Bowline Extensions for Security

Discuss vertical caving, equipment, & techniques. Also visit the NSS Vertical Section.

Moderator: Tim White

Bowline Extensions for Security

Postby knudeNoggin » Dec 29, 2008 4:38 pm

There is currently an updated (periodically) pdf file containing photo images
of several bowline extensions, as an Australian fellow searches for some version
with which to put the venerable knot in better stead in the kernmantle-rope
user communities.
here: http://www.paci.com.au/IGKT/Bowlines.pdf

I find many of these "too clever by half", but the End-Bound Dbl.Bowline
and a Cowboy bowline version of the Janus Bowline look pretty good
at giving security in moderately stiff, firm, slick rope. There are
plenty of further variations yet to get an image--something a D40
& I might remedy. Maybe the major benefit of this pdf is giving
the right "front" view of the knot--mostly, it's the other way 'round!

:woohoo:
knudeNoggin
Prolific Poster
 
Posts: 189
Joined: Mar 4, 2006 4:48 pm
Location: Falls Church, Virginia, USA
  

Re: Bowline Extensions for Security

Postby NZcaver » Dec 29, 2008 6:17 pm

Very interesting... but did I miss something? Even with all that effort this person seems to have ignored one of the most obvious solutions to the Bowline security problem:

Image

I'm also a bit mystified by the first photo in the PDF which shows the parts of the Bowline. What is labeled the "eye" I know as the bight (in the context of a completed knot). I'm not sure what the part of the knot labeled as the bight really should be called, but it doesn't seem consistent with what I know as the definition of a bight (a slack part or loop in a rope).

knudeNoggin, I think your "too clever by half" comment hit the spot. :clap: I'd even say too complicated by half!
User avatar
NZcaver
Global Moderator
 
Posts: 6316
Joined: Sep 7, 2005 2:05 am
Location: Anchorage, Alaska
Name: Jansen
NSS #: 50665RL
Primary Grotto Affiliation: CCG
  

Re: Bowline Extensions for Security

Postby Scott McCrea » Dec 29, 2008 7:06 pm

The beauty of the bowline, imo, is it's simplicity. And it doesn't use much rope to tie. Add a yosemite tie-off and it's pretty bomber.

I don't think I would hang on the Janus version, fig. 30. :yikes:
Scott McCrea
SWAYGO
User avatar
Scott McCrea
Global Moderator
 
Posts: 3198
Joined: Sep 5, 2005 3:07 pm
Location: Asheville, NC USA
NSS #: 40839RL
Primary Grotto Affiliation: Flittermouse Grotto
  

Re: Bowline Extensions for Security

Postby knudeNoggin » Dec 30, 2008 12:12 am

NZcaver wrote:Very interesting... but did I miss something?
Even with all that effort this person seems to have ignored one
of the most obvious [& well published--kN] solutions to the Bowline security problem:


Would you do that in PMI's Max-Wear ("No-Bend" :tonguecheek: !!) rope?!
I'm finding it rather hard to set the tie-off/safety/back-up Overhand knot
in some smooth, firm, 10.xmm climbing rope. And even done, that really
doesn't make the knot body so secure. Of course, using the Dbl.Oh./aka "Strangle"
knot tie-off redresses the security issues with this back-up. But on tying in,
it also puts a knot bulk in the eye. Yes, one can put it elsewhere.

... the parts of the Bowline. What is labeled the "eye" I know as the bight
(in the context of a completed knot). I'm not sure what the part of the knot labeled as the bight
really should be called, but it doesn't seem consistent with what I know as the definition of
a bight (a slack part or loop in a rope).


The nautical "bight" is a broad cove or something like that, which hardly matches
the things denoted by knotting uses. But it's not "slack part ...": only remotely so,
in the meaning "without ends" re tying ("tied in the bight"); and otherwise it's best
definition is probably "a u-shaped part of rope". Knots books like to distinguish
"bight" from "loop" by whether the legs of the structure cross, but I think that
crossing is really not germane: "loop" (too overloaded--many uses) seems to be
more round, "bight" elongated. The Bowline fits the knots-book definitions as
a marriage of a bight & a loop; and that sense and example of "bight" is
what's highlighted by the diagram. "eye" has less mixed usage--an "eye splice"
is well understood (whereas "loop" can mean a circle of rope--a grommet--
or an eye, or ... someone too involved in knots!).

The beauty of the bowline, imo, is it's simplicity. And it doesn't use much rope to tie.
Add a yosemite tie-off and it's pretty bomber.
I don't think I would hang on the Janus version, fig. 30


Would you use it in stiff rope? That Yosemite finish requires a 1-diameter bend
of the tail, and in much kernmantle rope that's going to meet w/firm resistance.
Interestingly, there's a pretty obvious other way to make a similar tucking
of the end out through the collar--the tail crosses itself on the opp. side (i.e.,
the crossing over/under relation is flipped), and then goes out (which forms
an Overhand vs. a Fig.8); this knot cannot be mis-oriented on setting, as
can the Yosemite one--as oddly illustrated in one of the two photo'd knots
on the cover page for 1st ed. On Rope chapter on Knots!

I've worked the EBDB into security in the PMI (and old BW) No-Bend rope;
the turns/wraps in it are all 3-diameter, except for the collar, which
needn't be tight anyway. As for that "Janus" variant in fig.30 (which differs
only in the crossing of the end with itself through the central "loop" from a
knot shown along with the Butterfly's debut in the 1928 Alpine Journal by
Wright & Magowan), while it indeed has an *airy* look to it, it resists
opening (further) surprisingly well. (You old-timers or other archivists
can find it in NHwy#26 (May 1988), pp.4,5, by Heinz Prohaska.) And,
really, the collar around the eye leg should be set tighter: it's the
holding of this leg relatively close to the knot body that keeps the
central loop from loosening, and a bend in the eye leg isn't a concern
re strength.) The 3 vs. 2 diameters of rope material in the central
loop might boost strength some, softening what can otherwise be
a pretty hard turn of the main loaded line there--a plus.

------------

Once I tied the EBDB in some thin (3-4mm?) twisted, slick polypropylene,
but it wouldn't set--for long: all of the binding loops just simultaneously
enlarged !! HUH???! Then I tried the Prohaska bowline, and although
the knot was loose, the loosening was arrested pretty quickly, as this
flexible but springy material wanted to open the two collars like
scissors, and the central loop easiliy impeded that.
Kernmantle is of a different nature, and the wraps hold well.
Anyway, it was a sharp reminder that materials bring qualities
to knots as much or more than the other way around!

*kN*
knudeNoggin
Prolific Poster
 
Posts: 189
Joined: Mar 4, 2006 4:48 pm
Location: Falls Church, Virginia, USA
  

Re: Bowline Extensions for Security

Postby ek » Dec 30, 2008 5:21 am

Though I once had similar concerns, I have since tied both the single-overhand stopper and the Yosemite backup many times with bowlines tied in stiff ropes such as 11mm PMI Max-Wear / PMI Pit Rope and 11mm Sterling SuperStatic. (To compare the two ropes: the Sterling SuperStatic seems to be a bit more supple, but also more slippery. I believe that 11mm Sterling SuperStatic is the most common static line used by rock climbers in the US for rigging, while PMI Pit Rope--which is functionally identical to 11mm PMI Max-Wear--is the most common static line used by cavers in the US for our pit ropes. But these are just my impressions--I do not have a source to cite for this.)

