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patto


May 14, 2012, 7:36 PM
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I too have seen little evidence of clove hitches in single dynamic lead ropes slipping.

However clove hitches have far less margin for error than other knots. Its not something that I would want to put to the test.

On a wet, glazed, icy, chalked up, old, stiff or new fresh rope you could suddenly find that clove hitches do slip. Smile


majid_sabet


May 14, 2012, 10:47 PM
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Observations Of The Clove Hitch
Observations by David Lane (PCGI Technical Director) & Zeke Federman (PCGI Secretary of the Board)

Over the past 12 months, we have experienced alot of guides coming to PCGI courses with some pre-conceived
and/or perhaps previously learned concepts. For example, we have heard many students saying things such as
"you can break a carabiner if you tie the clove hitch with the load on the gate side of a biner "or "you can't tie the
clove hitch with the load on the gate side of a biner, or the hitch will fail".

After hearing these types of comments from many different students from across the USA, PCGI Technical Director
Dave Lane decided it was time to observe how the clove hitch reacts when tied with the load strand oriented on the
spine side of the carabiner vs. the load strand oriented on the mouth/gate side of the carabiner. For these
observations, we chose to use a static pull test machine @ Yates Gear, with John Yates on the controls. We choose
this form of rope and carabiner abuse because it creates a constant and consistent load, hence creating harsh load
observation conditions. We also chose to convert, discuss and display the Kn/pounds of force measurement into
terms of actual pounds/LBS. This was done for simplification of reading and explanation purposes. The
observations as depicted in the chart at the bottom of this page suggest that it is more of a tie breaker type
situation when tying the clove hitch in spine side vs. mouth side load configurations, as the point of rope
failure/breaking and the point of the ropes slipping, were so close in terms of load, that we continue to think that it
probably really does NOT really matter which way you orientate the load strand when tying a clove hitch. It also
appeared to be impossible in these specific situations to break the carabiner before the rope breaks. We performed
many/multiple observations and also found that the variance between multiple observations was minimal and
ranged between 200-400 pounds of force difference per observation. We also operated under the obvious
understanding that if we applied a dynamic load, the load would obviously dissipate when the falling climber stops,
as compared to the static pull load machine which has the capability of loading ropes constantly. We would also like
to point out that if you load the rope, carabiner and clove hitch to the pounds of force we applied, you will find that
if you orientate the load on the spine, the rope will ultimately break every time (not the carabiner!) and if you load
it on the mouth side of the carabiner the rope will ultimately slip every time and interestingly enough, it seems to
slip at very close numbers to where the rope actually breaks
. This is where we developed what we referred to as
the "take your pick" position. In other words, you decide, would you rather have, for example, your 10mm rope
that is tied off with a clove hitch break at around roughly 2600-3000 pounds of force or slip at around roughly
2600-3000 pounds of force. We don't think you should let anyone decide that for you. We encourage you to decide
on your own terms, but in dynamic climbing load/fall situations, we are betting most of you folks would probably
choose slipping over definitive breaking of ropes!

Furthermore, in a fixed line scenario with a clove hitch being subjected to a dynamic climbing load/fall, as long as
you leave at least two feet of slack in the end/non load bearing side of the rope, from what we simply observed, it
would seem to be impossible to find the end of the rope slipping/pulling through that several extra feet of rope! It
is also important to note that if you tie a figure eight on a bite into a 10mm rope instead of a clove hitch, as we
observed in other observations (and as many other people have as well and have clearly documented this fact in
many common climbing anchor and knots books) that the breaking point of a rope with a figure eight on a bite tied
into it is roughly 10-15% higher compared to the strength of the rope with a clove hitch tied into it. This means in
the average 10mm rope, you would get about/roughly 260-390 pounds of force more strength out of that rope if
you tied a figure eight on a bite into it compared to a clove hitch. Obviously, the clove hitch is making the rope
weaker compared to the figure eight on the bite, and that is good to know, but in climbing load terms, most people
will probably agree, with that amount of strength difference, the percentage of pounds of force difference is fairly
inconsequential.

