Backups in SRT

[Tom Dunlap]

Are you talking about using a hitch as a lower ascender, connected to the harness?

I would NEVER allow a hitch that had to be adjusted every once in a while. The tool needs to have two modes...on or off. No dimmer switches allowed. There has to be full time backup not something that needs to be fiddled with occasionally.

there is no comparison to a rescue haul setup with a rope tech minding prusiks and the dynamic climbing that we do. In rescue systems that I've read about there is one person to watch each progress capturing system and slack is taken each inch of the way.

This is where the 'whistle test' comes in. A system MUST pass, failure is not allowed. At any time a whistle can be blown and it's hands off...what happens? If the hitch has gotten baggy or loose and the climber slips/falls it is a failure.

I can't imagine using a hitch for a lower because of the length on the rope. A microcender is so short and compact so it makes for a sleeker setup.

 

[Ron]

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KYlimbwalker, I think I just wrote that wrong. The technique does work and hold the climbers weight with no problem. The issue... I should'nt say issue becasue the hitch is just reacting the way it wants. Any time a hitch is applied to a line that moves thru the hitch or moves over the line via micro pully minding it and does not get tension applied each movement it will loosen a little at a time. This is more seen with a pulley minding it. Rescue companies use prusik hitches for safties. If you notice after long pulls the rescuer minding the tandem prusiks when setting them will also dress them. This is due to them loosening during a haul. Stressing to new climbers to check thier rig during climbing is that more important due to this. Back to the point, it has worked great for me. I have even had the plesure of useing it in a sloppy cave.

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Exactly! I have experienced that very thing. Once recently, I had two prusiks and neither would catch after a bit of climbing. They would hold once I set them, but as you point out, hitches that are advanced but not reset every stroke loosen to the point of not grabbing.

The puzzle to me is why those that claim ascenders "failed" won't disclose the brand, how they failed, etc., especially the ones that purportedly just suddenly come off the rope.

I climb on ropes as small as 9mm, rock climbers climb on ropes as small as 8mm and you just don't hear of ascenders just popping off the rope.

Which leads me to believe that some are using a particular brand of ascender, and some have 'leaked' it out, Kong, that were known for this problem. I know of no other ascender that just comes off the rope. Or, the other possibility is user error.

But, Fairfield you strike to the very heart of the issue that concerns me about backing up an ascender with a prusik - it does loosen if it isn't set frequently, but moreover, the treacherous hitch gives a false sense of security.

Compare the two philosophies presented in this thread, one is to make sure you don't get something like a twig in the ascender in the first place, i.e. regular equipment checks, before advancing, vs just back it up with a hitch and go.

There seems to be an awful lot of unsupported claims about ascenders failing with no details. Yet, as I've pointed out repeatedly, cavers, rock climbers, rope access workers, rescue workers don't seem to have a problem of ascenders just coming off rope. Do you realize how many accidents and deaths we'd be reading about if ascenders could just come off the rope?

I just re-checked the Petzl catalog for ascender useage in rescue, rope access, etc. Not one place is an ascender backed up with a hitch. They are backed up with another mechanical ascender. Wonder why that is? It's because mechanical ascenders are a more reliable backup than a hitch.

 

[KyLimbwalker]

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KYlimbwalker, I think I just wrote that wrong. The technique does work and hold the climbers weight with no problem.

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If it holds, it holds. I hope I didn't come off as preachy.

 

[Jesse]

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I just re-checked the Petzl catalog for ascender useage in rescue, rope access, etc. Not one place is an ascender backed up with a hitch. They are backed up with another mechanical ascender. Wonder why that is? It's because mechanical ascenders are a more reliable backup than a hitch.


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Could it be that Petzl wants to sell more ascenders?

 

[KyLimbwalker]

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There seems to be an awful lot of unsupported claims about ascenders failing with no details. Yet, as I've pointed out repeatedly, cavers, rock climbers, rope access workers, rescue workers don't seem to have a problem of ascenders just coming off rope. Do you realize how many accidents and deaths we'd be reading about if ascenders could just come off the rope?



