They've asked me for history on the "G.E." knot -- but all I know was it was allegedly handed down by a General Electric lineman to a river guide, who then taught the other river guides in California going back to the early 80's. Can this group help identify this knot's true origin and proper name?
I'm not sure if I'll be able to meet your request for ID
--but the knot at least has some similar ones, which
(I and) others should be able to bring to attention.
Let me remark, though, that "3-to-1" advantage is well
shy of that "theoretical" mark :: you can try doing the
figuring with dead weights and seeing what does/doesNOT
move a load --you'll be far from moving at 3:1 rate, more
like 1.6:1 (a figure got IIRC using 'biners at sheaves, even!).
Still, to your point, it does give advantage --and also holds
the gain well. (And it's a commonly used structure.)
As for this "G.E. knot's" behavior, I think that you'll go
a significant way to removing Roo's worked-to-extreme-loading
warning by making your final tuck of the slip-bight from the
opposite side (just as a fig.8 does vs. an overhand, a fig.10
aka "stevedore" over a fig.9).
IMO, I'd do things a bit differently.
Firstly, as a guard vs. any sliding along the metal rail,
if that supporting vertical piece is indeed convenient,
I'd wrap so that my line lay on both sides of it, and so
couldn't move along the rail. Another techinque to resist
such movement is making a full turn (or more) around
the rail --a sort of friction gripping.
I might favor an eyeknot so to deliver half-load to each leg's
turning around the square/hard-edged bar, vs. bringing full
tension to one turn/corner. (As you note, you're not just
musing but have a history of usage to consider, re how much
an injurious effect might obtain --YMMV and all ... . :-)
I'd finish tying by going around all parts of the trucker's
hitch, not just one line, and I might work the tail through
some closely set --and thus potentially pinching-- lines
for additional security. Also, a
slip-knot stopper makes
a nice guard against even vibration-induced slipping,
since vibrations won't being the stopper through anything!
In short, what your present is aimed at a sort of whizz-bang
dramatic quick untying, which I'd suggest is really of very
little importance vs. normal (merely) easy untying of the
conventional knots. Sometimes, the quickness can be
a real help; in many cases, hardly worth the bother (e.g.,
one might have one end of a securing line left securely
tied, and only awaiting re-loading of gear and tossing
over that ... and re-tying the tensioning structure).
Thanks for sharing,
--dl*
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