Froggers: have you ever USED your third ascender?

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Re: Froggers: have you ever USED your third ascender?

Postby Dwight Livingston » Jul 21, 2012 9:30 pm

Scott McCrea wrote:I said a cow's tail can be a QAS if the pitch is rigged for such.


Scott

Thanks. So what is it about the rigging that suits a cow's tail QAS? Or maybe I could ask: what is it about the rigging that allows a cow's tail to be a QAS?

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Re: Froggers: have you ever USED your third ascender?

Postby NZcaver » Jul 21, 2012 9:39 pm

Dwight Livingston wrote:
Scott McCrea wrote:I said a cow's tail can be a QAS if the pitch is rigged for such.


Scott

Thanks. So what is about the rigging that suits a cow's tail QAS?

Dwight

I think Scott means 'proper rigging' should include tying bights to clip a cowstail into at specific locations; e.g. for fall prevention near an edge, where ropes are joined, short pigtail below an edge, etc.
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Re: Froggers: have you ever USED your third ascender?

Postby Chads93GT » Jul 21, 2012 10:34 pm

By tying a bight at the lip for a cows tail clip. I assume this would be done on a second. Short piece of rope right? I couldn't imagine tying a butterfly knot In the main rappel rope a foot above the lip.
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Re: Froggers: have you ever USED your third ascender?

Postby Scott McCrea » Jul 22, 2012 6:55 am

Reblays, traverses, bights, loops, etc. There needs to be a piece of rope that is perpendicular to the drop (horizontal) in order to keep the cow's tail from sliding down the rope.

Pitches where the rope gets tied to a rock or tree and chucked down the hole works great with ascender QAS's, but there is nothing for a cow's tail to attach to. Therefore, I believe that an ascender QAS is much more versatile. It can be used in nearly every situation.

A QAS does not need to be separate from the climbing system. It can be part of the climbing system, like the upper ascender of a frog. Once you are on rope and climbing, the need for a QAS is small. QAS's are useful before and after you get off rope and doing work or moving around edges.
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Re: Froggers: have you ever USED your third ascender?

Postby Dwight Livingston » Jul 22, 2012 8:33 am

Scott

I got it.

See, when you said that a cowstail can be a QAS, I thought you meant that one can wear it clipped to an ascender. This is how I wear my long cowstail, with it clipped to a Basic. And as you and others have described, I use it as an upper ascender, as a QAS, and as a cowstail (by clipping the biner to a loop while letting the Basic hang).

On the other hand, what you were saying is that a cowstail without an ascender is a sort of QAS, if the rigging allows. That I understand.

Some people have told me that what I have is not a QAS. Whatever.

Thanks

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Re: Froggers: have you ever USED your third ascender?

Postby LukeM » Jul 22, 2012 12:03 pm

So, in conclusion - Is it quick to deploy? Is is an ascender that's attached to you? Ok, you have a QAS.
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Re: Froggers: have you ever USED your third ascender?

Postby PeterFJohnson » Jul 22, 2012 12:12 pm

Stridergdm wrote:
Your ropes are too clean and the teeth on your ascenders too new. :-)

(though hasn't happened to me, I have heard of others who have slid down ropes on their weighted ascenders, hence having two is helpful to keep them from descending too quickly.)


I've worn through a few sets of ascenders/teeth at this point. Hopefully those fancy pants new petzl ascenders coming out will have better longevity.

junkman wrote:Yup, very worn cam teeth on wet muddy project rope.
I replaced it after that trip.


Interesting Carl. Might start a new thread about this. I can't find anything on cavechat with a search. I was under the impression that the teeth were primarily for engaging the cam and once weighted the cam should stay engaged baring any other change in the friction? A bit more complicated than that I suppose. Hopefully some ascenders-physics-ninja can respond to my other thread.
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Re: Froggers: have you ever USED your third ascender?

Postby Chads93GT » Jul 22, 2012 12:24 pm

If there is no teeth there is no bite. If there is no bite the ascender will slide down the rope. Just like a prusic will slide without biting into the rope.
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Re: Froggers: have you ever USED your third ascender?

Postby PeterFJohnson » Jul 22, 2012 1:00 pm

Chads93GT wrote:If there is no teeth there is no bite. If there is no bite the ascender will slide down the rope. Just like a prusic will slide without biting into the rope.


Then how does a Petzl Shunt or a Gibbs function? Those devices can be used without them sliding down the rope and don't have teeth. Clearly there is some gripping function provided by the teeth, but I guess I am trying to determine the relationship between all the factors and how much the teeth are required once the cam has been engaged.

I started a new topic here:

viewtopic.php?f=5&t=14284
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Re: Froggers: have you ever USED your third ascender?

Postby Dwight Livingston » Jul 22, 2012 1:06 pm

And to your question, Jeff, my third ascender is a Prussik clipped to a gear loop on my harness, and I have not used it since an initial test.

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Re: Froggers: have you ever USED your third ascender?

Postby Chads93GT » Jul 22, 2012 2:53 pm

A gibbs ascender does have teeth. they are horizontal cam teeth like a sprocket, not sharp pokey teeth like a croll/basic style ascender. A shunt, i have never seen one, so no comment ;)

even gibbs ascenders wont grip anymore once those sprocket type teeth get worn down.
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Re: Froggers: have you ever USED your third ascender?

Postby PeterFJohnson » Jul 23, 2012 1:45 pm

I stand corrected regarding the gibbs. But the shunt does not have teeth of any sort. The device is also not originally designed to be an ascender, but it is what ACT recommends as an ascender in very muddy conditions and can certainly grab a rope. I wonder if the difference doesn't lie partially in the orientation of the fulcrum, the load, and the lever as described on Storrick's site. But as I mentioned in my other post, it would be interesting to see a more comprehensive analysis.

But from everyone's comments it seems reasonable to assume that most ascenders rely on the teeth to continue to provide gripping power after the cam is engaged - i.e. that even though friction should increase as the load increases it isn't enough.
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