The rescuers, who have been racing against time to bring out the 41 workers trapped inside the collapsed Sylkyara tunnel in Uttarakhand, began vertical drilling on Sunday and bored 19.2 meters on the first day.
"We have completed around 19.2 meters of drilling. We have to drill around 86 meters to be done within four days that is by November 30. Hopefully, there will be no further hurdles and the work will be completed on time," National Highways and Infrastructure Development Corporation Limited (NHIDCL) Managing Director Mahmood Ahmad said at a press conference.
According to officials, 700-mm wide pipes are being inserted to create an escape passage for the trapped workers as the drilling progresses. Another 200-mm pipe is also being pushed in a little distance away.
Ahmed had earlier informed that multiple options have been put into action to rescue the workers who have been trapped for the last 14 days after a portion of the tunnel being between Silkyara and Dandalgaon in Uttarkashi district collapsed in the early morning on November 12.
Vertical drilling was one of the five-six options for which authorities had begin preparatory work some days back. This option was picked as the next best alternative after the augur machine that was carrying out the horizontal drilling met with multiple snags.
In the latest setback, the machine broke and got stuck inside the debris on Friday. A plasma cutting machine has been brought to the site to bring the stuck blades and the auger's shaft out in pieces.
Authorities said they will start manual drilling once the broken parts of the augur machine are removed. A unit of Madras Sappers, an engineer group of the Corps of Engineers of the Indian Army has been called in for manual drilling.
“We are removing the broken auger faster than before. It cannot be told how much time will be taken to remove it, after it is cleared, we will do manual drilling inside. The Army's Engineering Regiment will also prepare a plan as to how to work further," Neeraj Khairwal, secretary in the Uttarakhand Government and nodel officer of the rescue mission, said.
“The exercise may be completed by Sunday midnight or tomorrow morning," he said.
Authorities were exploring multiple options for the rescue operation as anxiety mounted over the fate of the men trapped in the under-construction tunnel.
Earlier in the day, National Disaster Management Authority Member, Lt General (Rtd) Syed Ata Hasnain said 86 meters of vertical digging is required to reach trapped workers.
“We have done geological studies and studies are suggesting that there might be no obstruction. We are checking the stability," he said.
