Yea, except for that example in the Beal Video, the DMM Video in great depth and the evidence just presented by Jim Titt of individuals (live body) developing 27kn of force in short falls on static slings....
OP, you got ur choice, listen to former or current industry insiders that actually know something and have real experience, or listen to whomever you want to...choice is yours.
Dynema is great stuff. But you will not find me recommending to belay a leader off it...ever...when other choices are present.
Just watch the Beal/Dmm Videos....in every case Dynema puts more force on anchor, leader and belayer. If you don't think this will ever happen to you then more power to you, its your neck.
Watch this video as an example of tying in with the rope. Why you would be using Dynema slingage instead escapes me:
I know why industry likes the big steel block as a testing unit (consistent, easy to quantify) but has anyone done testing with something more squishy and human-like, say a crash test dummy? I know the flopping around would add some variability to your results but it'd be interesting to get a sense of just how much give a real body adds to the system.
Matt Westlake wrote: I know why industry likes the big steel block as a testing unit (consistent, easy to quantify) but has anyone done testing with something more squishy and human-like, say a crash test dummy? I know the flopping around would add some variability to your results but it'd be interesting to get a sense of just how much give a real body adds to the system.
I once had the opportunity to watch a few gear breaking demos at the Petzl Institute in Salt Lake. One of the 'tests' if you could call it that was looking at exactly this.
The test was a factor 2 w/ a 24" Dyneema sling. I can't remember if there was an overhand knot in it or not. In any case, the test was done with one 80kg steel mass and one 80kg rope filled haul bag. The Dynamic mass broke the Dyneema at 19kn. The sling held the haul bag drop with a max load of 14.7kn.
These videos definitely do prove, without a doubt, that dropping a large steel mass in a static system on a dyneema sling at FF2 in a drop tower will break the sling. So, I would definitely recommend that anybody who is a literal steel weight and who will be FF2'ing on a dyneema sling in a drop tower tie in differently. I would also inquire as to how they are typing, as steel weights do not have hands. For the rest of us, who are made out of human stuff, and tie in with a harness, and don't climb in drop towers, your results "might" vary.
Awesome dude.
This is the kind of stuff that people that didn't watch the Beal video (that uses real humans or sand filled manequins) or don't listen to Jim Titt's anecdote and with no real experience in climbing or inside the climbing industry post around here confidently.
Instead, responsible people at DMM document how the loads are higher with Dynema, the Beal people show how the loads are higher with Dynema and basically every other industry source tells you that other materials are superior for anchor construction...but Kyle Terry tell us he knows better because it is good enough for him and 14.7KN on your gear anchor and the human body would never be a problem (lol).
Which is perfectly fine with me.
OP you have the information you need to make your own decisions. Go forth and send. YMMV.
I do appreciate the range of perspectives offered. So thank you all for chiming in.
Like a lot of climbing questions, there is no simple answer here.
As a relatively new climber, what i am looking for is, first of all, something reliably safe and relatively simple as a place to begin. As the posts indicate, there is debate about the circumstances under which a dyneema PAS and/or anchor material is/ is not safe. What I am taking away from this is that nylon leashes and anchor materials do not appear to be subject to this uncertainty, and on that ground are perhaps a good place to begin (well, remain, for the time being).
Marco Velo wrote: What I am taking away from this is that nylon leashes and anchor materials do not appear to be subject to this uncertainty, and on that ground are perhaps a good place to begin (well, remain, for the time being).
I recommend you seek this information from a thorough reading of published instructional books such as Climbing: Mastering Basic Skills. While MP is a good place to learn things, as a beginner climber you're undoubtedly going to overcomplicate nearly everything if MP is your go-to source of instructional beta.
As for anchors: Dyneema, nylon, and rope are all suitable and all are recommended for these purposes by the manufacturers, guide institutions, etc provided you're tieing into the anchor with the rope! Tethering into anchors with nylon, Dyneema, pas systems etc is for statically loading the anchor while rappelling. While the rope can be used for this purpose as well, doing so isn't common and is a bit more complicated.
Keep it Simple. Keep it Safe.
Xam
·
Apr 30, 2018
·
Boulder, Co
· Joined Dec 2011
· Points: 76
Jeremy Bauman wrote: As for anchors: Dyneema, nylon, and rope are all suitable and all are recommended for these purposes by the manufacturers, guide institutions, etc provided you're tieing into the anchor with the rope!
Just want to double down on Jeremy's excellent clarification for emphasis...even the small bit of dynamic rope used to clove into the anchor has an order of magnitude more stretch then the nylon slings or cord in the anchor.
This is why, for a personal anchor system, I use something dynamic. There are other choices out there besides a nylon runner with a locker on it, girth hitched to your harness, or a PAS, or a daisy, and so on. The product I use is made of dynamic rope. So I trust it a bit more than a sling or PAS. But I still simply clove in direct as my main anchor and then use my personal as the backup. For anchor building... if people will be top roping off it, I'm fine with Dyneema. If I'll be hanging on it and belaying the leader on a multipitch, I will opt for cordelette. I know how to build an anchor with the climbing rope. And it's great in some circumstances, but generally I do prefer the freedom of a cordelette and keeping the climbing rope out of it.
