••
8 x
19
Seale
IWRC
d
8 x
25
Filler
Wire
IWRC
ROTATION
RESISTANT
ROPES
These wire ropes are designed so that the inner strands are laid counter to the
outer strands. Under certain operating conditions, this design can result in accel-
erated internal wear. Careful initial measurements
of
diameter and lay are essen-
tial for comparisons in future inspections.
Inspection procedures are generally the same
as
other ropes; however, the bro-
ken wire removal criterion is more restrictive. (see Table 14)
•••
18
x 7
FC
19
x 7
RESULTS
OF
ABUSE
19
x
19
Seale
35x
7
35
x
19
Seale
Abuse from handling and poor operating conditions may cause damage and
can result in reduced service life
of
the wire rope.
It
is important to recognize the
effects
of
these abuses to properly assess rope serviceability.
Kinks (see Figure a&b left) are tightened loops with permanent strand distor-
tion that result from improper handling when a rope is being installed
or
while in
service. A kink happens when a loop is permitted to form and then is pulled
down tight, causing permanent distortion
of
the strands. The damage is irrepara-
ble and the kink must be cut out
or
the entire rope taken out
of
service.
Doglegs (see Figure 53, pg 79) are permanent bends caused by improper use
or handling.
If
the dogleg is severe, the rope should be removed from service.
If
the dogleg is minor, (exhibiting no strand distortion) and cannot be observed
when the rope is under tension, the area
of
the minor dogleg should be marked
for observation and the rope can remain in service.
Wavy rope occurs when one or more strands are misaligned with the rope
body. This results from a variety
of
causes, including failure to properly seize the
end
of
a rope prior to wedge socket installation; tight sheave grooves;
or
permit-
ting torque
or
twist to develop during installation
or
operation. While not neces-
sarily resulting in loss
of
strength, this condition may accelerate rope deteriora-
tion and requires increased frequency
of
inspections. Ropes must be removed
from service when the height
of
the wave (d[) measures more than 33%
of
the
nominal rope diameter above the nominal rope diameter in sections not bending
around a sheave or drum
or
more than 10%
of
the nominal rope diameter above
the nominal rope diameter in sections bending around a sheave or drum.
Wire Rope Technical Board - Wire Rope Users Manual, Fourth
Edition'
71
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