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in length, depending on the size fitting used. The rule of
thumb for preferred length of the eye is 5 times the
diameter of the fitting. This prevent uneven loading of
the eye. The following is the procedure for splicing
four-strand rope:
1. Measure a distance of seven times the rope
circumference from the end of the rope and mark using
a temporary whipping. Determine the eye size and form
a loop which places the first whipping on the standing
part at the end of the eye and mark with a second
temporary whipping.
2. Unlay the strands of the rope to the first
whipping and cut out the center core. Looking in the
direction of the standing part, tuck the first strand under
the top strand of the standing part from left to right with
the lay at the base of the second whipping.
3. Tuck the second strand under the next strand of
the standing part with the lay. Tuck the third strand under
the next strand of the standing part with the lay.
4. Turn the rope over and tuck the fourth strand
under the last strand of the standing part of the lay.
5. This constitutes one full tuck. Ensure all
working strands are pulled tight and free of twists.
6. Continue tucking all four strands in succession
over and under the strands of the standing part for a total
of six tucks.
7. Using a light strain, set the splice.
8. Marry the working strands using an inside
whipping under the strands of the standing part at the
last full tuck.
9. Cut the remaining working strands off flush with
the rope.
NOTE
The last two tucks may be tapered, if
desired, by cutting approximately half of the
fibers for each taper. Chafing gear on the eye is
required for abrasion.
WIRE ROPE
LEARNING OBJECTIVE: Describe the
construction, use, and care of wire rope.
Although wire rope may have only a few
applications in some Navy ships, in others, wire rope is
very important. It behooves all seamen to learn all they
can about wire rope.
CONSTRUCTION OF WIRE ROPE
The basic unit of wire-rope construction is the
individual wire made of steel or other metal in various
sizes. These wires are laid together to form strands. The
number of wires in a strand varies according to the
purpose for which the rope is intended. A number of
strands are laid together to form the wire rope itself.
Wire rope is designated by the number of strands per
rope and the number of wires per strand. Thus, a 6 X 19
rope has 6 strands with 19 wires per strand, but has the
same outside diameter as a 6 X 37 wire rope, which has
6 strands with 37 wires of much smaller size per strand.
Wire rope made up of a large number of small wires is
flexible, but the small wires break so easily that the wire
rope is not resistant to external abrasion. Wire rope
made up of a smaller number of larger wires is more
resistant to external abrasion, but is less flexible.
The strands of the wire rope are laid up around a
central core, which may be fiber, a single strand of wire,
or an independent wire rope. A fiber core contributes
flexibility, cushions the strands as the wire rope
contracts under strain, and holds a portion of lubricant
for continuous lubrication. A wire core is stronger than
a fiber core and can be used where conditions such as
high temperatures would damage the fiber. Some end
views of the arrangements of strands in wire ropes are
shown in figure 3-25.
Wire rope may be fabricated by either of two
methods. If the strands of wires are shaped to conform
to the curvature of the finished rope before their laying
up, the wire rope is termed preformed. If the strands are
not shaped before fabrication, the wire rope is termed
non-preformed. When cut, preformed wire rope tends
not to untwist and is more flexible than other wire rope.
Wire rope is made of annealed steel, traction steel,
or improved plow steel. The basic metal may be plain
or galvanized. Galvanizing protects the rope from the
elements, but makes it stiffer and reduces its strength by
as much as 10 percent. Galvanized rope most
commonly is used for standing rigging, but also is used
for some running rigging (such as wheel ropes) where
it is not subject to much wear. Ordinarily, this rope is not
used for hoisting jobs because the constant bending and
flexing as the rope runs over the sheaves and around
drums causes the protective coating to crack and peel
off.
3-18
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