Tunnel collapse: Operation to rescue trapped workers through large pipes begins

The rescue operations continued at the under-construction tunnel at Silkyara in Uttarakhand’s Uttarkashi on Tuesday to evacuate the 40 trapped labourers as rescue teams launched the process of inserting 800 and 900 mm diameter pipes through the debris to create a passage for the trapped workers.

There are eight pipes of 900 mm each with a length of six metres and five pipes of 800 mm diameter, with a length of six metres each, said officials.

Meanwhile, state disaster response force (SDRF) commandant, Manikant Mishra, spoke to the trapped labourers through a walkie talkie.

The steel pipes will be pushed through the debris horizontally, one after another, using the auger drilling machine, for which a platform has already been made.

It’s been over 60 hours since the incident and the plan to remove debris using heavy excavator machines, and prevent more debris from falling using the “shotcrete method,” has been hurdled with fresh debris and mud continuously falling from the roof of the collapsed portion.

The large diameter pipes were dispatched from Dehradun and Haridwar after Uttarakhand chief minister Pushkar Singh Dhami conducted an on-site inspection of the rescue operation.

According to officials, a staging area has been at the accident site where vertical drill, horizontal drill machine, shotcrete, Poclain machines, JCBs, one hydra machine and two loader have been stationed. Inside the tunnel, 4 Poclain, 2 shotcrete, two boomer, two hydra and two trucks were in action.

Authorities also called in experts from the irrigation department to successfully push the steel pipes through the debris.

Explaining the process, Vijay Dangwal, a geologist from Rail Vikas Nigam Limited, said the auger machine (spiral shaped) will penetrate through the debris and simultaneously it will carry backward to the entry pit. He said even though complications can arise in any process, it was a less complex process.

Uttarakhand Disaster Management secretary Ranjit Sinha said, “Once it begins, the process to insert 900 pipes through the debris using an auger machine could take approximately from 24 to 30 hours. The rib of the tunnel that collapsed could come in the way of auger machine. We have also begun the process of removing the rib. Once drilled, the trapped workers can be pushed outside through pipes.”

When asked, Uttarkashi District Disaster Management Officer (DDMO) Devendra Singh Patwal said the rescue workers were building the platform to insert the evacuation pipe and drilling had begun to push it through.

He said it won’t be easy to tell how much time it would take to complete the process and rescue the trapped labourers.

Meanwhile, the officials on Monday reiterated that the trapped labourers in the buffer zone are safe and sound and are being supplied food, water, and oxygen through a pipe.

Chief mnister Dhami held a meeting with senior government officials at his residence in Dehradun and issued directions that they should maintain constant coordination with the district administration, agencies and officials deployed on the spot.

“If case of any need for relief material, it should be made available immediately, the CM said.

An expert committee constituted by the state government under the chairmanship of director, Uttarakhand Landslide Mitigation and Management Center to study and investigate the causes of the landslide that occurred in the Silkyara Tunnel, inspected the site and started its investigation.