Rock drill worker

1) Drives and operates tractor-mounted rock drilling machine to drill explosive-charge holes through hard materials to facilitate blasting operations: Moves lever to set out-rigger jacks to level machine. 2) Verifies level of machine, using spirit level. 3) Inserts steel drill or rock bit into chuck. [pdf]

Down-the-hole drill worker

DTH technique was used in well drilling exclusively to dig, accurate, vertical bores, and rotary drilling was used to turn the hole. The Directional DTH system, patented by Atlas Copco, was first used successf. [pdf]

What kind of job is it to operate a down-the-hole drill

DTH is short for “down-the-hole”. Since the DTH method was originally developed to drill large-diameter holes downwards in surface-drilling applications, its name originated from the fact that the percussion mechanism followed the bit down into the hole. Applications were later found for the DTH method underground, where the direction of drilling is generally upwards instead of downwards. [pdf]