PCGI encourages free thinking and open dialogue in its courses, assessments and within the rock climbing guide
community. This article and observations expressed within it are not intended to be "the answer" to this topic.
Rather, this article is intended to be food for thought on the educational frontier!

We hope you found this issue of PCGI Technical E-News interesting, thought provoking and educational at heart. If
you liked this article, be on the lookout, we have more technical e-news coming soon! Thanks for opening this
email and reading it!


Disclaimer: The following graph and above information is not to be deemed definitive and are not "tests". Errors
and Omissions may exist. By reading this information you acknowledge this article and graph are not to be used as
definitive resources and may not apply in the field of rock climbing. Readers agree to hold PCGI and its staff and/or
volunteers harmless.

http://www.climbingguidesinstitute.org/...-the-clove-hitch.pdf


patto


May 14, 2012, 11:17 PM
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Re: [majid_sabet] Equalette variation knots [In reply to]
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I'm sorry but what are you trying to say here by posting that big hunk of unformatted and hard to read text?

If anything it seems to be supporting a contention opposite of what you advocated earlier. But since you haven't actually said anything we can only guess at what you are trying to say. Crazy


majid_sabet


May 14, 2012, 11:50 PM
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patto wrote:
I'm sorry but what are you trying to say here by posting that big hunk of unformatted and hard to read text?

If anything it seems to be supporting a contention opposite of what you advocated earlier. But since you haven't actually said anything we can only guess at what you are trying to say. Crazy


read the article

Obviously, the clove hitch is making the rope
weaker compared to the figure eight on the bite, and that is good to know


patto


May 14, 2012, 11:54 PM
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majid_sabet wrote:
Obviously, the clove hitch is making the rope weaker compared to the figure eight on the bite, and that is good to know

Weakening the rope by 10-15% in not a concern of mine.


JimTitt


May 15, 2012, 12:59 AM
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majid_sabet wrote:
patto wrote:
I'm sorry but what are you trying to say here by posting that big hunk of unformatted and hard to read text?

If anything it seems to be supporting a contention opposite of what you advocated earlier. But since you haven't actually said anything we can only guess at what you are trying to say. Crazy


read the article

Obviously, the clove hitch is making the rope
weaker compared to the figure eight on the bite, and that is good to know

Since this was already well known it doesn´t seem particularly useful especially in the context of building belays where you can´t impose enough force. When you start using clove hitches in thinner materials and dynamically load them as they would be in practice this certainly is a matter of concern.
Building belays with slings used as they are intended to be (without knots) and the climbing rope removes all problems of breakage and potential slip in the hitches.

I´m suprised that a professional (if that´s the right word) body connected with climbing education can´t spell bight properly.


Partner rgold


May 15, 2012, 4:12 AM
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Majid, in those tests, under maximal loading, improperly oriented clove hitches slipped at a bit less than the 400 lbf increment needed to break a rope tied with a figure-8 knot, and the slipping consumed less than two feet of rope. Properly oriented clove hitches didn't slip.

The orientation issue suggests that the shape of the biner probably plays an role in the results.

In any case, there is nothing there that suggests clove hitches aren't fine for climbing applications, and there is even a hint that they might be safer, if they are capable of absorbing energy through a small amount of slippage and thereby avoid breaking.

The slight strength advantage of the figure-8 is deemed "inconsequential," and of course additional loads in an anchor system that might be the byproduct of the figure-8's lack of fine adjustability are not even on the horizon in this study.

Of course, the tests do not address what happens with a double strand of 7mm nylon.


(This post was edited by rgold on May 15, 2012, 4:22 AM)


shockabuku


May 15, 2012, 5:31 AM
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rgold wrote:
Majid, in those tests, under maximal loading, improperly oriented clove hitches slipped at a bit less than the 400 lbf increment needed to break a rope tied with a figure-8 knot, and the slipping consumed less than two feet of rope. Properly oriented clove hitches didn't slip.

