General > Practical Knots
Girth-hitched "Eskimo" bowlines
X1:
The "Eskimo" Girth-hitched bowlines are quite similar to the standard "Eskimo" bowlines - the only dfference is that the single nipping loop has been replaced by the double nipping loop, in the form of a girth hitch that encircles the two legs of the "Eskimo" collar.
As the girth hitch stays at a right angle to the standing end axis, the working end, when it enters the coil "tube" made by the two adjacent nipping loops, can pass from the one or the other side. ( See the first attached picture). The girth hitch itself is symmetric, but the nipping structure based on it is not - so the two loops shown at the first attached picture, although they might deceivably look like two mirror symmetric knots, they are, in fact, very different. If one compares the two structures under a moderate loading, it is easy to see that the one, shown at the left side of the picture, is much more stable than the other, shown at the right side of the picture. So, even without the help of the "Eskimo" collar, the nipping lstructure shown at the left will be able to bear some load, while the nipping structure shown at the right will degenerate into something else.
Therefore, it is reasonable to expect that the Girth-hitched "Eskimo" bowline based upon the nipping structure shown at the left, will be more stable, as an end of line loop, than the one based upon the nipping structure shown at the right. At the next two pictures, one cas see the left-handed and the right-handed variations of this type of the Girth-hitched "Eskimo" bowline. Pay attention to the way the tail passes under the continuation of the eye-leg-of-the-bight, that makes a sharp turn before it enters into the coil "tube". In this position, the tail is squeezed in between the rims of the nipping loops and the other leg of the collar, so we can expct that is secured very effectively.
Dan_Lehman:
--- Quote from: X1 on August 07, 2012, 05:58:53 PM --- ...
Therefore, it is reasonable to expect that the Girth-hitched "Eskimo" bowline based upon the nipping structure shown at the right, will be more stable, as an end of line loop, than the one based upon the nipping structure shown at the right.
--- End quote ---
Note the error.
My inclinations ran in the other direction (to your photos),
and I sought the knot with the main nipping part
(I resist "loop", nb!) ending up in the center of the
entanglement --the complementary half of the hitch
on one side, the reach & turn (= bight) of the tail
going to the opposite side.
.:. But, by any form, this is one unsightly and unappealing knot.
(In contrast to the more bowlinesque (vs. Eskimo'd) variations
in which the structure runs more in alignment with tension.)
--dl*
====
X1:
--- Quote from: Dan_Lehman on August 08, 2012, 07:25:18 PM ---
--- Quote from: X1 on August 07, 2012, 05:58:53 PM --- ...
Therefore, it is reasonable to expect that the Girth-hitched "Eskimo" bowline based upon the nipping structure shown at the right, will be more stable, as an end of line loop, than the one based upon the nipping structure shown at the right.
--- End quote ---
Note the error.
--- End quote ---
Note the error. :)
The part of the text that you have highlighted with red, is OK, it was the other part that was wrongly typed. In fact, the erroneous sentence was meant to be nothing more than a repetition of a previous sentence :
--- Quote from: X1 on August 07, 2012, 05:58:53 PM --- If one compares the two structures under a moderate loading, it is easy to see that the one, shown at the left side of the picture, is much more stable than the other, shown at the right side of the picture
--- End quote ---
Thank you - I have now edited my text.
--- Quote from: Dan_Lehman on August 08, 2012, 07:25:18 PM ---But,...this is one unsightly and unappealing knot.
(In contrast to the more bowlinesque (vs. Eskimo'd) variations in which the structure runs more in alignment with tension.)
--- End quote ---
It is not more unsightly and more unappealing that the standard "Eskimo" bowline/s itself / themselves. In any "Eskimo" bowline, the continuation of the eye-leg-of-the-bight, in order to enter into the coil "tube", makes a sharp turn - which is a good thing, because much of the tension that comes from the bight is dissipated and absorbed at this turn ( so the rim of the collar is relieved from a great part of its duty), AND a bad thing, because the orientation of the nipping structure is not in alignment with the standing end, indeed. So, I think that those bowlines should only be compared to the other types of "Eskimo" "bowlines" - and not to the "bowlinesque" bowlines.
Dan_Lehman:
--- Quote from: X1 on August 08, 2012, 10:58:09 PM ---Note the error. :)
--- End quote ---
Well, okay : but I really hadn't meant that the red was wrong,
just that the repetition was, though it was natural to think the
second was a bum copy ... . --bad use of (just one) color!
