TM5-3810-305-10
Breaking in a New Wire Rope
A new wire rope requires careful installation and
close adherence to all the appropriate procedures
previously noted. After the rope has been in-
stalled and the ends secured in the correct man-
ner, the mechanism should be started carefully
and then permitted to run through a cycle of
operation at very slow speed. During this trial
operation, a very close watch should be kept on
all working parts - sheaves, drums, rollers - to
make certain that the rope runs freely, and
without any possible obstructions as it makes its
way through the system. If no problems appear
in running the rope, the next step should include
several run-throughs of the normal operational
cycle under light load and at reduced speed. This
procedure allows the component parts of the new
rope to make a gradual adjustment to the actual
operation conditions.
Wire Rope and Ope rations Inspection
To insure a high level of safety while keeping the
annual cost of wire rope at a reasonably low
level, it is essential to maintain a well-planned
program of periodic inspection. Frequently,
there are statutory and/or regulatory agencies
whose requirements must be adhered to, but
whether or not these exist in a given locale, the
wire rope user can be guided by the suggested
procedures that follow,
Abrasion, bending and crushing represent the
ABC’s of wire rope abuse, and it is the primary
goal of good inspection practice to discover such
conditions early enough so that corrections can
be made or ropes replaced safely and with mini-
mum effort. When any degradation indicates a
loss of original rope strength, a decision must be
made quickly as to allowing the rope to remain in
service. But such a decision can only be made
by an experienced inspector. And this determi-
nation will be based on:
1.
2.
3.
4.
5.
Details of the equipment’s operation: Will
the rope break?
Frequency of inspection: Will it be safe
until the next scheduled inspection?
Maintenance history: How rapid is the
degradation?
Consequences of failure: Will it present
hazards to personnel?
Historical records of similar equipment.
To make certain that sufficient information is
obtained, following are guidelines that should be
adhered to:
The groove size is evaluated on the basis of how
the gage leaf fits the groove. Daylight under the
gage is not tolerable when using the worn groove
gage. If a full oversize gage is used, some
daylight may be acceptable, but this really must
be judged by relating the measurement to the
actual size of the rope.
For new rope, extra caution should be observed
as to its fit in the groove. Characteristically,
ropes become smaller in diameter immediately
after being placed in service. As a result, they
would operate satisfactorily in a “worn” groove;
one that was gaged OK by the” worn” groove
gage. Nonetheless, in some cases, a rope may
not “pull down,” and if this happens, abnormal
wear may occur.
It is important to remember that a tight groove
not only pinches and damages the rope, but that
the pinching prevents the necessary adjustment
of the wires and strands. On the other hand, a
groove that is too large will not provide suffi-
cient support; in this case, the rope will flatten
and thereby restrict the free sliding action of the
wires and strands.
4-43
