Uttarakhand tunnel collapse: Rat-hole mining experts begin manual drilling

Rat-hole mining specialists engaged in rescuing 41 workers trapped in the collapsed Silkyara tunnel in Uttarakhand's Uttarkashi initiated manual drilling through the debris. At least 12 rat-hole mining experts are tasked with horizontally drilling through the final 10- to 12-meter stretch of debris in the collapsed section of the under-construction tunnel on the Char Dham route in Uttarakhand. The alternative drilling approach was adopted after a large auger machine became stuck on Friday. Approximately 40 per cent of the necessary 86-meter vertical drilling has been completed.

As of Monday evening, the remaining portion of the stuck auger was successfully 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 vertical drilling, initiated on Sunday, has already reached a depth of 36 meters.

The rescuers aim to extract workers through this one-meter-wide shaft once it penetrates the top of the tunnel below, ideally by Thursday. Simultaneously, an eight-inch wide shaft, drilled from a nearby point, has reached approximately 75 meters down. This secondary probe, expected to serve as a supply line for the trapped workers, indicates no significant geological obstacles so far, according to statements from the NDMA member and Silkyara officials.