Got the old gears spinning....

[Jay]

Yup, the first thing I thought of after watching that video was that I'd probably be swapping out my PAS for one of these:

http://www.gearexpress.biz/Merchant2/me ... _Code=5440

[absolutsugarsmurf]

Before everyone cries out chicken little, notice that under the standard CE/ UIAA tests, the mass does not deform appreciably (i.e. it's a big block of concrete with a bolt in it). Your body, however, is not a big block of concrete. The test would likely be very different for a 80kg dummy made out of ballistics jell in a climbing harness (not that I'm criticizing the test, we do need standard test methods). Not that taking a factor 2 onto a daisy feels good, but it does happen often in aid climbing. Anecdotally at least, I've never heard of someone ripping off of the Captain because of a daisy fall. That being said, a dynamic connection to the anchor (i.e. your lead rope) is usually safer, but not always possible.

Short version: it's not likely you will generate the same peak force onto the sling as seen in that video because of deformation of your squishy parts. So go eat some brownies and be safe.

[Jay]

Before everyone cries out chicken little, notice that under the standard CE/ UIAA tests, the mass does not deform appreciably (i.e. it's a big block of concrete with a bolt in it). Your body, however, is not a big block of concrete. The test would likely be very different for a 80kg dummy made out of ballistics jell in a climbing harness (not that I'm criticizing the test, we do need standard test methods). Not that taking a factor 2 onto a daisy feels good, but it does happen often in aid climbing. Anecdotally at least, I've never heard of someone ripping off of the Captain because of a daisy fall. That being said, a dynamic connection to the anchor (i.e. your lead rope) is usually safer, but not always possible.

Short version: it's not likely you will generate the same peak force onto the sling as seen in that video because of deformation of your squishy parts. So go eat some brownies and be safe.

I wouldn't go so far as to say factor two falls onto a daisy happens "often" in aid climbing. In most aid scenarios, if you're above your top piece, and connected to it, your connection is via a fifi hook, not a longer daisy.

In any regard, squishy or not, the video clearly illustrates what could happen if you pitch off a ledge while connected to an anchor at waist height with just a sling-

Best case scenario- It will hurt like hell.
Worst:- Shit be breakin'

[absolutsugarsmurf]

Often was a poor choice of words. FF2 falls do SOMETIMES happen.

For anyone really concerned, this doc is a much better resource than the vid:

http://www.itrsonline.org/Papers/2009/H ... SPaper.pdf

It is a report on the usefulness of using dummies in drop tests. Their conclusion regarding FF1 falls onto Dynex slings (140cm) was (pg 12)

" More significantly, for dropping onto highly static systems such as steel cable (Figures3 and 5), or for dropping onto nonlinear systems such as Dynex (Spectra) daisy chains (Figure 8) or Purcell prussiks (Figure 10), the use of a steel load can lead to significantly unrealistic results (much higher peak loads, significantly more bartacks broken, very
different dynamics, etc.). In these tests, the use of steel loads may produce grossly misleading results rather than just conservative (higher force) results."

[p0bray01]

interesting....I guess I always tend to think linearly about physics in Force =force terms, but we do have to keep the properties of the mass that produces the force in mind as well. Good point smurf.

[jrathfon]

I'll back up sugarsmurf. There have been estimates into the forces generated by a falling (human) body vs. a steel or concrete mass, and they conclude that a rough estimate is that you AT LEAST half the forces.

FF1 and FF2's are definitely possible in aid climbing, not saying they happen all the time, this is why you keep your foot in the previous piece while bounce testing, but, well, sh!t happens (especially when moving fast and you forget to unclip your daisy from that previous piece while you step on to that next "bomber" piece, realizing it was not as "bomber" as you hoped for).

Another scenario for the FF1 or 2 was in an accident one or two years ago posted on rc.knob. A (not very educated) climber was clipped in direct to ~ the 3rd bolt, he "sussed" out some moves at this bolt, chalked, and when ready set out again climbing. Except, he forgot to unclip from being in direct (on a shoulder length sling), fell doing the "cruxy" sequence and FF2'd directly onto the bolt. Everything held (bolt, runner, biners, harness, etc.) but he had to be lowered due to extreme pain (I forget what his exact injuries were). So it could happen if you start to enact "sporto" tactics and ridiculousness (aiding through bolts, stepping in slings, high stepping on a bolt to make the next clip, while in direct, etc.), not saying it's common or not stupid, but hey, we're mainstream now!

[Jay]

Yup, I see videos like this:

http://www.youtube.com/watch?v=xparZFsBS40

and I wonder what would happen if an actual person were wearing that harness with that much force applied to it.

I assume person go breaky...