Author Topic: Rivet Hangers breaking?  (Read 3983 times)

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Offline *Mucci*

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Rivet Hangers breaking?
« on: June 23, 2014, 11:58:27 am »
In the new Yo Big walls book, under the gear pages in the beginning, it states that "cinch" style rivet hangers "do not hold falls".

Has this been the case in the past?  Any stories that would back up this statement?

Personally, I only use butterfly, or commonly called "cinch" hangers, and occasionally use keyhole and or regular wired hangers.

I make my own hardware with a nicopress tool, nicopress material, and the 7x19 wire.

More than a few falls on my cinch hangers, never a cause for concern, of course they do not last forever, and repetitive use wears down the slide oval eventually.


What was the reasoning behind this statement in the book?  In many cases, a cinch is the only thing that will stay on a dowel, button head, broken rivet etc...

The Cinch has been a long deployed tool of the rivet ladder, just wondering why they were painted in a bad light?

Cheers!

Offline lambone

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Re: Rivet Hangers breaking?
« Reply #1 on: June 23, 2014, 12:52:19 pm »
I know of at least one case where more then one broke in a long fall. It was Kate pitching solo off Tribal Rite. She pulled out a couple rivets and broke a couple cinch hangers as I recall and took a really big fall. Was just talking about it at the bridge with her a couple weeks ago. The story is on Supertopo somewhere.

I still use them though, though I like the beefy ones with #3 gauge wire I think.
« Last Edit: June 23, 2014, 06:00:44 pm by lambone »

Offline mungeclimber

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Re: Rivet Hangers breaking?
« Reply #2 on: June 23, 2014, 12:57:43 pm »
Josh, probably best to post a pic of the rivet hanger you are talking about. The old river hanger I used to call a cinch hanger isn't the more modern double loop style.

Offline *Mucci*

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Re: Rivet Hangers breaking?
« Reply #3 on: June 23, 2014, 01:33:55 pm »


I recall the issue with Kate's hangers were 2 fold:

The one that sent her on that monster winger failed due to a bad swage, then after pulling rivets/dowels out of the wall she was stopped by a similar rivet hanger on a dowel.  She made mention of the failed hanger saying that she should have bounce tested them on the deck.


The ones I show in the photo are of a #2 cable size, 3/32nds and are strong enough to stop 200+ pounder falls, on machine heads that were just placed, and a few other falls on in-situ rivets that were 25 years old.

I make #3 size too, but they are really overkill, and many times will not fit on a well placed machine head, buttonheads typically stick out a bit more and can accept a multitude of hanger options.

One issue with keyhole hangers (moses, RP, vermin) is that they can "torque" the rivet out of the hole in a long fall.  This I have seen first hand while bounce testing, fortunately not in a fall.

If using improper material, with a hardware store crimper, I can see that there would be a large margin of failure in certain runs of product.  Using only tools that are specified for rigging and high angle work is a sure way to meet specs and ensure that you have a sound product.  Nicopress is one of those tools.


So any other examples that would lead one to claim that cinch's do not hold falls? 





Offline mungeclimber

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Re: Rivet Hangers breaking?
« Reply #4 on: June 23, 2014, 01:50:56 pm »
Quote
They can "torque" the rivet out of the hole in a long fall.  This I have seen first hand while bounce testing, fortunately not in a fall.

by torque, do you mean outward force perpendicular to the plane of the rock surface?  A sort of prying action that a lot of use have talked about elsewhere?

I've seen this attempted to be mitigated by the use of screamers to reduce the overall fall factor on the 'one good piece' in a series (or screamers on all pieces that aren't hooks).



Offline cobbledik

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Re: Rivet Hangers breaking?
« Reply #5 on: June 23, 2014, 01:59:05 pm »
I've taken daisy falls on Mucci's cinch hangers. No problem except for getting them off after a massive force load like that.  Two kinds of keyhole hangers, the long thin-width ones are shit, visibly attempting to pry the rivet out of the wall while you're on them and even bending under Mungeclimber's bodyweight on ZOD. The squat wider ones with the sharp angle after the insertion holes are bomber and don't seem to be as liable in my experience to prying the rivet.

On tribal rite, I didn't have enough cinch and keyhole so had to use regular loop hangers. Sucked because they would easily slide off while you're above them. I ended up duct-taping all of my normal loop hangers when I used them to make it harder to slide off.
Sometimes the difference between a layman and a journeyman is simply what he is allowed to believe himself to be.

Offline *Mucci*

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Re: Rivet Hangers breaking?
« Reply #6 on: June 23, 2014, 02:00:55 pm »
Yup, the hanger pulls the rivet out of the hole when a large force is placed on the system.

Obviously, the placement, quality of rock, depth, and orientation of the hanger during the fall all contribute.

