THIS is so clearly a Practical knotting topic: why ChitChat about it???Errm, thanks Znex...but that site sheds absolutely zero light on the janus variant of the bowline that DL was referring to.
Yes, thanks much Znex for finding a ghost of the now-missing Dan Britton images!?
(Hmmm, I've been meaning to give him a ping re what's doing, and here's an obvious question to ask.)
Now, A_S, if you're keen to know, then Znex has put the Key in the words of mine you quoted
for you to get there (though I think the ghost images are upside-down to my reference).
--considerably more than M$ has done (they, under pressure, would seek to buy out the
innovative small firm with the answer).
And while we have THIS image available, let me again assert that a GREAT deal of trouble in learning
the Bowline can be attributed to its
backwards presentation of perspecitve--i.e., the "front" side that
is used in most of the instances I've seen is wrongheaded, and the opposite facing should be given.
In the images at the cited URLink (
www.thepirateking.com/knots/knot_bowline.htm ), it is the lowest one,
labeled (wrongly, I say) "rear view".
Similarly, the quick-tying method presented immediately following this image is going to again give
one the wrong facing (the "front view"). Moreover, this way of tying it--i.e., the initial maneuvre of taking
the end OVER the SPart vs.
UNDER it, is problematic in that upon completion it leaves a SPart
unsupported; whereas going the the opposite direction (take the end under, up-around-&-then-down)
will render both a better facing of the knot AND a self-supported SPart (i.e., it rests upon the closure
of the knot's loop component rather than falling away from it). BUT, dumb is dumb and knotters love
copycat repetition, it seems--errors and all!!
With the proper (so-called "rear view") facing, one can well see all of the interesting variations that
can be done with the bowline; it is very easy to understand where the hidden bight parts lie, in
contrast to the "front view" where the bight parts are atop the less obvious crossing(s) of the SPart.
Hmmm Roo, I'm aware of the Rosendahl bend and loop method you refer to.
The loop variation of the Rosendahl is interesting
As was presented to this forum a little while ago (this summer), that is but one way
of equating bend & eyeknot. The Butterfly is asserted to be another, and one can see
readily that it's a different relation (eye chopped off to reveal Bend ends). There is
another, wherein the SPart of one rope of the bend is converted into the eye, with
the re-entry tracing itself until necessary to *fuse* into the other rope's end and become
thus a single rope's eyeknot. In the case of Rosendahl's Zeppelin bend, the obvious
resultant knot is TIB (Tyable Inthe Bight), even! (There are some other variants that
center the SPart between the eye legs.) It is necessarily bulkier than the eyeknot
formed by simply directly fusing the one rope's end into the other's; but it better maintains
that particular P & Q loading profile.
Now if you cannot find any images of it, just how "preferred" can it be?
Sharp remarks like this can cut through the bs admirably!
But I must point out that I've not seen any real hint of what I call a
seizing hitch used in
commercial fishing, a (my term again) "Reverse Groundline Hitch", and yet I have found a good
many of them in use, in various capacities (e.g., being the hinges of some sort of holding cage
of wire mesh). --among other seizing hitches, some of which appear to be best-guesses.
But for rockclimbing/SAR/caving/canyoneering, yeah, the point is valid. And shows the
assertion/guess of "preferred" to be presumptive.
In any case, though, there is a good deal of knotting outside of mainstream knowledge
that merits much better attention and even use-in-place-of. I have long grumbled about
the too-popular "Yosemite Bowline" being a less than wonderful solution to the problem
of bowline security; but it has a considerable following. (Indeed, I'm surprised that in this
day that an Australian--or anywhere not deep in the outback or Amazon ...--would need
to refer to some exploratory party's physical traveling to have knowledge of it: it seems
de rigueur, to me, in rockclimbing circles. (And Spydey likes it climbing upright woody things.)
1) "Janus" is MY name for it: because it is the same form "coming or going" (from eye/SPart).
But there are other knots that could lay similar claim to the two-faced aspect (and, I guess, Janus
implies two but not two identical faces: the Angler's Loop is like this, then, and
in spades!!Angler's Loop (#1017) can take ANY of its four ends qua SPart, and yields a better YoBowl
in one case, a tenuous (dress/set carefully) quick-Bwl in opposite on that through strand,
and the two Overhand-based eyeknots with the other through strand qua SPart.)
Again, there are other identical-faced Bwls to be had, too; and I now favor a couple of these.
2) The knot was introduced (as has been presented here previously) in 1928 in the Alpine Journal,
same article that presented the better-known Butterfly mid-line eyeknot. It was later presented in
1990 (or thereabouts) by Heinz Prohaska in the Nat.Speliological Soc.'s newsletter
Nylon Highway(w/o awareness of the 1928 presentation). In fact, the two presentations differ (I think) in the exact
crossing of ends--left or right of each, a trivial matter. You can Search this forum for
http://charles.hamel.free.fr/Alpine_journal/ [Wright &Magowan in 300dpi format in pdf, courtesy of Bob Thrun]
Call it a lack of foresight, but the 1928 authors did not use synthetic or kernmantle rope.
You can also find it here (devoid of recognition of W&M's presentation, alas):
http://i3.tinypic.com/wjwh1t.jpg which might be manifest in image in-forum via ... (?)
Okay, now, with the rightmost, "Janus" image in mind, here's another version:
instead of the finishing tuck shown (end going turning around eye-leg and then exiting
Over_loop-Over_eyeleg-Under_loop), take the end around under the 2nd eyeleg and
then exit through the loop (turn Under-Over other eyeleg, Over loop Under loop in the exit).
