Boring through the rubble of the collapsed Silkyara tunnel was put on hold again on Thursday apparently after cracks appeared in the platform on which the drilling machine rests, in a fresh hurdle to the rescue of 41 workers trapped inside for 11 days.
The dampener came hours after the operation resumed earlier in the day, following a six-hour delay to cut through an iron girder that came in the way of the auger machine late Wednesday night.
This is the third time that the drilling exercise has been halted since the multi-agency rescue mission began on November 12 after a stretch of the under-construction tunnel in Uttarakhand's Char Dham route collapsed.
According to one official the drilling was stopped Thursday to ”stabilise” the platform on which the 25-tonne drilling machine is mounted. Some cracks apparently appeared in the structure, but there was no official confirmation.
In the afternoon, a government press statement in Delhi said minor vibrations were noticed at 1.10 pm and the auger was being pushed slightly back to ”reassess the force to be applied”. It said the operation will then restart.
Before the setback, officials were looking at the possibility of the operation ending during Thursday night -- provided no more obstacles emerged during the drilling as it entered the last stretch of 10 to 12 metres.
"I expect that in the next few hours or by tomorrow, we will be successful in this operation," National Disaster Management Authority (NDMA) member Lt Gen Syed Ata Hasnain said in Delhi, even as he warned that there could be more hurdles that could delay it.
Former advisor with the Prime Minister's Office Bhaskar Khulbe, who was at the site, said an iron obstruction that came in the path of the drill on Wednesday night had been removed.
At 10 am, he told reporters it would take 12 to 14 hours of drilling and about three hours on top of that for the National Disaster Response Force (NDRF) to evacuate the workers.
State government's nodal officer Neel Neeraj Khairwal told reporters at around 2 pm that drilling had progressed by 1.8 metres after the setback Wednesday night at the 45-metre mark. Another official said the drill had covered 48 metres.
Section-by-section, a steel pipe was being pushed through the rubble as the auger machine drilled.
Once the chute emerges from the other end, National Disaster Response Force (NDRF) men will enter it to help bring out the trapped workers one by one. The workers would lie on low, wheeled stretchers that will be pulled out of the horizontal chute using ropes.
The trapped workers are being sent food, medicines and other essentials through a new six-inch wide tube, which is also being used for communication.
Union Minister of State for Road Transport and Highways V K Singh and NDRF Director General Atul Karwal were at Silkyara on Thursday to review the rescue effort.
Chief Minister Pushkar Singh Dhami also arrived in Silkyara.
"We have come around 45 metres. We are very close to you now," he told the trapped workers through the communication system, before the operation was paused.
The CM asked two workers, Gabbar Singh Negi and Saba Ahmad, about the condition of others and praised them for keeping their morale up.
The drilling and insertion of 800-mm wide pipes from the Silkyara end was first put on hold on Friday afternoon when the auger machine encountered a hard obstacle around the 22-metre mark, creating vibrations in the tunnel that caused safety concerns.
The drilling resumed around midnight Tuesday but then there was the other, relatively minor, second setback the next night.
At the disaster site, international tunnelling expert Arnold Dix told PTI that the machine was facing ”some difficulties”, stressing that it has not been designed to be put through this level of stress.
He said he couldn't set a timeline but was certain that the rescue effort will be successful with several Indian agencies coordinating well in the effort. Dix also warned against rushing as it might "complicate" things.
"Since the trapped workers on the other side of the rubble are safe and fit, not rushing has enormous value because if we rush in a situation like this we might create problems we cannot imagine," he said.
When the workers come out, they will be rushed in ambulances under police escort through a ’green corridor” to a 41-bed special ward set up at the community health centre in Chinyalisaur in Uttarkashi district.
If needed, they will then be transferred to other medical facilities.
The NDRF chief earlier said the trapped workers appeared to be in good spirits.
"People who work in tunnels are mentally tough and these people are aware of the huge endeavour being carried out to evacuate them. So they are optimistic," he added.
