The auger machine drilling into landslide debris to rescue the 41 labourers trapped in an under-construction mountain tunnel in Uttarkashi ran into a mass of steel lattice on Friday night despite an all-clear and got mangled beyond repair, officials said.

No drilling was possible on Saturday, with the 25-tonne auger and its shaft twisted and jammed inside the channel of Hume pipes bored 49 metres into the 57-metre-thick barrier of debris, behind which the labourers have been penned for a fortnight.

With serial obstacles frustrating a rescue effort initially expected to be over in days, chief minister Pushkar Singh Dhami on Saturday said that after the damaged auger was extracted, the remaining 8 metres of debris would be removed “manually”. He did not explain.

An official involved in the operation told The Telegraph that a worker can crawl through the welded chain of 32-inch-diameter Hume pipes and remove the remaining debris with a handheld drill. He said it would be a slow process but not an impossible one.

Currently, the challenge is to remove the fragments of the auger stuck inside the Hume pipes.

Dhami said that rescue teams had manually cut and removed the fragments from about 20 metres of the Hume pipe channel till Saturday evening, clearing 1 metre per hour.

“We are bringing a plasma-cutter machine from Hyderabad, which will cut four metres of the damaged auger and shaft in one hour,” he said. “It will reach Jolly Grant airport (at Dehradun) tonight.”

Driving the plasma cutter to Uttarkashi from Dehradun should take six hours. Dhami hoped, rather optimistically, that the auger’s fragments would be removed completely by Sunday morning. “We shall then start clearing the remaining debris manually,” he said.

A steel girder in the debris had halted drilling for six hours on Wednesday night and bent steel pipes later hobbled the effort on Thursday through Friday morning, damaging the US-made auger’s blades and base.

The auger was repaired and resumed drilling. On Friday afternoon, with 46.8 metres drilled, authorities were buoyed by a report from US firm Parsons Corporation, which had probed the debris with ground-penetrating radar.

The report said there was no metallic obstacle in the next 5.4 metres of the debris, according to Mahmood Ahmed, managing director of National Highways and Infrastructure Development Corporation Limited.

However, after drilling through what Dhami said was another 2.2 metres, the auger ran into the mass of steel lattice.

Dhami, asked why the rescuers from over a dozen agencies had failed to survey the debris correctly and depended on a company that came up with a flawed report, passed the question to Anurag Jain, secretary, Union ministry of road transport and highways.

“They had seen it (surveyed the debris) in a conical shape and reported to us whatever they found in their survey,” Jain said.

Apart from the horizontal drilling from the Silkyara side of the Silkyara-Barkot tunnel, Dhami said, the rescuers would pursue five other options: vertical and perpendicular drilling from two spots each and 450 metres of horizontal drilling from the Barkot side.

But the chief minister appeared unsure of when these alternative efforts — being spoken about for at least five days now — would start.

Flawed approach

Dhami acknowledged that the government was aware of irregularities in the construction of the tunnel — part of the Centre’s Char Dham highway project — particularly the failure to follow the specification to have a safety exit on the side every 500 metres.

“We will address these issues once the labourers are rescued. Today, I talked to three trapped labourers, including Gabbar Singh Negi and Saba Ahmad, and they told me to take time but rescue them safely,” he said.