Air Force Crane Course Practice Test

Wire rope used in lifting is described by its construction, specifically how many strands and how many wires are in each strand. In cranes, six-strand ropes are the standard around the drum and sheaves. The two most common constructions are six strands with nineteen wires in each strand and six strands with thirty-seven wires in each strand. The difference in wires per strand changes flexibility and wear characteristics: more wires per strand (thirty-seven) provide greater flexibility and smoother bending on pulleys and sheaves, while nineteen wires per strand produce a stiffer rope but can offer higher strength for a given diameter. These two configurations cover the majority of crane hoisting rope applications, which is why this statement is considered true. Other constructions exist, but they are less typical in standard crane practice.