can throw excess oil onto crane cabs and catwalks,
making them unsafe to work on.
Wire rope should not be stored in places where
acid is or has been kept. The slightest trace of acid
coming in contact with wire rope damages it at that
particular spot. Many times, wire rope that has failed
has been found to be acid damaged. The importance
of keeping acid or acid fumes away from wire rope
must be stressed to all hands.
It is especially important that wire rope be
cleaned and lubricated properly before it is placed in
storage. Fortunately, corrosion of wire rope during
storage can be virtually eliminated if the lubricant
film is applied properly beforehand and if adequate
protection is provided from the weather. Bear in mind
that rust, corrosion of wires, and deterioration of the
fiber core greatly reduce the strength of wire rope. It
is not possible to state exactly the loss of strength that
results from these effects. It is certainly great enough
to require close observance of those precautions
prescribed for protection against such effects.
Wire rope should be inspected at regular intervals,
the same as fiber line. In determining the frequency of
inspection, you need to carefully consider the amount
of use of the rope and conditions under which it is used.
During an inspection, the rope should be
examined carefully for fishhooks, kinks, and worn,
corroded spots. Usually, breaks in individual wires
are concentrated in those portions of the rope that
consistently run over the sheaves or bend onto the
drum. Abrasion or reverse and sharp bends cause
individual wires to break and bend back. The breaks
are known as fishhooks. When wires are only slightly
worn, but have broken off squarely and stick out all
over the rope, the condition is usually caused by
overloading or rough handling. Even if the breaks are
confined to only one or two strands, the strength of
the rope may be seriously reduced. When 4 percent of
the total number of wires in the rope are found to have
breaks within the length of one lay of the rope, the
wire rope is unsafe. Consider a rope unsafe when
three broken wires are found in one strand of 6-by-7
rope, six broken wires in one strand of 6-by-19 rope,
or nine broken wires in one strand of 6-by-37 rope.
Overloading a rope also causes its diameter to be
reduced. Failure to lubricate the rope is another cause
of reduced diameter since the fiber core will dry out
and eventually collapse or shrink. The surrounding
strands are thus deprived of support, and the ropes
strength and dependability are correspondingly
reduced. Rope that has its diameter reduced to less
than 75 percent of its original diameter should be
removed from service.
A wire rope should also be removed from service
when an inspection reveals widespread corrosion and
pitting of the wires. Particular attention should be
given to signs of corrosion and rust in the valleys or
small spaces between the strands.
corrosion is usually the result of improper or
infrequent lubrication, the internal wires of the rope
are then subject to extreme friction and wear. This
form of internal, and often invisible, destruction of the
wire is one of the most frequent causes of unexpected
and sudden failure of wire rope. The best safeguard,
of course, is to keep the rope well lubricated and to
handle and store it properly.
WIRE ROPE ATTACHMENTS
Many attachments can be fitted to the ends of
wire rope so that the rope can be connected to other
wire ropes, pad eyes, or equipment. The attachment
used most often to attach dead ends of wire ropes to
pad eyes or like fittings on earthmoving rigs is the
wedge socket shown in figure 4-14. The socket is
applied to the bitter end of the wire rope, as shown in
Remove the pin and knock out the wedge first.
Then, pass the wire rope up through the socket and
Figure 4-14.Parts of a wedge socket.