Drifter Drill
A drifter drill, sometimes called a rock drill, is a tool used in mining and civil engineering to drill into rock. Rock drills are used for making holes for placing dynamite or other explosives in rock blasting, and holes for plug and feather quarrying. While a rock drill may be as simple as a specialized form of chisel, it may also take the form of a powered machine. The mechanism may be worked or powered by hand, by steam, by compressed air (pneumatics), by hydraulics, or by electricity. Machine rock drills come in two basic forms: those that operate by percussion (using a reciprocating motion), and those that are abrasive (using a rotary motion). A smaller, hand-held percussion rock drill is considered a type of jackhammer. History and types The simplest form of rock drill consists of a long chisel or drill steel that was struck with a sledgehammer. Mark Twain, who worked unsuccessfully as a silver miner in the early 1860s before taking up journalism, described the proc ...
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