I have never had any problems with either. Neither has ever slipped substantially on me. I've always been able to get both of them to tighten down quite easily. I do have to pull hard to cinch down the stopper (when that's the "lock" I've chosen to use). I usually use the Yosemite finish, but many of my caving buddies use the single or double overhand finish, and those seem to work perfectly well (except--as you point out about the double-overhand stopper--that it adds bulk to the loop of the knot).

In terms of giving stability to the body of the knot, I am not quite sure what you mean, but on a stiff rope (as on a supple rope) both the single-overhand stopper and the Yosemite finish provide stability in ring-loading (though I have not pull or drop tested this to verify that it is true for high loads...looking at what happens to the knot in moderate ring loading, I would expect it to be fine). They also all prevent the knot from capsizing into a slipknot. These would seem to be the qualities of stability pertaining to the body of the knot, if resistance to untying when cyclically loaded is to be considered less centrally related to the knot body.

A number of the suggestions in the PDF you posted seem likely to be technically superior in various ways to the simpler options such as single and double overhand stoppers and the Yosemite finish. And I certainly do not deny that these more common extensions to the bowline produce a looser knot than, for instance, a figure-eight on a bight would generally be. I have seen a Yosemite bowline with a 4+ inch tail tied on supple 9mm rope come untied when it was dragged across a whole bunch of cave. I've seen a figure-eight on a bight in the same rope come untied under similar conditions, but it took a lot longer.

However, the benefits of the Yosemite bowline and the bowlines with single and double overhand stoppers is that, not only have they been pull- and drop-tested repeatedly and extensively in a wide range of ropes, they have also been in use for many years in sport and rescue. All existing data appear to indicate that they are safe (and adequately strong) choices for users of high stretch, low stretch, and very low stretch kernmantle ropes made of nylon, polyester, and combinations of nylon and polyester--at least those of cross-sectional diameters up to 12.5mm. (This is by no means an exhaustive stipulation of materials in which these knots work well.) My understanding is that each of these three versions (Yosemite bowline, bowline with single overhand stopper, bowline with double overhand stopper) are used hundreds (perhaps thousands) of times every day around the world and that so far there are zero documented or even rumored cases of any of them proving inadequately safe. (Though for some time there were some murmurs, with no accompanied actual failure events, that the single overhand backup might under some imaginable conditions come untied in use.)
Eliah Kagan
NSS 57892
Syracuse University Outing Club

Fund vital White Nose Syndrome research--donate to the NSS and select the WNS Rapid Response Fund.
Facebook users can also donate here.
User avatar
ek
NSS Hall Of Fame Poster
 
Posts: 1040
Joined: Apr 3, 2007 2:45 am
Location: Syracuse, NY
Name: Eliah Kagan
NSS #: 57892
Primary Grotto Affiliation: Syracuse University Outing Club
  

Re: Bowline Extensions for Security

Postby NZcaver » Dec 30, 2008 9:58 am

As many of you know, the Bowline is one of the knots students are tested on at NCRC seminars each year. Students must tie and dress a series of knots correctly, within a limited time period. 11mm low stretch rope (probably PMI) is generally used. Acceptable finishes for the Bowline are the overhand and the Yosemite. The overhand seems to be more popular, mostly because it's easier for the average person to tie correctly and for others to recognize. With the Yosemite, if you don't get the whole cross-under then over-under-and-through thing just right - you fail the test. Even if it may "look right" at first glance.

Eliah makes a good point about knots (and variations of knots) which are already commonly used in the recreational/professional/rescue communities, and how their properties have been tested time and again in testing facilities and real-world conditions. Assuming a knot is safe and it works, I'd also argue that the simpler it is (easier to tie and to visually recognize as correct), the better. Of course each person's definition of what is simple and what isn't may differ. :wink:
User avatar
NZcaver
Global Moderator
 
Posts: 6316
Joined: Sep 7, 2005 2:05 am
Location: Anchorage, Alaska
Name: Jansen
NSS #: 50665RL
Primary Grotto Affiliation: CCG
  

Re: Bowline Extensions for Security

Postby ek » Dec 30, 2008 3:51 pm

The double overhand stopper is also still permitted by NCRC, right?

I have no beef with the overhand (or double-overhand) stopper, but I do think that in many ways the Yosemite finish is preferable. While it's easy to tie wrong if you don't know how, this is also the case with the bowline itself--general belief is that the "left-handed"/"cowboy"/"Dutch marine" bowline is not acceptable. A stopper knot as a finish will make it nearly impossible to tell if this has been tied (though, arguably, the differences between the "right-handed" and "left-handed" bowlines are minimized when a security extension is used...which it always should be, at least for applications involving human loads). The Yosemite finish, like the rethreaded figure-eight, has a distinctive look that makes it clear to someone familiar with the knot whether or not it is tied correctly.[1]

On the topic of simplicity, I would argue that the Yosemite bowline is simpler than a bowline with an overhand stopper, in that the rope goes through fewer turns to tie this knot. In addition, when tying the overhand stopper, it is necessary to cinch the stopper knot down onto the main knot (i.e. the body of the bowline). The extra step of ensuring this has happened does not pertain to the Yosemite bowline.

However, like any knot, the Yosemite bowline should not be tied by someone who doesn't know how to tie it. When I teach people to tie the bowline, I teach them to finish it with a single overhand stopper. It is simpler in the sense that they already know how to tie an overhand stopper, so they have to learn fewer rope manipulations to produce a finished, usable knot. I then encourage them to learn the Yosemite finish once they have mastered the bowline.

That said, if you were to not know the bowline but know that the version you'd prefer is the Yosemite finish, then I think it would be foolish to learn the version finished by a stopper first. I am generally a proponent of people learning whatever it is that they actually want to use first, provided that it is safe to do so, and I see no exception here. (As the Yosemite bowline, bowline with single overhand stopper, and bowline with double overhand stopper are all commonly used bowlines in sport and rescue, IMO all rope technicians--recreational or professional--should eventually learn all of them, so that they can recognize whether or not they are properly tied.)

One final thought: an advantage of the stopper finishes as opposed to the Yosemite bowline is that they can be applied readily to a bowline that has been tied and is being weighted.

[1] As knudeNoggin often points out, many properties of knots are really properties of specific cordage, and vary. This is also the case with the distinctive look associated with a figure-eight or a Yosemite bowline. A cleanly dressed figure-eight on a bight / rethreaded figure-eight has a distinctive look even in webbing, but unlike in rope, a poorly dressed figure-eight in webbing does not have a distinctive look. A Yosemite bowline in webbing doesn't have a particularly distinctive look, even if properly dressed...but then, neither does the bowline, in the sense that when tied in webbing, the "handedness" of the knot often appears reversed as the tail migrates outside (or, when tying a left-handed bowline, inside) the major loop.
Eliah Kagan
NSS 57892
Syracuse University Outing Club

Fund vital White Nose Syndrome research--donate to the NSS and select the WNS Rapid Response Fund.
Facebook users can also donate here.
User avatar
ek
NSS Hall Of Fame Poster
 
Posts: 1040
Joined: Apr 3, 2007 2:45 am
Location: Syracuse, NY
Name: Eliah Kagan
NSS #: 57892
Primary Grotto Affiliation: Syracuse University Outing Club
  

Re: Bowline Extensions for Security

Postby NZcaver » Dec 30, 2008 8:27 pm

ek wrote:The double overhand stopper is also still permitted by NCRC, right?

