Backups in SRT

Ron,
No it just says "backup." Mechanical ascenders can be backed up by another mechanical ascender.

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That is a good point, if you are going to ask someone to back up a system, what are you going to consider a standard or SOG.
 
The other point I was trying to make is this: In competition, a backup is required, we don't know what kind of back up, for mechanical ascenders. In doubled rope footlocking, isn't a redundant system used to backup a friction hitch?

The implication is that there must be more shortcoming to a friction hitch, since a redundant system is used instead of a backup.
 
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Where is a rule or regulation for 'backing up' ascenders? If that is the case it is inconsistent to not backup hitches too.

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Well, indirectly this applies:

ANSI Z133.1 8.1.13 "All load-bearing components of the climbing system shall meet the minimum standards for arborist climbing equipment."

Which is 22.24kN (5,000#)

To my knowledge, no ascenders are rated to meet this criteria.

BTW- I'm all for mechanicals. I just do not believe their application is consistently safe yet. I've had an ascender open up on me while ascending 11mm rope. Thankfully, I was only 4ft off the ground. But still, I learned my lesson.
 
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The other point I was trying to make is this: In competition, a backup is required, we don't know what kind of back up, for mechanical ascenders. In doubled rope footlocking, isn't a redundant system used to backup a friction hitch?

The implication is that there must be more shortcoming to a friction hitch, since a redundant system is used instead of a backup.

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In the footlock event the dorsal belay used is redundant. I think its used primarily because of the nature of the event (being solely about speed). In a Masters Challenge a dorsal belay is not employed. I don't see any implication that a properly tied/set friction hitch is unsafe.

Choosing an appropriate backup is left to the climber. Wether that be a cordage or mechanical backup is up to the climber.

Although competitions are not "real life," they should reflect and teach safe work practices.
 
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Where is a rule or regulation for 'backing up' ascenders? If that is the case it is inconsistent to not backup hitches too.

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Well, indirectly this applies:

ANSI Z133.1 8.1.13 "All load-bearing components of the climbing system shall meet the minimum standards for arborist climbing equipment."

Which is 22.24kN (5,000#)


To my knowledge, no ascenders are rated to meet this criteria.

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Do you know of any friction hitches that meet that 5000 lbs?
 
I was reading something related to this in "On Rope," although I only have the old 1987 edition. The issue seemed to be the concern that an ascender could cut a rope if you fell on it. In particular the Gibbs was graded poorly in this regard. Now I don't know if a smooth cam such as the USHBA solves this or not.
 
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I was reading something related to this in "On Rope," although I only have the old 1987 edition. The issue seemed to be the concern that an ascender could cut a rope if you fell on it. In particular the Gibbs was graded poorly in this regard. Now I don't know if a smooth cam such as the USHBA solves this or not.

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The only ascender I'm aware that can 'cut' a rope is the Gibbs. In the Gibb's instruction sheet, it states that if a load of 2000 lbs is applied to a Gibbs ascender, it can completely sever a 1/2" rope.

No other manufacturer of a shell and cam type ascenders, i.e. Petzl Rescuecender, PMI Grip, etc., that I'm aware of have such a warning. Hence we can only presume that the device will slip before it severs the rope.

As for the toothed type ascenders, they can rip the cover and peel the rope.

Two unique type ascenders, the Shunt and the Grigri and grigri types, i.e. Trango Cinch, Petzl I'd and now the new Petzl mini-I'D, which I'll probably buy tomorrow, at least have the potential of slipping at lower loads, reducing shock loading, without necessarily damaging the rope.

If these type devices are used in SRT configurations, there shouldn't be as much risk of them burning a rope as quickly as a hitch could, shock loading would be reduced because the SRT rope has more stretch than a DdRT, and they slip at lower loads and have the potential to be restarted.

I've heard some pretty bad stories about friction hitch backups catching and melting the hitch to the rope.

Also, we need to consider the nature of an ascender failure with a friction hitch backup. Some tests were performed on climbers, unaware of what was being tested. What was being tested was their reaction to the sensation of falling and if the friction hitch backup would catch the fall. They had them belayed separately IIRC. Only one very experienced climber turned loose of the friction hitch backup to allow it to catch. Most would have fallen with a death grip on the backup hitch.

