Yates Screamers, obsolete or niche?
|
So I bought some climbing gear from a close friend and with it came some various load reducing devices (see picture below). As I understand, these are mostly screamers made by yates and they seem either a bit old or maybe just dirty. Given that these are made of nylon (i presume), should I retire them? |
|
Dylan Tran wrote: So I bought some climbing gear from a close friend and with it came some various load reducing devices (see picture below). As I understand, these are mostly screamers made by yates and they seem either a bit old or maybe just dirty. Given that these are made of nylon (i presume), should I retire them? I used to carry one if I placed some tiny brass. As for ice climbing... you're not supposed to fall ice climbing. Enjoy! |
|
If you use them with the intent to lower the impact force on your anchor or your climber in the case of a fall, they're great. |
|
On a really loose choss aid, they make me feel a bit better. |
|
Recent research has shown them to be not as useful as once thought, probably only really useful for ice and really marginal trad https://eu.blackdiamondequipment.com/en_GB/qc-lab-to-screamer-or-not-to-screamer.html. |
|
You'll hear opinions all over the board in regard to ice pro. I choose to carry screamers. Reason being, screw strength is variable. Ice protection is dependant on a good quality placement in good quality ice. |
|
I use when leading ice. Usually attached to every other screw or so. Really it depends on the conditions, but I do use them. |
|
Not really useful for free climbing on rock unless it's roped soloing. If used wisely, they can be useful in aid climbing. I've heard that they are good for ice to mitigate force melting, but I'm not really well educated about ice climbing. |
|
Sweet guys, thanks for all the responses! Seems like most of you guys prefer these for ice climbing, but given that I have so many, and I won't be moving to somewhere where I can ice climb until after I graduate from school, I am considering selling some of these off. Would anyone be interested in buying a few? PM me if you are, or I might just make a post in the for sale section. I might keep five or so for personal use but I could use the extra pocket cash. |
|
Kong kisa is one example of them. Basically they are slings that are run through a plate with holes kind of like a rigging plate, except the spacing and size of the holes are designed to create a lot of friction. This friction is supposed to dissipate energy in the form of heat. |
|
Found the aforementioned shock absorber that used a sling. https://www.e-climb.com/en/e-climbcom-shock-absorbers-and-slings/61-dissip.html |
|
kevin deweese wrote: If you use them with the intent to lower the impact force on your anchor or your climber in the case of a fall, they're great. I don’t get it- they can lower the impact force on the anchor but they don’t lower the the force on a marginal placement- how do it know? |
|
Greg R wrote: It's because they're two different things. One question is does the screamer lower impact forces on a system that doesn't blow, allowing the screamer to do its thing. The other is does the screamer lower the impact on a marginal piece fast enough so that it doesn't blow. |
|
that guy named seb wrote: Recent research has shown them to be not as useful as once thought, probably only really useful for ice and really marginal trad https://eu.blackdiamondequipment.com/en_GB/qc-lab-to-screamer-or-not-to-screamer.html. "Our limited testing does show, however, that a Screamer (or similar energy absorbing device) could reduce the peak force that the piece is subjected to by up to 26%....The bottom line is: they do work to reduce the peak force applied to the piece of gear in the system" I've read this article before, and though they admit the tests are fairly anecdotal and not comprehensive in scope, as are many QC Lab reports from Black Diamond, this results themselves indicate that Screamers are useful for their intended purpose. That being said, I don't own screamers, I'm not doing anything hairy enough that I'd see them being worthwhile, especially when they're bulky, heavy and expensive compared to an average quickdraw. |
|
kevin deweese wrote: Its called psychologic pro. |
|
kevin deweese wrote: This makes no sense to me. The screamer levels out the load at the screamer activation value---2 kN, at least until full deployment, at which point the job of energy absorbtion passes back to stretching the rope. The load builds via rope stretching to 2 kN and stays there while the screamer deploys. If the piece blows anyway, it is because it can't withstand 2 kN, not because the load built up to 2 kN "too quickly." Moreover, if the screamer is only good on gear that "won't blow" anyway, then it is totally worthless. The issue with Screamers, (an issue the BD engineers, who did one of the tests, do not seem to understand) is that they are only capable of reducing fall energy by a fixed amount, which is determined by the activation level, the extension of the screamer, and the weight of the faller. (If you like formulas, the relevant energy reduction is (A-2W)E. ) The fall factor has nothing to do with this, so the idea of using screamers on gear near the belay because of potentially high fall factors is wrong, except for the fact that falls near the belay are perhaps likely to be short falls.As far as I can tell, for a 180 lb climber, the a screamer can absorb a