Strait Bend Testing?

[Dan Lehman]

Originally Posted by benz

Hi Dan,
I won't insult you by suggesting that you've never done a long series of rappels and thus don't know why the pulled rope alternates--I'll just say that I forgot the discussion was about ropes of different diameters.
//
an alternate pull on each successive rappel makes for maximum eficiency in my opinion.

But you could edify (for all of the readers)!
I still can't imagine why, and will note that it entails ensuring, each time that
the knot is on the proper side of the rap-ring/sling for the altered order.
Or is there some issue with torsion & kinking/rope-handling?
(But, yes, the OP is concerned w/thick-thin ropes.)

If as you suggest the EDK need be backed up by tying the smaller rope around the larger, we no longer have a perfect bend--we have one that requires a back-up and the extra bulk that that entails.

That's just a particular way of seeing this knot as compound or not --one could argue either way. As for bulk, it remains a compact small knot (the added overhand being in the thinner (or more flexible) line, and being half of what has been suggested by one of the above references --of repeating the base knot). And in either of these cases, one at least has a smooth-*flowing* *offset* knot.

To the question of the need for that, and of rope-pulling problems in general, I've seen the on-line discussions garner testimony such as Moyer's that there have been few if any problems (using whatever), and of those that occurred, a different knot wouldn't have mattered. .:. a big "YMMV" situation.

If you have not seen an EDK roll a little as it is weighted, I congratulate you on having partners who draw it up most carefully as they tie it: not all my partners have been so [careful].

But there is something inconsistent with remarking that as simple knot as the EDK cannot be assuredly tied while urging that a rather non-simple Butterfly bend be used instead! To my mind, it is better to retain *extant technology* (here, the overhand) and infuse in its use the purpose of its parts --being offset (and easily/quickly tied), being drawn snug with special focus on the part making the initial choke (where the thinner line should be) which is the line to be tied-off around the other's tail, for surety.

I would not call all the above-named bends novelty knots: most have existed for longer than climbing has been popular, and the climbing world still has much to learn from the sailing and rigging world.

Those I had in mind would be the butterfly & zeppelin end-2-end knots --though the former, in eyeknot form, was known 1928 even in one climbing source and regurgitated by Phil Smith's ca. 1960 book, and the latter seems to have surface ca. 1970 (its history w/airships being doubted), neither has been of much note in any practical application. And, of course, Ashley's quite like knots #1452 & #1408 (and the more slack-secure #1425!) saw daylight of published knots by 1950, but are scarce "in the wild," to my awareness. The cordage of sailing and climbing differs. Sailors have no qualms about using a bowline w/o further precautions; climbers had better add some security!

My favorite bend for rappel ropes is still the Strait Bend, ... it is the one I will always use. Does a nice job with docklines, too.

Ben, why not Ashley's #1452, 1408, 1425 or the zeppelin? It struck me as odd to use the butterfly in a situation when its asymmetry wasn't necessary (for tying) --go for a symmetric knot!
As for butterfly orientations, what looks best to me I think is crossing the tails, where --from the perspective of the knot w/tails UP, standing parts entering with first crossing UNDER their collars --and so then being horizontally parallel--, to have the LOWER line's tail be oriented adjacent to its standing part, the other tail crossing behind it. This makes the lower line's overhand take a *pretzel* form, and the other's a sort of *minimal timber hitch* form. The curvature of both lines into the knot looks good, and it seems to retain the easiest form to untie.

--dl*
====

ps:

... is to lead with two 3/8" ropes ...

Oh, how yesterday !! Hip, modern climbers are much sharper, able to discriminate between fractions of a millimeter --"Would a 9.4mm be okay, or should I carry a heavier 9.8mm ... ?!" !! (Older climbers cannot resolve as fine as even a whole millimeter, let along fractions thereof.)

[benz]

Which knot to use is largely a matter of preference. Why not use the Zeppellin? I have, but prefer the strait bend, esp since many of the old fuddy-duddies I climbed with understood the Alpine Butterfly it is similar to.
The EDK will be a hard sell on this forum among us cordage geeks who love a fair entry and symmetry in a bend. While the EDK may be suitable for some people, simple enough and all that, it isn't pretty, therefore it is unseamanlike, therefore we reject it. Stupid reasons? perhaps, but remember that we are geeks (and I'm probably the least geeky among them).
When rappelling with same-sized ropes, you are feeding the 'pull' rope through the rap rings you are at while pulling it to retrieve the other rope from the rings above. That way when the other rope falls free, the next rappel is ready to go. So (because of which side of the rap rings the bend is on), the alternate rope is the 'pull' rope. The bend is alternately on one side of the rings or the other, so there's no need to untie and re-tie to get the bend on the 'proper' side of the rings, like there is with different diameter ropes.
Would it be proper to note the incongruity in today's youth with being able to split millimeters and not being able to understand a proper bend? Perhaps, as I've always suspected, use of the Metric system kills brain cells.

[benz]

Which knot to use is largely a matter of preference. Why not use the Zeppellin? I have, but prefer the strait bend, esp since many of the old fuddy-duddies I climbed with understood the Alpine Butterfly it is similar to.
The EDK will be a hard sell on this forum among us cordage geeks who love a fair entry and symmetry in a bend. While the EDK may be suitable for some people, simple enough and all that, it isn't pretty, therefore it is unseamanlike, therefore we reject it. Stupid reasons? perhaps, but remember that we are geeks (and I'm probably the least geeky among them).
When rappelling with same-sized ropes, you are feeding the 'pull' rope through the rap rings you are at while pulling it to retrieve the other rope from the rings above. That way when the other rope falls free, the next rappel is ready to go. So (because of which side of the rap rings the bend is on), the alternate rope is the 'pull' rope. The bend is alternately on one side of the rings or the other, so there's no need to untie and re-tie to get the bend on the 'proper' side of the rings, like there is with different diameter ropes.
Would it be proper to note the incongruity in today's youth with being able to split millimeters and not being able to understand a proper bend? Perhaps, as I've always suspected, use of the Metric system kills brain cells.