The reality of the situation is you should be familiar with all the ways of doing it, then choose the best method for the situation.
Jeremy Bauman wrote: I once had the opportunity to watch a few gear breaking demos at the Petzl Institute in Salt Lake. One of the 'tests' if you could call it that was looking at exactly this.
The test was a factor 2 w/ a 24" Dyneema sling. I can't remember if there was an overhand knot in it or not. In any case, the test was done with one 80kg steel mass and one 80kg rope filled haul bag. The Dynamic mass broke the Dyneema at 19kn. The sling held the haul bag drop with a max load of 14.7kn.
Petzl should have known better, the 80kg steel mass represents the effect of a 100kg human body in a harness so the sandbag value is naturally lower. This has been established for many decades as the conversion factor for soft-body to rigid mass for testing climbing equipment. The numerous tests for fall-arrest equipment show the factor is probably as accurate as we need and an 80kg steel weight is the correct choice.
Yea, except for that example in the Beal Video, the DMM Video in great depth and the evidence just presented by Jim Titt of individuals (live body) developing 27kn of force in short falls on static slings....
OP, you got ur choice, listen to former or current industry insiders that actually know something and have real experience, or listen to whomever you want to...choice is yours.
Dynema is great stuff. But you will not find me recommending to belay a leader off it...ever...when other choices are present.
Just watch the Beal/Dmm Videos....in every case Dynema puts more force on anchor, leader and belayer. If you don't think this will ever happen to you then more power to you, its your neck.
Watch this video as an example of tying in with the rope. Why you would be using Dynema slingage instead escapes me:
The last time this video was posted, Tut criticized it.
Tut, please stop acting like a wanker, or at least post under your real name.
Rob D. wrote: I use the big Mammut dyneema sling (240cm maybe?) and it's great. Much lighter, MUCH less bulky than cord and if you use it thoughtfully then concerns posed above aren't an issue. The most obvious way to avoid the problem of shock loading is to always weight the anchor.
Harumpfster Boondoggle wrote: Why you would be using Dynema slingage instead escapes me:
Rope anchors can be appropriate, and I use them often. But as I've advocated elsewhere, they are not usually appropriate if leading in blocks and your follower is following on toprope solo, as I think competent followers should anytime it's appropriate. The traditional standard of the leader being occupied with belaying the second is dumb when he or she could be masturbating while the second climbs
This doesn't mean that Dyneema is the best choice, though it's my choice
Edit: I just noticed this is the Beginning Climbers forum, so disregard my post entirely
I don't think that anybody's arguing at forces won't be lower building an anchor with the rope or even nylon than doing so with dyneema. The anchor undoubtedly will see the lowest forces if it's built with rope, all else equal. The question is whether dyneema is good enough.
It is widely accepted that dyneema is good enough as long as there is a dynamic rope in the system. The short length of your tie in obviously won't provide as much stretch as a full rope length but this really shouldn't be an issue unless you are climbing above the belay and falling onto your tie in. Otherwise you will have not only your tie in but also the lead line in system.
What I really like is the video of the Snow and Ice climb where the narrator is building his anchor on solid bolts (lol).
That's the spirit and common experience of Alpinism? Maybe next it will be snow bollards with Dynema? Why on Earth does he use a sling to tie into 2 bolts instead of the rope?
Hint: To sell gear.
What it is, is a gulf between people having loads of experience building gear anchors, sometimes with concerns over their ultimate reliability that cannot be fixed and those that think using the most static materials couldn't possibly have any consequence despite the higher loads they generate on those anchors.
No matter how you slice it or what test protocol you use the loads on a properly built anchor out of dynamic materials will be up to ~50% of the loads on an anchor built of Dynema. If that is of no concern to you, go forth and have it your way.
There are two parallel discussions going on (interspersed with some Tuttery), one is regarding building a belay with Dyneema in order to belay a leading or following climber where the maximum forces involved in any fall will never be of any concern regarding the anchor material. The other is discussing climbing above an anchor and falling directly onto it when you are directly connected, this isn´t a belay in the normal sense of the word nor is it a circumstance that should ever occur as it it quite possible some part will fail. This is the major objection to building dynamically equalising anchors where one piece failing puts the belayer in this position and we know from testing it is possible the sling will fail. I use Dyneema, nylon and the rope, draws chained together, my chalk bag cord, whatever I´ve got basically.
Harumpfster Boondoggle wrote: No matter how you slice it or what test protocol you use the loads on a properly built anchor out of dynamic materials will be up to ~50% of the loads on an anchor built of Dynema.
"Could possibly be" might be a more accurate choice of words than "will be."
I´ve done hundreds (more than 600 as it happens) pull and drop tests on anchors and if you don´t build in potential extension and or climb above the anchor (and fall) it´s irrelevant which material you use. The force on the anchor is determined by the belay method under normal circumstances and this cannot be changed by using a different material to build the anchor. The anchor itself and the material used to construct it is considered a static system in the safety chain protocol by the industry and the standards system.
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