Home Dehradun Vertical drilling makes good progress in Silkyara, manual drilling set to begin

Vertical drilling makes good progress in Silkyara, manual drilling set to begin


Rescue work picks up speed on day 16 of rescue mission

By Arun Pratap Singh

Uttarkashi, 27 Nov: Today was day 16 of the rescue mission underway to evacuate 41 workers trapped in Silkyara tunnel on the Yamontri Highway in district Uttarkashi. The past 24 hours have seen some positive developments and significant progress in the mission which is proving to be a race against time and a major challenge. Work is underway on several fronts simultaneously. The vertical drilling has made good progress in the past 24 hours and by the time of filing this story, late this evening, vertical drilling of 1.2 metre diameter had been completed up to a depth of 38 to 40 metres. This is in addition to 200 mm vertical boring also carried out to test the soil and to serve as a backup lifeline for the workers. The 200 mm boring has been completed to a depth of 76 metres, according to officials. The rescue teams are drilling from multiple directions to reach the workers at the earliest. A tentative deadline of 100 hours has been estimated for vertical drilling to be completed.

All the parts of the broken auger stuck in the 900 mm pipe that has been drilled horizontally from the Silkyara end of the tunnel to reach the workers have been removed. As this story was filed, rubble and debris gathered in the pipe was being cleared by a team of rat miners and a portion of the pipe of a length of 1 metre that had also broken was being removed. After this, the manual drilling will begin to be carried out by a team of rat miners who have come from Delhi. At the same time, RVNL and ONGC are also engaged in making the tunnel from the Barkot end. So far, they have cleared the tunnel from that end to a distance of 12 metres. In all, the tunnel has to be cleared till around 500 metres to be able to reach the trapped workers. This is being done as a backup operation. There, too, no further blast was carried out in view of the dangers of landslide inside the tunnel. This work is making slow progress and to strengthen the walls of the tunnel at that end, shotcreting is being carried out.

Sources revealed that 1.2 metres diameter wide vertical drilling from Silkyara end has been completed till a depth of 38 metres. The final width of this boring will be reduced to 1 metre after the casing of the hole to prevent falling of debris. A back up vertical drilling machine has also arrived at the site, while another back up machine is also underway. The vertical drilling machine being currently used to perform the vertical drilling has the capacity to drill only up to a depth of 45 metres and, after reaching this depth, either this machine will be replaced by the second machine to reach the total desired depth of 86 metres or some parts of the second machine may be installed on the first machine to save time and then attempt vertical drilling beyond 45 metres.

Help of a rescue robotic system has also been sought in the rescue mission. Robotic engineer Milind Raj reached Silkyara today from Lucknow. The tools developed by him will be used to know the mental condition of the workers trapped inside the tunnel. Milind Raj, informed that Colonel Deepak Patil, in-charge of relief and rescue operations on behalf of the army, has called him from Lucknow. He said that the robotic tool brought by him is a homegrown indigenous technology to monitor health of trapped workers round the clock.

International Tunneling Expert Arnold Dix also spoke to the media and claimed that good progress has been made and that he is feeling very proud of the team and the progress that has been made so far. He added that manual drilling would be started soon.

Meanwhile, Lt General Syed Ata Hasnain (Retd), Member, NDMA, held a press briefing at the PIB building in New Delhi, today, and stated that the broken blades of the auger machine that were not completely retrieved yesterday have been fully retrieved this morning. There were some obstacles while doing so, but the damage has now been fixed. Now, the manual technique will be employed tonight with the help of Indian Army engineers, rat miners, and other technicians. Hasnain added that the rat miners would be moved inside in a group of two people. Hasnain also claimed that the things are under control, food and medicine are going inside as per requirements. Psychological aspects are also given importance. Backup communications have been established.

In Silkyara, Additional Secretary (Ministry of Road Transport Highways, Government of India) and MD (NHIDCL) Mahmood Ahmed and Secretary to Government of Uttarakhand, Dr Neeraj Khairwal also held a media briefing this evening and claimed that the work on vertical drilling is going on at a fast pace. Ahmed said that, till now, 30 metres (at the time of briefing) vertical drilling has been done. Further work is also being done with full speed and caution. During the briefing at Silkyara, DG, Information, Banshidhar Tiwari and SDRF Commandant Manikant Mishra were also present.