Good question. I don't recall the double overhand stopper finish ever being taught or shown in NCRC literature, but that's not a definitive answer. Greg or one of the others may be able to clarify this the next time they are trolling past. I think that particular Bowline finish is fine, but as you know NCRC doctrine likes to stick with a set repertoire of knots and options - otherwise a weeklong training would take a year to complete. :big grin:

I thought you brought up some excellent points in your previous post.
User avatar
NZcaver
Global Moderator
 
Posts: 6316
Joined: Sep 7, 2005 2:05 am
Location: Anchorage, Alaska
Name: Jansen
NSS #: 50665RL
Primary Grotto Affiliation: CCG
  

Re: Bowline Extensions for Security

Postby knudeNoggin » Dec 31, 2008 3:16 pm

Though I once had similar concerns, I have since tied both the single-overhand stopper and the Yosemite backup many times with bowlines tied in stiff ropes such as 11mm PMI Max-Wear / PMI Pit Rope and 11mm Sterling SuperStatic. ...
I have never had any problems with either. Neither has ever slipped substantially on me. I've always been able to get both of them to tighten down quite easily. I do have to pull hard to cinch down the stopper (when that's the "lock" I've chosen to use).


!! Well, all I can say is that in some firm 11mm climbing rope, an Overhand around
one diameter just does NOT like staying tight; I have some success when tightening
this knot up against the Bowline body--i.e., pulling on the end and snugging it in
(which is in any case a better plan than just having the stopper somewhere out
along the eye-leg, which allows the bowline body to loosen).
"Easily" ??? I must have much stiffer rope than you; again, trying to get the material
to come even close to a 1dia bend is futile.

I should point out--and hope to see illustrated in the (yet just updated!) pdf file
cited in the OP--that there is a Yosemite-like finish which sounds as though ...:
if you don't get the whole cross-under then over-under-and-through thing just right
- you fail the test. Even if it may "look right" at first glance.

this might be what's going on here (and should get bonus points, not failure!).
(Btw, I must emphasize that in MOST PRESENTATIONS, THE BOWLINE IS SHOWN
FROM THE WRONG PERSPECTIVE (for understanding its structure, and esp. for
understanding the various extensions to secure the structure; and even for the
better orientation of the quick-tie method of forming the knot's central loop).
The "front" perspective in the pdf should improve understanding & recognition,
a LOT.)

In the "front" orientation of the cited pdf, just bring the basic bowline's tail UNDER
the left eye leg and then up-around-over & through the collar; you form an
Overhand vs. Fig.8 with the tail; you bring it around 2dia curves vs. the 1.
And the tail could be loaded, for an Overhand-based eyeknot; like the Yosemite
Bowline, this variation can be tied "in the bight"--i.e., mid-line, w/o ends.
For that, "Single Bowline in the Bight" has merit as a name.

But if a simple wrap-&-tuck-back-through finish is sought, I find that second
(bottom half of page w/"Janus") Janus bowline, formed from a "Cowboy" base,
quick, easy, recognizable (it's symmetric), nicer. (For **lead** rockclimbers,
this has the advantage, like the Yosemite finish, of pointing the end DOWNwards,
gaining some gravity-assist against coming out of the tuck.)

While {Yosemite B.} easy to tie wrong if you don't know how, this is also the case with the bowline itself--general belief is that the "left-handed"/"cowboy"/"Dutch marine" bowline is not acceptable.


Which points to a meaning of "wrong" rather than to a characteristic of the knot.
I'm waiting to hear a rationale for why the Cowboy Bowline is unacceptable that stands up.

Frankly, if ring-loading is a concern, it should be noted that the Cowboy Bowline
resists it, the common ("correct") bowline does not. "Dutch marine" is a myth, according
to one Dutch knot researcher. For mooring lines, this Cowboy bowline better resists
capsizing (which sees the mainline nearly straightening from a coil from a loop, and
all the knotting put into the end which becomes a Pile Hitch (just got some pics of
this happening to an Eskimo Bowline)).

the "handedness" of the knot often appears reversed

Best to kill this misnomer in the moniker "Left-handed Bowline", as it has NOTHING
to do with handedness ("S" & "Z" twisting), but borrows from the colloquial sense of
"wrong"/"inferior" of lefties--at which any good lefty should take offense (and even
cite those studies showing higher mental abilities ... ! :o). (Handedness can be
seen of influence in knot behavior in laid/twisted rope and the Overhand knot
--where in one way it will better interlock the rope's strand-ridges and hold,
and in the opposite handedness not so.) In braided ropes, it's not an issue.

I don't recall the double overhand stopper finish ever being taught or shown in NCRC literature


The Strangle knot--which is a dbl.oh. of a particular orientation, that most familiar
here--is likely going to be known via the Grapevine Bend (aka "Dbl. Fisherman's knot"),
and should be common knowledge, as it's a quite useful make-it-secure structure
that might be employed in many places, **2 B Sure**; it works in many materials
(e.g., the Grapevine seems to be one of the strongest webbing bends; adding a few
extra wraps, and one has a good rope-end whipping).

*kN*
Last edited by knudeNoggin on Jan 1, 2009 1:55 am, edited 1 time in total.
knudeNoggin
Prolific Poster
 
Posts: 189
Joined: Mar 4, 2006 4:48 pm
Location: Falls Church, Virginia, USA
  

Re: Bowline Extensions for Security

Postby ek » Dec 31, 2008 5:26 pm

knudeNoggin wrote:!! Well, all I can say is that in some firm 11mm climbing rope, an Overhand around
one diameter just does NOT like staying tight; I have some success when tightening
this knot up against the Bowline body--i.e., pulling on the end and snugging it in
(which is in any case a better plan than just having the stopper somewhere out
along the eye-leg, which allows the bowline body to loosen).
"Easily" ??? I must have much stiffer rope than you; again, trying to get the material
to come even close to a 1dia bend is futile.

You are unable to make the single overhand stopper and Yosemite finishes work on a climbing (i.e. dynamic, i.e. high stretch) rope?

The standard for these types of ropes stipulates a required "knottability" which is better than that of most semi-static ropes of similar thickness. I am extremely surprised that I am able to easily cinch down a knot in 11mm cave rope which you are unable to cinch down in 11mm climbing rope.

Is it possible that your 11mm climbing rope is actually 11.5mm and quite old?

knudeNoggin wrote:I should point out--and hope to see illustrated in the (yet just updated!) pdf file
cited in the OP--that there is a Yosemite-like finish which sounds as though ...:
if you don't get the whole cross-under then over-under-and-through thing just right
- you fail the test. Even if it may "look right" at first glance.

I just want to point out that you're quoting NZcaver here--I did not say that.

Regardless of whether or not doing the Yosemite bowline "wrong" produces an acceptable knot (or even one superior in stability), there are three problems with it, the first two of which are quite substantial:

(1) It's not gone through real world testing, nor has it gone through lab testing. We know the Yosemite bowline works.
(2) It looks jumbled when tied. It would be very hard to know for sure that it is tied correctly. I concede to NZcaver that the Yosemite bowline, like any knot, cannot be correctly recognized by someone who doesn't really know how to tie it. But I think the Yosemite bowline, tied in kernmantle rope, has a very distinctive look. I think it's nearly as easy to evaluate for correct tying as is the figure-eight on a bight / rethreaded figure-eight.
(3) It uses a bit more rope, whereas the Yosemite bowline uses very little extra rope.

knudeNoggin wrote:this might be what's going on here (and should get bonus points, not failure!).
(Btw, I must emphasize that in MOST PRESENTATIONS, THE BOWLINE IS SHOWN
FROM THE WRONG PERSPECTIVE (for understanding its structure, and esp. for
understanding the various extensions to secure the structure; and even for the
better orientation of the quick-tie method of forming the knot's central loop).
The "front" perspective in the pdf should improve understanding & recognition,
a LOT.)

