Because criteria for removal are varied, and because diameter, in itself, is a vague
criterion, the table of minimum diameters has been deliberately omitted from this manual.
4. Corrosion
Corrosion, while difficult to evaluate, is a more serious cause of degradation than
abrasion. Usually, it signifies a lack of lubrication. Corrosion will often occur internally
before there is any visible external evidence on the rope surface. Pitting of wires is a
cause for immediate rope removal. Not only does it attack the metal wires, but it also
prevents the rope’s component parts from moving smoothly as it is flexed. Usually, a
slight discoloration because of rusting merely indicates a need for lubrication.
Severe rusting, on the other hand, leads to premature fatigue failures in the wires
necessitating the rope’s immediate rope removal from service. When a rope shows
more than one wire failure adjacent to a terminal fitting, it should be removed
immediately. To retard corrosive deterioration, the rope should be kept well lubricated.
In situations where extreme corrosion action can occur, it may be necessary to use
galvanized wire rope.
5. Kinks
Kinks are permanent distortions cause by loops drawn too tightly. Ropes with kinks
must be removed from service.
6. “Bird Caging”
Bird caging results from torsional imbalance that comes about because of
mistreatments such as sudden stops, the rope being pulled through tight sheaves, or
wound on too small a drum. This is cause for rope replacement unless the affected
portion can be removed.
7. Localized Conditions
Particular attention must be paid to wear at the equalizing sheaves. During normal
operations this wear is not visible. Excessive vibration, or whip can cause abrasion and/
or fatigue. Drum cross-over and flange point areas must be carefully evaluated. All end
fittings, including splices, should e examined for worn or broken wires, loose or
damaged strands, cracked fittings, worn or distorted thimbles and tucks of strands.
8. Heated Damage
After a fire, or the presence of elevated temperatures, there may be metal
discoloration, or an apparent loss of internal lubrication; fiber core ropes are
particularly vulnerable. Under these circumstances the rope should be replaced.
9. Protruding Core
If, for any cause, the rope core protrudes from an opening between the strands the
rope is unfit for service.
10. Damaged End Attachments
Cracked, bent, or broken end fittings must be eliminated. The cause should be sought
out and corrected. In the case of bent hooks, the throat openingsmeasured at the
RT500
Applicable Standards / Regulations
318 REVISED:
To Next Page
