Wherever wire rope transmissions are used it is necessary to splice the
rope or cable so that it will run smoothly over the sheave wheels. For
this purpose a long splice is invariably used. (Taken from “American
Wire Rope” published by American Steel and Wire Company). The tools
required are a small marlin-spike, nipping cutters, and either clamps
or a small hemp rope sling with which to wrap around and untwist the
rope. If a bench vise is accessible, it will be found very convenient
for holding the rope.
“In splicing a rope, a certain length is used up in making the
splice. An allowance of not less than 16 feet for ½ inch rope, and
proportionately longer for larger sizes, must be added to the length
of an endless rope, in ordering. The length of splice relation to the
diameter of the rope is approximately 50:1.”
This extra length is equal to the distance EE´ in Fig. 117. The
additional length recommended for making a splice in different sizes of
wire rope is as follows:
───────────────┬──────────────────────────
Diam. of Rope │ Extra Length Allowed for
in Inches │ the Splice, Feet
───────────────┼──────────────────────────
⅜ │ 16
½ │ 16
⅝ │ 20
¾ │ 24
⅞ │ 28
───────────────┼──────────────────────────
1 │ 32
1⅛ │ 36
1¼ │ 40
1½ │ 44
│
───────────────┴──────────────────────────
Fig. 117. Having measured carefully the length the rope should be after
splicing and marked the points M and M´, unlay the strands from each
end E and E´, to M and M´, and cut off the hemp center at M and M´.
Fig. 118. First. Interlock the six unlaid strands of each end
alternately, cutting off the hemp centers at M and M´, and draw wire
strands together, so that the points M and M´ meet, as shown.
[Illustration: FIG. _117_; FIG. _118_; FIG. _119_;
FIG. _120_; FIG. _121_]
Fig. 119. Second. Unlay a strand from one end, and following the unlay
closely, lay into the seam or groove it opens, the strand opposite it
belonging to the other end of the rope, until there remains a length of
stand equal in inches to the length of splice EE´ in feet, e. g., the
straight end of unlaid strand A on one-half inch rope equal 16 inches
for 16 foot splice. Then cut the other strand to about the same length
from the point of meeting, as shown at A.
Fig. 119. Third. Unlay the adjacent strand in the opposite direction,
and following the unlay closely, lay in its place the corresponding
opposite strand, cutting the ends as described before at B.
The four strands are now laid in place terminating at A and B, with
eight remaining at M and M´ as shown in Fig. 119.
It will be well after laying each pair of strands to tie them
temporarily at the points A and B.
Fig. 120. Pursue the same course with the remaining four pairs of
opposite strands, stopping each pair of strands so as to divide the
space between A and B into five equal parts, and cutting the ends as
before.
All the strands are now laid in their proper places with their
respective ends passing each other.
[Illustration: FIG. _122_; FIG. _123_]
All methods of rope splicing are identical up to this point; their
variety consists in the method of securing the ends.
Fig. 121. The completed splice with ends secured results in a cable
with scarcely any enlargement at that point. A few days’ use will make
it difficult to discover at all.
The final part of the splice is made as follows:
“Clamp the rope either in a vise or with a hand clamp at a point to the
left of A (Fig. 119), and by a hand clamp applied near the right of A
open up the rope by untwisting sufficiently to cut the hemp core at A,
and seizing it with nippers, let your assistant draw it out slowly.
Then insert a marlin spike under the two nearest strands to open up
the rope and starting the loose strand into the space left vacant by
the hemp center, rotate the marlin spike so as to run the strand into
the center. Cut the hemp core where the strand ends, and push the end
of hemp back into its place. Remove the clamps and let the rope close
together around it. Draw out the hemp core in the opposite direction
and lay the other strand in the center of the rope in the same manner.
Repeat the operation at the five remaining points, and hammer the rope
lightly at the points where the ends pass each other at A´, B´, etc.,
with small wooden mallets, and the splice is complete, as shown in Fig.
121.”
A rope spliced as above will be nearly as strong as the original rope,
and smooth everywhere. After running a few days, the splice, if well
made, cannot be pointed out except by the close examination of an
expert.
Fig. 122. If a clamp and vice are not obtainable, two rope slings and
short wooden levers may be used to untwist and open up the rope.
Fig. 123. A marlin spike is absolutely necessary in order to separate
the strands in making a splice in steel cable.