The orientation issue suggests that the shape of the biner probably plays an role in the results.

In any case, there is nothing there that suggests clove hitches aren't fine for climbing applications, and there is even a hint that they might be safer, if they are capable of absorbing energy through a small amount of slippage and thereby avoid breaking.

The slight strength advantage of the figure-8 is deemed "inconsequential," and of course additional loads in an anchor system that might be the byproduct of the figure-8's lack of fine adjustability are not even on the horizon in this study.

Of course, the tests do not address what happens with a double strand of 7mm nylon.

Your use of the phrase "properly oriented" (i.e. the orientation that breaks the rope) confuses me. I think I'd rather have my clove hitch slip than the rope break.


Partner rgold


May 15, 2012, 5:44 AM
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Yeah, that is confusing. Perhaps I should have said "conventionally oriented," since conventional wisdom requires the load strand be the strand closest to the spine.

I don't believe that a rope has broken at a knot ever in an actual climbing situation. When tests are performed that break ropes at the knot, the loads imposed can very safely be assumed to exceed any climbing application.

From that perspective, this particular test asserts that clove hitches don't slip, are adequately strong for any climbing application, and it does not matter how they are oriented.

None of this is news, except possibly for the orientation issue. (If you use superlight biners, I'd still pay attention to proper orientation until a definitive test on those items appears.)

As Jim points out, whether we should trust the expertise of experts who can't correctly spell "bight" is a question worth pondering.


Partner drector


May 15, 2012, 8:07 AM
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A figure-8 is not an EDK.

Using a figure-8 where it can be ring loaded is like not using a knot at all. Even an EDK ring loaded as part of an anchor is not so good considering what load it might need to hold.

Dave


JimTitt


May 15, 2012, 8:30 AM
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rgold wrote:
As Jim points out, whether we should trust the expertise of experts who can't correctly spell "bight" is a question worth pondering.

Majid spells it `bite´ and you trust him surely?


majid_sabet


May 15, 2012, 10:25 AM
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rgold wrote:
Yeah, that is confusing. Perhaps I should have said "conventionally oriented," since conventional wisdom requires the load strand be the strand closest to the spine.

I don't believe that a rope has broken at a knot ever in an actual climbing situation. When tests are performed that break ropes at the knot, the loads imposed can very safely be assumed to exceed any climbing application.

From that perspective, this particular test asserts that clove hitches don't slip, are adequately strong for any climbing application, and it does not matter how they are oriented.

None of this is news, except possibly for the orientation issue. (If you use superlight biners, I'd still pay attention to proper orientation until a definitive test on those items appears.)

As Jim points out, whether we should trust the expertise of experts who can't correctly spell "bight" is a question worth pondering.

the million dollar question of the day is this

why even bother using CH with possibility of slippage or wondering if the orientation of biner is correct or its nylon vs 7 mm when you could just simply attach the cord with fig-8 or other alternative knots?

if CH is used as an habit or convenience, then its understandable but claiming that this system is superior or its safer, I just don't personally buy it


(This post was edited by majid_sabet on May 15, 2012, 10:27 AM)


patto


May 15, 2012, 1:17 PM
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majid_sabet wrote:
the million dollar question of the day is this

why even bother using CH with possibility of slippage or wondering if the orientation of biner is correct or its nylon vs 7 mm when you could just simply attach the cord with fig-8 or other alternative knots?

if CH is used as an habit or convenience, then its understandable but claiming that this system is superior or its safer, I just don't personally buy it

Nobody here is claiming the system pictured is superior or safer. In fact the people you are debating this with have all mentioned their reservations about the use of an "equalette".

As far as clove hitches go I do use them in 90% of anchors I build. They are in 10mm rope with no free end. I use them because they are FAST and easy to adjust thus they save time.