Good point. For the "landlubber" method, the common view is preferable for a student to follow and verify correct tying. For actually seeing how the knot works, the other side makes more sense.

knudeNoggin wrote:But if a simple wrap-&-tuck-back-through finish is sought, I find that second
(bottom half of page w/"Janus") Janus bowline, formed from a "Cowboy" base,
quick, easy, recognizable (it's symmetric), nicer. (For **lead** rockclimbers,
this has the advantage, like the Yosemite finish, of pointing the end DOWNwards,
gaining some gravity-assist against coming out of the tuck.)

I think we have different ideas about what is "recognizable." It's more recognizable than some of the other knots in the paper...but it's not as distinctive as: (1) a Yosemite bowline, (2) a Yosemite mountaineering bowline (a.k.a. double bowline with Yosemite finish, i.e. with a double minor loop....which is the most commonly used bowline that climbers use to tie in), or (3) a rethreaded figure-eight (a.k.a. figure-eight follow-through).

knudeNoggin wrote:
While {Yosemite B.} easy to tie wrong if you don't know how, this is also the case with the bowline itself--general belief is that the "left-handed"/"cowboy"/"Dutch marine" bowline is not acceptable.

Which points to a meaning of "wrong" rather than to a characteristic of the knot.
I'm waiting to hear a rationale for why the Cowboy Bowline is unacceptable that stands up.

As you say, the cowboy bowline (with no extension for security) resists ring loading whereas the more common bowline (with no extension for security) doesn't resist ring loading. On the other hand, the common bowline (with no extension for security) seems to resist capsizing when the tail is pulled better than the Cowboy bowline (with no security extension).

With an appropriate extension for security, both bowlines resist ring loading and pulling-back of the tail. Since for life support applications neither is acceptable without a security extension, I think you have a good point when you suggest that the inferior status of the Cowboy bowline is probably mythical.

Of course, only the (standard) bowline, and not the Cowboy bowline, can be secured with a Yosemite finish (and appear clean and recognizable). The Yosemite finish performed on a Cowboy bowline also does not add nearly as much friction, and changes the geometry of the knot more significantly. I would not want to use it until testing had been performed.

knudeNoggin wrote:"Dutch marine" is a myth, according to one Dutch knot researcher.

Interesting--can you provide more details?

knudeNoggin wrote:
the "handedness" of the knot often appears reversed

Best to kill this misnomer in the moniker "Left-handed Bowline", as it has NOTHING
to do with handedness ("S" & "Z" twisting), but borrows from the colloquial sense of
"wrong"/"inferior" of lefties--at which any good lefty should take offense (and even
cite those studies showing higher mental abilities ... ! :o). (Handedness can be
seen of influence in knot behavior in laid/twisted rope and the Overhand knot
--where in one way it will better interlock the rope's strand-ridges and hold,
and in the opposite handedness not so.) In braided ropes, it's not an issue.

I believe the term handedness, in the general sense of duality in anisotropy, is appropriate when discussing ropes, knots, and rigging. However, I put it in quotes because even in this expanded sense (related to but not limited to rope directionality) it is incorrect to refer to the Cowboy bowline as "left-handed." I recognize that.

You'll have to show me some historical evidence, though, to get me to believe that the term "left-handed bowline" is based on the notion that left-handed people are inferior. Discrimination against left-handed people pervades our society in numerous ways and extends readily into sport and rescue. Some examples include (1) which wall bolts are usually placed in, (2) the total or near total absence of left-handed chest ascenders (this discussion has motivated me to post about that...if you know of one, please let me know), and (3) the fact that rarely can one buy a rack in the configuration preferred by most left-handed people (with the rope entering from the front, as it does to a right-handed rack--if you don't care which way you put the rope in, you can just turn a right-handed rack around...and make sure you're not accidentally rigging a death rack!).

The reason that I am reluctant to believe that anti-left-handed prejudice is the direct source of the term "left-handed bowline" is that this explanation (by itself, without supporting evidence) fails the Occam's Razor test with flying colors. Consider the common (but, as you point out and as discussed above, non-ideal) depiction of the bowline. In this depiction, the standard bowline has the tail coming out inside the major loop, whereas the Cowboy bowline a.k.a. left-handed bowline has the tail coming out to the left side of the major loop! I think this is a far more probable explanation.

Ultimately, though, I do think that if most people were left-handed then the Cowboy bowline would be called the "right-handed bowline" instead of the "left-handed bowline." This is because of the connection between right-handedness and counterclockwise-and-up. If you are to push something with the closed palm of your right hand, it is substantially more natural (anatomically) to push it counterclockwise. When you have your thumb pointing at a right angle to your fingers and push something counterclockwise, your thumb points up. This idea may seem rather arcane, but I think that it (or similar ideas) is actually quite embedded in Western thought. One example is the way in which a screw is almost always threaded (and then it is removed--i.e. brought up--by screwing counterclockwise). Here's another, to illustrate how pervasive this convention is: In mathematics and physics, this idea is called the Right-Hand Rule and is used to create sign (i.e. + / -) conventions for coordinates. Push the increasing (+) side of the x-axis into the increasing side of the y-axis with the palm of your right hand and the direction your thumb is pointing is the right-handed convention for the direction in which the z-axis is increasing. The Left-Hand Rule also exists and sometimes left-handed coordinate systems are used, but right-handed systems are far more common, probably because they're more intuitive for right-handed people. The right-handed rule is, through incorporation as a convention into technical definitions, also written into our Laws of Physics. If most people were left-handed, our convention would be different, and many of our fundamental statements about the Universe would incur (or drop) a minus sign.[1]

What does this have to do with tying a bowline, you ask? Well, the standard landlubber method of tying a bowline is to make both the minor and major loops by running the working end of the rope counterclockwise and up. (What "and up" means for the minor loop is clear--but for the major loop, I'm referring to the way the working end is run through it--going up or going down--to complete the major loop.) The standard, poorly illustrative way of depicting the bowline is consistent with this. Consider the other options--you could tie an identical knot upside down by making your minor and major loops clockwise and down. Or you could tie the actual mirror-image (i.e. left-handed) version of this knot, not to be confused with the cowboy bowline, by going clockwise and up or counterclockwise and down with both the major or minor loop. (Hold a standard bowline in a mirror to see what this looks like. It's equivalent in any cordage that has no overall twist of any kind, but potentially could perform differently otherwise. knudeNoggin and I have discussed this before on Cavechat, so this description is primarily for the interest of other readers.)

Just make sure that both the minor loop and major loop are tied in the same way. If they're different then what you get is a non-bowline that, when loaded, will fail and kill you. :yikes:

If most people were left handed, probably the standard way to tie/orient/depict the bowline would have the tail-side be the right side, so then if you tied a Cowboy bowline, that would be called a right-handed bowline.

knudeNoggin wrote:
I don't recall the double overhand stopper finish ever being taught or shown in NCRC literature

The Strangle knot--which is a dbl.oh. of a particular orientation, that most familiar
here--is likely going to be known via the Grapevine Bend (aka "Dbl. Fisherman's knot"),
and should be common knowledge, as it's a quite useful make-it-secure structure
that might be employed in many places, **2 B Sure**; it works in many materials
(e.g., the Grapevine seems to be one of the strongest webbing bends; adding a few
extra wraps, and one has a good rope-end whipping).

