WIRE ROPE INSTALLATION AND MAINTENANCE
Folio 931-8
Broken Wires
Thoroughly clean the wire rope so breaks can be seen.
Relax the rope, move it off “pick-up points,” and flex it as
much as possible. Use a sharp awl to pick and probe
between wires and strands, lifting any wire which appears
loose or moves excessively.
Wire rope shall be take out of service when it has following
number of broken wires
(Refer to Figure 10 for an
explanation of lay length):
• Running Ropes (working lines) — six randomly
distributed broken wires in one lay length, or three
broken wires in one strand of one lay length.
• Rotation Resistant Rope — two randomly distributed
broken wires in six rope diameters or four randomly
distributed broken wires in thirty rope diameters.
• Standing Ropes (pendants) — more than two broken
wires in one lay length in sections beyond the end
attachment, or more than one broken wire at the end
attachment (see Figure 11).
• Any Rope — one outer wire broken at the point of
contact with the core. The broken wire protrudes or
loops out of the rope structure.
NOTE: United States Steel states “Replacement criteria for
galvanized strand boom suspension pendants are
25 percent of the outer wires fractured, or 10
percent of the total numbers, whichever comes
first.”
Wear and Other Damage
It is normal, due to friction, for outer wires of the rope to wear.
Wire rope shall be taken out of service if wear exceeds one-
third original diameter of outside wires.
Wire shall also be taken out of service if kinking, crushing,
bird caging, or any other damage resulting in distortion of
wire rope structure exists, including heat damage from any
cause.
Refer to Figure 12 for examples of wire rope damage.
FIGURE 10
A925
LAY LENGTH is distance measured
along rope in which one strand makes
one complete revolution around core.
Core
One
Wire
One Strand
WARNING
Falling Load Hazard!
Wire rope can break if following precaution is not
observed.
Replacement wire rope must meet specifications given in
Wire Rope Specifications Chart (load lines) or Boom
Rigging Drawing (boom hoist) supplied with your crane.
FIGURE 11
WARNING
Replace wire rope when more than one
broken wire appears at point marked by
arrow.
S140
Poured Zink Socket
S142
S141
S143
Hand Splice
Swaged Socket
Wedge Socket
395143
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