Drilling at the collapsed Silkyara tunnel to rescue 41 men trapped inside for 12 days was halted again on Friday, in yet another setback to the multi-agency effort.
An official said the auger drilling machine faced a hurdle, apparently a metal object, a little after drilling resumed Friday, a day after officials had put the operation on hold following technical problems.
Those problems were set right earlier in the day and the 25-tonne machine was restarted in the evening.
According to one official, the boring continued for about an hour before the drill bit hit the metal girder.
The multi-agency rescue effort began November 12 when a portion of the under-construction tunnel on Uttarakhand's Char Dham route collapsed, trapping workers who were still inside.
As the machine drills, six-metre sections of a steel pipe are welded together and pushed into the narrow passage.
Once this steel chute crosses the stretch of debris of the collapsed portion, the trapped workers would be pulled out on wheeled stretchers.
Rescue workers suggested in the evening that the drill bit was now being pulled out through the passage already bored by the machine.
The two hurdles in two days have come as a blow to anxious relatives camping at the site for the past several days.
Before the brief period of drilling on Friday, 46.8 metres of the 800 mm wide steel pipe had been pushed into the drilled passage -- out of the collapsed stretch estimated to be about 60 metres long. The six-inch wide tube for supplying food and other essential items to the workers had travelled 57 metres.
The latest setback comes just hours after officials expressed hope that the operation could be over soon, provided no further obstacles came in the way.
A ground penetrating radar used for the first time in the operation had indicated that the next stretch of 5.4 metres did not have any major metal hurdle.
In the morning, former advisor to the Prime Minister's Office Bhaskar Khulbe told reporter that the issues that stalled the drilling on Thursday had been set right.
"We have 12-14 metres more to go. And I hope if all goes well we might conclude the operation by Friday evening," he had predicted.
Over Thursday night, officials said, the auger machine's platform was strengthened with quick-settling cement.
Workers went over 45 metres inside the passage to cut off the damaged 1.2 metre front end of the steel pipe -- an operation in confined space that took several hours. That portion of the pipe had bent after hitting a hurdle.
A damaged portion of the auger's blade was also repaired.
But later in the day, the fresh snag forced the operation to be paused again. Garhwal range IG KS Nagnyal told PTI that arrangements are in place to take the rescued workers to medical centres under police escort through a 'green corridor'.
Road Transport and Highways Minister V K Singh, who has been camping in Uttarkashi since Thursday, visited the Silkyara site during the day to take stock of the operation.
Chief Minister Pushkar Singh Dhami has been staying at nearby Matli and visited the disaster site again on Friday. Prime Minister Narendra Modi talked to Dhami once again for updates.
The National Disaster Response Force conducted a mock drill at the site. An NDRF jawan went into the escape passage, pushing a wheeled stretcher tied to a rope and was then pulled out. He said there was enough room inside the pipe and he had no difficulty breathing during the exercise.
Forty-one ambulances are stationed outside the tunnel to rush workers after their evacuation to Chinyalisaur community health centre, where a separate ward has been set up with 41 oxygen-supported beds for them.
Similar arrangements have also been made at the Uttarkashi district hospital. Trauma and ICU beds have also been readied for them at AIIMS, Rishikesh where they could also be airlifted if required.
The trapped workers are being sent food, medicines and other essentials through the six-inch wide pipe.
A communication system has been set up, using the pipe, and the workers' relatives have spoken to them. An endoscopic camera was also pushed through this pipe, allowing rescue workers to see the condition inside.
The workers are in a built-up two-kilometre stretch of the tunnel. Alternative rescue plans include drilling from above the tunnel, an option that could take up to 45 days.
Some work, including mobilisation of machinery, has already been done over the past few days on these alternatives approaches.