I concede that a double-overhand stopper is a generally more secure knot than an overhand stopper. Indeed, I have been taught that a single overhand stopper if used as an endline knot in a pit rope (or climbing rope) can roll off if hit hard by an errant rappeller, while a double-overhand (or a figure-eight) will stay put. And the single fisherman's bend is certainly less secure than the double-fisherman's bend.

However, the question is not whether or not the double overhand stopper is more secure than the single overhand stopper, but whether or not the single overhand stopper (or, speaking generally, any knot) is secure for the application in which it is being used. Real world use bears out the idea that the single overhand stopper is a secure finish for a bowline tied in dynamic and semi-static kernmantle ropes.

(As a side note, the double overhand stopper is not secure in all applications. For instance, the double fisherman's bend fails to hold the core inside the sheath in kernmantle 5.5mm Spectra cord, resulting in failure at unacceptably low forces in pull tests. Thus, the triple fisherman, which is adequately secure for this application, is considered the acceptable variant.)

[1] This is perhaps less of a revelation than it initially seems. If left-handed coordinate systems were preferred, the laws of physics would be written differently, and they would be visualized differently, but they would not be making different claims about the actual Universe.
Eliah Kagan
NSS 57892
Syracuse University Outing Club

Fund vital White Nose Syndrome research--donate to the NSS and select the WNS Rapid Response Fund.
Facebook users can also donate here.
User avatar
ek
NSS Hall Of Fame Poster
 
Posts: 1040
Joined: Apr 3, 2007 2:45 am
Location: Syracuse, NY
Name: Eliah Kagan
NSS #: 57892
Primary Grotto Affiliation: Syracuse University Outing Club
  

Re: Bowline Extensions for Security

Postby Chads93GT » Dec 31, 2008 9:04 pm

time for a noob question. I hope you are ready for it.

I know the bowline is extremely easy to untie after being weighted. In fact, next time I go rock climbing (after my belayer has her kid ((my wife)) I may tie off using the double bowline instead of the trace figure 8 with a fishermans backup. Kind of makes me nervous how easy it is to undo but whatever.

Just did my first pit cave 3 days ago, wow. My question is this, what is the actual use of the bowline that I see people so frequently talk about in this forum? Since im just getting into vertical caving, I figured I would ask. Im sure I will read it in the next few weeks in On Rope (just borrowed it from a friend), but I figured I would ask and get a real answer. Thanks
User avatar
Chads93GT
NSS Hall Of Fame Poster
 
Posts: 2293
Joined: Jun 24, 2008 1:27 pm
Location: Missouri
  

Re: Bowline Extensions for Security

Postby ek » Jan 1, 2009 2:40 am

EDIT: Replaced an instance of "bowline" with "figure eight" where "figure eight" was originally intended. ("well, you know how long it can sometimes take to untie a figure-eight")

EDIT: Corrected some punctuation.

EDIT: Added mention of what is perhaps the most significant advantage of the bowline on a bight over the double figure-eight: that it's easier to clip a carabiner through both loops.

Chads93GT wrote:I know the bowline is extremely easy to untie after being weighted. In fact, next time I go rock climbing (after my belayer has her kid ((my wife)) I may tie off using the double bowline instead of the trace figure 8 with a fishermans backup. Kind of makes me nervous how easy it is to undo but whatever.

The double bowline (i.e. bowline tied with a 2-loop coil as the minor loop) is more secure than a standard bowline, but (unlike a rethreaded figure-eight) it still needs to be backed up (i.e. still needs an extension for security--the backup is not in case the bowline fails, but to prevent its failure by the tail sliding through). I believe that the most accepted and widely used bowline used by climbers for tying in is the Yosemite mountaineering bowline--i.e. the double bowline with Yosemite finish. This doesn't need any additional backup, but if you tie a stopper knot on top of the figure-eight, there's no specific reason not to do so to the Yosemite mountaineering bowline.

The other thing is--please remember that when you're assessing whether or not you have tied a knot with enough tail (i.e. with four inches or more, generally), you need to look at how much tail there is *after* any backup knot that you have tied, if the backup knots are actually necessary. If the backup knot is just there to keep the tail from smacking you in the face then of course you needn't worry about it and need only ensure that you have 4" of tail after the main knot (though you may risk the backup coming undone and receiving rope-slappage). A stopper knot used as a safety extension also needs to be tied immediately next to the main knot, with no space in between. If it has to slip down before coming into effect, then (1) your knot is slipping, which is undesirable, and (2) potentially some rope damage (due to melting) or even failure could occur. If your backup knot is tied just to keep the tail out of the way then it's still a good idea to tie it down at the main knot, because this gives you the most freedom for clipping your rope to anchors. (As a thought experiment, imagine if the loop of your tie-in knot were four feet long...think of the problems this would cause you on lead...) If it doesn't take up enough tail when it's tied low, just make more wraps--i.e. instead of a double overhand, tie a triple, quadruple, quintuple, sextuple, or whatever overhand (and consider tying in with less tail next time).

Chads93GT wrote:what is the actual use of the bowline that I see people so frequently talk about in this forum?

That is an excellent question.

In vertical caving, I most often use the bowline to tie around a BFR (i.e. a rock big enough and well enough seated to be a reliable anchor point), or perhaps a sturdy formation or chockstone. I have also used the bowline to finish a tensionless hitch when a carabiner is unavailable or I do not wish to use one, as it is faster to tie than a rethreaded figure-eight. I've also used it in situations where I was low on rope, because it uses up considerably less rope than a figure-eight. And to tie around trees near the base or at a branch (where I don't need wraps to prevent it from slipping down), if I judge the usefulness of the releasability of the tensionless hitch to be negligible.

Whenever an easily untied knot is desired, the bowline is a choice to consider. So if an anchor system already exists and you are clipping a rope to it, usually a figure-eight on a bight would be used, but if it's necessary to be able to untie it quickly, a bowline would likely be preferable. There are situations in caving where it useful to belay someone, too (e.g. ladders, some climbs), in which case they will likely have to tie into the rope, so you can tie in with a bowline or clip a bowline to your harness.

If you don't have a harness and it won't be necessary to hang in place, you can tie a bowline around someone (or, to make it stay in place and break fewer ribs, a bowline on a three-wrap coil, which is actually what rock climbers tied with their manila, hemp, and sisal ropes before the climbing harness was invented). There would be two substantial disadvantages of using a rethreaded figure-eight (or rethreaded figure-eight on a coil) for this: (1) you would have to slide the initial figure-eight knot around to get it right, rather than simply making the minor loop wherever it needs to be, and (2) if you need to get it off fast...well, you know how long it can sometimes take to untie a figure-eight.

You can also tie a bowline on a bight of rope. (There's a knot called the "bowline on a bight", but ironically that knot is not a bowline tied on a bight.) This is called the triple bowline on a bight (because it has three loops in total--the major loop becomes two loops and the tail becomes one loop) or the double bowline on a bight (I don't know why it's called that). This is primarily useful for tying around an anchor (such as a tree or metal bar) in the middle of the rope. If the Yosemite finish is used as the "extension for security" then there is a loop to clip into at the anchor. The triple bowline on a bight is also an ideal knot if you wish to rig a (statically "equalized") load-sharing anchor with the rope from three bolts (or other protection to which you can clip carabiners). The loops are easily adjustable. This knot used to be popular with rescuers for tying emergency harnesses (a waist loop and two leg loops), but I believe that's no longer common.

