The rescuers, who have been trying to evacuate 40 trapped workers inside a tunnel in Uttarakhand, suffered a setback after the plan to drill through the debris and install pipes using an auger machine failed on Tuesday evening.
The machines deployed for drilling the rubble couldn’t work on Tuesday evening as falling debris from a fresh landslide hampered efforts to insert steel pipes through the collapsed part of the tunnel.
Officials said that all workers are reported safe and communication has been established. The trapped workers, who remain inside the collapsed tunnel since Sunday, are also being provided ration and other essentials through pipes.
Over 160 personnel from the National Disaster Response Force (NDRF), State Disaster Response Force (SDRF), Border Roads Organisation (BRO) and Indo-Tibetan Border Police (ITBP) are racing against time to reach the trapped workers, who are stuck for over 70 hours.
Why There Has Been a Delay in Rescue?
A portion of the under-construction tunnel, spread over 30 metres, which is part of the ambitious Chardham All Weather Road project, collapsed on Sunday.
The rescuers planned to create an escape passage by inserting a large-diameter pipe of 900 mm diameter through the rubble and create an escape passage for the trapped workers. The process involved inserting the large-diameter pipes through the rubble using an auger machine.
Heavy excavator machines were successful in removing around 21 metres of loose debris till Monday night, but the falling rocks blocked the passage with fresh debris. On Tuesday night, the rubble from the landslide fell on the collapsed part of the tunnel, hampering operations as well as injuring two rescue workers.
Moreover, officials said that the drilling machine turned out to be too slow and technical issues developed later.
What’s Next?
A heavy drilling machine is being airlifted from Delhi on Wednesday to replace the “failed” equipment which was being used to dig the tunnel. A new platform will be built inside the tunnel for the new drilling machine.
According to a report in The Indian Express, rescuers have started on a new “trenchless” technique of digging, where the ‘auger’ machine will create 900-mm wide stable passage of mild steel to evacuate the trapped workers.
The report added that this will be the first time that a “tunnel inside a tunnel” will be created as part of a rescue operation in India and there is a “more than 90 per cent chance” of success.
The plan involves installing or repairing underground infrastructure without any excavation or open trenches, which minimises disturbance on the surface. The method is already in use in sewage systems for installation, repair, and rehabilitation.
The trenchless method will be used for drilling horizontally using an American-made auger machine, which is a bigger than the previous one. It will use mild steel (MS) pipes which will be used to create a stable passageway.
“We will start installing it as soon as it arrives and in four-hours hours it will begin the drilling operation. With a capacity to penetrate 4-5 metres of rubble per hour, we can expect it to penetrate 50 metres through the rubble in 10 hours,” NHIDCL Director Anshu Manish Khalkho said.
