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line. This type of construction in cotton is used for sash
cord (heaving lines).
Solid-braided lines are fashioned in various ways.
One familiar construction is that used for leadlines,
taffrail log lines, and the like. This braid is of large
yarns, either single or plied, tightly braided to form a
hard, relatively stiff line that will not kink, snag, or
swell in water.
Single braided line consists of 12 strands in a twill
pattern, where one strand of one direction of rotation
about the axis of rope passes over two strands of the
opposite direction and then passes under the next two
strands of the opposite direction. Single braided line is
used for mooring lines and towing hawsers.
Double braided line is, essentially, two hollow
braided lines, one inside the other. The core is made of
large, single yarns in a slack braid. The cover is also
made of large, single yarns but in a tight braid that
compresses and holds the core. Double braided line is
manufactured only from synthetics, and about 50
percent of the strength is in the core. It is used for
mooring lines, towing hawsers, signal halyards,
dressing lines, and many other purposes.
Plaited line is made of eight strands–four
right-twisted and four left-twisted. The strands are
paired and worked like a four-strand braid.
Consequently, there are two pairs of right-hand strands
and two pairs of left-hand strands formed into a line that
is more or less square. Plaited line is used for towing
hawsers, ship mooring lines, messengers, and other
applications.
USE AND CARE OF LINE
Manila line is not used as it once was. The
replacement lines for the personnel highline, the inhaul
and outhaul lines, the light freight transfer line, and the
replenishment-at-sea messenger are made of spun
polyester. Other synthetics have taken over other uses
with some exceptions where manila will be retained.
Manila lines of 4 inches or more should be reserved
for fueling-at-sea riding lines.
Following are some pointers on the use and care of
fiber line for you to remember:
Coil right-laid line right-handed or clockwise.
Flake down braided and plaited line.
Keep line from touching stays, guys, or other
standing rigging.
When surging line around bitts, take off enough
turns so the line does not jerk but surges smoothly.
If line becomes chafed or damaged, cut and
splice. A good splice is safer than a damaged section.
However, do not cut a line without your supervisor's
permission.
Do not lubricate the line.
Whip all line ends.
Inspect natural fiber line frequently for
deterioration. Open the lay and inspect the fibers. White,
powdery residue indicates internal wear.
Dragging a line over sharp or rough objects cuts
or breaks the outer fibers. When line is dragged on the
ground, other particles are picked up and eventually
work into the line, cutting the inner strands.
Natural fiber line exposed to the atmosphere
deteriorates about 30 percent in 2 years from weathering
alone. Natural fiber line received from supply that is 3
years old should be returned to supply noting
uneconomical to use.
WARNING
If a natural fiber line is more than 5 years
old (either used or unused), you must not use it
for critical operations or those involving the
lives of personnel. You can use these lines only
for lashing, fenders, and matting.
Line loaded in excess of 40 percent of its
breaking strength can be permanently damaged.
Inspection of the inside yarns reveals whether they are
broken. Synthetic line that has been overstressed will
have inside yarns fused together.
SMALL STUFF
LEARNING OBJECTIVE: Identify small stuff
line.
Line 1 1/2 inches or less in circumference is called
small stuff. Its size specification is governed by the
number of yarns it contains (called threads in this
instance).
Line larger than 1 1/2 inches in circumference is
always designated in size by its circumference in
inches. In general, any line larger than 5 inches that is
used in towing, mooring, and similar operations is
3-2
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