There is also a double-loop variant of the bowline--this is the knot (albeit incorrectly) referred two as the "bowline on a bight." (For disambiguation, I sometimes refer to this as the "two-loop bowline on a bight" and to the triple bowline on a bight as the "three-loop bowline on a bight.") The bowline on a bight is to the bowline as the double figure-eight on a bight is to the figure-eight on a bight (and fittingly, the double-figure eight on a bight is not actually some other knot tied "on a bight" either--both are tied *with* a bight though, and thus can be tied anywhere). The bowline on a bight is harder to tighten down than the double figure-eight, and there's a point where the two loops rub together and could abrade. But it's faster to tie, hugely faster to adjust (to get tension on both loops, limiting extension and possibly producing some degree of equalization), and takes up WAY less rope than a double figure-eight. The preferred way to clip into a double anchor with a cowstail is to clip the cowstail carabiner into both loops of the double loop knot, minimizing extension in the event that one of the anchors fails while you're clipped to it. This is easier to do with a bowline on a bight than with a double figure eight because the loops cross. The double figure-eight and the bowline on a bight are the two most accepted knots for rigging off of two bolts.

The bowline on a bight is actually a bowline with the tail run around parallel to the major loop and then followed back through the knot to meet the standing end. General consensus is that (unlike the bowline) it does not need to be backed up. If you have two fixed anchors--say, two smallish trees that you want to rig off of--then you can actually tie it around them. I have yet to rig this way for vertical caving, but I have rigged toprope anchors this way.

I know people who never, ever use the bowline when vertical caving. But I find it quite useful.

Are you reading On Rope, 2nd Edition? That is the most current edition.
Last edited by ek on Jan 1, 2009 12:07 pm, edited 3 times in total.
Eliah Kagan
NSS 57892
Syracuse University Outing Club

Fund vital White Nose Syndrome research--donate to the NSS and select the WNS Rapid Response Fund.
Facebook users can also donate here.
User avatar
ek
NSS Hall Of Fame Poster
 
Posts: 1040
Joined: Apr 3, 2007 2:45 am
Location: Syracuse, NY
Name: Eliah Kagan
NSS #: 57892
Primary Grotto Affiliation: Syracuse University Outing Club
  

Re: Bowline Extensions for Security

Postby knudeNoggin » Jan 1, 2009 2:57 am

ek wrote:You are unable to make the single overhand stopper and Yosemite finishes work on a climbing (i.e. dynamic, i.e. high stretch) rope?
The standard for these types of ropes stipulates a required "knottability" which is better than that of most semi-static ropes of similar thickness. I am extremely surprised that I am able to easily cinch down a knot in 11mm cave rope which you are unable to cinch down in 11mm climbing rope.
Is it possible that your 11mm climbing rope is actually 11.5mm and quite old?

Possible, yes. And in the dynamic, although it can make the bend, it just wants to and CAN
un-bend/loosen, with its firm roundness & smooth/fine/slick sheath. The PMI, though, also
old (but little worn), doesn't begin to make the bend! "In your dreams!" it screams.

knudeNoggin wrote:I should point out--and hope to see illustrated in the (yet just updated!) pdf file
cited in the OP--that there is a Yosemite-like finish which sounds as though ...:
if you don't get the whole cross-under then over-under-and-through thing just right
- you fail the test. Even if it may "look right" at first glance.

I just want to point out that you're quoting NZcaver here--I did not say that.

I'm an equal-opportunity quoter; NZ hailed from another year--the future--, briefly!

Regardless of whether or not doing the Yosemite bowline "wrong" produces an acceptable knot
(or even one superior in stability), there are three problems with it, the first two of which are quite substantial:
(1) It's not gone through real world testing, nor has it gone through lab testing. We know the Yosemite bowline works.
(2) It looks jumbled when tied. It would be very hard to know for sure that it is tied correctly....
(3) It uses a bit more rope, whereas the Yosemite bowline uses very little extra rope.


??? You talk as if you know the knot to which I refer, and yet your remarks belie that,
for the most objective aspect--#3--is clearly wrong, as the version I'm talking about
takes the end only 180 around an eye-leg and YoBowl wraps 360 (with space, if not
adequately flexible). And there's no "jumbled" look, either.
As for lab testing, I haven't seen much of that for the Yosemite that comes to mind,
but I've no trouble trusting this other version irrespective of a lab test; we're talking
about issues of security, anyway, and there isn't a lab test for that (though I'm thinking
that there SHOULD/could be--some uniform back'n'forth shaking of eyeknots tied to
a bar, where largely it would be a binary (pass/fail) grading).
To re-state this simpler knot: vice the YoBowl's turning the end X-wise around the
end-side eye-leg and then tuck it out through the collar beside the mainline,
take the end ANTI-X-wise around the leg & out. Quicker, simpler, millimeters less rope (!),
and better able to be hauled tight (the end part alone, which has an Overhand form.

Incidentally, if the collar (where br're rabbit runs "around-the-tree") is a full,
"round turn", you get excellent grip on the Yosemite-tucked end.

knudeNoggin wrote:this might be what's going on here (and should get bonus points, not failure!).
(Btw, I must emphasize that in MOST PRESENTATIONS, THE BOWLINE IS SHOWN
FROM THE WRONG PERSPECTIVE (for understanding its structure, and esp. for
understanding the various extensions to secure the structure; and even for the
better orientation of the quick-tie method of forming the knot's central loop).
The "front" perspective in the pdf should improve understanding & recognition,
a LOT.)

Good point. For the "landlubber" method, the common view is preferable for a student to follow and
verify correct tying. For actually seeing how the knot works, the other side makes more sense.


I don't buy this: seeing correctness and the knot's working go hand'n'hand.
The trickiest part to see (of such a simple marriage of a bight & loop!) is the crossing
that the mainline makes in forming the loop; the in-&-u-turn bight part is easily
understood and perceived. And, again, beyond that, all the interesting extenstion
stuff is going to happen in the proper "front" side, pretty much.

The quick-tie method of taking the end and reaching across the mainline then
back into the space that will become the eye-space and continuing the motion
to cast the central nipping loop into the mainline has also be presented wrong-headedly:
doing it by reaching OVER the mainline leaves it crossing UNDER in closing the loop
and so it will fall away unless somehow supported, if one is tying the eye around
oneself (where the non-moving hand grips the mainline's side of the eye);
whereas reaching up under the mainline and ... will leave the mainline resting
against itself (if one is in a normal upright orientation to gravity, etc.).

I think we have different ideas about what is "recognizable."


I think you're too long at the Yosemite alter! Old is more familiar than new,
but the symmetry and simplicity of some other versions are plenty recognizable
(and what passes for a Fig.8 often is different one case to the next, each of
which gets *recognized* as okay--indeed, there was a rather comical case in
which RescueMan adamantly insisted on one image of a Fig.8 being wrong
even after my insistence to the contrary, and only some posts later wast its
form *recognized*. I'm pretty sure I can marry a Fig.8 & Overhand form to
pass the average recognize-the-Fig.8 test by most of those who think they
know-it-when-they-see-it. Heck, it'll look BETTER than some bona fide 8s!

knudeNoggin wrote:I'm waiting to hear a rationale for why the Cowboy Bowline is unacceptable that stands up.

