Author Topic: The shape of a knot after dressing-before loading : does it determine the knot ?  (Read 22294 times)

Tex

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Who says the Farmer's loop is only a inline[sic] loop and not an end-of-line loop? The Parrot parroting the parroters? :)

   I believe Ashley knew very well that his in-line loops ( #1049 - #1056 ), when they are loaded as EEL end-of-line loops, with ends parallel to each other and to the eyelegs, they are transfigured or even deformed regarding their geometry and their structure, they are turned into some altogether different animals, and they become either unstable, or even more amorphous/ugly than they are already ! And that is why he did nt presented them as such in the first place...

I haven't used farmers knots much (ok, not at all).  If it actually becomes unstable if it is pulled against only one parent line, possibly in the same act that relieved previously existing tension on the other,  then it is not a good loop of any kind and I would never want to use it (I never did so far).  But of course, this is obvious (and yet here I am apparently still needing to say it to someone who talks of being amazed about not getting a point after pages of discussion)

At least you finally quit talking about EEL loading with ends perpendicular to the eye legs.  Something got through. 


« Last Edit: May 24, 2015, 03:08:50 PM by Tex »

xarax

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OK gentlemen, let's see if you can communicate more efficiently/effectively so there is no more straying from the topic.

SS

   Mea culpa. I had though that the gap ( I will not specify it more...) could had been bridged, somehow. Evidently, for the time being it is too deep and too wide...
   I had edited some of my posts in this thread, and deleted the ones which were addressed to nowhere. Horror vacui !  :)  :) Nature abhors a vacuum, why should an infinitesimally tiny part of nature, me, dare to think otherwise ?
This is not a knot.

Tex

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  The point of this thread, in the particular case of the loops, was exactly this : We should not use in-line loops as EEL end-of-line loops, and vice versa, because, most of the times, the knots will be forced to be transfigured, or badly deformed, and they will "work" in a different way than before, and also they will "work" in a completely different way if they are loaded by their one or by their other end.

And my point has been that ANY loop WILL get EE loaded as if end of line.  If loops are tied, they will get tugged to and fro, and if the parent lines are tensioned between fixed objects, this tugging can and does relieve tension on one parent line creating an end-of-line loading.  This is (obvious) reality. 

A very important property of any PRACTICAL in-line loop is how well it handles being (transformed to or otherwise) an end of line loop.  If it fails in this aspect, it is no practical inline loop at all.  We might call them different names, but the quality(ies) of one cannot be considered without the qualities of the other.  Not every different knot can accidentally become every other knot, but these pairs (ok triplets), if you wish to think of them that way, can and will.  You can think of them as different all you want, but doing so does not simplify nor compartmentalize the discussion at all.
« Last Edit: May 24, 2015, 04:02:14 PM by Tex »

Dan_Lehman

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  The point of this thread, in the particular case of the loops, was exactly this :
We should not use in-line loops as EEL end-of-line loops, and vice versa,
because, most of the times, the knots will be forced to be transfigured, or badly deformed,
and they will "work" in a different way than before, and also they will "work" in a completely
different way if they are loaded by their one or by their other end.

And my point has been that ANY loop WILL get EE loaded as if end of line.
If loops are tied, they will get tugged to and fro, and if the parent lines are tensioned
between fixed objects, this tugging can and does relieve tension on one parent line
creating an end-of-line loading.  This is (obvious) reality.
I apologize if I sound out-of-synch. w/discussion, as I've not read
allllll of the back'n'forth preceding, though did make some effort
to read the previous page where this seems articulated.

I take (and concur in) X.'s point to be that there are eyeknots
(I avoid "loop" --too overloaded in uses) that do NOT work well
EEL : e.g., the fairly well known directional fig.8 --where this
aspect (limited loading profile) is hinted at by "directional",
meaning that one can load it only in one way, with one S.Part,
not EEL.  X. notes that such a knot will be distorted (greatly)
if loaded the *wrong* way --by the end running parallel to
the eye in *through/end-2-end* loading.

And I don't see why Tex believes this to be a false circumstance?!
Consider one of the uses for such a "directional" eyeknot, setting
up a "Y hang" --i.e., a two-point anchor for a rappel line, which
is it seems common in caving.  One makes such an eyeknot with
the tail tied to one anchor point and the eye directly or by some
connector cordage to the other.  Loading will be on both tail and
eye in expected circumstances, usually balanced as best one can
(though I could see one maybe setting up with a bias, and the
2nd point being more purely "back-up").  If one anchor point
fails, then either the loading is end-2-end/through, or it is on
the eyeknot qua end-of-line eye, but never is the one anchor
point'd tail loaded in opposition to the eye --which would make
it EEL.  (When they are both loaded, they are in joint
opposition to the other "end".)

