GUIDELINES
FOR
THE
INSTALLATION
OF
ROTATION
RESISTANT
ROPE:
• Follow instructions for removing rope from a reel
or
coil in Section 4.
• Use a pulling grip fitted with a swivel when pulling new rope through the reev-
ing system with a used rope. This
practice will prevent residual twist in the
pu1ling rope from being transferred to the new rope. The pulling rope should be
the same lay direction as the rope being installed. Except for Rotation Resistant
ropes that are lang lay, lang lay ropes should not be used
as
pulling ropes.
• Apply back tension to the payoff reel during installation or tension the rope
after installation and before being put into service. This will promote uniform
spooling and help prevent rope pull-in. Recommended tension values range from
2% to 5%
of
the minimum breaking force
of
the rope being installed.
• Operate the new rope through several complete cycles at progressively higher
loads. This will allow the rope to adjust gradually to operating conditions.
The proper operation
of
Rotation Resistant ropes depends on maintaining the
torsional balance
of
the rope during use. Imbalance between inner and outer lay-
ers
of
the rope can be caused by twist induced in the rope as a result
of
incorrect
installation procedures or undesirable operating conditions. Common causes
of
twist are improper fleet angles (Figure 39), improper sheave alignment, or poor
spooling.
Odd part reeving with off center attachment
of
the dead end to the
block or improper reeving can cause misalignment
of
the traveling block induc-
ing twist into the rope.
Although these ropes are classified as Rotation Resistant it must be realized
that some slight rotation may occur, particularly in the early stages
of
rope life.
This rotation may result in undesirable block rotation or
"cabling", in multipart
systems, or rotation
of
the load in single part.
If
this occurs, it is advisable to
relieve the twist by disconnecting the most accessible end
of
the rope, letting the
twist out
of
the rope and then reconnecting it. In some applications, swivels are
used to relieve accumulated rope twist during installation and periodically during
operation. When using Category 2 or 3 Rotation Resistant ropes, the swivel
should be locked off after twist is relieved to prevent uncontrolled rotation. Most
Category 1 ropes may be used with a swivel. Consult the rope manufacturer for
guidance on any specific rope construction.
Wire Rope Technical Board - Wire Rope Users Manual, Fourth Edition
-19
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