In 2011 it started investigating previous successful rescue operations where boreholes were drilled to rescue miners trapped underground.

This gave insight into what specialisations were needed to ensure successful future operations.

The Office of Mining Safety and Health Research saw benefit in documenting the knowledge, methodology and drilling equipment used in previous rescues. It felt it would certainly increase the probability of successful future mine rescues.

The NIOSH system involves specialised drilling equipment that can be used to drill a 700mm-diameter borehole from the surface to an underground location.

The equipment consists of a 300mm-diameter bit used for the drilling of the pilot hole and a 700mm-diameter bit capable of penetrating hard rock and creating a hole large enough for a rescue capsule.

The 450mm can rods maintain the physical relationship between the drill bit and sides of the drill hole, allowing rapid removal of rock cuttings as drilling progresses.

In the event of an underground emergency, the drill bits and about 61m of can rods are available for immediate use.

In addition to the equipment, a protocol has been developed to be integrated into a mine’s rescue response plan.

The protocol includes a list of 60 drilling companies, in the US, capable of using the specialised equipment.

The 700mm rapid rescue drill bit is on show at booth 1917 of the Society for Mining, Metallurgy and Exploration Annual Meeting in Salt Lake City.