Offline Erik Sloan

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Re: Rivet Hangers breaking?
« Reply #7 on: June 23, 2014, 02:58:40 pm »
Yo Josh,

Great post!

I can't name examples of other cinch hangers breaking(I've heard of many)right now, though I"m sure some will come to me soon, but I am the reason for that statement in the book.

Kate's fall brought a lot of questions about cinch rivet hangers, and it is my, possibly erroneous, understanding that cinch hangers are less strong because when you fall on them you don't load a loop or wire - you just load one side of the wire. I thought the explanation went that when a traditional 'loop' rivet hanger is loaded the cable is doubled and loaded evenly, essentially increasing the strength of the cable, and when you fall on a 'cinch' hanger the cable is loaded at a smaller spot(The cinch), which compromised the cable(I swear it was explained that the loop doubled the strength of the cable, or allowed it to hold to spec, while the cinch halved the strength, but not sure if I'm getting that right right now).

Anyway, that's how the keyhole hangers came about, because many folks fell when cinch rivet hangers broke.

You're dead wrong about the super bent keyhole hangers Kev - you want the ones with the least amount of bend, because in a hard fall they're going to deform and if there is just a gentle scoop to the hanger it will just straighten out, prying the bolt less than if there is a more pronounced angle, which will deform and really lever the bolt/rivet out of the hole. It's just hard to get them over the rivets, owing to inconsistencies in the rock, so you have to have a variety of types.

I'll dig around and see if I can find more info.

Woot!
Erik
erik@yosemitebigwall.com

Offline *Mucci*

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Re: Rivet Hangers breaking?
« Reply #8 on: June 23, 2014, 03:28:00 pm »
Thanks for the response Erik.

I have pretty much all available hangers at home, I will post up a shot of them so we have samples to work with.

The PDF hangers, which have a 40 degree bend are one of the worst imo, second to that would be the pika hangers which Moses sort of modeled his thin hanger from, they are bent @ 30 degrees.

The Vermin and RP are the best, as they keep the biner parallel/flat to the rock, but are really only made for 5/16ths or 3/8ths studs, a 1/4" button head is pretty sloppy inside the channel.


Well, the problem with examples of hangers breaking is there is not a clear line to the manufacturer.  Fish, Yates, and anybody who works with proper equipment can testify to the quality, and strength of what is produced.  If a aluminum oval is placed in the middle rather than a copper one, you have a reduced rating in the unit.  Not everybody with a swage tool knows what material works best, strongest cable and oval combo etc... Even the way you crip, as in where you start the process has an effect on the overall strength rating.

I Pull tested a few of my heads, hangers etc..  All of the breaking strengths were above what we thought.

I believe my #2 cinch pulled through the copper sleeve @ 1,450lbs or so (going on memory).  Static, not dynamic load, so once you introduce a rope into the mix, even 20 feet or so, that number is hard to attain in a standard fall.


Here is an example of using Aluminum ovals in place of the proper copper swage for maximum strength. 

http://www.ebay.com/itm/3-Nicopress-Rivet-Hangers-Circle-Head-Aid-Big-Wall-Rock-Climbing-Gear-/161296753786?pt=LH_DefaultDomain_0&hash=item258e09247a
« Last Edit: June 23, 2014, 04:44:54 pm by *Mucci* »

Offline cobbledik

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Re: Rivet Hangers breaking?
« Reply #9 on: June 23, 2014, 06:39:40 pm »
A photo to make sure we're talking about the same.

The keyhole hangers I like are the following:


I've noticed that these lock the spine of the carabiner against the rock so I'd be surprised (and haven't noticed in the couple of times I've loaded them in small falls - irresponsibly small sample size, I know) to see the hanger deform in a fall since the lack of possible movement should transfer the force through the hanger and onto the carabiner spine so the force remains down instead of levering out.

I've waited to see it happen with these hangers because Mucci is so against them but I love them. I bounce test all of my rivets after I place them (and anybody else's rivets as well) much to the raucous laughter of Mucci and Bosque below me and what I've seen so far hasn't supported the reasons for getting rid of these from my rack. (Obviously, still an irresponsibly small sample size for me to spout off online about it)
Sometimes the difference between a layman and a journeyman is simply what he is allowed to believe himself to be.

Offline lambone

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Re: Rivet Hangers breaking?
« Reply #10 on: June 23, 2014, 06:58:29 pm »
while we are talking about the keyhole hangers...I'll mention this.

Keenan was trying to get a Pika keyhole hanger onto a machinehead dowel on Tribal and it just barely wouldn't fit. He took out his hammer to tap it on and the Machine Head which was drilled pretty deep popped right out after the second tap. Keenan was above it on a bad hook and was pretty freaked out about falling onto the belay.

So i guess becareful doing that!

