Handling and Care of Rope
Manmade fibers, as well as being
much stronger than natural fibers, are very tolerant of those factors
that reduced the working life of the latter. For example, synthetic
lines can be stored while still damp and they won't rot (although you
may see mildew on them). Physical damage must be guaranteed against
(as with natural fibers); you should particularly bear in mind that
rope under tension is easily damaged by chafe. Lines that are under
tension but static (e.g., mooring lines) should be protected at any
angular point or rough service by placing plastic tubing over the rope
or parcelling it with canvas.
The effects of chafe from normal
friction surfaces such as sheaves, fairleads, and cleats is
considerably reduced if the bearing surfaces are large. In the case of
sheaves, the diameter should not be less than five times the diameter
of the rope - and preferably more. The groove of a sheave should have
such a radius that it supports one-third of the rope's circumference.
Whenever possible, avoid making sharp "nips" in a rope. If, however,
you have to lead a line through a sharp angle, the bearing surface of
the lead should be smooth and at least that required of a sheave. Rope
can be severely damaged if led through a thin shackle or eye bolt,
particularly if the angle is sharp.
If possible, always avoid heavy
shock loads. For example, when passing a towline between a stationary
vessel and a moving one, never make both ends fast at once. The
resulting jerk imposes a tremendous strain on the line which, if it
does not damage it, may rip a cleat or bollard out. When one end has
been made fast, the correct procedure at the other end is to make a
figure-eight turn around the cleat or bitts, and allow the line to
ease out smoothly as the load comes on. Then, check steadily and make
fast as the vessel gathers way.
turns on a winch, must be avoided. They are caused by a line wrongly
lead or tailed. Often they can only be undone by using another winch
and a rolling hitch to take the strain off the line.
When coiling a line, always begin at
the end that is made fast so that and twists or kinks can be chased
along and run out at the far end. It is particularly important to
ensure that load is never applied to a line when there is a kink in
it; doing so will almost inevitably damage and weaken it. Rope that
has been badly overloaded in any way may be identified by being
usually hard in parts. The hardness is caused by the heat that is
produced by the overload friction that fuses some of the filaments
Unless lines are properly coiled,
kinks will occur - with subsequent snags - when the line is run out.
Nearly all laid ropes are right-handed and should be coiled clockwise
to ensure smooth running out.
To make sure that your ropes wear
evenly, it's a good idea to change them end for end occasionally.
The life of a rope can be extended
considerably by washing it in fresh water to get rid of salt crystal,
grit, and dirt. Use only soap powder - not detergent - to wash rope.
Many products are designed for a specific
purpose. When a use is specified on the product, use the rope for its
intended application. This will add life to the product and reduce the
possibility of a product failure.
Safe working strength for rope
varies from 5:1 to 12:1 or higher. For example, a rope rated at 10,000
pounds minimum breaking strength may be loaded to 2,000 pounds at a 5:1
safe working load and at 833 pounds at a 12:1 safe working load. Ignoring
safe working loads can cause personal injury, damage to property or even
death. If your rope is old or worn, make allowances for safety.
Downgrade rope to a less critical application or discard and replace.
Outer and inner rope fibers contribute
equally to the strength of your rope. When worn, your rope is naturally
weakened. Where it is necessary for a rope to rub over and object,
protect it with chafing gear, such as canvas wrapped and tied around the
AVOID SUDDEN STRAIN
Rope that is strong enough under
a steady strain can be broken with a sudde3n jerk. Avoid shock loads
When rope is repeatedly turned or twisted
in one direction, it is certain that kinks will develop, unless twists are
repeatedly thrown in, or out of rope. Pulling a kink through a restricted
space such as a tackle block will seriously damage the rope fibers.
AVOID SHARP ANGLES
Sharp bends greatly affect the
strength of a rope. Any sharp angle is a weak spot. Pad it for safety,
and even then, be careful!
AVOID WRONG REEVING
Always use the right size rope
for the sheaves in block or pulleys. Too small a sheaves diameter can
cause added friction and rope wear.
Prolonged use, or wear, on one part of a
rope will naturally decrease its effectiveness at that point.
Occasionally reverse your rope, end-for-end, to distribute the wear more
evenly. A good example is an anchor line aboard a boat.
Virtually all synthetic fiber ropes
are immune to damage from oil, gasoline, paint and most chemicals. To be
on the safe side, however, keep your rope free of any type chemical.
Natural fiber ropes are, of course, severely damaged by exposure to
KEEP ROPE CLEAN
Dirt on the surface and embedded in
rope acts as an abrasive on fibers. When rope becomes dirty, wash it
thoroughly with clean water. Be sure to air-dry natural fiber ropes
AVOID IMPROPER STORAGE
Synthetic fiber ropes require
no special storing conditions other than keeping them out of sunlight and
out of extremely hot rooms. The ultra-violet rays of sunlight have a
weakening effect on rope that is exposed for prolonged periods of time.
Natural fiber ropes must be kept dry or they will rot in a very short