Slings or wire ropes must be taken out of service if they have ______ broken wires in one strand in one lay.

Slings or wire ropes must be taken out of service if they have ______ broken wires in one strand in one lay.

• A. two
• B. seven
• C. five
• D. four

Answer: (C)

In rigging safety, fatigue damage in wire rope is a critical red flag. The test uses a clear take-out criterion: if five wires are broken in a single strand within one lay, the sling or rope must be removed from service. A lay is the length of rope in which the strands complete one twist around the rope's axis, so “one strand in one lay” means inspecting a single strand over the length that all its wires align together around the rope. Why this threshold matters: five broken wires in one strand indicate a significant crack pattern due to repeated loading and bending. With that many broken wires in the same localized area, the remaining strands and wires can no longer share the load safely, increasing the risk of sudden, catastrophic failure under normal service conditions. Removing the rope at this point helps prevent an accidental break during lifting. If you’re inspecting and you see this or any other substantial damage, replace the rope rather than attempt to repair it. Different rope constructions might have other thresholds, but the five-broken-wires rule is a common, conservative standard used to keep lifting operations safe.

In rigging safety, fatigue damage in wire rope is a critical red flag. The test uses a clear take-out criterion: if five wires are broken in a single strand within one lay, the sling or rope must be removed from service. A lay is the length of rope in which the strands complete one twist around the rope's axis, so “one strand in one lay” means inspecting a single strand over the length that all its wires align together around the rope.

Why this threshold matters: five broken wires in one strand indicate a significant crack pattern due to repeated loading and bending. With that many broken wires in the same localized area, the remaining strands and wires can no longer share the load safely, increasing the risk of sudden, catastrophic failure under normal service conditions. Removing the rope at this point helps prevent an accidental break during lifting.

If you’re inspecting and you see this or any other substantial damage, replace the rope rather than attempt to repair it. Different rope constructions might have other thresholds, but the five-broken-wires rule is a common, conservative standard used to keep lifting operations safe.