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Mine is an HMI. And yes, it still pops off if I am too jerky while footlocking. Several others have written that their ascenders have popped off. That is a supported claim.

And you never did answer my question

 

[emr]

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And you never did answer my question

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Why does it matter? I think you know the answer and it really doesn't matter to this discussion. Lets be nice here.

 

[Ron]

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And you never did answer my question

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Why does it matter? I think you know the answer and it really doesn't matter to this discussion. Lets be nice here.

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It matters because when one is backed into a corner and can't debate the issues, they commonly try evasion, if that doesn't work, they try diversion, if that doesn't work, they try to discredit the person. He made a very brazen attempt to discredit Tom and now he's attempting the same thing with me for the same reason. I've been expecting it.

Also notice the claim of 'supported' yet there are zero details about how an ascender just pops off a rope. Obviously, since they have seen this more than once with specific brands, it is a faulty design. Can't figure out why that's so difficult to understand.

Then looking at what sketchy details we do get, we finally see that in a few instances somebody let a 'stick' get in the ascender. A user error - kinda like letting your car wander into a ditch and then blaming the steering wheel.

I ask, if a stick getting in an ascender causes it to fail, which makes more sense, back it up with a hitch that we know may not catch and let it happen, or avoid the problem in the first place?

They say a sign of insanity is doing the same thing over and over and expecting a different outcome. I ask, if you have an ascender that so easily pops off the rope, why do you continue to use it?

How about some details? If you want to convince anyone that the gear is at fault, we need enough details to reproduce the circumstances that cause the problem.

I promise you if I can make a Petzl Ascension, ABC, CMI ultras long or short, CMI Expeditions, pop off the rope I'll become your biggest ally and start spreading the word that ascenders pop right off the rope.

Heck, I'll even contact Storrick and tell him he needs to start including on his website that ascenders will just pop right off the rope. I can tell Bruce Smith, owner of On Rope 1 FTF, because he's not aware of it either. Actually, Bruce probably is and can tell exactly which ones do that and if the problem has been corrected.

 

[DSMc]

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And you never did answer my question

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Why does it matter? I think you know the answer and it really doesn't matter to this discussion. Lets be nice here.

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I agree. As a general rule, I prefer sifting through as much information as possible to get a broader spectrum of opinion.

But as I stated earlier I do not like the gold standard of some other industry dictating what we do in ours. Also I will repeat, the reason the hitch has lasted in the tree industry for as long as it has, is it functions on a 2:1 system.

A set back and catch on a 2:1 is a non-event. In the 1:1 system, the slack created in the knot can travel too far before grabbing.

Mechanical backups are very good on a 1:1 system.

Dave

 

[Fairfield]

[ QUOTE ]


there is no comparison to a rescue haul setup with a rope tech minding prusiks and the dynamic climbing that we do. In rescue systems that I've read about there is one person to watch each progress capturing system and slack is taken each inch of the way.

This is where the 'whistle test' comes in. A system MUST pass, failure is not allowed. At any time a whistle can be blown and it's hands off...what happens? If the hitch has gotten baggy or loose and the climber slips/falls it is a failure.

[/ QUOTE ]

I think that I have to respectfuly disagre with the comparison not being the same. Although you are correct about the whistle stop, you have to keep in mind all of the problems that we have been talking about in a large part come down to climber error. Yes durring a rescue there is/should be a person minding the prusiks. With that said to mind them you cant hold them to tight because they wont move due to to much friction, and holding them to light will cause them to marry with the pulley. Understanably teams that work all the time together and all they do is rope rescue have this down to an art, but im sure if you ask them they still will dress them to make sure they hold properly. Then you have youre local fire/rescue company that might do a rescue once a year and that is at a drill (im sure you know how that turns out). Back to the point, both fields have to constantly mind the hitch to make sure it will correctly react to a drop. Plus both have the rope running thru the hitch in basicly the same manner.