[allene]

According to this report LINK, the EDK is just plain dangerous and shows up 3:1 in accident reports even though it is not used by most climbers.

It also talks about the desire to have an asymmetric knot so that the knot can be flat on one side and therefore not get stuck on a ledge. The EDK excels in that regard but the Strait Bend doesn't seem that bad.

But the bottom line is safety and more people are injured from the EDK rolling than from having to go back to free a knot stuck on a ledge.

The article I linked has a pretty good discussion in the EDK.

Allen

[Dan Lehman]

Originally Posted by allene

According to this report LINK, the EDK is just plain dangerous and shows up 3:1 in accident reports even though it is not used by most climbers.

??? ! This is a gross misreading on both accounts : (1) the "EDK" is by consensus
--and w/o further qualification-- the denotation of the offset water knot (overhand)
and of the 4 listed possible knot failures in this article only *1* of them pertains to that
(the others are for the similar, offset fig.8 bend );
(2) I see nowhere a basis for your assertion about knot-use frequency?!
Indeed, one might find an opposite implication in Tom's
> ... is widely used for joining two rappel ropes together.
> Most of the people I know use the [offset]-overhand,
> ...
> I also know that millions of rappels have taken place on these knots without failures.

I forget what some occasional on-line/per-forum polls have shown re usage, but let's
just agree that the OWK (aka "EDK") is used a lot --in pure count of instances--,
regardless of overall proportion, be that a half, a third, a fifth, or whatever.
.:. It has been put to a practical test of usage, by any measure. And there are NOT
(m)any reports of it failing --you can read the one cited by Tom and regard it, as does
the reporter, as dubious in significance (too little is know for sure).

It also talks about the desire to have an asymmetric knot
so that the knot can be flat on one side and therefore not get stuck on a ledge.
The EDK excels in that regard but the Strait Bend doesn't seem that bad.

Better terminology: "offset knot", "knot is offset from the axis of tension", "butterfly
bend". Indeed the butterfly (knots) are asymmetric, but not in the way (mis)used
here, but in pure terms. They are not offset knots and so do not present the pure
ropes strands aligned with the axis of tension that is regarded as beneficial in some
applications; i.p., the collars of the knots encircle the knot. --just having tails exiting
together and perpendicular to the axis of tension isn't a sufficient condition for "offset".

But the bottom line is safety and more people are injured from the EDK rolling than from having to go back to free a knot stuck on a ledge.

Here, again, I see no basis for this assertion from the article. Tom does say that he
has not, as a member of an SAR team, witnessed problems from stuck ropes. (This
is a bit shy of saying that such problems didn't occur; they might have, but simply not
have resulted in a call for SAR --a matter of inconvenience/annoyance w/o rescue need.)
Some of the on-line surveys I've read have had similar personal testimony ("I've used
a grapevine bend for decades w/o ever a stuck rope.", e.g..)

> The article I linked has a pretty good discussion in the EDK.

But a not-so-good illustration of it (as Tom has been advised) : the lighter-grey
tail should be shown exiting on the right/below the darker one (for symmetry and
for security, resistance to flyping). As it is, it has come to a position that loading will
want to draw it to, and which drawing can be resisted by tying off this lighter tail around
the darker one with an overhand or in making a full encircling of the joined lines at
the *throat* of the knot (which greatly inhibits flyping) and thus forming a figure nine
(sort of 1-turn-shy-of stevedore knot ) in that lighter-grey line.

The EDK will be a hard sell on this forum among us cordage geeks who love a fair entry and symmetry in a bend

Which love should make you discard the butterfly bend in favor, perhaps,
of the truly symmetric Ashley's bends #1452 or 1408 ! The asymmetry of the former
was a consequence got from circumstance --tying mid-line, w/o tails--; presented with the
happier condition of using tails, why stay asymmetric?! (But do note my recommended
precise butterfly form described in a separate post above --that does look good!)

you are feeding the 'pull' rope through the rap rings you are at while pulling it
... when the other rope falls free

I thought that this might be what you had in mind. I can see this as okay in instances
of pretty sheer wall & need for such haste, but in some cases I should think that one
would prefer to coil and re-toss the lines out away from the wall in order to ensure a
free fall back into it, vs. risking a dropping of the line straight down into who-knows!
Thanks.


The thrust of my comments here should be understood as this:
knots are too frequently given cursory and inaccurate consideration,
with all sorts of myths echoed. I hope that one can achieve a better
understanding of the knots, here; and that one can see how much has been mis-stated
and misunderstood but yet advanced as popular wisdom.
(Frankly, were it to come to relying on some hastily tied end-2-end joint by someone
with limited appreciation of knotting, I'd feel more assured of an offset water knot
backed by the same, then of the somewhat complex butterfly
(which has one known mis-formation that has led some to seek nominal distinction
between "butterfly" & "Alpine butterfly" !). If ya can't tie knots, tie lots!?
But should an activity countenance such limited knotting knowledge?
--as we might soon see with driving, and vehicles equipped with new-fangled
collision-detection/-warning systems that some might cite in defence of using
cell phones while driving?!)


--dl*
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