Pieces Pulling

[Yossarian]

A pricey piece pops plummeting Pete as he pisses his pants.

Lo and behold, his lower daisy catches him!

"Alleluia!"(choir of angels singing)

Whenever I found myself in pathetic Pete's predicament, I hand one hand on the lower daisy which absorbed some of the impact from the fall. However, if one was to fall straight on the daisy itself, would a factor two fall of this kind be a cause of concern? Allot of force is generated falling above an anchor on a static system.

I've seen small screamers that are made to be placed where your daisy attaches to your harness. I have also considered clipping the daisy to the aider by the second or third loop. This way the bar stitching could rip and absorb some of the impact.

Is the impact from falling directly on a daisy something to consider? Or has the prospect of portraying pathetic Pete paranoid me?

[This message has been edited by Yossarian (edited 07-24-2001).]

[Lambone]

Good question Yossarian, yes it is something to be worried about!

First, a static fall on to a daisy generates at least a factor 2 fall if not greater. Which is enough to severly tweak your back, and sends the impact forces on to your piece through the roof.

The real problem comes when you daisy fall on a hard aid climb, you risk ripping the pitch.

What can you do about it? I get my daisy off ASAP. After I bounce the piece above, and commit to it, I unclip my last daisy and flip the rope in. Once the rope is in you are golden.

I have heard (from petzl rep) that spectra daisies are more static than regular nylon. Adjustable daisys may slip under a factor 2 fall. And yates now makes a daisy with a mini screamer built in.

The best thing, get the rope in and your daisy off!

[Dru]

quote:

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Originally posted by lambone:

The best thing, get the rope in and your daisy off!

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Yeah, if you get it in quick, she won't have to pull your piece for you... and you will get it off - is that what this thread is really about????

 

[Ibex]

I have heard of some Petzl reps espousing lots of anecdotal advice against the use of spectra in daisy's/anchors/etc.

Rule to live by: "beleive 1/2 of what you read and none of what you hear"

*especially* when it comes from company reps

The stretch of a short piece of nylon under "normal use" is such a negligible amount (both as a percentage of its own length and in comparison to spectra) that spectra vs nylon would make no difference. Same holds true for web-o-lette's, runners etc....

In the event of a shock load on a daisy, the individual loops would rip around 800lbs (depending on your daisy) at which point the minor difference in elasticity is again... negligible because of the energy disapation from the stitches tearing. I am not saying it would be comfortable, fun, or advisable to use one's daisy as a mini-screamer, only that there is no appreciable difference b/w spectra and nylon in this instance.

I am no "aid master", and I can only agree with the above comment on clipping the rope ASAP and not risking a fall on a piece of webbing when possible. I only wanted to comment on the spectra vs. nylon issue.

Cheers!

------------------

Put a high price on your own head, or rest assured, no one else will.

[This message has been edited by Ibex (edited 07-24-2001).]

[Beck]

dropping more than just rope stretch/ runner stretch, any fall that generates any movement prior to loading is a dynamic fall.

the rigger mentioned a fall of 1 foot as a test drop length on some spectra runners they did. (If I'm remembering this all correctly)

[Dru]

I still don't get how falling on a daisy could generate dynamic fall. What pulls through to generate the dynamic extension???

I can see, if you were belaying someone on a rope made out of spectra, and they whipped, and you let a few feet slide through your atc, that would be a dynamic fall. but on a daisy??

[Yossarian]

quote:

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Originally posted by Beck:

any fall that generates any movement prior to loading is a dynamic fall.

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I think I understand what you are saying, but looking at your definition of a dynamic fall, it seems ALL falls would fall under this classification. After all, if there is no downward movement your not really falling are you?

 

[Ibex]

Dru,

In this sense we are refering to a dynamic fall as any load that is not gently settled onto an anchor.

ie. daisy off to a piece, climb up 2 ft, peel, and you take a 4 foot 'dynamic' fall.

[This message has been edited by Ibex (edited 07-24-2001).]

