Once the drilling is complete, the passage will be used to evacuate the labourers from the tunnel.
Drilling with the American auger machine resumed at the Silkyara tunnel overnight to prepare an escape passage for the 41 workers trapped inside for more than 10 days, officials said on Wednesday.
According to officials, 800 mm diameter steel pipes have been inserted up to 39 metres through the rubble, with another 14 metres to go before the rescuers reach the trapped labourers.
Once the drilling is complete, the passage will be used to evacuate the labourers from the tunnel.
"We have pushed in the pipes up to 39 metres by now. Everything is fine. I have spoken to them (trapped workers). Their morale is high," former advisor to the PMO Bhaskar Khulbe told reporters in Silkyara.
Asked to spell out a timeline for the evacuation, he said, "We hope to celebrate Igas with them".
Igas is a festival celebrated in the Garhwal region after Diwali. It will take place on Thursday.
The drilling was suspended since Friday when the auger machine hit a hard object. But the resumption is likely to speed up the rescue efforts, officials said.
NHIDCL officials supervising the rescue operations on the spot had on Tuesday said the auger machine will be put back into operation after the 800 mm diameter steel pipes are pushed through the 900 mm diameter steel pipes already laid through the rubble using the telescopic method.
Prime Minister Narendra Modi talked to Chief Minister Pushkar Singh Dhami once again on Wednesday morning to take updates on the rescue operations underway at the tunnel and food and other essentials including medicines being supplied to the trapped workers through a new wider pipeline laid for the purpose.
It was through this new pipeline that the first visuals were captured of the trapped workers early on Tuesday with the help of an endoscopic flexi camera sent beyond the rubble.
Mr Dhami briefed the prime minister about the positive progress made over the last 24 hours in the rescue efforts being carried out at the tunnel with coordination between the state government, the central agencies and the international tunnelling experts.
"We are getting continuous guidance from the Prime Minister in this difficult situation. It provides us with a new energy every day to evacuate our trapped brothers safely at the earliest applying all our strength," Mr Dhami said on X.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)