Uttarkashi Tunnel Collapse: Vertical Drilling Makes Progress, 'Horizontal Tunnelling Remains Best Plan'

Uttarkashi Tunnel Collapse: Vertical Drilling Makes Progress, ‘Horizontal Tunnelling Remains Best Plan’

The rescuers have begun vertical drilling of the Uttarkashi tunnel to evacuate 41 workers trapped inside the rubble as the rescue mission drags on for the last 15 days.

The vertical drilling to rescue the trapped workers inside Uttarkashi’s Silkyara tunnel began on Sunday afternoon after the auger machine failed to make any headways.

The development comes even as a plasma cutter was flown in from Hyderabad on Sunday to cut and remove parts of the auger machine stuck in the rubble inside the Silkyara tunnel.

Considered as the second-best option, the work on vertical drilling started around noon and 17 meters of drilling has already been completed, Former advisor to PMO Bhaskar Khulbe said.

National Disaster Management Authority (NDMA) Member Lt Gen (retd) Syed Ata Hasnain said that after 86 meters of vertical drilling, the crust of the tunnel will have to be broken to bring out the trapped workers.

The vertical drilling, which was scheduled to begin earlier this week, was halted due to some problems on the upper part of the hill.

So far, two locations have been identified for the vertical drilling and both are on the Silkyara side of the under-construction tunnel, part of which caved in on November 12.

On day 14 of the multi-agency rescue mission, officials shifted focus to two alternatives — manual drilling through the remaining 10- or 12-metre stretch of the rubble or, more likely, drilling down 86 metres from above.

Syed Ata Hasnain also said that the best plan so far remains horizontal drilling. “The best plan so far is plan 1 (horizontal drilling) where the drilling inside will be done manually. The second-best alternate technique remains vertical drilling.”

Several agencies are working on the rescue efforts in a synchronized manner. The Indian Air Force has also joined in as it flew critical DRDO equipment to Dehradun.

The American auger machine, which started its horizontal drilling, hit a metallic grinder in the rubble of the collapsed rubble and broke down, putting a halt to the rescue operations for the third time in 15 days. The auger machine has already drilled 47 metre inside the tunnel.

Meanwhile, work is on to retrieve broken parts of the auger machine, the NDMA member said, adding magna and plasma cutters are being used for the purpose.

Once the broken parts are retrieved, manual digging of 15 meters will be done to reach out to the trapped workers though it may take time, he said, stressing that all concerned agencies are working to make the rescue operation a success.

Uttarakhand Chief Minister Pushkar Singh Dhami said that a plasma machine from Hyderabad was shipped in, and has started cutting out the pieces of the auger to advance the rescue operations.