There are uses in SAR for such knots in attending to a litter/carrier,
I believe.  Again, there is no real situation here in which the knot
would be EEL.

 - - - - - - - - - -

Also, EEL doesn't ensure that the knot would behave well
in end-2-end/through loading.  E.g., those TIB bowlines --of
which the infamous "Yosemite bowline" is like-- can do well
EEL, but not with ends loaded in opposition to each other.
(Interestingly, the fig.8 eyeknot would seem to be like this too,
but in the CMC 3rd edition testing report it did better in break
strength than the directional fig.8 and close to the butterfly (!!)
--resp., 65% vs. 59% & 69%.  (Now, elsewhere, we learn of some
recidivism on some other test results, and in any case can wonder
about deformation, particular loading & dressing and so on ... .)

It has long bothered me that testing for the such various-loaded
knots doesn't match possible actual-factual loading --where it is
one way AND THEN another (and maybe back again), and the
first loading amounts to a hard setting!?  I suspect that one
will have a spread of results.  (With the butterfly, my surmise
is that greater disparity (strength loss) will occur for through
loading after eye loading has made a hard set (as the latter
will more distort the geometry than the former; the unloaded
end's collar can collapse around it). )


Quote
A very important property of any PRACTICAL in-line loop
is how well it handles being (transformed to or otherwise) an end of line loop.
If it fails in this aspect, it is no practical inline loop at all.
Now, here I don't see a huge disagreement (though I could
imagine a case where only non-EOLine loading was needed),
but this isn't asserting EEL, just through- & EOL-loading.



--dl*
====

xarax

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EEL doesn't ensure that the knot would behave well in end-2-end/through loading.

   Of course not - because, most of the times, this loading would force it to become ANOTHER knot, just as, most of the times, a knot that is meant to be loaded end-to-end, will be transfigured ( at least...), and will become ANOTHER knot, if it is tied at the end of the (double) line, and it is loaded by both ends.
   It is very rare ( an exception is the Linfit loop ) for a 90 degrees rotation of both ends, to leave the rest of the knot in the same general geometry / structure - either if we start from the aligned ends, in the case of a in-line loop, or vice versa : if we start from an end-of-ine loop, and load it as you say. By changing, so much, the directions two of the four loaded limbs are pointing to, the shape and the structure of the nub can not remain the same. 
   I did not repeat it as often as I should, perhaps, that I was talking about TIB loops throughout this thread - which is yet another restricting condition, which narrows the number of possible suitable loops.
« Last Edit: May 24, 2015, 06:30:27 PM by xarax »
This is not a knot.

Tex

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Hi DL I can agree that I've probably allowed EEL and simply EL to be interchanged to liberally (partially just because I didn't want to make a fine point about yet another thing when we had enough trouble with the fine points already).  Yes in situations where the potential direction of pull is clear, especially where gravity is involved, then single-end loaded is enough to consider for a midline loop.

DL I certainly never said that EEL implies good end-to-end loading.  In fact in my original post on the matter I very clearly made the point that while practical end-to-end loadable knots better be single end loadable, the opposite probably doesn't need to be true.   If that was true, then we'd need to avoid tying slipped-tail loops. (ok, those aren't EEL, so there are more interesting examples than that to be considered, but still...)

« Last Edit: May 25, 2015, 01:15:51 AM by Tex »

Tex

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D.L please realize that much of the original conversation was modified or deleted by xarax.

Much of the pointless back and forth here had nothing to do with these simple observations, but with aimless and oddly self-contradicting criticism of them.  You are imagining that I have been arguing against such reasonable points as you have made.  I have not and would not.

Tex

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To reiterate, here was what started all this:


Not true. I've read, and understood, all of your arguments and thanks for not repeating them. Who says the Farmer's loop is only a inline[sic] loop and not an end-of-line loop? The Parrot parroting the parroters? :)

I have trouble seeing how any loop can be an called an inline loop and not an end-of line loop.  Maybe I misunderstand the use of the word "in-line", but to me, any loop that gets a habit of being tied in the middle of a rope is VERY likely to end up loaded by the two eye legs and one parent leg, with the 4th leg left slack and having no effect on the knot, just as a tail would be.  This is not different than how an end-of line loop is loaded.

I can certainly understand an end of line loop that cannot tolerate end-to-end loading and thus wouldn't be very robust as an in-line loop, but the other way around doesn't make much sense to me.

No mention of EEL here or in a couple of other places I've said it.  This EEL stuff just slipped  in response to something xarax said.