4 min readUttarkashiNov 27, 2023 07:30 AM IST
First published on: Nov 26, 2023 at 09:21 PM IST
After the machine drilling through the debris in the collapsed Silkyara-Barkot tunnel broke on Saturday – a major setback in the efforts to reach the 41 workers trapped inside for 15 days – rescuers on Sunday were engaged in cutting through the blade of the drill and removing it piece by piece.
After the drill blade is removed, rescuers plan to manually dig through the remaining debris to reach the trapped workers, officials said. A plasma cutter was brought in on Sunday from Hyderabad to cut and remove the drill blade.
As another option to reach the workers, rescuers on Sunday also started vertical drilling to create an 86-metre-long tunnel from the top of the hill under which the 41 are trapped.
The Satluj Jal Vidyut Nigam (SJVN) has so far drilled around 19.2 metres of that alternate vertical passage, which will have a diameter of 1.2 metres. If all goes well, it will take 100 hours to complete drilling through the 86 metres, officials said.
Lieutenant General Syed Ata Hasnain (retd), member of the National Disaster Management Authority (NDMA), said that going horizontally through the collapsed debris in the tunnel was still the best option. The horizontal drilling machine had drilled 47 metres into the debris when it broke on Saturday.
While a large part of the machine has already been pulled out, the rest will be removed by Sunday night, he said. Once that is done, manual digging of the remaining 15 metres will be done to reach the trapped workers.
“Even though manual digging may take more time, it is the safest option,” he said.
The trapped men are healthy and are getting food and medicine through supply pipes, Hasnain said. According to him, they have also been able to communicate with their relatives, and medical and psychological experts are working with them.
A unit of the Madras Sappers, from the Corps of Engineers of the Indian Army, arrived at the site on Sunday to assist in the rescue operations.
The operations had suffered a major setback on Saturday when the auger joint of the drilling machine, which had been creating a passage through the debris from the Silkyara side, broke. This blocked the passage that had been created so far, and necessitated rescuers to manually cut the drill blade to remove it from the passage.
Apart from the primary plan to manually dig through the debris after the removal of the blade, and the 86-metre vertical drilling, which is being seen as the next best option, other plans are also in place for the rescue operation.
One such plan is to horizontally drill perpendicular to the tunnel from the left side of the hill. This would require drilling of 180 metres to reach the part of the tunnel where the workers are stuck. Work on this will start on Tuesday and could take around 14 days, officials said.
Rail Vikas Nigam limited (RVNL) will undertake this work, and the resulting passage will be used in the future as an escape tunnel for the primary tunnel, according to officials.
The Tehri Hydro Development Corporation (THDC) has also started horizontal drilling from the Barkot end of the tunnel. However, this is expected to take 35-40 days to reach the place where the workers are trapped.
With work underway from different sides of the hill, special sensors are also in place to keep a tab on vibrations, officials said.
After the drill blade is removed, rescuers plan to manually dig through the remaining debris to reach the trapped workers, officials said. (File) 
Share
