(MENAFN- AsiaNet News) First images of the manual drilling activities within Uttarkashi's Silkyara tunnel in Uttarakhand, aimed at rescuing 41 trapped workers, surfaced on Tuesday morning. As of now, approximately two meters of manual drilling have been successfully completed. Rat-hole mining experts, enlisted to aid in the rescue effort, initiated manual drilling through the debris on Monday. The ongoing manual drilling also involves the use of an auger machine to push the pipe.
Concurrently, vertical drilling from above the tunnel has reached a depth of 36 meters, out of the required 86 meters. Twelve rat-hole mining experts are engaged in horizontally drilling through the last 10- or 12-meter section of debris in the collapsed part of the under-construction tunnel on Uttarakhand's Char Dham route.
Previously, extensive auger machine drilling, which became stuck on Friday, led officials to shift focus to an alternative option: drilling downward from above the tunnel. Approximately 40 percent of the required 86-meter vertical drilling has been completed.
For the horizontal through-the-rubble approach, officials determined that the final stretch would be handled manually. Individual workers will enter the escape passage equipped with drills and gas-cutters to address obstacles like iron girders.
By Monday evening, the stuck auger had been meticulously cut out piece by piece, and a steel pipe was inserted further into the partially completed escape passage.
Lt Gen (retd) Syed Ata Hasnain, a member of the National Disaster Management Authority (NDMA) in Delhi, mentioned that the vertical drilling, initiated on Sunday, has reached a depth of 36 meters. Rescuers aim to extract workers through this one-meter-wide shaft when it breaks through the top of the tunnel, expectedly by Thursday.
An additional eight-inch-wide shaft drilled from a nearby point has reached about 75 meters down. This probe, intended to serve as a supply line for the trapped workers, indicates no serious geological obstacles so far, as per NDMA member and officials at Silkyara.
Although the vertical drilling encountered some underground water, "dewatering" was performed without significantly affecting the operation. Two teams, consisting of seven and five experts in rat-hole mining techniques, were called in by private companies involved in the rescue operation.
It is emphasized that these individuals are not rat-hole miners, but rather experts in the technique. They are likely to be organized into teams of two or three, each entering the steel chute laid into the escape passage for brief periods, according to Uttarakhand government's nodal officer Neeraj Khairwal.
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