A sailor judges knots for their holding qualities and also their ability to be quickly
unfastened,
without regard to the strain they have been subjected to. A knot's main
office is to hold, without working loose or slipping, yet
they do
occasionally fail absolutely to accomplish this, when made by
inexperienced hands. The accompanying diagrams show some of the simpler
knots that may be of everyday use. In these, the mode of formation can
be readily discerned, because the rope's position is shown before
tightening. The overhand knot, Figure 1, is probably the simplest of
all. It is used only for making a knot at the end of a rope to keep it
from fraying or to prevent another knot from slipping. If a slight
change in formation is made, as in Figure 5, it develops into a slip
knot or, as it is sometimes called, a single sling, and its purposes are
obvious. A double sling is represented in Figure 6, and though it is
slightly more complicated, it is considerably more useful for any
purpose where a rope is to be attached to a bar or beam and stand a
steady strain.
Probably for convenience and emergencies
no knots equal the bow-line, Figure 7, because it will not slip or
give, no matter how great the tension; in fact, the rope itself is no
stronger, and the instant the strain ceases it can be untied as easily
as a bow. When the end of a rope is to be secured, the two half-hitches
or clove hitch, Figures 2 and 3, are of great importance, for either of
these
bends can be attached instantly to almost anything, and their holding
powers are exceeded by none. The square knot, Figure 4, can be used for
infinite purposes, from reefing a sail to tying a bundle, the advantage
being, if made properly, of resisting any separating strain on either
cord, and yet can be untied immediately by pulling one of the short
ends.
One of the best and safest slip knots is shown in
Figure 9, made with the overhand at the end, which, until loosened by
the hand, maintains its grip. When a rope requires shortening
temporarily the sheep shank, Figure 8, affords a means of so doing. This
knot can be applied to any part of the rope without reducing its
strength of rectilineal tension
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