New Delhi: The rescue operation for 41 workers who have been stuck inside a collapsed tunnel in Uttarakhand for 16 days has entered a crucial stage, as rescuers have crossed 50 metres and have to dig through only 10 more metres of rubble using the rat-hole mining technique. The tunnel, which is part of the Char Dham route project in Uttarakhand, caved in on November 13. The workers are trapped in a two-kilometre section of the tunnel and are being supplied with food, medicines and other essentials through a six-inch pipeline.
The rescuers, who have been hired by two private companies, are using the rat-hole mining technique to clear the last 10- or 12-metre stretch of rubble horizontally. Rat-hole mining is a risky method of extracting small amounts of coal by digging narrow holes in the ground, usually done in Meghalaya.
The rescuers, who have come from Delhi, Jhansi and other places, will work in teams of two or three. They will enter the steel pipe that has been inserted into the escape passage and drill by hand, using hand-held drilling machines and gas cutters.
One of the rescuers, Rajput Rai, said they can remove five-six metres of rubble in 24 hours. The horizontal drilling was earlier done by a huge auger machine that got stuck in the rubble on Friday at around 47 metres.
“We have just crossed 50 metres,” L&T team leader Chris Cooper said. He expressed hope 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.
A skilled team of workers is doing muck removal by hand while the 800-mm diameter pipe is being pushed by the auger machine through the rubble. Praveen Yadav, who is involved in cutting and removing the obstacles from the debris, said 51 metres have 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.
The officials in charge of the rescue operation said the cause of the tunnel collapse is still unknown, but they are hopeful that the rat-hole mining technique will help them reach the workers soon.