An iron mesh that came in the path of the drilling machine creating an escape passage for the workers trapped in the Silkyara tunnel was removed on Thursday morning but has delayed the rescue operation by 12 to 14 hours, a senior official said.

Former advisor to the prime minister's office Bhaskar Khulbe said removing the mesh in a claustrophobic environment inside the pipe was difficult.

"It took us six hours to remove it. But the good news is that we have cleared the hurdle which came yesterday after drilling up to 45 metres had been done," Khulbe told reporters.

Now the process of assembling to go beyond 45 metres which requires welding the pipes has been restarted. The drilling will also resume soon, he said.

It will take around 12 to 14 hours more to complete the whole operation of reaching the workers. After that, it will take three more hours to take out the workers one by one. That will be done with the help of NDRF, Khulbe said.

Union Minister of State for Road Transport and Highways Gen V K Singh and National Disaster Response Force (NDRF) Director General Atul Karwal have arrived in Silkyara for an on-the-spot review of the rescue efforts.

Chief Minister Pushkar Singh Dhami is also likely to arrive soon.

The drilling of 800 mm diameter steel pipes through the rubble had to be halted for some hours after hitting the hurdle late Wednesday.

Meanwhile, all arrangements have been made to provide immediate medical care to the 41 trapped workers after they are evacuated, officials said.

A 41-bed separate ward has been readied at the Community Health Centre in Chinyalisaur for Silkyara tunnel evacuees and 41 ambulances wait outside the tunnel to rush them there as soon as they crawl out, officials said.