The past few months, my articles have centered around wire rope safety and inspection, and this month is no different. However, this is the last of the wire rope articles. The topic this month is end connections and rigging. End connections and rigging? It’s a fancy way of talking about what attaches the hook to the wire rope, as well as everything that hangs below the hook. Although wire rope failures can happen, much of the time when I have witnessed a deficiency or incorrect usage, it is at or below the hook. This is particularly alarming because drilling crews are next to or handling the hook often, increasing the likelihood of injury in event of a failure.
An end connection attaches a hook or other load-bearing item to the end of a wire rope. These come in many forms, from buttons and sockets swaged on by the manufacturer of the wire rope, to wire rope clips and wedge sockets installed in the field. All types of connection are widely used in drilling. However, all but an open spelter socket come with a 5 to 25% reduction of the breaking strength of the wire rope.