... On the other hand, the common bowline ... seems to resist capsizing
when the tail is pulled better than the Cowboy bowline ... .


I think that it's a leg that's being pulled when this supposed failure
vulnerability is brought up--a tall tale. How is this supposed to occur?
(In some scenario one might imagine that the knot reties itself after
capsizing into a Marlinespike hitch to the tail when the tail's released
--it is one of the Bowline's given tying methods, anyway.) But, we are
going to secure the knot somehow, so this is academic.
The Cowboy bowline better resists the sort of capsizing that does occur (in such
frequency that I wonder if it's desired!?) in mooring lines I've examined. (Which
could be worked into the "Dutch marine" myth somehow, but ... .)
((I'll see what I can find re the Nederlander's account.))

You'll have to show me some historical evidence, though, to get me to believe
that the term "left-handed bowline" is based on the notion that left-handed people
are inferior.

Ashley's glossary so defines it, as perverse or somehow out of the accepted way.
Beyond that, Occam's Razor cuts differently for me, without so much conjecture
about a foundation of particular knot orientation! (When you go a few paragraph's
deep and bring in mathematical coordinates, you have Occam upside-down. :rofl: )

Just make sure that both the minor loop and major loop are tied in the same way.
If they're different then what you get is a non-bowline that, ...


I call thus an "anti- bowline; there are some interesting, quite decent ones,
but we'll leave them aside for now. (Just realized one of the mooring line capsized
knots was one--a Buntline Hitch, e.g.: haul the hitch into straightness to see what
it puts into the mainline, and that is a fully symmetric anti-bowline, which is nice
to look at and esp. if the end gets seized, but isn't so great otherwise.)

(As a side note, the double overhand stopper is not secure in all applications.

Nor is a bowline: also in Spectra, but pure 12-strand, the end needed to be stoppered,
after which it was found to break at about 33% tensile strength! (Amsteel Blue)

*kN*
knudeNoggin
Prolific Poster
 
Posts: 189
Joined: Mar 4, 2006 4:48 pm
Location: Falls Church, Virginia, USA
  

Re: Bowline Extensions for Security

Postby ek » Jan 1, 2009 5:20 am

EDIT: There's one paragraph in this post that verges on being off-topic. I want to retain it because it's germane to the discussion, but I have moved it to the end and demoted it to the status of a footnote, so that any replies to it will more likely also be more separated from the other lines of discussion.

knudeNoggin wrote:The PMI, though, also old (but little worn), doesn't begin to make the bend! "In your dreams!" it screams.

That seems rather inconsistent with the hundreds of these bowlines tied in thick PMI ropes every day. Or when you say "doesn't begin to make the bend," do you simply mean that the Yosemite finish doesn't touch the rope it's tied around for the whole turn?

With thicker rope, it doesn't. So what?

Over a lot of use over time on thick, slippery rope the tail of the Yosemite bowline will begin to work itself back up. Again, so what? Water knots in webbing are known to slip through very slowly too...we haven't stopped tying those, though.

knudeNoggin wrote:
Regardless of whether or not doing the Yosemite bowline "wrong" produces an acceptable knot
(or even one superior in stability), there are three problems with it, the first two of which are quite substantial:
(1) It's not gone through real world testing, nor has it gone through lab testing. We know the Yosemite bowline works.
(2) It looks jumbled when tied. It would be very hard to know for sure that it is tied correctly....
(3) It uses a bit more rope, whereas the Yosemite bowline uses very little extra rope.

??? You talk as if you know the knot to which I refer, and yet your remarks belie that,
for the most objective aspect--#3--is clearly wrong, as the version I'm talking about
takes the end only 180 around an eye-leg and YoBowl wraps 360 (with space, if not
adequately flexible).

When I tried tying it on 11mm Sterling SuperStatic, I found that it took more rope than a Yosemite bowline. The downward turn that the tail takes could not be cinched down nearly as well as the Yosemite finish could. The Yosemite finish had more friction associated with it, which held it tight once I cinched it down. Perhaps I am thinking of a different knot from the one you're thinking of. I'm thinking of tying a bowline, wrapping the tail the opposite way from which you'd wrap it in a Yosemite bowline, but (unlike in the Yosemite bowline) wrapping it around only a very small angle until it can be pushed down through the body of the knot to follow the standing end.

When I tie this now with supple dynamic rope, I find as you do that it takes up less rope than the Yosemite bowline.

I don't agree that #3 is the most objective aspect. I have just discovered that it depends on the cordage. I think it's quite objectively verifiable that more people have used the Yosemite bowline than the bowline to which you refer.

knudeNoggin wrote:And there's no "jumbled" look, either.

I'm holding them both in front of me right now (tied in supple dynamic rope), and the Yosemite bowline looks a lot less jumbled than the alternative knot we're discussing. Do you have a camera? Can you post pictures of a Yosemite bowline, and this knot, side-by-side? You could even do a poll about which looks more "jumbled," though the possibility that I am partial to the Yosemite bowline due to my having used it for a long time is a good point, and that phenomenon generalized might skew a poll too.

This would also address the possibility that we are not talking about the same knot.

knudeNoggin wrote:As for lab testing, I haven't seen much of that for the Yosemite that comes to mind,

My understanding is that Dave Merchant tested the Yosemite bowline to substantiate his claim that it is slightly weaker than the Yosemite mountaineering bowline. He tested (and published strength figures on) the Yosemite mountaineering bowline, which was the only bowline he recommended be used for rescue rigging. (I don't know anybody who agrees with him on that, but his testing procedures were sound.) Granted, I cannot name another test of it offhand...though I think I remembered some earlier ones... In any case, one test is inconclusive.

As you say of the alternative knot you're championing, I have no trouble trusting the Yosemite bowline without a lab test. This is not for any theoretical reason, but rather because it has seen and continually sees such a high level of real-world use, and all without incident.

knudeNoggin wrote:but I've no trouble trusting this other version irrespective of a lab test; we're talking
about issues of security, anyway,

I should have been more explicit, because I am not just talking about security/stability. We're talking about new and different knots, with potentially quite different properties. It's worth knowing what happens when you load them heavily in a single event, before trusting your life and the lives of others to them.

knudeNoggin wrote:and there isn't a lab test for that (though I'm thinking
that there SHOULD/could be--some uniform back'n'forth shaking of eyeknots tied to
a bar, where largely it would be a binary (pass/fail) grading).

I thought there had been lab testing of bowlines, to artificially induce the tail-slipping-through failure mode. In any case, there has been lab testing of the stability of other knots, such as when the water knot was tested by cyclic loading.

knudeNoggin wrote:The quick-tie method of taking the end and reaching across the mainline then
back into the space that will become the eye-space and continuing the motion
to cast the central nipping loop into the mainline has also be presented wrong-headedly:
doing it by reaching OVER the mainline leaves it crossing UNDER in closing the loop
and so it will fall away unless somehow supported, if one is tying the eye around
oneself (where the non-moving hand grips the mainline's side of the eye);
whereas reaching up under the mainline and ... will leave the mainline resting
against itself (if one is in a normal upright orientation to gravity, etc.).

Good point--come to think of it, I've experienced this drawback of the more commonly presented way of tying it myself.

knudeNoggin wrote:
I think we have different ideas about what is "recognizable."

