Rat-hole mining technique behind successful rescue

Aditi Tandon

New Delhi, November 28

The technique behind rat-hole coal mining, a practice that was banned by the National Green Tribunal in 2014 for being unsafe, came to the rescue of 41 workers trapped inside the Silkyara tunnel in Uttarkashi for 17 days.

The rat-hole mining technique involves digging very small tunnels not more than 5 feet high to enable workers to go inside and extract coal. The practice, specific to Meghalaya, was banned to ensure the safety of miners and protect lives.

In Meghalaya hills, the coal seam is often very thin, less than 2 metres mostly, with children preferred as rat-hole miners for extraction purposes. Once miners locate the coal seam, rat hole-sized tunnels are horizontally dug, and then workers enter and extract coal. The technique was used by 12 expert rat-hole miners called in at the site of partial tunnel collapse in Silkyara to rescue the trapped workers.

National Disaster Management Authority member Lt Gen Syed Ata Hasnain (retd) today termed the efforts of rat-hole mining technique experts as phenomenal, saying that they manually dug through 12 metres of rubble in 24 hours after the auger machine broke down having drilled nearly 45 metres.

As for the practice, it was banned after serial incidents of miners going missing in Meghalaya, which has a coal reserve of 640 million tonnes.

The immediate trigger for the ban was 15 coal miners going missing in an accident on July 6, 2012, in South Garo Hills district. The Gauhati High Court had taken suo motu notice of the deaths of young miners. It was this HC petition which was finally transferred to the NGT, which banned the practice on April 17, 2014.

In the 2012 accident, 30 labourers were trapped in the rat-hole mine in South Garo Hills of Meghalaya. While 15 escaped mine flooding, 15 died leading to the registration of an FIR.