The benefits of clove hitches to me are real and tangible. The strength reduction is absolutely not relevant, my pro would likely break before the rope would.


blondgecko
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May 15, 2012, 8:59 PM
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Re: [Rob.hack] Equalette variation knots [In reply to]
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Rob.hack wrote:
I was reading through this article on a variation of the standard equalette, it included the photo below.



There are two types of knot shown in the photograph that I have not come across before. Clove hitches tied with a bight and overhand knots on three pieces of cord.

Would anyone care to comment on the suitability of either of the knots?

Have any strength tests been conducted on either knot?

Were they both to prove adequate, I could see the system being a viable alternative to the traditional equalette, providing an easily accessed power point in which following climbers could clip into and a quicker and more easily adjustable method of tying one side of the equalette into a single piece of protection than tying a overhand on a bight or figure eight on a bight.

Thanks in advance.

Rob

Simplify this down to its essence: take an 8-foot sling, bar-tack together a 1-2 foot section in the middle and tack on (with 18+kN bar tacks) a differently-coloured section to close the oh-fuck loop, and you might have something that's worth carrying on the rack. Simple, light, fast and damned difficult to screw up.


JimTitt


May 15, 2012, 11:59 PM
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You´ll find producing 18kN+ bar tacks a bit of a challenge though which is why commercially you have to sew a ring and then the sling to that.


blondgecko
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May 16, 2012, 1:29 AM
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Well, I'm no expert on sling manufacture, so I'll defer to you on that. But, what the design pictured in the OP boils down to is a loop with sufficient strength to ensure it won't be the failure point, fused to a couple of tails for connection to the anchor. If something like that was properly manufactured it would be lightweight, versatile and foolproof enough to be a useful addition to a rack. The version tied out of cord, though... I'll stick to existing methods.


Partner rgold


May 16, 2012, 9:35 AM
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BG, if you read to the end of the article, you'd see this:




blondgecko
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rgold wrote:
BG, if you read to the end of the article, you'd see this:

[img]http://gsm.org.es/gsm/wp-content/subidas/2010/10/640_Tecnica6.jpg[/img]

In my case it'd be "if you looked at the pictures to the end of the article...". I'm an Aussie. My Spanish extends only as far as recognising that something is in Spanish.

But I see your point. Blush


knudenoggin


May 27, 2012, 12:22 PM
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Rob.hack wrote:
There are two types of knot shown in the photograph that I have not come across before. Clove hitches tied with a bight and overhand knots on three pieces of cord.

Would anyone care to comment on the suitability of either of the knots?

Have any strength tests been conducted on either knot?

In short, while the knots should be adequate, there is much about
them --and whatever particular conditions (i.e., cordage, tying) of use--
that is unknown.

I was struck by the orientation of the clove hitches putting the
TWO load strands towards the gate --despite some evidence given
here that that's okay (and arguably preferable : slippage vs. breakage)--;
we don't have any clear testing of this particular configuration.
(I don't know if the article speaks to this point, or if it's just some
circumstance left unexplained.) Of other cases, it's worth noting
the set of references RGold presented (he's great to have around,
in addition to those wonderful pretzels! Tongue ) among Searchable
threads on this:
http://www.rockclimbing.com/...ove%20hitch;#2352976

Esp. interesting is the point-blank contradiction to away-from-spine
loading given by
http://www.guidetricksforclimbers.com/cloveHitch.art.html
--to wit:
In reply to:
• slow static pull was used rather than a dynamic load
WORTH NOTING THIS, IMO --NOT **DYNAMIC LOADING** !

ACK, also worth noting: "An HMS style carabiner was used" --boo.

