Screamers??

[underworld]

what's the general cunsensus on using a screamer that is semi deployed? seems like it could still be good if only a few of the threads actually ripped. they are cheap, i know, just wondering and starting discussion.

 

one shows a few ripped threads cuz it was used at a re-direct and weighted during jugging.

 

the other was fallen on 1st piece after the belay. a few threads ripped.

 

any thoughts?

[counterfeitfake]

I was reading something today that said the webbing in daisy chains is weakened where the bartacks blow... here, about halfway down, "Re: Belay anchors: why not use daisy chains?". I don't know whether this would be relevant for screamers, but I guess even if it is, you're not worse off than if the screamer deployed all the way at once...

 

I'd guess the screamer is still plenty good for absorbing some force, just not as much as it was originally.

[ketch]

The deal with Daisys is not that the webbing is weaker but that if you clip and the stitching blows you could be clipped into air.

 

As to the screamer I think that you probaly won't die. I have finished some trips with partial screamers and had no troubles. (of course after the initial fall I was a little more careful next time around ) Just be aware that it is not capable of dissapaiting as much force.

[counterfeitfake]

I'm aware of the issue you are talking about, this is a different point. From the article to which I linked:

 

Daisy's are weaker than runners because, as the pockets rip out, damage to the webbing occurs at the pocket tacks. In static testing the pockets rip out until you are in the standard runner configuration. The web breaks at the damaged area of one of the pocket tacks.

[JosephH]

They're good to the very last drop! I've done routes where between three or four of us we went through a couple dozen of them at the crux circular nest of equalized rp's before sticking the route. Given it was a very fragile nest we pre-sliced the screamers (Wild Things Air Voyagers back then) at a steep angle to flatten out the loading curve and then pre-sliced them again after each fall. We'd also sport tape them together with one thickness of tape after the first fall. Don't sweat it, they're fine to keep using...

[Jens]

Does anybody have any experience with clipping two screamers together in a row?

[crackers]

call (530)222-4606 and ask to speak to John. He made the very first screamers, and he's still making them for his company yates...he'll be happy to talk to you about it.

 

let us know what he says.

[underworld]

Does anybody have any experience with clipping two screamers together in a row?

 

think of springs... in a series (if they are the same type), then it will be no different in impact force. just more extension capability. if they are in parallel they will add up.

 

fyi springs in a series:

 

keq= (1/ka + 1/kb)^-1

 

parallel: keq = ka + kb

 

[selkirk]

Time to brush up on your math

 

Keq =(1/ka + 1/kb)^-1 if ka=kb (two identical screamers)

Keq =(1/ka + 1/ka)^-1 = (2/ka)^-1 = ka/2

 

The activation force should be the same but it should absorb more energy

 

From the Yates website

"Screamers can be combined in series to double or triple the total absorption. "

 

I'm such a geek!!