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Uttarakhand tunnel collapse: Manual drilling advances, breakthrough soon

Uttarakhand Chief Minister Pushkar Singh Dhami said almost 52 metres of drilling has been done, and it is expected that there will be a breakthrough around 57 metres

Uttarakhand tunnel collapse

Uttarakhand tunnel collapse

BS Web Team New Delhi

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As the 17th day of the Silkyara tunnel rescue efforts began, rescuers crossed the 50-metre mark and needed to dig through seven metres of rubble using rat-hole mining techniques to bring out the 41 trapped workers. Twelve rat-hole mining experts are involved in the horizontal excavation through the last 10 or 12-metre stretch of debris of the collapsed portion of the under-construction tunnel on Uttarakhand's Char Dham route.
 
Rat-hole miners have been manually drilling since Monday night. The debris thus generated is taken out manually using ropes from the rescue pipe. 

On Tuesday morning, Uttarakhand Chief Minister Pushkar Singh Dhami reached the site and said almost 52 metres of drilling had been done, and it was expected that there would be a breakthrough around 57 metres. 
 

"Almost 52 metres has been done [pipe inserted]. It is expected that there will be a breakthrough around 57 metres. One metre of the pipe was pushed in before me, if two metres more of it is pushed in it will be around 54 metres in. After that, one more pipe will be used in...Earlier steel girders were found [during drilling]. This has reduced now. Right now, we are finding more concrete, it is being cut with a cutter," Dhami told reporters.

Here are the top updates on Uttarakhand tunnel collapse:

  • News agency ANI, citing official sources, reported that about 57 metres of drilling work from the mouth of the tunnel is to be done in total to lay a pipe inside the tunnel to reach the trapped workers.
  • Earlier, the rescuers had completed about 47 metres of drilling work using the auger machine to lay the pipe. The drilling work was put on hold as the auger machine got stuck in the debris, which was later cut and removed using a plasma cutter.
  • The work being done now is designed to create a passageway for evacuating the trapped workers. Rescue teams have inserted pipes into dug-out areas and welded them together so the trapper workers can be brought out on wheeled stretchers.
  • Devendra Patwal, a disaster management official at the site, said that rescuers worked overnight to pull out parts of the broken drilling machine stuck inside the pipes so manual digging could start.
  • "We have just crossed 50 metres," L&T team leader Chris Cooper told news agency PTI on Tuesday. "It raises hopes of an early evacuation as rescuers have to go only up to 10 metres to make a breakthrough. However, the speed of the operation depends on whether or not the rescuers encounter any hurdle in the course of excavation which has often been hampered by something or the other," he added.
  • A skilled team of workers is doing muck removal by hand using the rat hole mining technique while the auger machine is inserting the 800-mm diameter pipe through the rubble, PTI reported.
  • Praveen Yadav, who is involved in cutting and removing the hurdles from the debris, said 51 metres had been drilled.

  • A worker from the Trenchless company, which is pushing the pipes with the auger machine, said if no hurdles are faced, some good news could be expected by this evening.
  • Rat-hole mining is a controversial and hazardous procedure in which miners in small groups go down narrow burrows to excavate small quantities of coal. Uttarakhand government's nodal officer Neeraj Khairwal made it clear that the men brought to the site were not rat-hole miners but rather experts in the technique.
  • Speaking to ANI on Tuesday morning, Naseem, one of the workers, said they have already done five metres of manual drilling work so far, and 51 metres have been completed in totality. He added that it takes about 1-2 hours to drill 1 metre and if any obstacle comes by it may take longer but so far the work has been progressing well.
(With agency input)

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First Published: Nov 28 2023 | 12:23 PM IST

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