Abstract: On August 28, 2008, an employee and Coworkers #1 and #2 were attempting to restring a new boom hoist cable to replace one that had become worn. Employee #1 and Coworker #1 #2 were working with a friction hoisting device called a cathead on the right hand side of the oil rig. Coworker #3 had climbed up the derrick structure to connect new lifting cable to old to facilitate replacing the support cable. Employee #1 had tied a 1.625-in. manilla rope to the 0.5-in. cable and was assisted by Coworker #1. Employee #1 looped the manilla rope around the cathead and began pulling the old cable down when the manilla rope crossed over itself on the cathead. Employee #1 and Coworker #1 attempted to uncross the rope by trying to flip the rope off the cathead when Employee #1's arm was caught in a loop of the manilla rope. Employee #1 had his arm pinned to the cathead which was still spinning which severed his arm below the elbow. The emergency services of Reno County, Kansas were called and both Medical and Police arrived at the oil rig. Employee #1 was airlifted to Wesley Medical Center in Wichita, Kansas, where he was hospitalized and treated for an amputation of his arm.