Note the area of the breaks and carefully inspect these areas in the future. Keeping a detailed inspection record of the wire breaks and other types of damage will help the inspector determine the elapsed time between breaks. Also examine the rope near the end connections. Check as the rope runs at a slow speed over the sheaves, where crown (surface) wire breaks may be easier to see. The inspector may use a type of spike to gently probe the strands for any wire breaks that do not protrude. The number of broken wires on the outside of the wire rope is an indication of its general condition and whether or not it must be considered for replacement. The inspector must know the ASME standard for the equipment being inspected. The table below shows the number of allowable wire breaks per crane type. If this condition persists, it will lead to severe corrosion which promotes premature fatigue failures in the wires and strands, necessitating the rope’s immediate removal from service. A slight discoloration caused by rusting usually indicates a need for lubrication which should be tended to immediately. Usually signifying a lack of lubrication, corrosion will often occur internally before there is any visible external evidence on the rope’s surface. CorrosionĬorrosion is very difficult to evaluate but is a more serious cause of degradation than abrasion. A badly corrugated or worn sheave or drum will seriously damage a new rope, resulting in premature rope replacement. Therefore it is vital that all components be in proper working order and of the appropriate diameter for the rope. Abrasion damage may occur when the rope contacts an abrasive medium or simply when it passes over the drum and sheaves.
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