After 17 days of rat-hole mining, 41 workers in Uttarkashi’s Silkyara Bend-Barkot Tunnel were rescued. The tunnel collapsed due to poor ventilation, structural support, and safety.
An ambulance stands by at the Silkyara Bend-Barkot Tunnel entrance during the rescue of 41 workers trapped within the under-construction tunnel in Uttarkashi district on Tuesday, Nov. 28, 2023. Uttarakhand Chief Minister Pushkar Singh Dhami said pipelines through Silkyara tunnel rubble have been laid, and 41 personnel stranded there for 16 days will be freed soon.
After 17 days, pipes were installed in the final portion of the collapsed Silkyara tunnel to rescue 41 trapped workers. For when the trapped workers are released, ambulances, garlands, and hospital beds are ready.
Tuesday saw rescuers drill through 60 meters of Silkyara tunnel rubble. Over the previous few days, National Disaster Response Force (NDRF) officers were scheduled to enter the steel chute shoved into the drilling passage and pull out workers one by one.
The training involves each worker lying on a wheeled stretcher dragged by rescue workers outside with ropes. Time was estimated at two to three hours.
After multiple delays due to the US auger equipment breaking down, ‘rat miners’ accomplished the last part of the rescue mission by drilling and clearing all debris to establish pipelines and rescue trapped workers from the collapsed tunnel.
Manual rat-hole mining is popular in Meghalaya, where specialized workers dig. Digging narrow trenches for one person is common.
Rat holes are narrow excavations excavated into the ground for one person to obtain coal.
The miner uses ropes and bamboo ladders to descend into the pits after excavating. This dangerous procedure is used to extract coal. Asphyxiation, lack of oxygen, and hunger are killing more miners, making it illegal in many countries.
Another sort of rat mining exists. This involves cutting a 10–100-sqm rectangular aperture and digging a 100–400-foot-deep vertical hole. After finding the coal seam, miners dig horizontal rat-hole tunnels to extract it.
Why is rat-mining illegal?
This rat-mining technology has been criticized for its unsafe working conditions, environmental harm, and numerous incidents that have killed and injured workers.
Experts say unregulated mines lack safety precautions including ventilation, structural support, and worker safety gear, creating a dangerous situation for rat-miners.
Deforestation, water pollution, and land degradation can result from mining.
The NGT prohibited the practice in 2014 and again in 2015. The NGT reported numerous incidences of rat-hole mining causing flooding during rainy seasons, resulting in the deaths of civilians, including employees/workers.
Other ways to rescue Silkyara tunnel workers
Vertical drilling: Electrically powered boring machines delve straight down. In the Uttarakhand tunnel collapse, a vertical drill bore into the ground and an 800-mm pipe was introduced to rescue workers.
Auger mining (horizontal drilling): A horizontal auger machine or directional drill is used to drill horizontal bores or tunnels without disturbing the ground. These devices lay water and gas pipes and dig tunnels.
In the Uttarakhand tunnel collapse, the auger machine hit metal impediments and broke down, preventing removal of the trapped workers.
Conclusion
Uttarakhand Chief Minister Pushkar Singh Dhami said pipes were placed in the end of the collapsed Silkyara tunnel to rescue 41 workers. Ambulances, garlands, and hospital beds were ready for their evacuation on November 28, 2023. Rescue workers drilled through 60 meters of rubble, and NDRF personnel were scheduled to enter the steel chute put into the drilled passage over many days. In the final part of the rescue mission, ‘rat miners’ drilled out all debris to lay pipelines and free the trapped workers from the collapsed tunnel. Rat-hole mining, manual drilling by expert personnel, is dangerous and illegal in many nations due to rising asphyxiation, oxygen deprivation, and hunger deaths. Vertical drilling uses electrical tools to dig straight down from the ground, and auger mining (horizontal drilling) is used to drill horizontal bores or create underground tunnels without disturbing the ground to rescue Silkyara tunnel workers.
