News Excerpt:
Recently, 41 workers have been rescued from the collapsed Silkyara tunnel using the technique of rat mining.
Why is rat-mining banned?
- This rat-mining practice has received harsh condemnation due to the hazardous working conditions, environmental degradation, and frequent accidents resulting in injuries and fatalities.
- According to experts, the mines are often unregulated, without safety precautions such as sufficient ventilation, structural support, or worker safety gear, resulting in a highly hazardous situation for the rat miners.
- Furthermore, mining can lead to soil degradation, deforestation, and water contamination.
- The National Green Tribunal in 2014 imposed a ban on coal mining using the rat-hole mining technique in Meghalaya.
Other methods used to rescue the trapped workers in the Silkyara tunnel:
- Vertical drilling:
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- It is accomplished by employing a boring machine to dig straight down from the ground while using electrical tools and equipment.
- To extract the trapped miners in the Uttarakhand tunnel collapse, a vertical drill was bored into the ground and an 800-mm pipe was installed.
- Auger mining (horizontal drilling):
- A horizontal auger machine, also known as a directional drill, is specialized equipment used to drill horizontal boreholes or tunnels without disturbing the ground.
- These machines are used to lay water and gas pipes as well as to excavate tunnels.
- However, in the case of the Uttarakhand tunnel collapse, the auger machine failed to release the trapped miners after hitting metal impediments and subsequently breaking down beyond repair.
