Uttarakhand Tunnel Rescue: Manual Drilling Underway, Trapped Workers Just 5-6 Metres Away

Rat-hole mining experts called in to help rescue 41 workers trapped inside the collapsed Silkyara tunnel began manual drilling Monday through the rubble.

Simultaneously, vertical drilling from above the tunnel has reached a depth of 36 metres out of the 86 metres needed. Here are the top developments:

• Micro tunnelling expert Chris Cooper on Tuesday morning said that 3 metres of manual drilling has been done so far and about 50 metres of drilling work has been completed in total. As per official sources, 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. He said, "We have crossed 50 metres. It's now about 5-6 metres to go.
• Experts from Delhi, Jhansi and other parts of the country from Trenchless Engineering Services Private Limited and Navayuga Engineers Private Limited are applying the rat-hole mining technique horizontally in the collapsed part of the main structure.
• 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 drilling required is now done.

• For the horizontal through-the-rubble option, officials decided that the final stretch would be handled through a manual approach in which individual workers will go into the escape passage with drills, as well as gas-cutters to tackle obstacles like iron girders.
• In Delhi, National Disaster Management Authority (NDMA) member Lt Gen (retd) Syed Ata Hasnain said vertical drilling, which began Sunday, has already reached a depth of 36 metres.
• Rescuers hope to pull out workers through this one-metre-wide shaft when it breaks through the top of the tunnel below, hopefully by Thursday. Another eight-inch wide shaft being drilled from a nearby point has reached about 75 metres down.
• This probe, which is also expected to act as a supply line for the trapped workers, has indicated that there were no serious geological obstacles for the main shaft up to this point, the NDMA member and officials at Silkyara said.
• The vertical drilling, however, encountered some water underground and "dewatering" was carried out, officials said. But it didn't seriously affect the operation. Rajput Rai, a rat-hole drilling expert, said one man will do the drilling, another collects the rubble with his hands and the third place it on a trolley to be pulled out.
• Billionaire Gautam Adani's group on Monday said it has no direct or indirect involvement in the construction of Uttarakhand's Silkyara tunnel. In a statement, an Adani group spokesperson said the conglomerate does not own or hold any share in the company involved in the construction of the tunnel.