Evidently, stoppers are never tightened as hard as other types of knots ( loaded bends, for example ),
"Evidently" ?
At least, evidently stoppers do not appear in commonly presented
knot-strength charts (and if one saw e.g. "fig.8 (stopper) knot"
there'd be the question as to whether this was actually loaded qua
*end* stopper in resistance against some object, or merely as a
knob in the lint --what was given to me for the Dyneema 12-strand
line I used for eye-knots and which was said (overhand) to yield
about 31% strength).
So, I don't know how one would employ a stopper knot in terms
of presumed strength, other than to use a "50%" rule of thumb
(obviously, not for HMPE or other hi-mod cordage!).
... so they do not not run the danger to jam to the same degree.
Fair enough. But one will read recommendations for the
Fig.8 stopperand vs. the
overhand based on expected difficulty of untying.
The double and the triple overhand knot stoppers can, obviously, be tightened to the point they become a solid mass of rope, if one has enough rope length on both ends ( a rare situation in stoppers setting or use ), ...
Yes, and with mere one-side loading, things are not severe
(though just loading some aged arborist-like 5/8"? braid
and it got firm, but the stopper-face end could be easily
pried loose ...) . But those float-bracing stoppers of the
commercial fisher need to be
set tight --they'll not get
much tensioning in use, but ageing.
> I do not know any application where a stopper is supposed to be tightened,
> in settng or in use, to, say, 50 % of the rope strength, as a bend is, ...
"50%" ?? What rope use do you know of that expects this?
Usual safety factors, WLLs (working-load limit) are 10-20%,
possibly higher slightly(?) for hi-mod standing rigging.
The way stopper knots are loaded is very different from the way bends and other types of knots are loaded
By definition, perhaps. But then what does one call a knot loaded
on both ends --one use being in dock lines qua position marker,
another in gym/fitness climbing ropes (for purchase)? --a
symmetric
Fig.9 (#
521=> 525) is good here, in common materials.
--dl*
====