17), the son of trapped worker Gabbar Singh Negi (51) of Kotdwar, said he once again spoke to his father through a pipe on Thursday morning. “Every time we speak to him, he says he is fine. But I know he is living in a difficult situation. Hope he is taken out by the rescuers very soon. Had the rescuers brought the bigger machine much earlier, it would have saved precious time,” he said.
Officials, however, have been unable to deliver on their timelines so far, blaming lack of “proper geological inputs” on how to work in a soft mountain range prone to landslides. “We can’t predict the timeline when the auger machine will be over and trapped labourers will be rescued. We don’t have machines that can see inside the rock. The speed of drilling could increase or decrease as per the circumstances,” Patil said.
Officials familiar with the matter said that they are also faced with the possibility that one of the excavators may be under the rubble, and if the drilling machine hits that, then it may be another hurdle.
On this possibility, Patil said that the excavators are generally parked on the far side. “The probability of vehicles coming in the way of drilling machine is very low… unless the vehicles toppled and fell towards the centre… which is also unlikely,” he said.
Union minister General VK Singh (retired) also visited the site and spoke to the trapped labourers. “The new machine is faster and powerful. We are aiming to complete the task in two-three days. It could be done sooner… but we have set an outer limit so that obstructions can be addressed,” he said addressing a press conference. “All efforts are being taken to rescue the trapped labourers. I have spoken to labourers. Their morale is high.”
Meanwhile, an earthquake of magnitude 3.1 struck Uttarkashi district in Uttarakhand at 2.01am on Thursday, the National Centre for Seismology said. While rescuers initially feared a disruption in the rescue operation, they said they were able to continue without any hindrance.
Article source: hindustantimes.com