MAINTENANCE CHECKLIST OPERATOR MANUAL 500E2
6-4 Published 07-26-2019 Control # 111-06
Environmental Conditions
The life expectancy of wire rope may vary due to the degree
of environmental hostility and other conditions to which these
mechanical devices are subjected. Variation in temperature,
continuous excessive moisture levels, exposure to corrosive
chemicals or vapors or subjecting the wire rope to abrasive
material may shorten normal wire rope life. Frequent/
periodic inspections and maintenance of wire rope is
recommended for preventing premature wear and to insure
long-term satisfactory performance.
NOTE: Refer to Wire Rope Lubrication, page 5-9 for wire
rope lubrication requirements.
Dynamic Shock Loads
Subjecting wire rope to abnormal loads beyond the
endurance limit will shorten the wire rope life expectancy.
Examples of this type of loading are listed below.
• High velocity movement, for example; hoisting or
swinging of a load followed by abrupt stops.
• Suspending loads while traveling over irregular surfaces
such as railroad tracks, potholes, and rough terrain.
• Lifting a load that is beyond the rated capacity of the
lifting mechanism, such as overloading.
Precautions and Recommendations During
Inspection
• Always use safety glasses for eye protection.
• Wear protective clothing, gloves, and safety shoes as
appropriate.
• Measure the rope’s diameter across crowns of the
strands when determining if rope has become damaged,
refer to Figure 6-1.
Inspection
All hoist cable in service needs to be inspected on a daily,
monthly, and quarterly basis. Cable which has been idle for a
period of a month or more must be given a thorough
inspection before it is placed in service. These inspections
should cover all types of deterioration including:
• Distortion such as kinking, crushing, un-stranding, bird
caging, main strand displacement or core protrusion.
• Reductions from nominal diameter of more than 5%.
• Severe corrosion as evidenced by pitting.
• Core failure in rotation resistant ropes.
• Prior electrical contact with a power line or other electric
arc damage.
• Significantly cracked, bent, or worn end connections.
• In running ropes, six randomly distributed broken wires
in one lay or three broken wires in one strand in one lay.
• In standing ropes, more than two broken wires in one lay
in sections beyond end connections or more than one
broken wire at an end connection.
• In rotation resistant rope, two randomly distributed
broken wires in six rope diameters or four randomly
distributed broken wires in 30 rope diameters.
• National Crane recommends that for cable extended
booms, a single damaged wire rope assembly shall
require replacement of the entire set of extension
cables.
• National Crane recommends for cable extended booms,
that boom extension cables be replaced every seven (7)
years.
Only inspect the outer surface of a cable. Never attempt to
open the cable.
Pay particular attention to areas of the rope where wear and
other damage is likely to occur:
• Pick-up Points: Sections of wire rope that are repeatedly
stressed during each lift, such as those sections in
contact with sheaves.
• End Attachments: The point where a fitting is attached to
the wire rope or the point where the wire rope is attached
to the hoist drum.
• Abuse Points: The point where the wire rope is
subjected to abnormal scuffing and scraping.
Daily Inspections
All cable in continuous service must be inspected at the
beginning of each work day. Inspect the eye end and length
of cable that is used in daily operation. The end should be
inspected for abrasion, corrosion, broken wires, and loose or
broken servings. Inspect the remainder of the cable length
used for daily operations for points showing kinks, sharp
bends, or any other evidences of damage or excessive wear.
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