Uttarkashi (Uttarakhand) [India]: 13 days after an under construction tunnel collapsed at Silkyara in Uttarkashi there appears to be some headway made in the rescue operation to evacuated 41 trapped workers.
A 25-tonne platform mounting the Heavy American Auger machine being used to drill through the debris has been strengthened using an accelerating agent for rapid hardening of concrete, and the rescue operations is expected to resume shortly.
The platform on which the equipment was mounted had developed some cracks when the rescue operation was underway on Thursday, and the process of horizontal drilling through the debris had to be paused.
As per the official bulletin, the pushing of the 9th pipe started at 1:10 am on Friday and the pipe reached an additional 1.8 meters, but suddenly, a minor vibration was noted.
Following this, the auger was pushed slightly back to re-assess the force to be applied wherein the rescue team observed the obstructions.
“A bent part of forepole (pipe) from tunnel lining was struck in the auger assembly which led to vibration. The platform for the auger machine is strengthened using an accelerating agent for rapid hardening of concrete,” the official bulletin said.
However, the auger was required to pull back fully to assess any other damage to the pipe.
It further said that the welder’s team has gone inside the pipe to cut of bent pipe which is ongoing.
“Auger reassembly will start shortly thereafter,” it added.
To give an emergent safe passage of the workforce for pipe pushing activities by auger machine, from near the pipe drilling machine, an escape passage by way of placing concrete culvert block, hume pipe and steel pipe for a length of 67 m (187 m to 120 m) has been taken up and work has been completed.
The trapped workers are safe, the bulletin added.
“Modified communication system with wire connectivity has already been developed by State Disaster Response Force and through which clear communication is being made regularly. People inside have reported that they are safe,” it said.
Freshly cooked food and fresh fruits are being inserted inside the tunnel at regular intervals using 2nd lifeline service (150 mm dia pipe).
2nd service lifeline (food pipe, 150 mm) has been extended from the initial position to a distance of 12 m to ensure higher stability and safety.
The last food consignment consisting of roti (200 nos), Dal (12 litres) and mixed veg was sent at 6:30 pm on Thursday.
On November 12, a portion of the under-construction tunnel from Silkyara to Barkot collapsed and debris falling in the 60-metre stretch on the Silkyara side of the tunnel trapped 41 labourers inside.
The workers are trapped in a 2 km-built portion, which is complete, including concrete work that provides safety to the workers.