:-[
--- Quote from: X1 on August 07, 2012, 05:58:53 PM --- If one compares the two structures under a moderate loading, it is easy to see that the one, shown at the left side of the picture, is much more stable than the other, shown at the right side of the picture
--- End quote ---
But my take is that this stage is incomplete and with the
closure of the collar in the right one there will be balance in the
entanglement around the SPart left & right, in contrast to the
left-side basis, where all the knotting falls on one side.
(They are both ungainly.)
--- Quote --- In any "Eskimo" bowline, the continuation of the eye-leg-of-the-bight, in order to enter into the coil "tube", makes a sharp turn - which is a good thing, because much of the tension that comes from the bight is dissipated and absorbed at this turn ( so the rim of the collar is relieved from a great part of its duty), ...
--- End quote ---
Hmmm, how much force is there to dissipate in the like structure
of a sheepshank --i.e., where a bight is nipped without collaring
anything?! Methinks you overpay the turn, for services unneeded!
--dl*
====
X1:
--- Quote from: Dan_Lehman on August 09, 2012, 03:29:40 AM ---But my take is that this stage is incomplete and with the closure of the collar in the right one there will be balance in the entanglement around the SPart left & right, in contrast to the left-side basis, where all the knotting falls on one side. (They are both ungainly.)
--- End quote ---
Correct. However, I tried to compare the stability of the bowline-like nipping structures themselves, in isolation / independently of the presence of the collar rims - not the finished knots. Nowadays, I follow a standard procedure : I do not consider the finished knot right from the start. Instead, I try to examine how the knot behaves when : 1 , there is only one leg of the would-be collar penetrating the nipping loop(s), and : 2, when both legs are penetrating the nipping loop(s), but the collar rims are very loose, or - as agent_Smith suggested - cut off ! If you do this, you will see what happens : The nipping structure at the left t is able to bear some loading, and remains in the same compact shape, while the nipping stricture at the right degenerates into someting else ( at the best case, into two separated nipping loops, the one above the other).
It is reasonable to suppose that, under extreme circumstances, the nipping loops would be forced to rely to nothing else than themselves, i.e. that they would confront their tendency to degenerate into open helices by their own structures, without any the help offered by the collars ( that would have been already pulled off the coil "tube", and so they will be very loose).
If you do that, if you remove the one leg of the collar/s, or of you cut of the rim, and examine the "adjustable noose" that is left , you will see what I mean immediately. It might be a good strategy or a misleading one - but, at the time being, it is the only thing we can do - because we can not imagine, without experiments, what the bowline would look line under severe, almost catastrophic loading. To my view, this strategy gives an indication of the ability of a nipping structure to be self-stabilizing or not - and so of the security of the bowline, in the broader sense. That is why I have appreciated the double nipping loops of the Water bowline, the Girth-hitched common bowline, and the double crossed nipping loops bowline. They are very stable structures, that will resist opening up and degenerating into open helices, even without the help of the collar s second leg, or of the collar s rim.
--- Quote from: Dan_Lehman on August 09, 2012, 03:29:40 AM --- you overpay the turn, for services unneeded!
--- End quote ---
The fact that, at the standard, common bowlines, or their close relatives ( the Sheepshank, the ABoK#160, and the Gleipnir ), indeed,this turn is not needed, does not mean it is a bad thing ! On the contrary, I have seen that it is very effective - although one might say that it forces the strands of the the rope to make a tight turn, not so-good a thing...I have even seen that there are knots where this turn, and this turn only, is sufficient to relieve the leg coming from the loaded bight so much, that we do not need the collarany more ! I have followed this strategy to tie adjustable nipping loops, where the orientation of the nipping loop(s) "tube" remains at right angle in relation to the standing end - so that the continuation of the eye-leg-this-bight is forced to make this sharp turn,and it was proved to be very effective. In fact, this strategy ( to force a tensioned line to make a sharp 90, or more, degrees turn, so a great portion of the tensile forces will be dissipated / absorbed at the area of the turn, and there will remain mush less that has to be dealt by the subsequent nipping structure ) is one of the the main reasons behind the effectiveness of many adjustable tensioners / binders. See:
http://igkt.net/sm/index.php?topic=3315.0
http://igkt.net/sm/index.php?topic=1870.msg21229#msg21229
http://igkt.net/sm/index.php?topic=2996.msg17836#msg17836
http://igkt.net/sm/index.php?topic=2996.msg17841#msg17841
http://igkt.net/sm/index.php?topic=2996.msg17842#msg17842
http://igkt.net/sm/index.php?topic=2996.msg17843#msg17843
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