As the rescue operations continue for the ninth day on Monday to evacuate 41 labourers trapped in the collapsed Uttarakhand tunnel, the rescuers have now come up with a new approach to reach the workers.
The American-made heavy-duty auger machine, deployed to drill and push in pipes through the rubble to prepare an escape passage, failed to make any breakthrough and was put on hold on Friday as it encountered a hard obstacle after digging in for 22 metres.
The rescuers have finally given up the approach of vertical tunnelling using different auger machines and the rescue work at the collapsed Silkyara tunnel was virtually on hold Sunday as the agencies prepared for the next stage.
The authorities have now planned multi-pronged approach to reach the trapped workers in the Silkyara Tunnel in Uttarkashi, which collapsed on November 12. Five options have been decided and five different agencies namely- Oil and Natural Gas Corporation (ONGC), Sutluj Jal Vidyut Nigam (SJVNL), Rail Vikas Nigam Limited (RVNL), National Highways and Infrastructure Development Corporation Limited (NHIDCL), and Tehri Hydro Development Corporation Limited (THDCL) are working to rescue the trapped men.
Vertical Tunnelling
The Sutluj Jal Vidyut Nigam (SJVNL) has started working on vertical drilling to rescue the trapped labourers. Accordingly, equipment has been mobilized from Gujarat and Odisha through Railways as being 75-tonne equipment it could not be airlifted. The vertical drilling equipment is too big to be transported by air and will be brought to the site by road.
BRO Builds Road to Hill Top
A road to the top of the hill has already been laid by the Border Roads Organization (BRO) in a single day for digging a vertical shaft down into the tunnel.
The Rail Vikas Nigam Limited is, meanwhile, working on a vertical pipeline for supplying essential items after the completion of the approach road to the top of the hill.
Vertical Drilling from Barkot End
The Oil and Natural Gas Corporation (ONGC), having expertise in deep drilling, has undertaken the task of vertical drilling at the Barkot end of the Silkyara tunnel on the Char Dham route.
The ONGC drilling head is set to visit the site on Monday and a report is expected to be submitted on Tuesday.
Micro tunnelling from Barkot end
Tehri Hydroelectric Development Corporation (THDC) has started working on micro tunnelling from Barkot end of the under-construction tunnel on the Char Dham route for which heavy machinery has already been mobilised.
Drilling from Silkyara end
The National Hydroelectric Power Corporation (NHPC) and the Satluj Jal Vidyut Nigam Limited (SJVNL) are currently tasked with drilling a 1-1.2 metre-diameter borehole at the Silkyara end. The tunnelling work will start from today.
Horizontal Boring to Continue
Though boring through the debris was put on hold on Friday afternoon when the American-made auger machine encountered a hard obstacle, the method has not been abandoned.
Union Road Transport Minister Nitin Gadkari said boring horizontally through the debris with the huge auger machine appeared to be the best bet. “Preparations are underway to restart the auger machine and resume drilling and pipe-laying at the tunnel,” Gadkari said.
The drilling is expected to resume on Monday, after safety arrangements for rescue workers are put in place. The auger machine had worked well through the soft soil, but there were vibrations in the tunnel when it encountered a hard object, which could have posed a danger to the safety of the rescue workers.
Other Plans
Uttarakhand Disaster Management Secretary Ranjit Kumar Sinha said Union Minister Gadkari has suggested that there could be space between the top of the debris and the tunnel roof, and this could be explored by robots to see if another pipe for life support could be pushed through.
(With inputs from PTI)
