OSHA Guide – Cranes and Derricks in Construction

Section 1413 – Wire Rope Inspection

Wire rope must be inspected as part of the shift, monthly, and annual inspections required by section 1412. The shift and monthly inspections must evaluate all rope that is visible during the shift in which the inspection is conducted. The annual inspection must include the entire length of the rope. The shift and monthly inspections must pay particular attention to the following:

  • Rotation resistant wire rope in use
  • Wire rope being used for boom hoists and luffing hoists, particularly at reverse bends
  • Wire rope at flange points, crossover points, and repetitive pickup points on drums
  • Wire rope at or near terminal ends
  • Wire rope in contact with saddles, equalizer sheaves, or other sheaves where rope travel is limited

In addition to these items, the annual inspection must include:

  • Those sections that are normally hidden during shift and monthly inspections
  • Wire rope subject to reverse bends
  • Wire rope passing over sheaves

You must take certain action if an inspection reveals a defect in the rope. Some defects require either that the rope be removed from service or the damaged section be severed. For others, the inspector must evaluate whether the defect constitutes a safety hazard, with the corrective action depending on the outcome of the evaluation. Note that, if a wire rope must be repaired or replaced, either the equipment (as a whole) or the hoist with that wire rope must be tagged-out during the repair/replacement process.

Severing Wire Rope

Where severing the rope is permitted, the section that is damaged must be discarded. Two undamaged sections may not be spliced to make a longer rope. If the undamaged part that remains is too short for the drum to have two full wraps of rope when the load and/or boom is in its lowest position, the rope cannot be used and must be replaced.

Electrical Contact with Power Line

Wire rope that has made electrical contact with a power line (either by the rope, the equipment, or the load contacting the line) must be immediately removed from service even if no damage is visible. The rope may have suffered internal damage that cannot be repaired.

Defects that Require Removal from Service or Severing

The following defects require that the rope either be removed from service or the defective part severed.

  • Visible broken wires, as follows:
    • In running wire ropes: six randomly distributed broken wires in one rope lay, or three broken wires in one strand in one rope lay, where a rope lay is the length along the rope in which one strand makes a complete revolution around the rope
    • In rotation resistant ropes: two randomly distributed broken wires in six rope diameters, or four randomly distributed broken wires in 30 rope diameters
    • In pendants or standing wire ropes: more than two broken wires in one rope lay located in rope beyond end connections, or more than one broken wire in a rope lay located at an end connection
  • A diameter reduction of more than 5% from nominal diameter
  • In rotation resistant wire rope, core protrusion or other distortion indicating core failure.
  • A broken strand.

Exception: If the wire rope manufacturer has approved different criteria for visible broken wires or diameter reduction, you may follow those criteria instead of those above.

Defects that Require Evaluation

The following defects must be evaluated by the inspector to determine whether they constitute a safety hazard:

  • Significant distortion of the wire rope structure such as kinking, crushing, unstranding, birdcaging, signs of core failure, or steel core protrusion between the outer strands
  • Significant corrosion
  • Electric arc damage (from a source other than power lines) or heat damage
  • Improperly applied end connections
  • Significantly corroded, cracked, bent, or worn end connections (such as from severe service)

If these defects are found to be hazardous: The rope must be removed from service or the defective part severed.

If they are not found to be an immediate hazard:  You may continue to use the rope. However, if such a defect is identified during an annual inspection, you must check it during each monthly inspection. Note that this may require a more complete monthly inspection than would otherwise be required because the annual inspection must cover the entire rope and may reveal a defect in a part of the rope that would not normally be visible during a shift or monthly inspection.