Vertical drilling begins in Uttarkashi tunnel to rescue trapped workers

Auger parts being pulled out to rescue 41 tunnel workers

Hopes of an expedited rescue for the 41 workers trapped in the Silkyara-Barkot tunnel in Uttarakhand have been dashed as the auger drilling machine, which ended up breaking inside the tunnel, has still not been fully taken out, officials said on Sunday evening.

“The equipment to cut the broken parts had to be flown in. With the help of the Air Force and an IndiGo chartered flight, a magna rod cutter, laser cutter, and Defence Research and Development Organisation’s plasma cutter have reached the site,” National Disaster Management Authority (NDMA) member Syed Ata Hasnain said at a press conference on Sunday evening in New Delhi.

Cutting of the auger with a plasma cutter started at 0400 hrs on November 26, which had to be stopped due to operational difficulties at the site, and cutting using gas cutters resumed at 0710 hrs on November 26. At the time of reporting, 33.8 metres of the auger had been pulled out, the Ministry of Road Transport and Highways said in a statement with updates until 4 pm.

According to NDMA, the remaining 13 metres of the auger would be pulled out by Sunday night.

The machine is being cut with a combination of gas and plasma cutters.

This is significant as manual drilling at the site cannot start until the auger machine has been entirely pulled out. This continues to be the primary plan of action for the authorities. Despite the shift to manual drilling after the auger failure, it continues to be the fastest option to evacuate the trapped workers.

Hasnain said that the speed of 4-5 metres per hour will no longer be achievable with manual drilling, resulting in a slowdown in the evacuation timeline.

Manual drilling will be conducted in a coordinated effort by the engineers of the Indian Army and the National Highways & Infrastructure Development Corporation.

 Meanwhile, efforts are also being made to protect the structure of the Silkyara side of the tunnel, where rescue efforts are underway. Agencies have erected false ribs on the face of the tunnel to protect the operational area.

The second option has now been set into motion, with a vertical tunnel by SJVN being built from the Silkyara end, which can be used to pull the workers up using buckets — a method that the National Disaster Response Force has rehearsed several times. So far, 15 metres of the total 86-metre distance have been covered via that route.

Separate vertical drilling exercises are also being undertaken by Rail Vikas Nigam and Oil and Natural Gas Corporation, according to the highways ministry.

The drift tunnel being created by the Indian Army, along with several public sector undertakings, has also made some progress. It is the slowest but the most fail-safe option at the rescue team’s disposal.