NEW DELHI: The government officials remained non-committal about the timeline for the breakthrough at Silkyara tunnel to rescue 41 trapped workers citing the situation getting technically “more complex” after the joints of the auger used for horizontal drilling got broken.

But going by the time it would take for taking out the entire auger machine and then carrying out manual excavation, the breakthrough is possible not before late Monday, sources said.While cutting the remaining portion of the collapsed stretch manually remains the best option, the government has also expedited the Plan B — vertical drilling to push a 1.2 meter pipe through 85 meter — and drilling machinery arrived at site on Saturday.As per an official update on Saturday evening, a “Magna cutter” machine and specialised workmen were being brought by air from Rajahmundry (Andhra Pradesh), which will speed up the cutting and extraction of the damaged auger.

“Air lift from Rajahmundry Airport to Dehradun and transit from Dehradun Airport to Silkyara site are being arranged by ONGC and likely to reach at site tomorrow (Sunday) morning and likely to reach at site tomorrow (Sunday) morning,” it said.Earlier, the plan to reach the trapped workers quickly received a big jolt when the auger machine met with a fresh obstruction while pushing the 10th pipe on Friday.

The official communication said the agencies started pulling back the auger and around 15 meter of it came out initially and thereafter its joints got broken.

Thereafter, manual cutting of auger in small pieces by gas cutter and taking them out from inside the 800 mm pipe was happening.

Till evening 23 meter of the auger out of the total 47 meters had been taken out.“The deployment of “Magna cutter” will accelerate the cutting of the auger blades and shaft and only after this task is completed, manual excavators will be put to the job.

It would take around 18-24 hours to clear the remaining stretch,” said a source.Speaking to media persons, Syed Ata Hasnain, member of the National Disaster Management Authority, said that the rescue operation has become technically complex and that rescuers are working in an environment of unpredictability.

He added that the workers who remained trapped in the tunnel were stable and safe.He added that the process of drilling will start in the next 1-2 days.

“Whatever methods we are using right now, we have to have some patience.

We need to understand that a very difficult operation is going on.

Two methods are being used currently, but a third method, the ‘drift’ method may also be used soon.

Currently, the situation is that the 47-meter digging has been done, we have to keep it stable and remove the broken part of the Auger machine,” Hanain said.Amid reports that the environment impact assessment (EIA) for the project has not been done, Vishal Chauhan, member, NHAI, who has been the nodal coordinating officer for the rescue officer at the road ministry, said, “The environmental impact assessment of this project has also been done.

There are several things that cannot be predicted but our first priority is to rescue the workers.” He also said that the agencies needed to dig another 12-15 meters for the breakthrough.