Dont get jammed up with the thought that hitches are a set it and forget it system. They always need to have an eye on them. Kind of off topic but, there was a guy (i will find his name later for you) that does rope/gear testing and teaches classes on what he finds. He tryed to come up with a way that rescue teams wont have to plase a rescuer to mind prussiks at a pulley. He drilled a two inch disk out of a plastic container and then drilled a half inch hole in the ceneter for the rope to pass thru. This would meet up at the pully and not allow for the prusik to pass into it. I know I know thats what prusik minding pulleys are for. People at the class thought it was great. I turned around and asked him who was going to dress the prusik when it became to losse. He had no answer, the thought never crossed his mind. Thought that was interesting.

 

[Fairfield]

DSMc, That a good point about the 2:1 and the 1:1.

 

[Ron]

Somebody explain to me how any one of these ascenders can just pop off the rope.

Bear in mind that in every one of these pics, the sole reason my hand is in the pic, is to rotate the cam as far toward an open position as the safety will allow.

BTW, the rope is 9mm PMI EzBend.

 

[Fairfield]

Ron, It's more of a movement thing. When the climber progress the ascender up and on a bad angle you can roll the rope out. Well I was able to do that with my Petzl hand ascender (singal). Mind you it was all my fault for not having the biener in the top hole on the ascender. Thats the only way I have seen it happen or heared of it happening.

 

[Ron]

DSMc,
If I've given you the impression that I was dictating what we should be doing, please accept my sincere apology - that was certainly not my intent.

I've been one of several that took issue with the claim that a properly designed and used ascender can just pop right off a rope, and the attendant implication that that proves all ascenders will do that, so I want to be sure I didn't give you the wrong impression.

The key issues here seem to be that one, something is happening to a few climbers that causes an ascender to pop off a rope for no apparent reason. Two, the erroneous solution to this problem is to back up the magic ascender with a hitch. As Fairfield pointed out, this general solution brings with it the possibility of a contiunally loosening hitch that will fail to catch as expected. I have personally had that happen more than once.

A third issue is that if you climb on an ascender, it will fail. No real details or reasons are given for this other than if one allows a stick to get in one's gear it won't catch - duh!

 

[Ron]

[ QUOTE ]
Ron, It's more of a movement thing. When the climber progress the ascender up and on a bad angle you can roll the rope out. Well I was able to do that with my Petzl hand ascender (singal). Mind you it was all my fault for not having the biener in the top hole on the ascender. Thats the only way I have seen it happen or heared of it happening.

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Thanks for being candid enough to put the cause where it belongs, user error. That explains that the ascender doesn't just pop off, the user has to get it into a pretty specific situation, likely due to bad technique, to force it off.

And there's a very simple solution to the problem - put a biner in the top hole, i.e. prevent the problem from happening in the first place.

That also explains why I have never been able to force an ascender off a rope - I climb on a RADS which requires a biner through the top hole for the pulley.

The biner would also help, not necessarily eliminate, but help, to prevent getting a twig etc, in the cam.

Also, I'm not against backing up ascenders; typically in any ascender setup, there are two ties to the harness. In the RADS I use, there is of course the tie from the Grigri to the harness, but there is also a tether from the handled ascender to the harness.

The same is true for Texas and Frog sit-stand systems - there is a tie from each ascender to the saddle if done properly.

 

[DSMc]

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DSMc,
If I've given you the impression that I was dictating what we should be doing, please accept my sincere apology - that was certainly not my intent.

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No apology necessary. My comments were much more generalized in regards to things I often hear when describing which technique or system should be used within our industry.

Dave

 

[monkeyman503]

I will share my story on having a KONG double handled ascender pop off the rope! I was SRTing up and did not have a biner in the top hole and kinda jerked it up and at a angle mind you i was even going way too high with my hands and it popped off. I had a footlock prusik above and was only 10 feet off the ground practicing! I have been experimenting with this for some time since and it was my fault no biner bad movement and trying to go to high with my hands. Now i use the petzl ascentrees with croll below and use short straight up movements and have never had it even feel like it was gonna pop off! It seems to come down to getting in a hurry as production arborists and pushing the tool to do something it is not designed to do. I think Tom and Ron probably have more experience with this topic than we are giving them credit for and bashing them for what it seems to me is them trying to help us avoid getting hurt or killed is why i dont post much on this site. I would like to commend them for their efforts and hope my story helps in any way!