So while there are guidelines, that doesn't mean they are gonna work like we expect.
 
I think footlocking on a prussic is only safe because footlocking is fairly safe. I do not believe that hitch is neceasrily going to catch all the time. Ive had some scary moments with rolled Hitches and coming too close to limbs etc. It is just very difficult to fall off a footlock line unless you are struck by something, attacked by bees or just completly pass out. the hitch is rarely used even. Thus you could have lots of hitches that would fail if tested but that rarely if ever happens.

In the case of an acender, your going to know if it fails because you have your weight on it and you will fall. I can definitly see popping open an acender happening. But it seems kind of rare for you to be just attached to one acender right?
 
This kind of goes back to what Tom had said, but do all of you that use some kind of hand ascender secure it with a lock of some kind at the top hole ie; biener or something eles? Or are all the "coming off the rope problems" you are talking about go to some kind of total failure of the device? I have had the problem of it coming off the rope in the past (once) put a biener on it and never had an issue again. Even in caves with a muddy slick on the rope and gear, still no issue.
 
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In the case of an acender, your going to know if it fails because you have your weight on it and you will fall. I can definitly see popping open an acender happening. But it seems kind of rare for you to be just attached to one acender right?

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One thing i think people over look, is that an ascender can fail due to simple malfunction if it not made properly or wears improperly. These things can not always be seen by the naked eye. A hitch i agree will fail from time to time, but only if tied dressed or set wrong. All of these are user malfunctions. We have a lot more control over a hitch than a mechanical ascender.

If i'm not mistaken, clutches have to be changed regularly. That is a little unsettling to me as i can't see at what point a clutch may need changed (I could be wrong on this i have no experience) But a hitch i can clearly see when it becomes to worn.
 
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If i'm not mistaken, clutches have to be changed regularly. That is a little unsettling to me as i can't see at what point a clutch may need changed (I could be wrong on this i have no experience) But a hitch i can clearly see when it becomes to worn.

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This is my biggest problem with mechanical descenders/friction devices... But like you, I have little to no experience with them. How DO you know when the clutch is about to fail? Anyone?

-Tom
 
The only rope tool with a 'clutch' are the ART family. when I climbed on them it was evident when a clutch needed replacing because the tool would creep a little.

The term 'creep' has been carefully chosen and agreed on. It is MUCH different than 'slip'. Creep is where the tool moves down just a little but still locks off.

Something that I've had a concern about with hitches is how often I talk to climbers who use a VT who tell me that they have to milk or stretch the VT or it will slip or slide a bit. if the cord is too stiff and the VT isn't 'set' it will slide to failure. This isn't uncommon. To me this is NOT safe. After reading about how a 'whistle test' is used in rope rescue to test the whole, complex, setup I've used it as a criteria for using certain pieces in my system. If at any time a whistle were blown it means let go...no setting hitches, adjustments or dressing. If this happens at the time when the climber hasn't 'set' the VT think of the consequences...slip or fall.
 
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Something that I've had a concern about with hitches is how often I talk to climbers who use a VT who tell me that they have to milk or stretch the VT or it will slip or slide a bit. if the cord is too stiff and the VT isn't 'set' it will slide to failure. This isn't uncommon. To me this is NOT safe.

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Once again this is user error though, they are taking the risk. As dumb as it seems, guys still do it. But that is easily prevented, and comes down to TDS. They aren't tying it right. I know what your talking about and it makes no sense to me either. When i tie a hitch i know that it is going to catch if i set it or not.

I've said it before and i'll say it again, i was climb next to a guy that had a hand ascender fail midline. If it wasn't for his backup he is stuck midline with no connection point essentially.
 
Tom, are you trying to swerve the debate to "climbing hitches aren't safe!"??

Are you kidding me? There is no comparison. Thousands of climbers uses hitches everyday with very few mishaps. Very few climbers use ascenders on a daily basis, many on the 'buzz. Just an informal discussion of ascender use has turned up several climbers who warn of their potential dangers. Backing up ascenders (whether with a hitch or mechanical devise) is simple and safe.

I'm starting to wonder if you are a production climber or not.
 
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