Roo mentioned problems with the Highwayman's Hitch; I think they should
be spelled out, as they might not be obvious to a user, yet cause a problem.
(Books and other presentations of the knot don't even hint at them, usually.)
I call such knots as the Highwayman's Hitch "slip-free" hitches--they release
not only spilling the knot but coming completely free of the hitched object. As such,
they pose sometimes a greater danger on inadvertent release--complete failure!
These knots often have three components: a slip-tuck finish which acts qua
toggle within a nip-bight binding it against some frame; pulling the end pulls
out the toggle and the nip-bight is free to fall clear of the frame and spill the knot.
In the High.H. case, the SPart forms the nip-bight, and thus the slip-tuck
is heavily loaded against the frame; the frame, however, is just adjacent rope
and the object, and enough space can be within this frame that the heavily
loaded slip-tuck can be pulled out through it. With a long bight finish, there
might be sufficient material to be caught and hold (though losing any quick
release aspect); but otherwise the knot can spill.
In any situation where failure would have serious consequences, the user
should be attentive to this vulnerability of the High.H. The knots Roo shows
(esp. the lower one) are more rugged, though they consume more rope
on larger diameter objects. If one changes the High.H. so that the SPart's
turn nips the nipping bight (1. form SPart turn/bight; 2. form 2nd bight to
come THROUGH this 1st one; 3. finish with slip-tuck going through the
2nd bight (not, you see, through the SPart's)), one has a more stable knot.
(This is presented in Outdoor Knots, by Clyde Soles.)
--dl*
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