--the end sort of makes a shoelace tying Overhand with the right eyeleg.
All of these knots put THREE diameters of rope through the nipping loop component,
which is a better approximation of a circle (than just 2 dia.), and can be oriented in
favor of better strength, kinder bending of SPart, IMHO. The turn around the eyeleg
on the left is what gives security: by keeping this handle-end of the nipping loop from
springing open, the inevitable feed of material through the main collar (corresponding turn)
around the SPart should not result in a loosening of the nipping loop, which holds the
ends etc. tight. This is to some degree a matter of degree, but I think you'll find it practically
effective in many common materials.
I'm not sure if the 'water bowline' is the 'janus' variant that DL was specifically describing.
We are: it is NOT.
However, later exploration revealed that the Clove Hitch & --mayBEtter-- Cow Hitch
("LarksHEAD" (not "...foot", which Brits on the rocks can't free themselves from)
make for some interesting & satisfying "Mirrored Bowlines" (guess-who's names?).
And, no, geesh, I don't have color pics to post, but the simple tying advice:
form the said structures (around fingers/air), and take them as the loop/"rabbit hole"
of a bowline through which the end is reeved in a bight form,
but make a bight
"coming AND going"--both directions (going around the corresponding/through leg of the eye.
The result is a complex-looking knot that can be pretty loose w/o fear of failure;
in a LEAD (not 2nd, not TR) climber's orientation--i.e., eye-up, SPart-down--, the end will hang
down, gravity-assisted to staying in place. IF it were to come out of both knot-loops (loops of
the two so-called "mirrored" knots), you would have in the Clove case THEN a Water Bwl,
and it would be nipped still by those loops (and long & dangly obvious).
There is yet another trick that can be played with either of these two (Clove/Cow) starts:
having inserted the end INTO the two loops (but not back through opp. way),
pull-straighten the eye-side loop, capsizing its turn into the inserted end (!!);
now finish the knot w/the 2nd pass of the end back through. Esp. with the Cow/LarksHEAD
version, the eye-side loop can be brought pretty snug up into the SPart-side loop.
(And, yes, one can stop here, or make the "... & going" further turn & through-tucking
of the end, gaining that 3rd diameter and pointing the end towards SPart.)
ANNNND, although this by my terms removes the classification of "bowline",
one can use the Clove/Cow basis but reverse the orientation of its ends--i.e.,
the SPart will be seen to come in OVER the "2nd loop" into the first (in the same
sense as both Two Half Hitches & Buntline Hitch use a Clove Hitch form--it is
the direction that the Clove's ends go that determines the knot). I think that
the Cow works better, here. There is a matter further of how the two ends
cross, as they must, each en route to the other's side of the world.
ANNNND-2, all above versions/variants can add the difference between the
Cowboy & Common Bwl.s--the direction of the turns in the collar(s). Please
don't ask for some large matrix of variants & testing, in added dimensions of
materials & setting & loading & ... . For some of these in practical terms, it
will not matter. For the simple variation I verbally presented above to the
Janus Bwl (which knots have equally "Janus" faces), both the given one
and its Cowboy cousin look good.
What all of these Lehman-suggested secured Bwls HERE do (not the EBDB, or not in same way)
as a means to improved security is to
hold the eye-side of the central nipping loop more snug
to itself, to inhibit it from opening/loosening. (The EBDB more directly binds the (dbl) loop.)
In some cases, this even seem more effective than the EBDB's direct binding: I've some quite
resilient, slick, soft-laid PP cord in which the EBDB just ... loosens--all the turns of the knot just
opening in unison; but in the Janus Bwl, the cord is bent more sharply in its two
collars,
and the cord there tries to open like scissors, and the central loop's enclosure prevents this;
the knot is (like many Bwls) loose in a way, but doesn't seem to quickly get
too loose.
In contrast, for a stiff--nearly intractable re knotting(!)--kernmantle rope such as PMI's Max-Wear
(aka "no-bend"), the EBDB can be tied and the knot holds, and I'd feel better about it than any
of the Janus variants, for long-term (fixed ropes?) security; the EBDB takes a bit more effort
and a proper method to untie (1st draw some SPart through the collar; 2nd pull the bight
ends (end & end-side eye leg) apart to lever some SPart through the End-Binding; 3rd,
now push & pull and work looser).
And as for technical data, I did say any data would be helpful. But if I really need to be that damn specific, try this:
[ ] Original developer of the janus variant
[ ] Details about its security - particularly if it might be suitable for rescue applications...evidence to support a theory.
[ ] Any test data on breaking strength in comparison to ABoK #1010, the water bowline (ABoK number?), and say comparison strength to #1047, etc, etc
[ ] Stability - any experience, evidence, any info whatsoever to support claims that the janus variant might be more stable than the original #1010
[ ] Evidence of the knots performance in kernmantel rope (ie EN 1891 certified rope, and EN 892 certified rope)
[ ] Any other data, information, history or even just personal notes...?
Citations above show two innovators (at decades remove), and me, for further variations.
Breaking strength is (1) a dubious attribute to a knot (your safety margin should well accommodate any),
and (2) not an obvious thing to determine (what material(s), how loaded to rupture, how conditioned
prior to loading, and (3) the exact geometry of the knot taking the load--differen tyers, different settings).
In some testing of nylon-to-HMPE slings, Kolin Powick found the nylon to be what broke in most/all
cases of slow-pull loading; and the reverse in drop-loading (suggesting that the HMPE's low-temp
threshold played a role); that is ONE case.
www.bdel.com/scene/beta/qc_kp.php#current [Kolin's 2006-11-09 test of nylon & HMPE slings]
--dl*
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