[Dru]

If I get you right, by "dynamic" you mean a "sudden" fall instead of a slow steady pull like you would get with a pull-tester?

[Beck]

Thanks, Ibex, exactly.

I'm just passing along the beta that spectra is best suited to use on belay stances, loaded/tensioned anchors and the like, the new data shows the stuff fails under short shock loads at less than rated strength.

[jblakley]

Ok I'll jump on the semantics bandwagon...what the hell is a static fall? Anyway you look at it you're accelerating at 32 ft/sec ^2 right. Ok I know I'm skewing the context of this but I'm bored at work right now. :-)

[Yossarian]

To venture further away from the topic but to expand on Beck's comments...

I also found spectra to fail before its rated strength. In a study comparing perlon and spectra on a tensile test machine, the spectra failed about 20% below its rated strength. However, it is also worth noting that all failure points were at the point where the cord was tied around the biner.

[chriss]

I think you are confusing "loading" and falling.

Static load or a dynamic load on a peice of gear..

Static load being a heavey mass (gravity).

Dynamic load being an instantious load of mass x velocity (falling).

I don't use a daisy at all. Use the rope in the lower piece as you shift weight to the upper peice. The rope at least has some dynamic absorption should the upper peice fail.

I use a fifi hook to hold in positon but a daisy could work. But only for that.

chris

 

[Dru]

Once upon a time i was nailing up "leviticus" (now free at 13a) and clipped into a fixed head, bounced, its rusted cable blew and i fell 2 feet onto a set of stacked Peenuts on my (nylon) daisy. it held. then when I bird beaked into the deadhead, and bounced, and moved onto the beak, the Peenuts fell out!!!!

so is this just theoretical or has anyone ever died or been injured by a spectra daisy or sling breaking in a climbing-type (aid or free) fall situation?

[This message has been edited by Dru (edited 07-24-2001).]

[Billy]

Just use one daisy. Then, you'll never be falling on a lower daisy, you'll have the rope clipped through.

[Dru]

if you aren't connected to your aiders, though, you face the all to real possibility of dropping them and/or falling out of them.

[Offwidthmeister]

Where is pencil puller's response? He seems to pull a lot of things.....

[Beck]

Regarding spectra vs. nylon, some guys I know that attended this years' Rigging for Rescue course in BC last month came back with new results that spectra slings and runners fail considerably below their kilonewton rating when even a small dynamic fall is induced on them. Don't know all the specifics, maybe is not so big a deal, but I went and replaced my spectra daisy with a fresh nylon one. Also, C&S (some WACKY manufacturer in Marysville ) makes some way burly daisy chains and other bomber gear.

[Dru]

quote:

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Originally posted by Beck:

Regarding spectra vs. nylon, some guys I know that attended this years' Rigging for Rescue course in BC last month came back with new results that spectra slings and runners fail considerably below their kilonewton rating when even a small dynamic fall is induced on them.

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Spectra is static, what do you mean by a dynamic fall????

 

[allthumbs]

quote:

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Originally posted by Dru:

Yeah, if you get it in quick, she won't have to pull your piece for you... and you will get it off - is that what this thread is really about????

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Heh there Dru, when I grow up and become a wannabe climbing legend like you, will I be able to make dumb-assed comments like yours? Get over yourself.

 

[Dru]

You don't have to grow up to become a dumb ass like me, you are one already...

[Beck]

Matt P and myself were talking about this at the Pub Club last night and think there have been no reports of spectra sling failure in Accidents in NA Mountaineering; it's all based on the relative brittle nature of kevlar used in spectra slings. Maybe we can get an industry rep response on this, I don't have any solid beta, just anecdotal. Also, that most slings are rated 16-22 Knewtons so even a 50 percent reduction in strenght is still pretty burly.

[This message has been edited by Beck (edited 07-25-2001).]

[allthumbs]

You're right about Kevlar being brittle. All offshore racers have known this forever. That's why no builder makes an all Kevlar boat. Kevlar is great stuff as an ADDITIVE to a well built FIBERGLASS boat. Probably should be used less liberally in ice tools too.