Officials trying to reach 41 workers who have been trapped underground in the tunnel in Uttarkashi for eight days were contemplating alternative rescue plans.
The snags with a drilling machine caused them to halt digging. Now powerful machines are considered for the drilling.
The workers are being sent medicines and dry fruits via pipes into the tunnel. The electricity in the tunnel is working.
A new drilling machine arrived at the accident site in Uttarakhand state to replace one that was damaged while breaking through the rocks and debris.
They had been using the drill to create a space to insert wide pipes through which the trapped workers could crawl to their freedom.
Authorities have so far drilled 24 meters through rubble and debris, but it would require up to 60 meters to allow the workers to escape, said Devendra Patwal, a disaster management official.
Officials were considering new angles for extracting the workers. Officials said this included possibly using the new machine to drill from the top of the hill, under which the workers have been trapped.
