Refer
to Important Warnings & Definitions and Wire Rope Warnings.
These warnings also apply to cordage (rope). Only additional warnings
and information
are
listed
below.
Never
exceed the Working Load Limit of rope.
Use Working Load Limits as published as guidelines only. Working
Load Limit may have to
be reduced when
life, limb or valuable property are at risk, or other than new rope is
used. When using multiple leg rope slings, the Working Load Limit
of each leg will
have to be reduced considerably. Consult industry recommendations for information
such as published by the Cordage Institute. Working Load Limit does not
apply if rope has been subjected to severe dynamic loading, which
may not be visible.
Avoid
overheating. Exposure to high temperatures
will cause ropes to lose strength rapidly. Even temperatures
as low as 150°F (66°C) can reduce
the strength of some ropes by 50%. When using synthetic rope (especially
polypropylene) on a capstan or a winch, be careful to avoid excessive friction
which heats, melts and fuses the outer fibers of the rope. Avoid repeated
surging or hard rendering around poles or over cross arms. Polyester rope
resists overheating best because its melting point is highest.
Attachments
must have at least the same Working Load Limit as the rope
used. Hooks, links, shackles, etc. must be of suitable
material and strength
to provide adequate safety protection. Splice rope properly and use thimbles
if applicable. Choose rope to match gear or gear to match rope. Sheaves,
pulleys, thimbles, etc. that do not match the size of rope being used can
cause dangerous friction, abrasion, overload, etc.
Keep
out from under a raised load. Do not move load over people. Do not ride
on load. Conduct all lifting operations in such a manner that
if equipment
were to fail or break, no personnel would be injured. This means KEEP OUT
FROM UNDER A RAISED LOAD, DO NOT OPERATE LOADS OVER PEOPLE AND KEEP OUT
OF THE LINE OF FORCE.
Avoid
shock loads. Rope that is strong enough
to withstand a steady pull can be broken with a sudden jerk.
Be aware of all possible dynamic loading
situations. Avoid them when possible and allow for strong enough rope when
they cannot be avoided. Keep in mind that the effects of dynamic loading
are greater on shorter ropes than on longer ones and greater on low elongation
ropes (such as Manila and polypropylene) than on high elongation rope (such
as nylon). Never stand in the line of rope under strain. If the rope breaks
it will recoil with considerable force, especially if it is nylon.
Inspect
rope frequently. Closely examine entire length of rope
for damage to determine general condition and detect localized
wear. Excessive abrasion,
fusing of outside fibers, hockles, rust or other chemical stains, broken
fibers or other obvious damage to rope are reasons to retire rope from
service. Internal damage can be assessed by twisting strands open
and checking for
powdered fiber. Rope that is suspected of having been exposed to severe
shock loads or loads close to its catalog Breaking Strength should
be retired immediately.
Such damage may not be visible. Actual remaining strength of damaged or
used rope can only be established by laboratory analysis and tension
tests.
Destroy,
rather than discard, rope to be retired. It might be used again by someone not aware of the hazard or
defect. This
is best achieved by cutting
it up into short pieces.
Rope
Slings. Refer to OSHA standard 1910.184
and ASME standard B30.9 for design factors and other important
information. Other standards and information
may apply in specific applications.
Refer
to “Proper Care of Rope” below for
additional important cautions.
PROPER CARE OF ROPE
Avoid abrasion
and unnecessary wear. Outer fibers as well as inner fibers contribute
to a rope’s strength. When outer fibers are worn by chafing
or dragging over splintered, rough or gritty surfaces, the rope is worn
and weakened. When rope is used on cleats, winchheads, etc. make
sure they are
smooth and use chafing gear if necessary.
Avoid sharp angles and
bends. Sharp angles greatly affect the strength of a rope. Any sharp
angle or bend is a weak spot. Use thimbles or chafing
gear
or padding where possible. Knots are also weak spots. They can reduce
strength by as much as 50% or more. Use splices instead. Splice
rope correctly.
