Drilling to rescue 40 men trapped in Indian tunnel halted after snag, cracking sound

SILKYARA, India, Nov 17 (Reuters) - Rescuers trying to reach 40 workers trapped in a collapsed highway tunnel in the Indian Himalayas since last weekend suspended work temporarily on Friday after hearing a sudden "cracking sound" and the drilling machine developed a snag.

The men have been stuck in the hillside tunnel in Uttarakhand state since Sunday morning after it caved in and are safe, authorities said.

During efforts to restart the drilling machine, a "large-scale cracking sound" was heard, according to a report from the state-run National Highways and Infrastructure Development Corporation (NHIDCL).

The sound "created a panic situation in the tunnel as well as to the team working," the report said.

Similar sounds have been noted previously and there was a "strong possibility of further collapse", the report said, adding that a meeting to discuss further steps in the rescue effort has been called.

The trapped workers have light and receive oxygen, food, water and medicines via a pipe, and can communicate via walkie-talkie. Their families are waiting anxiously, some camped outside.

Efforts to reach them were slowed by falling debris during drilling and a new machine flown from New Delhi began work on Thursday with the intention of creating space to push through pipes for the men to crawl to safety.

Pipes had been pushed 22 metres (72 feet) - about one-third of the way - when the cracking sound was heard and the machine developed a snag on Friday afternoon, said NHIDCL, which is building the tunnel.

"The machine is not able to push further as the machine is getting lifted" and its bearings are getting damaged, the statement said, adding that work was underway to anchor the machine to the platform.

Engineers at the site are fabricating spare bearings to start it again, NHIDCL director Anshu Manish Khalkho told Reuters.

A rescue mission is currently underway at the Silkyara tunnel in Uttarakhand to free 40 workers who are stuck inside following a landslide.

Chief medical officer of the district, R.C.S. Pawar, said the temperature inside the tunnel is higher than outside and there have been no complaints of feeling cold by the men.

Night temperatures have fallen to 13 degrees Celsius (55°F) as winter sets in.

The 4.5 km (3 mile) tunnel is part of the Char Dham highway, one of the most ambitious projects of Prime Minister Narendra Modi's government.

Authorities have not said what caused the cave in, but the region is prone to landslides, earthquakes and floods.

Arnold Dix, the Australia-based president of the International Tunneling and Underground Space Association, who is among experts being consulted by rescuers, said it was essential to take time and care.

"We cannot go fast and risk a second disaster," he told Reuters. "This situation is extremely dangerous and we must be extremely careful."