Efforts to free the 40 workers trapped in a tunnel in India have been slowed by difficult ground condition and falling debris.
Multiple media outlets including Reuters have reported that the an emergency mini tunnel successfully reached the trapped workers and is able to provide the workers with food, water, medicine and fresh air. However, attempts to bore a large tunnel that the workers could use for an escape have been slow.
As on Nov. 17, rescuers were preparing to deploy an advanced machine to cut through the rubble faster.
Loose rocks have been falling into a tunnel that rescuers are trying to create and this is the main challenge facing the operation at the moment, said a top official in Uttarakhand state, where the disaster occurred.
Reuters reported that the men are trapped in an area of about 50 me (150 ft) and are safe, officials said, and frequent contact is being made with them through walkie-talkies.
“The plan is to drill through the debris, put mild steel pipes in it and make a path for the laborers to move,” Ranjit Sinha, the top disaster management officer in Uttarakhand, told Reuters by phone.
“The only challenge is to remove the debris as it is very loose and it keeps coming back.”
In a LinkedIn Post, Arnold Dix, president of the International Tunneling and Underground Space Association (ITA) wrote “Fresh & renewed attempts to auger a 800 mm evacuation tunnel with much more powerful equipment are slowly progressing. Several new segments have been completed in the newest 800 mm diameter tunnel attempt. The ground is a mixture of soft ground and hard boulders and collapsed structural steel ribs and lattice girders. There is a very high risk of encountering impenetrable obstacles.”
Dix has been in contact with rescue teams on sight and said ITAs international emergency response teams are ready to assist.
India’s Himalayas are prone to landslides, earthquakes and floods. The tunnel collapse follows incidents of land subsidence that have been blamed on rapid construction in the mountains.
A high-powered auger drilling machine is being set up at the site to cut through the debris at 2.5 metres an hour as opposed to 1 m/hour by the previous machine that suffered a glitch, Sinha said.
An estimated 50 m remains to be drilled through before the trapped workers are reached, said Anshu Manish Khalkho, an official of the state-run highway management company NHIDCL.
The men were working on the Char Dham highway, one of the most ambitious projects of Prime Minister Narendra Modi’s government, but the plan has faced criticism from environmental experts.
The project aims to connect four Hindu pilgrimage sites in the mountains through 890 km (550 miles) of roads at a cost of $1.5 billion, but some work was halted in January after hundreds of houses were damaged by subsidence along the routes.
The federal government has said it employed environmentally friendly techniques in the design to make geologically unstable stretches safer.
Work on the tunnel began in 2018 and was initially meant to be finished by July 2022 but delays prior to Sunday’s collapse had already pushed the expected end-date back to next May, the government said in a statement.