Guwahati: As the rescue operations reached the 17th day in Uttarkashi’s Silkyara tunnel where 41 workers are stuck, the government has now taken the help of rat-hole workers to do manual drilling to clear the rubble.
Simultaneously, the vertical drilling from above the tunnel has reached a depth of 36 metres out of the 86 metres needed.
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More than 20 rat-hole mining experts are involved in manual drilling and excavation horizontally 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.
This drilling was earlier being carried out by a huge auger machine that got stuck in the rubble on Friday, forcing officials to focus on an alternative option — drilling down from above the tunnel.
About 40 per cent of the 86-metre vertical required is now done
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Rat-hole mining involves extracting coal from shallow, horizontal seams via cramped tunnels. The term “rat hole” refers to the diminutive size of these pits, barely large enough for a single miner to enter and extract coal.
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 people who are experts in the technique.
They are likely to be divided into teams of two or three. Each team will go into the steel chute laid into the escape passage for brief periods.