Uttarkashi tunnel collapse: 'Good news' in next 40 hrs if...’ say officials

livemint.com:

mission to rescue 41 trapped workers in the collapsed tunnel on 10th day, Additional Secretary Technical, Road and Transport Mahmood Ahmed Tuesday said the time from tonight is the 'most crucial' and if everything goes right, some 'good news' will come up in the next 40 hours, ANI reported. Ahmed said the rescue teams are now pushing 800 mm-diameter pipes with the telescoping method instead of 900 mm used earlier. Ahmed said the rescue teams are now pushing 800 mm-diameter pipes with the telescoping method instead of 900 mm used earlier.

"From this morning on, we started the process of horizontal drilling. Four 900-mm-diameter pipes of 6 metres each were pushed to 21-22 metres last week before they hit an obstacle. Now we have decided that we will lay an 800-mm-diameter pipe through the telescoping method.

We have started that work. After that, we will do further drilling inside it with the American Auger machine. For us, the entire day until tomorrow from tonight on is most important," ANI quoted Additional Secretary Ahmed as saying.

As per the earlier rescue plan, 900-mm diameter pipes were planned to be pushed in using horizontal drilling equipment to create an escape route for the trapped workers. The National Disaster Management Authority (NDMA), while sharing details about the progress made towards reaching the trapped workers, said the focus would be on “horizontal digging" instead of finding a route through vertical digging as rock formation has created challenges for vertical drilling. Ahmed said out of the total 60-metre length of horizontal drilling from the Silkyara end, around 22-45 metres are rubble.