Offline mungeclimber

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Re: Rivet Hangers breaking?
« Reply #11 on: June 23, 2014, 07:00:52 pm »
The lighter 1/4 Moses ones flex substantially (lateral flex and deform) under a big guy. Not horrible, but rock face, size of carabiner and what you can slip over the diameter of the rivet shaft will dictate best option.

Offline mhudon

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Re: Rivet Hangers breaking?
« Reply #12 on: June 23, 2014, 08:39:58 pm »
+1 for what cobbledik wrote about. Much ado about nothing, imho.
« Last Edit: June 24, 2014, 07:38:11 am by mhudon »

Offline Skully

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Re: Rivet Hangers breaking?
« Reply #13 on: June 23, 2014, 10:30:52 pm »
I concur.  :mrgreen:

Offline Erik Sloan

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Re: Rivet Hangers breaking?
« Reply #14 on: June 24, 2014, 05:19:48 pm »
Wow, that's a trip Josh - I'd swear one party per year, on average, would take a big fall and bail - say a 40 footer when they were only 10 ft above the piece. When asked what happened they would say the rivet hanger broke. I'd ask what kind of rivet hangers they were using and they always said cinch. I'd say 'I can't believe they still sell those things after Kate's fall, when we all learned that they are body weight only'. Kate had a bunch of rope out, and fell a long way on the second and third cinch hangers that broke. I guess we'll never know with different manufacturers. 

That's how I got into making the keyhole hangers with Moses.

Kevin - when Theron pull tested those hangers you posted they did pull straight out in a levering type action. That's why we made the thin, barely scooped ones(funny to hear you guys say you like those the least as from all Theron's testing those were the only ones that didn't produce significant levering on the bolt. The thicker ones you like are good for bolts that got beat up a little when they went in so you can't get the scooped(less bent) ones on.

I hear ya that the metal is thin Munge, on the scooped ones, but it has to be to fit over the rock. They broke at over 3,000 lbs If I recall.

Got my boy all week so not much time to write back. Fun to hear how it goes though - like a bunch of first time cavers, hahaha. We gotta figure this stuff out and start doing it right(also/mostly in regards hardware that is fixed in the rock)!

Offline mungeclimber

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Re: Rivet Hangers breaking?
« Reply #15 on: June 24, 2014, 10:18:47 pm »
Quote
I hear ya that the metal is thin Munge, on the scooped ones, but it has to be to fit over the rock. They broke at over 3,000 lbs If I recall.

word. I still use them. Like you said, they need to be smallish to fit.

Offline cobbledik

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Re: Rivet Hangers breaking?
« Reply #16 on: June 24, 2014, 11:09:40 pm »
Hmmmmm. Well I trust Theron's testing. Damn, I like those things too. Guess I'll take them off my normal rack and just use them for FAs where I know how much of the rivet and/or splitshaft is in the rock.
Sometimes the difference between a layman and a journeyman is simply what he is allowed to believe himself to be.

Offline mhudon

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Re: Rivet Hangers breaking?
« Reply #17 on: June 26, 2014, 10:39:42 am »
Skot Richards, my Albatross partner and a certified rigger, made and tested some butterfly rivet hangers. The ones made with 1/16th wire tested out at 480lbs (2Kn) and the ones made with 3/32nd wire, 920lbs (4kn). They were tested in their use configuration with a dynamiter.

Really, for what they are, for their intended use, "Rivet Hangers" not "Bolt" hangers, they are appropriate. If you use them to sling a bolt, well then you are using them in an inappropriate situation. And by "bolt", I'm talking about what we used to call bolts in the old days, 1/4" split pin hex and button heads, you know, what was commonly used as anchors back then!

A real rivet, machine head or dowel, should always be seen as suspect and not expected to hold a fall.

The appropriate tool needs to be used for the appropriate job with the appropriate expectation of it.

Offline SLareau

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Re: Rivet Hangers breaking?
« Reply #18 on: June 27, 2014, 08:44:53 am »
Back in May I watched my buddy take a pretty big fall onto a #1 yates cinch style hanger on P1 of Zodiac after he ripped some mank above it.  All told it was probably a ~40 footer and it fully deployed a screamer on the hanger.  Not sure if all the gear ripping above or the screamer helped slow him down enough, but I was shocked that it didn't snap either way.  It definitely wasn't designed for that.  The keyhole hangers certainly inspire more confidence.   

Offline mhudon

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Re: Rivet Hangers breaking?
« Reply #19 on: June 27, 2014, 09:47:12 am »
Screamers are pretty much only good when you fall directly onto them, when they are the first piece below your fall and not more that five feet away. After that you are generating too much force for them to do anything.

Offline mungeclimber

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Re: Rivet Hangers breaking?
« Reply #20 on: June 27, 2014, 11:47:31 am »
^^^ disagree

that equation doesn't address the strength of the piece and rock the screamer is attached to, so to say a fully deployed screamer doesn't reduce forces sufficient to do 'anything' smacks of internet posting.