When a small section of a rope has been worn or damaged, cut out the
section and
splice it together. Splice in extra tucks for synthetic fiber ropes.
Use proper splicing procedures as outlined by the Cordage Institute.
Do not
resplice rope that broke due to being overloaded - discard it instead.
Its remaining
strength will only be a fraction of the Working Load Limit when new.
Prevent unraveling of rope - whip or tape cut ends.
Avoid sustained
loads. Fiber ropes subjected to heavy loads for long periods
of time can break well below catalog Breaking Strength. Natural
fiber ropes
such as Manila and Sisal have less ability to take sustained loads
than
synthetic fiber ropes such as nylon or polypropylene. Never exceed
the Working Load
Limit and do not subject fiber rope to sustained loads for more than
two days.
Avoid rust. All ropes, synthetic
or natural, should be kept away from rusting iron or steel. Rust
can cause rapid loss of strength,
sometimes
in as short
a time as one to two weeks. If ropes become rust stained, inspect
the extent of the stain. If it is halfway through the rope, then
rope strength
may
be reduced by as much as 50%.
Keep rope away from chemicals. Even though synthetic rope is generally considered to be resistant
to
damage from oils, gasoline, paint and
most chemicals,
exposure to any of these may cause some damage. Avoid contact with
such things as storage battery solution, washing compounds or solutions,
and
animal wastes.
Strong acids, alkalis and solvents can damage any rope. Natural
fiber rope is extremely vulnerable to all chemicals and solvents.
Avoid
the use of swivels in ropes under load - a loss of turn will
cause permanent damage to the rope.
Never use a nylon line
which has a high stretch factor in combination with another rope
of
low stretch. The nylon line will stretch
and not carry
its proportionate share of the load, thus putting extra strain
on the other lines.
Reverse ends of the rope
periodically. Especially in tackles and winches, reverse the rope end-for-end
periodically
so that
all
sections will
be worn equally. Also, using a line in one direction over
a winch many times
can
also damage the rope by twisting it too tight or untwisting
it so that hockles occur. Kinks pulled through a restricted
space
such
as a tackle
block, can
seriously damage rope fibers. The initial use should be in
a clockwise direction, then reverse the rope periodically.
Slack
off guys in wet weather. When ropes are used as guy lines or
other supports exposed to weather, they should be
slacked
off in
wet weather,
or damage to the rope, as well as what it is supporting,
may result.
Store rope properly. Rope is best
stored in a dry, unheated place where air circulates freely, off
the floor,
and away
from direct
sunlight
and other
contact with the elements. Keep in mind that synthetic
ropes will deteriorate in direct sunlight due to exposure
to ultraviolet
radiation.
Light
colored polypropylene especially is severely affected,
smaller diameters more
so than larger sizes. Natural fiber ropes (Manila and
Sisal) will deteriorate in storage even under ideal conditions.
Dry
rope properly. Whenever natural fiber ropes become wet they should
always be thoroughly dried before they
are stored
or they
will rot
in a very short
time. Do NOT dry synthetic fiber rope in direct sunlight.
Keep
rope clean. Dirt on the surface of rope can become embedded inside
and act as an abrasive on fibers. When
rope gets dirty,
wash it thoroughly
with
clean fresh water. Remember to dry natural fiber
rope before storing.
Remove rope from coils and reels properly. Regular
right hand laid rope should be uncoiled in a counter
clockwise
direction.
Coiled rope: Lay the coil on the
floor with the inside end at the bottom, then reach down
through the center
and pull
the inside
up through the
coil.
Reeled rope: Remove the rope from
a reel by pulling it off the top while the reel is free to rotate.
Rope should
never
be taken
from
a reel lying
on its end because it is more likely to kink
or
hockle or pull yarns on the wooden flange.
When
substituting natural fiber rope with synthetic fiber ropes (or
substituting one synthetic rope
for another)
substitution should not be made on a
straight breaking strength-for-breaking strength
basis only. Other important factors
must be considered.
Consult the Cordage Institute
or other sources listed on the inside cover for additional information.
|