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Back Chapter 4 Fiber Line, Wire Rope, and Scaffolding | Up Builder 3&2 Volume 01 - Construction manual for building structures | Next Strength of Fiber Line |
Types of Line Lays
Size Designation
There are three types of fiber line lays:
hawser-laid, shroud-laid, and cable-laid lines. Each
type is illustrated in figure 4-2.
Hawser-laid line generally consists of three
strands twisted together, usually in a right-hand
direction. A shroud-laid line ordinarily is composed
of four strands twisted together in a right-hand
direction around a center strand, or core, which
usually is of the same material, but smaller in
diameter than the four strands. You will find that
shroud-laid line is more pliable and stronger than
hawser-laid line, but it has a strong tendency toward
kinking. In most instances, it is used on sheaves and
drums. This not only prevents kinking, but also
makes use of its pliability and strength. Cable-laid
line usually consists of three right-hand, hawser-laid
lines twisted together in a left-hand direction. It is
especially safe to use in heavy construction work; if
cable laid line untwists, it will tend to tighten any
regular right-hand screw connection to which it is
attached.
Figure 4-2.Time type of fiber line.
Line that is 1 3/4 inches or less in circumference
is called small stuff this size is usually designated by
the number of threads (or yarns) that make up each
strand. You may use from 6- to 24-thread strands, but
the most commonly used are 9- to 21-thread strands
(figure 4-3).
You may hear some small stuff
designated by name without reference to size. One
such type is marlinea tarred, two-strand, left-laid
hemp. Marline is the small stuff you will use most for
seizing. When you need something stronger than
marline, you will use a tarred, three-strand, left-laid
hemp called houseline.
Line larger than 1 3/4 inches in circumference is
generally size designated by its circumference in
inches.
A 6-inch manila line, for instance, is
constructed of manila fibers and measures 6 inches in
circumference. Line is available in sizes ranging up
to 16 inches in circumference, but 12 inches is about
the largest carried in stock. Anything larger is used
only on special jobs.
If you have occasion to order line, you may find
that in the catalogs, it is designated and ordered by
diameter. The catalog may also use the term rope
rather than line.
Rope yarns for temporary seizing, whippings, and
lashings are pulled from large strands of old line that
Figure 4-3.Some commonly used sizes of manila line.
4-2
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