New Delhi, Sept. 15 -- Tunnel experts and rescuers at the Chilime 22 MW hydropower project in Nepal have started using rat-hole mining, a technique adopted duringthe 2024 Uttarakhand Silkyara tunnel rescue, in order to find and pull out six workers trapped after the devastating floods on August 26. The rescuers have dug almost 35 metres deep into the debris using the method and are hopeful of a breakthrough in their search , officials monitoring the rescue operations said on Monday. Twenty tunnel experts from the Indian Army and the National Disaster Response Force (NDRF), along with 37 Nepalese Army personnel are carrying out the rescue. Rat-hole mining is fraught with dangers and is usually used to extract coal from thin seams, often illegally. It involves digging narrow, unventilated tunnels that fit a single miner to directly access the seam. Data maintained by hydropower companies showed 909 people went missing at 11 sites after the floods. At Chilime, rescuers are yet to make contact with the trapped workers. But rescuers believe the workers are still alive as they were last spotted by survivors at the underground power station, where there was stored drinking water stored for the workers. A project official said around 90 metres of debris, including large boulders, were cleared using excavators. The rescuers then created a rat hole and slowly went 35 metres further to a total depth of 125 metres and are removing water that has collected after this point, said Bimal Khadka,deputy manager of the Chilime Hydropower Company Ltd. Indian envoy in Nepal Naveen Srivastava said the clearing work is expected to continue on Tuesday to reach the powerhouse. Chilime Hydropower's information officer, Shree Raj Bajracharya, said that rescuers on Monday morning came across oil mixed with water. "This makes us believe that we are near the power station. Our teams are working round the clock in different shifts to reach the power station. " he said....