Petzl guideline on choked carabiner anchor for spar work

moss

moss

Been here much more than a while
Location
Carlisle, Massachusetts, U.S.
ghostice said:
Moss I've wondered if someone has seen a failure comparison between side loading of our "normal paradigm" locking biners and screw gate biners (standard size), and now we have small size screw gate biners ( https://www.mec.ca/en/product/5024-013/Bravo-Locking-Biner as an example) and even Grivel's new offering - the Vlad - http://www.grivel.com/products/rock/carabiners/44-vlad - maybe available one day in a screw gate design? Splice into bottom eye? Hmmm
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Ya I like that grivel biner, thinking about coppin one of them. Just made a thread in the rant and rave section I think... Lookin for reviews or thoughts
 
Right you are:

Anyone ever use one of these?

https://www.rei.com/product/142219/grivel-vlad-twin-gate-rig-carabiner
www.treebuzz.com
I am wondering why somebody maybe doesn't come up with a "mini biner style", using a thicker stock to lower rope bend radius - bent a bit on the back and maybe flattened a bit to sit on the tree stem and with screw gate or three way locking - so the gate'll stick out - or is it the scotch again? Call it the Choke-o-Tronic?
 
I am chippin’ what your cutting Moss. Still, there are many other “better” options as you well know.

Where I see the problem, is inexperienced climbers. While the choked carabiner is most likely never gunna see the force it needs to fail in life support, the tacit approval of using it for life support spills over in to so many other scenarios of life support/rigging/ you name it. I see it time and time again.

Tony
 
Tony said:
I am chippin’ what your cutting Moss. Still, there are many other “better” options as you well know.

Where I see the problem, is inexperienced climbers. While the choked carabiner is most likely never gunna see the force it needs to fail in life support, the tacit approval of using it for life support spills over in to so many other scenarios of life support/rigging/ you name it. I see it time and time again.

Tony
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It’s another tool in the shed for the right situation, I’m glad to see Petzl verify that choked carabiners can have a role. Inexperienced climbers need to see there is factual basis when a practice is considered unsafe by the community, not just “Believe me because I told you so”. In this case there is generally a misunderstanding in the tree climber community about what constitutes cross-loading the spine of a carabiner.
-AJ
 
As I've mentioned in the past there is specific implementation/protocol and use scenario for a choked carabiner. It should only be used for an anchor that is within fairly close reach, ie: it is a temporary anchor to be used potentially while re-pitching, or secondary positioning while performing a task, or as Petzl shows an option for a secondary rope anchor chunking down a spar. I think it's possible to be clear about that when describing strong and weak uses of the technique as opposed to throwing out the baby with the bathwater.
-AJ
 
As far as chunking down spars goes I use a choked steel carabiner. For positioning and temporary repitching anchors I've been choking alloy carabiners on sufficient diameter wood for at least 8 years, have never had an issue damaging/bending the spine or causing gate problems. Gate always up and opposite the direction of loading as Petzl shows in the diagram.
-AJ
 
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Tom Dunlap said:
Like so much Internet related advice: It depends...

...on a long list of criteria that takes patience and time to type out. That means that we're limited to sound bytes of discussion.
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Yep. I'm touchy on the subject, probably because of my "unconventional" path to tree climbing/tree work. For my entire time climbing I've had many experiences of climbers tell me something I'm doing is wrong or unsafe, the assumption being that if they never saw it, means I don't know what I'm doing. Classic problem when good people are trying to improve safety culture in arboriculture. I think we all understand the tension innovation or out-of-the-box thinking creates within a culture of trying to improve safety in the industry.
-AJ
 
Yes...when I was touting SRT and the Unicender I dodged many rocks and arrows from people saying it was unsafe...the Uni was too complicated...so many parts that could fail...double loading on TIPS...climbers were going to be falling like rain. Generally no reply when I'd try to draw out an explanation or justification for their skepticism. Rare dialog.

YOur approach has always been admirable. Your thought process and willingness to take the time to share complicated ideas is rare...and appreciated
 
I like it - now just have to canvass ISC or DMM or Rock Exotica. Or where's that Bingham guy? I'd even be fine with screw gate if you could tighten with a wrench initially maybe. Edges to the trunk side could even have bumpy teeth of some sort? I'm surprised that nobody has come up with a thing like this considering the number of choked spar setups that are in use daily around the world.
StarChoke - To choke where no man has choked before . . . because Gene would have wanted it that way . . .
Cue the music.
 
Check out the gate strength specs for ANSI 359.12 bikers [biners :) ]

All of this discussion is based on an understanding of ‘it depends’. To me, when the ‘it depends’ discussion or annotations gets too long it might be enough to try another solution. I’ve been comfortable choking bikers if I hand place them and they’re not going to jiggle around. Or the bark of the tree has lots of bumps and furrows. In actual practice I have a lard steel delta screwlink on my saddle all of the time. It reduces the ‘it depends ‘ list
 
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This might be a good option.

59353

Something like a ring, or rigging ring on the end of the climb would be needed. And would only be good if choking only.
 
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Would say majorly depends on the diameter and roundness of host mount.
Have abused plenty of old krabs dragging logs etc. as reality check;but favor professional life and overhead gear be kept in different class; even shining reverence to be witnessed by those around to take all the gear seriously etc.
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See no reason not to use soft link of Bowline etc. in situation presented (in ropes i've worked). Would seat better and not leverage rigid device.
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If doing removal, related to previous cut and going krab route might carve out more favorable flat geometry for krab to bed.
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Strength of chain is dictated by it's weakest link(in other things can be mechanical fuse).
Force to gate side or angle towards many times is gate as lever on small hinge pin for gate that is cross-loaded(possibly both ends of gate are , and also is why wire gates can give about same weakness therefore strength).
>>Exception perhaps more towards the braker bar shown that would seat gate to frame work in some krabs rather than wrenching across axle pin.
Force direction always and all ways very important.
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Would always groom system to best geometry for lowest forces for predictability and lowered fatigue. Also, over time train eye to want to view things groomed so in all things, so eyes alert when something rough and out of align.
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Even when rope is working hard and loaded iron bar tight
>>it doesn't like being twerked harder than needed to fatiguing any better than iron.
i think rope, steel etc. lasts longer more predictably if forces not leveraged higher than needed thru devices during usage..
Especially rope's elasticity.
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It's nice to have the max headroom for safety,but would seek not to beat it out of the working devices. Icarus should not walk nearer the thinner ice unless has to(might melt).
 
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