Union Minister Nitin Gadkari stated that all options were being explored to rescue the workers, and the operation could take two to three more days.
There was little progress in efforts to reach 41 workers trapped inside a collapsed tunnel in Uttarkashi as the operation entered its second week with rescuers on Sunday adopting a five-pronged approach to evacuate the people. The rescuers were also carving out a track on the mountaintop to reach the top of the tunnel from where they can drill a vertical hole to pull the workers out.
One pipe, or “lifeline” as the authorities call them, was being pushed through the 65-metre-thick wall of debris to provide the trapped workers with solid food, officials said, adding that it had already reached a depth of 40 metres. A second “lifeline” was being pushed in vertically from top of the tunnel.
Union minister for road transport and highways Nitin Gadkari, who reached the site on Sunday to review the situation, said all options were being explored to rescue the workers. “Our priority is to save the lives of the trapped workers. We have been exploring all options,” Gadkari told reporters.
The construction workers have been trapped since November 12 when a portion of the 4.5-km tunnel they were building collapsed about 200 metres from the Silkyara entrance in the Uttarakhand district. The tunnel is part of the busy Chardham all-weather road, a flagship project connecting various pilgrimage sites.
Now the rescue team is working on alternatives including drilling from one end to the other on both Silkyara and Barkot sides, vertical drilling from the top of the tunnel and perpendicular drilling.
Elaborating the plans, MoRTH secretary Anurag Jain said that the Oil and Natural Gas Corporation (ONGC), Sutluj Jal Vidyut Nigam (SJVNL), Rail Vikas Nigam Limited (RVNL), National Highways and Infrastructure Development Corporation Limited (NHIDCL), and Tehri Hydro Development Corporation Limited (THDCL) have been engaged for the operation, Jain sai
“NHIDCL is creating another six-inch pipeline for food and they have completed drilling through 39 metres out of 60. Once this passage is ready, it will facilitate delivery of more food items,” he sai
NHIDCL, the agency entrusted with building the tunnel, will simultaneously drill from the Silkyara end of the tunnel, Jain said. “To facilitate this, the Army has prepared the box culvert. A canopy framework is being made to ensure workers’ safety. Work of pipeline laying will recommence tomorrow,” he said.
The Rail Vikas Nigam Limited (RVNL) has started working on another vertical pipeline for supply for essential items after the Border Roads Organisation (BRO) completed building an approach road.
“Further, THDC shall start work of micro tunnelling from Barkot end for which heavy machinery has already been mobilised. THDC shall start the operation tonight (Sunday) itself,” Jain said.
The vertical drilling from the top of the tunnel, a plan proposed on Saturday, will be carried out by SJVNL. “Accordingly, equipment has been mobilised from Gujarat and Odisha through Railways, as the equipment weighing 75 tonnes could not be airlifted,” he said. This involves creating an alternative route at the top of the mountain to enable drilling vertically from a pre-identified spot on the tunnel to a depth of about 103 metres where the workers are stuck.
NHIDCL MD Mahmood Ahmed said that the agencies started working on the second lifeline service late on Saturday night.
“Since Saturday night, another lifeline service is been creating by the way of pushing a 150mm diameter steel pipe through the debris by ROC machine. As of now 40 metre length has already been inserted out of probable length of 60m and is still in progress,” he said.
The current 4 inch lifeline service (pipe) through which food and other essential items are being supplied to trapped workers has been shifted from the existing point to a safer place.
“Escape passage from the service point has been created to the area which is prone to further collapse by way of placing concrete Hume pipe and steel pipe and work has been completed,” the NHIDCL official said.
Separately, to create a safe passage for rescuers, “concrete blocks and steel pipe for a length of around 65m up to the safe zone covering area which is prone to further collapse” have been placed, NHIDCL said in a statement.
“Parallelly gantry structure is being fabricated in house to cover the pipe drilling machine and likely to be completed by Sunday evening and thereafter pipe pushing activity are to be resumed,” the statement said.
While experts and rescue teams have attributed the delay in the operation to difficult terrain, Gadkari, who was accompanied by Uttarakhand chief minister Pushkar Singh Dhami, sounded hopeful that the workers could be rescued in two to three days if the drilling through augur machines resumes.
“If the auger machine drilling works properly, we can rescue the trapped workers in the next two to three days… some hard material came in its way and stopped the machine from working. When the machine was exerting further pressure to push further, it increased the vibrations. They (experts) have found a solution to the problem,” Gadkari told reporters.
The rescue operation is challenging as the soil strata in the Himalayan region is not uniform, he sai
Horizontal drilling with the American auger is the quickest method in the given circumstances to reach the trapped workers, Gadkari said.
Rescue operations stalled around 2.45pm on Friday. During the positioning of a fifth pipe, a big cracking sound was heard in the tunnel upon which rescue operation was suspended immediately, a statement from the NHIDCL tasked with the construction of the tunnel said in a statement on Friday night.
There was a brief pause in the drilling on Friday morning as well, when the augur machine, flown in from Delhi, sustained damages after drilling through nearly 24 metres. This plan involved drilling through the debris to push pipes — 800mm and 900mm in diameter — one after the other to create a passage for trapped workers to crawl out of.
Before that, as part of Plan A rescuers tried to dig through the rubble using heavy excavator machines, but loose rock and sand collapsing from the roof of the tunnel impeded progress.