The Press Trust of India news agency reported “preparations to drill a vertical hole from the top of the hill” had begun, as an alternative route out.
Indian media carried a photograph showing an excavator starting to clear soil on the forested hilltop high above the tunnel.
Rescuers have been communicating with the trapped workers by radio, and food, water, oxygen and medicine have also been sent to them via a 15cm-wide pipe.
Tunnel expert Arnold Dix, an independent disaster investigator and president of the International Tunnelling and Underground Space Association, said he was on his way to India after being asked to help.
“We are discussing right now our options for the safe rescue of these men,” Dix told India Today.
Experts have warned about the impact of extensive construction in Uttarakhand, where large parts of the state are prone to landslides.
Dix said the tunnel was in “one of the most difficult areas”, but said he was confident they would be rescued.
“We are going to bring those 41 men home”, he said.
Source: CNA
