Uttarakhand Tunnel Rescue Anytime, Hospital, Chopper On Standby: 10 Facts

Only two meters are left for the rat miners to dig, after which the evacuation process can begin. The workers are going slow, implementing all safety measures.

Elaborate preparations have been made for the rescue. A temporary hospital has been made inside the tunnel to acclimatise the the workers to the outside weather and an Air Force Chinook chopper is standing by for emergencies. Chief Minister Pushkar Sing Dhami is at the spot.

"Rat miners" -- labourers used to drilling narrow shafts as part of a primitive and currently illegal method of coal extraction -- had to manually dig the rocks that proved too tough for an American Augur drill and several other devices.

Manual drilling is a slow and labour-intensive process in which the rat-hole miners had to go through the 800 mm pipe, drill manually and bring out the debris by shovels.

The American Auger drill -- a corkscrew-like device with a rotary blade at the front end -- which drilled around 46.8 metres, had to be withdrawn as its blades got fouled up by the rocky debris and iron rods that formed part of the tunnel ceiling.

Around 4 am on November 12, a 200-km area of a tunnel on the Brahmakhal-Yamunotri National Highway had collapsed, trapping 41 labourers working there in a 400 meter buffer zone.

The rescue workers had reached immediately and have been providing them with food, water, medical supplies and other essentials through pipes. a pipe already in place in the tunnel had been providing the area with fresh oxygen.

Videos from the spot showed huge piles of concrete blocking the tunnel. Poking among it were twisted metal bars from its broken roof.

The rubble had been frustrating the efforts of multiple agencies armed with various drilling equipment and excavators for over two weeks.  Worse was the unplastered roof of the tunnel, from which rocks showered down frequently, setting back the rescuers several times.

The 4.5-km tunnel on the Brahmakhal-Yamunotri National Highway, which will join Silkyara and Dandalgaon in Uttarkashi, is part of the Chardham project. Once finished, it is expected to cut down the distance by 26 km.