Rescue efforts at the collapsed Silkyara tunnel in Uttarakhand were largely halted on Sunday as the agencies participating in the rescue prepared for the next stage, which would include using different ways to reach the 41 men who had been trapped within for a week, news agency PTI reported. Officials claim that a road to the top of the hill was built in a single day in order to construct a vertical shaft down into the tunnel. In addition, the Tehri Hydroelectric Development Corporation planned to start "micro tunnelling" Sunday night from the Barkot end of the Char Dham route's under-construction tunnel, a portion of which collapsed on November 12.


Boring through the wreckage of the collapsed 60-metre portion from the Silkyara end was halted Friday afternoon when the heavy-duty auger equipment, built in the United States, hit a hard obstruction after around 22 metres.


On Friday, the setback compelled a reassessment. Officials devised a number of different ways to approach the besieged workers within the under-construction tunnel.


However, after visiting the site on Sunday, Union Road Transport Minister Nitin Gadkari stated that digging horizontally through the rubble with the massive auger machine looked to be the best option. He was expecting a breakthrough in two and a half days.


According to a media brief provided in Delhi, the drilling will resume Monday when safety precautions for rescue personnel are put in place.


By Sunday evening, rescue crews had driven a six-inch-wide tube into the rubble up to 39 metres. Once it crosses the collapsed section, the trapped workers will be supplied with food and drink via this conduit as well.


According to officials, a smaller four-inch wide "compressor pipe" is already running through the wreckage and is being used to bring in food, water, oxygen, and medications.


The section of the tunnel where the workers are stuck is around two km long and 8.5 metres high. According to a press statement, electricity and water are accessible.


Following the construction of the approach road to the top of the hill, Rail Vikas Nigam Limited has commenced work on a vertical pipeline to provide critical materials.


"Saving the trapped workers and evacuating them at the earliest is the biggest priority," Gadkari informed reporters at Silkyara after a meeting with the experts. "Preparations are underway to restart the auger machine and resume drilling and pipe-laying at the tunnel," he was quoted by PTI in its report.


Gadkari stated that the auger machine performed admirably in the soft soil, but there were vibrations in the tunnel when it came into contact with a hard item. This presented a risk to the rescue crews' safety.


"Though I am no technical expert, in the given circumstances horizontal digging seems the best option. If the auger machine does not encounter any obstacles it might reach the trapped workers in two and a half days," he said.


According to Uttarakhand Disaster Management Secretary Ranjit Kumar Sinha, the minister has indicated that there may be room between the top of the rubble and the tunnel ceiling that robots may examine to determine if another pipe for life support could be put through.


The besieged workers are being given multivitamins, antidepressants, and dried fruit, according to Road Transport and Highways Secretary Anurag Jain.


"Fortunately, there is light inside because the electricity is on. There is a pipeline, and so water is available. There is a four-inch pipe that was used for compression. Through it we are sending food from day 1," he said.


The multi-pronged strategy is the result of a series of failures, including a part of the Silkyara-Barkot tunnel collapsing the previous Sunday morning, barring the route out for workers who were finishing their night shift.


When earth-moving equipment proved ineffective, an auger machine was brought in. When it failed, the IAF transported the bigger American-made drilling machine from Delhi.


In case a replacement was required, an identical machine was also shipped from Indore. The vertical drilling equipment arriving next is too large to be transported by plane and will be transported to the site by road, according to officials.