In reply to:
When the knot was tied incorrectly, with the load strand farthest ...
CAN WE TRUST SOMEONE W/EITHER BAD COUNTING OR GRAMMAR
ISSUES WHO MISSES "FARTHER" (at least it's not "furthe..."!) ?
In reply to:
... away from the spine of the carabiner, it was found that the knot tried to align itself with the spine at 250 lbs., and carabiner failure occurred–before rope breakage–at approximately 38% below the carabiner's rated strength.
EGADZ, WOULD IT SO TERRIBLY INCONVENIENCE THEM
TO GIVE SOME ABSOLUTE DATA HERE, VS % OF UNKNOWN ???!
In reply to:
Incorrect tying of the knot will result in substantial loss of carabiner strength. This fact is little appreciated by most users of the clove hitch. The UIAA recommends use of the Munter Hitch in the same configuration with load next to the spine to maintain carabiner strength, but the clove seems to have been ignored to date. Bill Griggers of Bluewater considers incorrectly tied clove hitches to be of far more concern than rope slippage or melting, and all users, professional and recreational, would be advised to note this and to tie the knot correctly. Incorrectly tied, carabiner failure becomes a real possibility.
HEARSAY RE BW SUGGESTING THERE MIGHT BE FURTHER DATA
SUPPORTING THIS ASSERTION (which isn't = data itself!).
In reply to:
Strength of the knot varies between 63% and 77% of the static breaking strength of new rope (compare this to 75%-80% for a figure eight and 60% for a bowline), with thinnest rope having the highest percentage. This is attributable to the greater difference between the size of the rope and the object around which it is tied.
AND IN THE PRESENT CASE, WE'RE LOOKING AT WELL THINNER
"CORD" (possibly of a "static"/=>"low elongation" nature
(but such product information (stretch) is hard to find, alas)).

RGold refers to some testing showing slippage in "static" ropes;
that was from a Lyon Equip testing, and what's of special note
to that is not only that all their (5?) low-elongation ropes slipped,
but they did so at widely different forces!! (Their lone dynamic rope
--Beal...-- held to break (10.5mm?).)


"Known unknowns" abound!
"Unknown unknowns" yet to be found.
.:. What makes your decision sound?


The fig.8 eye knots (well, sort of) should have sufficient bulk
of cordage to resist flyping under expected loads, but, here, too,
there can be factors of how the knots are tied and in what materials
and the nature of (dynamic) loading that would make be hesitant
to feel all so sure.

(I'm tempted to muse about other knots here, but find myself
running into issues when loading changes --from the initial form
to a 1-anchor-fails loading, and how angles of incidence of ends
into knots must change, and hence tensions.)

In reply to:
Were they both to prove adequate, I could see the system being a viable alternative to the traditional equalette, providing an easily accessed power point in which following climbers could clip into and a quicker and more easily adjustable method of tying one side of the equalette into a single piece of protection than tying a overhand on a bight or figure eight on a bight.

And you've read others' doubts about this. Frankly, it strikes me
as a too-rigid and somewhat clumsy structure. Especially in contrast
to one I've sketched as an implementation of an "ELET" --2-legged
anchor ("extension-limiting equalization triangle"). It seems to me
that using the common, handy materials of 7mm (twinned) cord
(or other) and a 24"/60cm HMPE (Dyneema, mostly, these days)
tape sling, one gets simplicity, looow friction (for the *equalization*),
and greater flexibility (thinking that UNtying this will be possible,
and so the materials can do other tasks as needed; and the particular
tying --length of legs-- can be set per need, not pre-set & fixed).





Full images (+/- 130kb ; 888pix long side):

http://s14.postimage.org/...ord_sling_M888_1.jpg

http://s13.postimage.org/...ord_sling_M888_2.jpg


These have yet to meet a test device, but seem sound IMO.

*kN*

ps: gratuitous pokes for fun
"PCGI encourages free thinking and open dialogue"
and apparently this applies to spelleen, tu !
'caribiner', 'carabineer' (for canyoneers?), though mostly 'carabiner';
and then there's the back-formation "orientate".

Crazy Cool

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