In the early 1920s, during the heyday of mining in Butte, Montana, Arthur L. Hawkesworth, Master Mechanic for the Anaconda Copper Mining Company, came up with an invention that revolutionized drilling in the mining industry…the detachable drill bit. His “Hawkesworth Drill,” as it was first known, enabled a length of steel to remain productive in the mine by merely changing its tip. A small, newly sharpened bit was simply slotted into a matching groove on the end of a piece of drill steel. Prior to the invention of the Hawkesworth Drill, a driller working underground needed numerous pieces of all the various lengths of steel, from “starters” to 4, 6, and 8 feet, etc., to keep working. For years, Arthur Hawkesworth had watched the conventional method of sending various lengths of drill steel into the mines to be used, sent back up the shaft for re-sharpening, then sent back down again for reuse, until eventually they were worn out and thrown away. Hawkesworth sought and found a better way.
On Friday May 21, 1922, the Anaconda Company organized a demonstration of the “Hawkesworth Drill” in Butte, Montana. All of the district’s leading owners, managers, engineers, and mechanics were in attendance, along with Montana Senator H. A. Gallway. “We appear to have all the brains of the mining world present,” Senator Gallway said. “Let her go, Mr. Hawkesworth!” The test was an unqualified success. In the allotted time of two minutes, the “Hawkesworth Drill” cut two holes 20.5 and 22 inches deep into a block of solid granite. A competing conventional drill managed two holes only 9.5 inches deep. Said James Graham, a manager of the Sullivan Machine Company, “For years we have been drilling with doorknobs…and have compelled, in fact to make drilling machines heavier and heavier. With this device, we can reduce the weight of our machines from 200 to 115 pounds—a one-man drill!”
Arthur Hawkesworth’s invention generated tremendous savings for the mining industry—savings in time, in dollars, and in safer operating conditions. Savings in time came with increased drilling speed and efficiency, as miners could now always drill with a sharp bit. Time was also saved by the elimination of the manpower required to continuously send worn lengths of drill steel back and forth along the stopes, drifts, and tunnels of the mine to the shaft, up and down the shaft, and back and forth from the shaft to the steel shop. Savings in time translated into savings in dollars through increased drilling efficiency, lowered labor requirements, and the elimination of the loss of tons of steel in the form of eventually discarded drill shafts. Safety was greatly improved through the elimination of injuries and even occasional deaths that occurred during the transport of drill steel to and from working faces.
Over time, Arthur Hawkesworth’s detachable bit has become a commonplace tool in the mining industry. His bit’s long-lasting contribution to mine economics is simply immeasurable.