 


Offline mhudon

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Re: Rivet Hangers breaking?
« Reply #21 on: June 27, 2014, 01:26:18 pm »
There was a giant thread about it on Mountain Project a few years ago. I respect the ideas of Richard Goldstone (rgold) quite a bit.

You quote me yet attribute my comment to an overly broad situation. I said that if it is the piece immediately below you, it has an effect. Further than that, it does not.
« Last Edit: June 27, 2014, 01:32:06 pm by mhudon »

Offline cobbledik

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Re: Rivet Hangers breaking?
« Reply #22 on: June 27, 2014, 02:44:22 pm »
Are you arguing that the force absorbed by the screamer is negligent or that it doesn't have a force reduction at all?
Sometimes the difference between a layman and a journeyman is simply what he is allowed to believe himself to be.

Offline SLareau

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Re: Rivet Hangers breaking?
« Reply #23 on: June 27, 2014, 03:21:19 pm »
I knew I shouldn't have mentioned the "S" word. 

I've put a decent amount of thought into the effectiveness of screamers and have read pretty much all the available literature/testing and ultimately concluded that there are too many real world variables/scenarios to definitively conclude whether they are effective or not.  I did my undergrad in mechanical engineering so I tend to find this stuff fascinating from a thought experiment perspective.  From a somewhat high level though, anything that "absorbs energy" or extends the period of time at which a force is being applied will lessen the impulse (p=f/t).  Some of this advantage is likely eroded by the increased fall distance (increased energy) that the deploying screamer introduces.  I rationalize it as a trade of decreased impulse for a longer fall.     

I will say that after witnessing that fall, I'm glad there was a screamer on the hanger as if it had ripped my buddy would have two broken legs right now. 

Anyone know what the breaking strength of a #1 yates hanger is?  I can't seem to find it anywhere.  I can't imagine it's more than 5kn.   
« Last Edit: June 27, 2014, 03:24:59 pm by SLareau »

Offline mhudon

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Re: Rivet Hangers breaking?
« Reply #24 on: June 27, 2014, 03:53:45 pm »
Pretty much the take home message of the Mountain Project  thread was "it probably won't hurt and it might help".

Offline *Mucci*

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Re: Rivet Hangers breaking?
« Reply #25 on: June 27, 2014, 03:55:53 pm »
According to slot Richards test, 1/16th cinch hanger failed at 480 lbs.  #1=1/16, #2=3/32, #3=1/18"etc.

Hard to argue the screamer had no effect on a 2kn peice holding the fall described. I garnered higher breaking strength on the ones I made, which says nothing of the actual real world translation.

One of my hangers held a really hard fall on a machine head, 210lbs of leader and gear, no screamer.

Once again, a proper 3/32" cinch will most certainly hold hard falls.  BS that you get hand me down style should never be trusted.

Also, when I place a rivet, it is never considered "suspect" .  However that junk you find on traveled routes, I would agree, unless that have been replaced with button heads.

I just thought it odd to make that statement in the guidebook which has no factual evidence, yet reads as so.

Well if you want shit that will hold falls, let me know.

http://www.wwewirerope.com/aircraftcable/

Minimum breaking strength noted in link.
« Last Edit: June 27, 2014, 04:12:39 pm by *Mucci* »

Offline Erik Sloan

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Re: Rivet Hangers breaking?
« Reply #26 on: June 28, 2014, 02:53:39 pm »
Sorry Mucci,

Very busy week here so haven't had time to look into this more. Will dig up some stuff next week.

Offline *Mucci*

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Re: Rivet Hangers breaking?
« Reply #27 on: June 29, 2014, 05:11:18 pm »
Here is Kate's recollection of her fall. 

http://www.supertopo.com/climbing/thread.php?topic_id=109179&tn=80

Breaking under body weight, sounds like #1 size cinch hangers.

Vermin hangers purchased at the mountain shop. 

You may have to read a bit through it for clarity, kinda 2 topics Rollin.
« Last Edit: June 29, 2014, 06:44:37 pm by *Mucci* »

Offline cobbledik

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Re: Rivet Hangers breaking?
« Reply #28 on: June 29, 2014, 09:11:25 pm »
Quote
The rivits were 1/4 inch or less was in the wall, they are 1/2 inch 5/16 rivits, and they pointed downward a bit, making the pullout strength (weak) more important than the shear strength (a bit stronger) the key player in whether or not they held. (I know they aren't typically fall-holders and was never expecting that)

1/2" machine heads? Damn, and I've been spending all my time placing 1" machine heads.
Sometimes the difference between a layman and a journeyman is simply what he is allowed to believe himself to be.

Offline *Mucci*

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Re: Rivet Hangers breaking?
« Reply #29 on: June 29, 2014, 10:07:54 pm »
It is a craft.