By 5pm Wednesday, the 40 workers trapped 260 metres inside a 4.5km road tunnel in Uttarakhand’s Uttarkashi district, had been trapped for 84 hours, and two rescue attempts to cut through 50 metres of rock blocking the tunnel had failed – to the despair of the families and colleagues of the workers.

On Wednesday morning, the families and other workers staged a protest outside the tunnel, alleging that the construction company Navayuga Engineering Company Limited (NECL), and rescue teams were not doing enough to rescue the trapped men. The rescue operation is being managed by the National Disaster Relief Force (NDRF) and Uttarakhand Disaster Management Authority. NDRF officials positioned at the spot said they are awaiting the completion of the drilling of the passage through which NDRF personnel can enter and bring back the workers.

National Highways and Infrastructure Development Corporation Limited (NHIDCL) officials blamed loose rocks and sand above the broken part of the tunnel for the failure of the two attempts. But experts claimed the attempts were botched because they lacked “proper geological” inputs on how to work in a soft mountain range prone to landslides.

According to state disaster management officials, for the first two days, the rescuers tried to remove the piled debris in a 55-metre stretch of the tunnel using heavy excavator machines and sought to prevent more debris from falling using the “shotcrete method” (shotcrete is a construction technique that involves spraying concrete onto surfaces using high-velocity air).

“This did not work,” said a rescue worker who asked not to be named, blaming the structural instability (continuous falling of loose material from the roof the tunnel).

Officials from NDRF and Uttarakhand Disaster Management Authority then decided to create a “safe” passage using an auger machine and fitting in large diameter pipes of 800 and 900mm to bring the workers out.

“The idea was to create a small passage without having the fear of debris falling to bring the workers out,” a senior official at the rescue site said, asking not to be named.

The plan did not work. After building a concrete platform to launch the augur machine that reached the site on Tuesday morning, it was put to use at night.

“After drilling for about two metres there was fresh landslide inside the tunnel forcing us to suspend the operation,” the senior official quoted above said. When the machine was dismantled from the platform, the rescuers discovered that its blades were worn out and they needed a heavier machine.

The auger drilling machine, which was provided by Delhi-based Vardhman Engineering Works, was not able to cut through the debris at enough speed due to boulders in the debris, said Devendra Patwal, Uttarkashi district disaster management officer (DDMO), adding that the machine was removed. The team then decided to bring in a new high-capacity machine.

An Indian Railways officialwho is part of the rescue effortsaid that the machine did not seem to have the capacity to do what was asked of it. The rescue team requisitioned an American-made horizontal dry drilling equipment in three parts. All three parts were flown in from Delhi on a Hercules C-130 plane by Wednesday evening; two parts have reached the tunnel site, the remaining one was expected to reach in the evening, Patwal said.

Adesh Jain of Vardhman Engineering Works, who provided the first machine, said he was not sure whether a bigger machine would work. “The auger machine provided by me was 35 HP (horsepower) and weighs 9 tonnes, while the new machine could be 175-200 HP and considerably heavier.”

Anshu Manish Khalkho, director, NHIDCL, the project proponent, expressed confidence that the new machine would work. “The new machine is fully automatic and faster. It can drill 5 metre per hour,” he said, ignoring a question on why a more powerful machine was not requisitioned in the first instance.

He hoped the drilling would start late on Wednesday night and that the team would reach the trapped workers in 12 hours.

Bhupendra Singh, DGM, Rail Vikas Nigam Limited (RVNL) said if this plan does not work out, the final option will be conventional drilling . “Under this plan, we will build an entire tunnel. It will take five to six days.”

Saurabh Majumdar, a worker from West Bengal, expressed dismay at the way the rescue has been managed so far.

“When the company was building the tunnel, were they not aware of the soil and its fragile mountain? Didn’t they know that such an incident could happen? Now they say fresh debris and muck is falling and that’s what is hampering the rescue. They are just bringing in new machines, one after another, but failing to execute their plans,” he said.

NDRF officials said personnel at the scene are equipped with harness, mats, torches, collapsable stretchers, and other devices, which can help them get the works out, especially if they are feeble and unable to crawl on their own.

“Our teams are on standby and coordinating with the agency engaged in building a passage through which the workers can come out. The authorities there are doing their best to find a solution and rescue the workers. The state government is also fully involved and coordinated with the Indian Air Force to ensure that new machines were lifted and flown to the nearest airport. We are hopeful that they build a passage with the new machines quickly and we are able to go inside and rescue the workers,” Atul Karwal, NDRF director general, said.

Another worker who didn’t wish to be named said, “I spoke to one of my fellow workers trapped inside. He said they were losing hope and their confidence has been shaken with the delayed rescue operation.”

Singh said that the rescue team is in the process of installing an additional 125mm diameter pipe for air and food.

An SDRF official who didn’t wish to be named said, “The rescuers from the multi-agencies were not expecting the boulders in the piled up debris. The new auger machine may become successful to penetrate through the debris. Even though its success chances are higher, we can’t ignore the complications involved.”