Table 15. Diagnostic Guide to Common Wire Rope Degradation

Mode Symptoms Possible Causes
Fatigue Wire break is transverse – either straight across or Z shape.  Broken ends will appear grainy. Check for rope bent around too small a radius; vibration or whipping; wobbly sheaves; rollers too small; reverse b ends; bent shafts; tight grooves; corrosion; small drums & sheaves; incorrect rope construction; improper installation; poor end terminations. (In the absence of other modes of degradation, all rope will eventually fail in fatigue.)
Tension Wire break reveals a mixture of cup and cone fracture and shear breaks. Check for overloads; sticky, grabby clutches; jerky conditions, loose bearing on drum; fast starts, fast stops, broken sheave flange; wrong rope size & grade; poor end terminations. Check for too great a strain on rope after factors of degradation have weakened it.
Abrasion Wire break mainly displays outer wires worn smooth to knife edge thinness. Wire broken by abrasion in combination with another factor will show a combination break. Check for change in rope or sheave size; change in load; overburden change; frozen or stuck sheaves; soft rollers, sheaves or drums; excessive fleet angle; misalignment of sheaves; kinds; improperly attached fittings; grit & sand; objects imbedded in rope; improper grooving.
Abrasion plus Fatigue Reduced cross-section if broken off square thereby producing a chisel shape. A long term condition normal to the operating process.
Abrasion plus Tension Reduced cross-section is necked down as in a cup and cone configuration. Tensile break produces a chisel shape. A long term condition normal to the operating process.
Cut or Gouged or Rough Wire Wire ends are pinched down, mashed and/or cut in a rough diagonal shear-like manner. Check on all above conditions for mechanical abuse, or either abnormal or accidental forces during installation.
Torsion or Twisting Wire ends show evidence of twist and/or cork-screw effect. Check on all above conditions for mechanical abuse, or either abnormal or accidental forces during installation.
Mashing Wires are flattened and spread at broken ends. Check on all above conditions for mechanical abuse, or either abnormal or accidental forces during installation. (This is a common occurrence on the drum.)