U-BOLT
Double Saddle
Figure
29.
Wire rope clips
are
obtainable
in
two
basic
designs: U-Bolt
and
double
saddle. Their efficiency
is
the
same.
SOCKETING
Improperly attached wire rope terminals lead to
serious-possibly
unsafe-
conditions.
To
perform properly all wire rope elements must be held securely.by
the terminal so that all parts
of
the rope are taking their proper share
of
the
applied load.
Poured Sockets - Zinc or Resin
Poured sockets have traditionally been the method for determining the rope's
actual breaking strength. All other types
of
terminations have been compared to
poured sockets. Their efficiency is therefore established to be
100% for all
grades and constructions
of
rope.
Rope assemblies with poured attachments are generally used as a straight ten-
sion member. In such cases, where the rope is used as a pendant line, the mini-
mum recommended design factor is 3.0.
If
the assembly is used as a sling the
minimum recommended design factor
of
5.0 should be used to calculate the
rated capacity.
Length tolerances for poured attachments can be somewhat more stringent
than other types
of
assemblies. The manufacturer should be contacted and agree-
ment reached before the order is placed. Tolerance as small as plus or minus
1/4"
per 100'is not out
of
the ordinary for this type
of
assembly. Specifications such
as type
of
fitting, pin orientation (See Appendix B), whether zinc or resin should
be used, and type
of
application should also be supplied to the manufacturer
when ordering these types of assemblies.
When preparing a wire rope for socketing it is
of
extreme importance to follow
procedures recommended by API (American
Petroleum Institute) RP-9B or by
ISO standards. Poured socketing should only be done by thoroughly trained per-
sonnel.
Several industry standards require that all zinc or resin poured sockets be
proof tested after fabrication.
WIRE
ROPE CLIPS
Wire rope clips are widely used for making end terminations.
Clips are available in two basic designs; the
U-bolt and double saddle (Fig.
29). The efficiency
of
both types is the same.
When using
U-bolt clips, extreme care must be exercised to make certain that
they are attached correctly; i.e., the
U-bolt must be applied so that the
"U"
sec-
tion is in contact with the dead end
of
the rope (Fig. 30). Also, the tightening and
retightening
of
the nuts must
be
accomplished as required.
Use only forged clips for critical, heavy duty, overhead loads, such as support
lines, guy lines, towing lines, tie downs, scaffolds, etc.
Malleable clips are to be used for making eye termination assemblies only with
right regular lay wire rope and only for light duty uses with small applied loads,
such as hand rails. fencing, guard rails, etc.
36'
Wire Rope Technical Board - Wire Rope Users Manual, Fourth Edition
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