Stay safe
You can go to my facebook page and see one video where i am going too high with my pulls and one where i think it is more short easy strokes.

http://www.facebook.com/home.php?

 

[Waldo]

In most of the handled ascender instructions i have read, they say to use ascenders in tandem. In every account i have read posted here of ascenders failing, they were unweighted and being pushed up the rope at an odd angle that caused it roll out. It seems unlikely that when using two ascenders (this does not include foot ascenders) that one would be able to pop both off the rope.

 

[Tom Dunlap]

Ron's pics will lead to the weak point of the last version of the two headed Kong ascenders.

If you own them, or can find some, do this:

Thumb the cam open like Ron is doing in the pic. Don't grab the thumb tab, just pull the cam back. Now, look at two dimensions:

First, look at the ascender straight on, so that the cam pin is pointing straight away. See how much of the leading edge of the cam is tucked in behind the metal shell? Compare that overlap with the other side. Notice the difference? Pretty big difference and not symmetric.

Next, rotate the head a little and look at the distance from the outer edge of the cam to the inner radius of the shell. The air gap is pretty large.

A small diameter rope can, and has, gotten rotated into that gap, loaded and pried back the shell and cam...hence...popping off the rope..when it's really a combination of bad design and bad practice.

climbing 'off lead' and having a rope move diagonally across the cam instead of straight down the shell is another way that ropes have shoe-horned off the Kong's.

Putting a pin or biner through the top holes of the Kongs is a minimal 'safety' practice. Even better...get a better designed tool or go to SRT which is much easier to use and backup/add redundancy.

The only time an ascender has ever malufunctioned on my watch was when mu climber thumbed the cam and slid down about 10 feet or so. this was years ago before I had dialed in a good system. I learned from that accident...add redundancy into the system. Two good friends who have many miles of rope climbing in trees under them each had a stick/bark flake get under the cam and the ascender slipped. One fell into a lilac shrub which took the force of the fall and he wasn't hurt. In the other slip the friction of the rope running over the bark flake/cam scraped away like a carrot shredder and the cam teeth grabbed. Both climbers change to two attachment points right away.

 

[KyLimbwalker]

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And you never did answer my question

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Why does it matter? I think you know the answer and it really doesn't matter to this discussion. Lets be nice here.

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This is an important discussion. Qualifying an opponent in a debate has nothing to do with nice. It matters. A recreational climber may have any opinion they want concerning the use of ascenders to climb a rope, but they should not have an opinion as to whether they are appropriate without a backup for professional tree climbing.

For example: I hardly ever agree with Holly, but I respect his opinion because I know he is a professional (no disrespect, Holly).

 

[Ron]

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...For example: I hardly ever agree with Holly, but I respect his opinion because I know he is a professional (no disrespect, Holly).

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BS! If that's true, then why did you make such disparaging remarks about Tom? That totally contradicts what you stated above. Or, maybe you don't know that Tom is a professional so you see no need to respect his opinion the way you respect Holly's opinion.

Speaking of credentials and professionalism, were you aware that the simple fix to prevent an ascender from coming off is simply a biner in the top hole?

So you can't use this as an excuse not to answer my question, I'm a rec climber. Believe it or not, we do know a few things.

Like this - a new RADS setup - it will not come off the rope under any circumstances BTW:

Or how about this rigging so I could bring down a huge limb from my neighbor's tree and place it exactly where I wanted it to land and never leave the tree - all by myself - remotely controlled from the tree:

Or how about the locked brumel tests I ran on 8mm beeline:

And accompaning documentation of the test:

So I answered your question and here's mine:
When the you had the ascender come off, did you have a biner in the top hole? Ok, I can't resist another, since you're a professional another question shouldn't bother you. Did you know you were using the wrong technique?

You might want to keep this in mind too, the differnce in a professional and an expert is a professional gets paid for doing something whether it's right or wrong. An expert has thorough knowledge of the tools of his trade and uses them, well, expertly.