Silkyara rescue operation reaches close to trapped workers
Rat hole mining technique starts yielding results
PrashantNews (1245 hours)
Using rat hole mining technique, rescuers on Tuesday pierced more deep into the debris reaching close to 41 workers who are trapped since November 12 in the Silkyara tunnel in Uttarakhand.
Rat hole mining is an old and hazardous technique to remove coal deposits through narrow passages in India.
As the ordeal entered 17th day on Tuesday, rescuers were now focusing on the horizontal mining through Silkyara side as the rat mining technique was yielding good results. By this morning, a total of 55.3 meter long MS pipe escape passage has already been built, Chief Minister Pushkar Singh Dhami said. Now only 5-7 meter of mining was left in the tunnel to reach the workers, officials said. “If everything goes well, we will soon get a breakthrough,” said Dhami.
It was not yet clear whether rescuers would also focus on the vertical drilling as the rat mining technique was giving good results. The state-run power producer SJVN is engaged in vertical drilling using all modern equipment to bore from the top of Silkyara tunnel side. A considerable length of 36 meter boring has already been completed by Monday evening. A total of 86 meter vertical boring will be done to reach the trapped workers, said Mahmood Ahmed, Additional Secretary of the Union Ministry of Road, Transport and Highways. At least 4 days are expected in this process which began on Sunday.
In yet another move, the state run RVNL has started perpendicular drilling also to evacuate the trapped workers, an official statement said.
Chief Minister Dhami had earlier stated that the all options to reach 41 trapped workers inside the tunnel were being explored. “Our main priority is to bring all the trapped workers safely. All the other queries are secondary this time,” Dhami said.
Dhami said the auger machine which was drilling the debris has been damaged after it hit some girder or steel rod on Friday. The machine is now being withdrawn from the tunnel completely. After withdrawing the machine from the tunnel, the manual drilling would also begin. Plasma and laser cutters were brought to remove the remains of the auger machine inside the escape pipe.
Rescuers said all the workers are safe and in good condition. They are also getting food, water and medicines regularly.
The workers were trapped on November 12 when a big portion of the 4.531 km long tunnel caved in. Initially, JCBs were used to remove debris. But when more debris fell, the authorities pressed auger machine to drill the debris to make escape passage for the trapped workers. But the auger machine on Friday developed some big fault and experts said it is now completely out of order. Ends