As promised, here is a link to a pdf file which illustrates some bowlines... www.paci.com.au/IGKT/BOWLINES.pdf
I have included a terminology page to ensure that we are all cooking from the same recipe book...any errors/omissions please advise.
Change "loop" to "eye"--"loop" is a much overloaded term, and it can be rid of this job to
a ready, understood non-confusing one.
[ "EYE SPLICE" is a univerally used term, yes? (Dutch, German, French folks ... ?!)
I'm shifting from "loopknot" to "eyeknot", myself. ]
Now, seeing the Bwl as a marriage of a
bight and
loop returns the term and
possible confusion, where here "loop" must go vice your (or should we say, Chisholm's)
"hitch"--but this is how many knots books
define "loop".
(And you could end up talking more easily of a "double loop" rather than "double hitch",
aka "round turn" (which really sn't so well defined as 720degrees but more like 540).)
Also, for "hitch=>loop" and "bight", the arrow should somehow--by multiplication or different
graphic from arrowhead--point to a broader segment of material (as the bight entails both
the end and one leg of the eye). "Stem" (a dubious distinction) is shown as an outlined
segment--which, btw, will quickly move out of the nub on serious loading (or the exact bit
of material so delimited will change.
MOST IMPORTANTLY, I REJECT THE DEPICTION AS "FRONT" / "REAR"--that is one damnable
failing of the presentation of the Bowline, and actively works against ready comprehension of it,
as I have well argued above (prior msg. here)!! I do not care re Bwl what others have done; I do care
about getting it RIGHT for a change (if that is how to see it--"for a change", i.e.).
I would particularly appreciate comments/analysis of the #1013 (3 core variant) on page 3.
Why depart from the EBDB, which is pictured previously in this thread?
I see no reason to prefer the variant you show. You wrote above that you were going to do something
which was tantamount to tying the EBDB (though why you didn't refer to that puzzled me)--to wit:
>
I've used #1013 as the starting point and then
> taken the tail and performed a 360 degree loop around the cross-over of the hitchwhich yields precisely the End-Bound Dbl.Bwl. But now in your pdf, you do NOT go
around the
CrossOver Point, but
beside it--omitting the key element of security that the EBDB had
--preventing the SPart-through eye leg from loosening, from jointly w/SPart relaxation loosen
the central, nipping
loop of the knot!
Just to recap my objectives/performance criteria with ... the Bowline ... :
1. Easy to untie - particularly after high loadings
2. Can be tied around an object (eg tree or structural member) without first having to pre-tie a knot (eg re-threaded figure 8 loop)
3. Offers security
4. Is stable in all loading profiles
5. Relatively easy to learn and remember (with correspondingly low error rates with learners)
6. Offers reasonable level of strength relative to same design/model of unknotted rope
These are good criteria--to the point and readily comprehended (#2 might take some example
to make clear: around a big boulder, e.g.; and possibly the forming of an eyeknot when at
first it wasn't expected (and so, of course, no Fig.8 was pre-tied in anticipation)--a sort of,
impromptu, on-the-fly capability). I still believe that #6 is overstated: it comes with such
a nice
apparent ranking aspect--i.e. e.g., 75% > 65% --, that it appeals; but it hardly
comes with direct relevance to what is of importance (even at THIS point of immediate testing
--i.e., the slow-pull standard might yield a different result that rapid loading (as per Dave
Merchant's asseritons re Fig.8 & esp. Fig.9 eyeknots vs Overhand)). At this point, we don't
have testing of any of the 3-dia Bwls; we can look at testing non-differences between
2- & 4-leg (bunny ears) Fig.8 eyeknots, and muse that the extra material will NOT matter;
but we can also cite >one< test report showing breakage in the Fig.8 to come at the collar
but in the Bwl at the loop/"hitch", and muse that since that is where the extra dia. will come
into play, that it might matter, at least a little (and not much separates the two).