net of about 324 ft-lbs of fall energy. One way to think about this is that the piece gets the load it would have gotten if the fall was about two feet shorter. So if the total fall is four feet, the screamer effectively cuts that in half, but if the total fall is 20 feet, the screamer reduces that by 10%. Clearly, the bigger the fall, the less (percentage) load reduction a screamer provides, and so the less relevant it becomes. Screamers are best suited to short falls, which are more likely with aid climbing but can also happen with hard free moves near small gear. In the real world, there are enough additional variables to make even these modest conclusions less likely. Indeed, some tests by the CAI found very little effect in general and even found the screamer increased the load to the gear. No one I've heard from is exactly sure what that mechanism is, but one of the hypotheses is the tests were conducted with ordinary belay methods and the screamer decreased the loads enough for the belayer to hold the fall without any rope slippage, whereas having the rope slip a bit was actually more effective. You can find internet testimony about how gear that would certainly have pulled didn't because of a screamer. No one making these claims went back and ran exactly the same scenario without the screamer, so the claims are about as meaningful as saying the rabbit's foot you carried for good luck kept the gear from blowing. (Well, not exactly the same; we know the screamer might do something...) If you look a little more carefully, you'll also find accounts of gear with screamers blowing. It seems to me to be pretty much a wash in terms of testimony. So what to do? Screamers might do something for relatively short falls, although the same or better results might be obtained from a belay that allows some rope to run. For long falls there is very little chance that a screamer will have any effect. Is there a threshold fall length after which the screamer doesn't matter? I don't know and I've never seen anything that addresses that question. Climbers on sketchy ground often employ things that may not work, and screamers would seem to fit into that category. The danger would be a change in one's behavior predicated on the assumption that a screamer makes bad gear good. |
|
I take 2 when I'm on ice. I place them on my first 2 screws, when I have less rope in the system. After you have 30-40 feet of rope in the system the rope stretch limits enough "peak" force for me to be comfortable. They're also good to clip the top piece in your anchor when your leaving for the next pitch. |
|
rgold wrote: So, what you're saying is that in any force higher than 2kn, the screamer effectively isolates the piece from all force until full deployment? The screamer thus acting like a bridge that diverts the force through the effort required to rip through the stiches. My understanding from what I've read in various sources many years ago (that I'm having difficulty finding now in my cursory search while at work) was there there's an issue with the instantaneous application of force greater than 2kn that is transferred to the marginal piece because of the time it takes between the application of the force and the stitching to begin tearing. My understanding is that if you're using it to prevent a piece of gear from blowing, then it is totally worthless.My understanding at the time was that it seems like a similar issue to the equalization isn't real debate, where a force hits the marginal pieces of the anchor before the self-equalizing anchor setting has a chance to adjust itself. Meh, I'm probably wrong though as this kind of stuff is not my wheelhouse and I'm working off of faint recollections from research I did many years ago. |
|
kevin deweese wrote:That is my understanding. Edit: but not "isolation from all force." The screamer keeps the load on the piece at 2 kN during deployment. If the work done against the stitches doesn't exhaust the fall energy (and it is not very likely that it will in general), then the rope goes back to stretching, but doesn't have to stretch quite as much because of the absorbed energy, and so with less elongation attains a lower peak tension which would save some load on the gear. That's possible but I've never heard it Yates says the activation force varies by only +- 5%, so maybe the load gets up to 2.1 kN before activation. And as you can see from the following graph, the load builds (via rope stretch) until activation and doesn't climb to some much higher value for a short time, so I don't think see nor have I heard of evidence for some instantaneous high peak before the stitches rip. My understanding is that if you're using it to prevent a piece of gear from blowing, then it is totally worthless.I wouldn't go quite that far, but I do think its effect cannot be counted on and there pretty certainly isn't going to be an effect for long falls. My understanding at the time was that it seems like a similar issue to the equalization isn't real debate, where a force hits the marginal pieces of the anchor before the self-equalizing anchor setting has a chance to adjust itself.I'm not at all sure that's the mechanism for the failure of equlization, as there were static pull tests involved that didn't find equalization either, and the effect of different arm lengths is another mechanism altogether. |
|
Thanks rgold |
|
How many more pages can we go with no conclusion whatsoever?!?! I bet 10. |