Lines are classified by both their
construction and their material. Nearly all
line used in the Navy is three-strand line.
Line is made by twisting fibers into
threads (or yarns), threads into strands, and
strands into rope. Taking the process further,
ropes twisted together form a cable—an item
seldom seen nowadays. Most of our lines are
three-strand and right-laid; that is, as you
look along a line, the twist is to the right.
During construction of natural fiber line, a
lubricant is added that also serves as a
preservative.
Large line is measured by circumference. Line 1 3/4 inches
and under in circumference, called small stuff, is identified by the
number of threads in the line. A line with twenty-four thread is 1
1/2 inches in circumference. Inasmuch as the numbers of threads
per strand are equal, thread numbers in a three-strand line are
divisible by 3—24, 21, 18, and so on, down to the
smallest—6 thread (3/4 inch). Line from 1 3/4 inches to about 4
inches is manufactured in 1/4-inch graduations. The length of all
line and wire rope is usually measured in feet.
The chart shown below lists tips on the care of natural fiber
line. You should be thoroughly familiar with them and observe
them at all times.
7-9
Student Notes:
NEVER
ALWAYS
Stow wet or damp line in an unventilated
compartment or cover it so that it cannot dry. Mildew
will form and weaken the fibers.
Dry line before stowing it.
Subject line to intense heat nor unnecessarily allow it
to lie in the hot sun. The lubricant (natural oils) will
dry out, thus shortening the useful life of the line.
Protect line from weather when possible.
Subject a line to loads exceeding its safe working
load. To do so may not break the line, but individual
fibers will break, reducing the strength.
Use chafing gear (canvas, short lengths of old firehose,
and so on) where line (or wire) runs over sharp edges or
rough surfaces.
Allow line to bear on sharp edges or run over rough
surfaces. The line will be cut or worn, reducing the
strength and useful life.
Slack off taut lines when it rains. Wet line shrinks, and
if the line is taut, the resulting strain may be enough to
break some of the fibers.
Scrub line. The lubricant will be washed away, and
caustics in strong soap may harm the fibers.
Coil right-laid line to the right (clockwise).
Put a strain on a line with a kink in it.
Inspect a line before using it. Overworked or
overstrained line will have a bristly surface. Mildew can
be seen, and it has peculiar, unpleasant odor. Untwist the
line so that the inner parts of the strands can be seen. If
they have a dull, grayish look, the line is unsafe.
Try to lubricate line. The lubricant you add may do
more harm than good.
Give line the care it deserves—someday your safety
may depend on it.