Also, "security" has practical significance for both in-tension & out-of-tension states:
testing of Amstel Blue HMPE half-inch (IIRC) 12-strand rope saw it slip free in a Bwl,
as it did in testing reported by Brion Toss in SAIL mag (2001-09?). Putting an Overhand
stopper resulted in the knot holding for the former testing (Left Coast forestry interest
in replacing heavy cable for logging), but breaking at about 33% (!!). YOUR and most
kernmantle-rope concerns are NOT of this sort, but of UNtensioned loosening; and the
testing of this property takes some innovation & insight--my "jiggling" remark, above.
(I think of maybe a washing-machine's vibrations, but really something with a cyclical
back'n'forth of, what, 6 inches (stroke) would be good?! Flapping from a flagpole line
might be nice, but I'd think that were several eyeknots attached, there might be some
variation in the stimulus given to each; still, if one treats it as I assert with pass/fail
judgement at the end of sufficient duration, the flagpole shaking might suffice.
(It seems that the Bwl loosens most readily if the end points UPwards, and gravity
thus is pulling it out--otherwise, the end will have to be raised: for rockclimbers,
LEADING, thus the Janus re-tucks have the benefit of pointing the end down.)
(Re "not of [tensioned loading] sort" concern: Dave Richards did testing of kernmantle
ropes--10.5mm dynamic, 12.7mm low-elongation, & 7mm low-elongation--and did find
tensioned slippage (instead of breakage) for some knots (Sheet Bend, Fisherman's).
--not for Bwl, which was tested.)
cf.
www.caves.org/section/vertical/nh/50/knotrope.html[advisory NB re report: 2 bar graphs 3,4 have swapped indicated data (12.5, 10.5mm);
"bend back" = bight, "turn through" = loop/hitch, re Sheet bend; data listings are right, IMO]
The inclusion of a 2nd diameter of rope through the
collar (sorry, but I see this as a section
of the "bight") tends to increase the collar's size ("tends", for in stiff rope that collar might be
wider just from resistance to bending around the 1-dia of SPart), and a larger collar makes
the Bwl more vulnerable to capsizing--where the "hitch"/=>loop goes from a HH-like form to
a round turn form to an opening coil, and nearly straight. The side-by-side end & SPart will
in my experience tend to orient themselves more, should we say,
parallel with bight sides
than compressed against each other--the SPart will press against the bight/collar tip, alone.
Secondly, let me remind you that the Bwl (#1010) is
vulnerable to ring-loading--a sort
of "abnormal loading" in some people's terms. So, starting with the Cowboy Bwl (#1034.5),
you have a base that is resistant to coming untied upon ring-loading (it becomes a Reverse
Sheet Bend so loaded).
I will use your Terminology image to define a "Janus" variation that look good:
1) (magically/mentally) swap legs of the bight--i.e., make this a Cowboy Bwl #1024.5
2) take the new-end --as per (1), the rightmost strand-- leftwards OVER TOP of eye legs;
3) then turn the end around the left leg, and come BEHIND all parts to tuck INTO the
triangular open small space at the knot's center (where the end, emerging, will run OVER whatever.
These "Janus" variants, as I've defined them, amount to making the same "rabbit-around-tree"
maneuvre a 2nd time, around the tree's *root* so to speak; if one can be expected to do that
once, surely it can be repeated.
AND, frankly, most any such re-tucking even gone slightly awry will still give a more secure
knot and the trio of rope diameters through the nipping loop. QED.
I'm going to add photos of the water bowline, Janus & EBDB tomorrow... I'll end up having
a smorgasbord of photos illustrating high quality photos of all the secured bowlines and its derivatives!
Great. And do try making the 2nd around-the-tree(root) maeuvre with the Water Bwl,
and see THAT variation; you might then be moved to do so with a Larkshead vs. Clove base,
and achieve "Mirrored Bowlines" variation. They seem to survive even when amply loose
(in the two nubs, if you will--keeping these two halves close to each other). Conceivably,
the Water Bwl can be tied in the quick-tie method by simply repeated the loop-forming
maneuvre, but practically I don't find this so easy; better to form the intended base
structure (Cow, pref. to me, or Clove), and make the "rabbit" run.
--dl*
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