I think you're too long at the Yosemite alter! Old is more familiar than new,
but the symmetry and simplicity of some other versions are plenty recognizable
(and what passes for a Fig.8 often is different one case to the next, each of
which gets *recognized* as okay--indeed, there was a rather comical case in
which RescueMan adamantly insisted on one image of a Fig.8 being wrong
even after my insistence to the contrary, and only some posts later wast its
form *recognized*. I'm pretty sure I can marry a Fig.8 & Overhand form to
pass the average recognize-the-Fig.8 test by most of those who think they
know-it-when-they-see-it. Heck, it'll look BETTER than some bona fide 8s!

A "poorly" (i.e. nonstandardly) dressed figure eight sometimes looks wrong to some people even when tied correctly. It's quite another thing to say that something that isn't a figure-eight would likely be recognized by an experienced rope technician as a figure-eight. Can you show me, or at least explain, the hybrid knot you're thinking of? Is it something that anybody would likely tie by accident when intending to tie a figure-eight?

knudeNoggin wrote:
knudeNoggin wrote:I'm waiting to hear a rationale for why the Cowboy Bowline is unacceptable that stands up.

... On the other hand, the common bowline ... seems to resist capsizing
when the tail is pulled better than the Cowboy bowline ... .

I think that it's a leg that's being pulled when this supposed failure
vulnerability is brought up--a tall tale. How is this supposed to occur?

Pull on the tail and see for yourself!

Or do you mean, how would the tail ever be pulled in a real-world situation? Someone might reach out and grab hold of it, I suppose. This might seem unlikely for a bowline but for a Cowboy bowline the tail is also more exposed, being on the outside of the major loop rather than the inside. It does seem that resistance to ring-loading is more important. And as you say, we add safety extensions to these knots when using them for life-support, so who cares.

knudeNoggin wrote:
You'll have to show me some historical evidence, though, to get me to believe
that the term "left-handed bowline" is based on the notion that left-handed people
are inferior.

Ashley's glossary so defines it, as perverse or somehow out of the accepted way.

You have on your side a respected (though dated) knot authority. I was not aware that Ashley had said that. On the other hand, I have on my side an extremely simple explanation.

knudeNoggin wrote:Beyond that, Occam's Razor cuts differently for me, without so much conjecture
about a foundation of particular knot orientation! (When you go a few paragraph's
deep and bring in mathematical coordinates, you have Occam upside-down. :rofl: )

It bothers me that you conflate my extremely simple explanation for the name "left-handed bowline"--i.e. that when you look at the knot in the way it is depicted in the vast majority of sources discussing it, the tail is on the left side--with my conjecture as to why it happens to be that the knot is depicted in this way. My suggestion as to why the knot is depicted in this way (which we agree is not an ideal way to show it) does not need to be accepted before using as a premise of my argument that it is depicted that way. We agree that it is most often depicted that way. My ruminations about the centrality of counterclockwise-and-up in Western thought are indeed complex and not in a state where they can justifiably be accepted with anything approaching certainty. They are also not in any way part of my argument. They can be entirely ignored and my one sentence case still holds that blaming the term "left-handed bowline" on moral prejudice against left-handed people is needlessly complex to the point of silliness.

On the other hand, if there is evidence that the term "left-handed bowline" has been in use longer than the current faulty presentation of bowlines has been popular (if indeed there has ever been a time when this faulty presentation has not plagued us), then this would refute my simpler explanation and make way for your more complex explanation.[1]

knudeNoggin wrote:
Just make sure that both the minor loop and major loop are tied in the same way.
If they're different then what you get is a non-bowline that, ...

I call thus an "anti- bowline; there are some interesting, quite decent ones,
but we'll leave them aside for now. (Just realized one of the mooring line capsized
knots was one--a Buntline Hitch, e.g.: haul the hitch into straightness to see what
it puts into the mainline, and that is a fully symmetric anti-bowline, which is nice
to look at and esp. if the end gets seized, but isn't so great otherwise.)

I'm not sure I understand what you're saying here. I had previously thought that the knots you referred to as anti-bowlines were what you see when you hold a bowline up to a mirror. Do you rather use the term anti-bowline to refer to knots of a totally different and often unstable structure?

knudeNoggin wrote:
(As a side note, the double overhand stopper is not secure in all applications.

Nor is a bowline: also in Spectra, but pure 12-strand, the end needed to be stoppered,
after which it was found to break at about 33% tensile strength! (Amsteel Blue)

Well then, that suggests that once stoppered it's secure...just perhaps not strong enough.

What did they stopper it with in the test? Was a single overhand stopper sufficient in Spectra?

My spectra footloop (which actually is double-braid construction rather than kernmantle) is tied to my upper ascender with a Yosemite bowline further stoppered by a triple overhand. I figured that since the triple fisherman is the recommended knot for joining ends of Spectra cord that it would be a better choice here. But perhaps this is overkill.

[1] If it turns out that you're right and prejudice against left-handed people is the foundation of the term "left-handed bowline," then benefit would be achieved by recognizing and understand that, but I don't think that would be a good reason to stop using that term. I think we already have a good reason not to call it the "left-handed bowline"--specifically, that it makes it likely to confuse it with the isometric mirror image of the standard bowline (the knot you see when you hold a standard bowline in a mirror). This is why I have recently myself begun substituting "cowboy" for "left-handed." But I think that understanding and recognizing how our language has been a representation of and a vehicle for oppressive ideas (and oppressive constraints on ideation) enables us to maintain the language as a form of documentation for that oppression, a tool for us to remember and resist it. We would have to change a lot of words if we were, for instance, to try to rid English terms based in misogyny. And removing from a language all signs of past oppression would conceal the continued nature of much of it and would constitute a form of complicit silence. (If the push for more gender-neutrality in English--the unpopularization of generalized use of male pronouns--has yielded social good, it has done so because it is awkward, because it requires us to realize the degree to which the language associates masculinity with primacy. Actually removing all traces of prejudice from the language would accomplish nothing.)
Eliah Kagan
NSS 57892
Syracuse University Outing Club

Fund vital White Nose Syndrome research--donate to the NSS and select the WNS Rapid Response Fund.
Facebook users can also donate here.
User avatar
ek
NSS Hall Of Fame Poster
 
Posts: 1040
Joined: Apr 3, 2007 2:45 am
Location: Syracuse, NY
Name: Eliah Kagan
NSS #: 57892
Primary Grotto Affiliation: Syracuse University Outing Club
  

Re: Bowline Extensions for Security

Postby NZcaver » Jan 1, 2009 10:36 am

knudeNoggin wrote:
I don't recall the double overhand stopper finish ever being taught or shown in NCRC literature


The Strangle knot--which is a dbl.oh. of a particular orientation, that most familiar
here--is likely going to be known via the Grapevine Bend (aka "Dbl. Fisherman's knot"),
and should be common knowledge...

I should clarify my previous statement:

"I don't recall the double overhand stopper finish specifically used with the Bowline ever being taught or shown in NCRC literature."

As you can imagine, the Double Fishermans/Grapevine knot itself is a staple of the NCRC diet.
User avatar
NZcaver
Global Moderator
 
Posts: 6316
Joined: Sep 7, 2005 2:05 am
Location: Anchorage, Alaska
Name: Jansen
NSS #: 50665RL
Primary Grotto Affiliation: CCG
  

Next

Return to On Rope!

Who is online

Users browsing this forum: No registered users