UKC

Charlie Woodburn has made the fourth ascent of The Walk of Life at Dyer's Lookout in Devon.

"I'm pleased that a shandy-swilling southerner has done it at last. It makes a nice change from all these northern wads coming down and having all the fun..."

Full report and photos by Simon Wilson:

Read more at http://www.ukclimbing.com/news/item.php?id=59099

In reply to UKC News:

well done! I think this is probably going to be a lifetime goal of mine

In reply to UKC News:

amazing effort!

In reply to UKC News:
Fantastic work, congratulations!

One question - why is it quite common for top climbers using marginal gear on long routes to use short quickdraws?
I know that if I were in that position I'd be, if not extending them, using 25cm draws to prevent rope drag (which would be hellish on such a long pitch, even if it is straight). On this route I noticed that James Pearson in Committed 2 also used 10cm draws. Am I missing something clever?

Also why do very few climbers using marginal gear on top-end routes use screamers? I think I noticed DM using some on the picture of his latest slab, but I can't think of any other examples.

In reply to Tdubs:

I think the line is pretty direct so sporty draws used

Nice one Charlie, becoming a trade route that WOL.

Screamers don't work for falls greater than a metre or so - so I'm told be someone who really should know. Also - no-one gets on a hard route expecting to fall. Re: quickdraws - I suspect that this could be because you don't have time to lengthen quickdraws on hard routes, and not really the mental space to make a decision as to which QD to choose - easier to simply take them all the same and put up with moderate rope-drag.

In reply to Adrian Berry:


That is so wrong. Screamers work by lowering the peak force of the impact. Distance of fall has nothing to do with it.

In reply to Adrian Berry: Perhaps for falls of more than a metre the force will always be high enough to fully rip a screamer? Nonetheless it will have dissipated some of the force for you.

In reply to yesbutnobutyesbut:

Is it so wrong? I have increasingly seen reference to the fact that screamers are not as useful as we are lead to believe. I haven't seen much in the way of hard evidence, but there are clearly people about who have formed an educated opinion that there are situations where they aren't going to help much. For example, when you have more rope between you and the gear, will the stretch in that extra rope not result in a reduction in the peak impact force? From personal experience, I can vouch that short falls are harder than long ones.

In reply to Adrian Berry:

>Also - no-one gets on a hard route expecting to fall.

In a sense, on that basis you needn't bother with the gear at all. I know it's not that simple, but still you'd think an analytical type like Dave Macleod would have considered it, wouldn't you?


Surely on a headpoint like this the gear will be pre-racked at least (if not actually pre-placed)?

Top effort by Charlie W, lest we forget. I had some idea he'd been injured and had to retire - obviously I was wrong!

jcm

In reply to UKC News: good effort charlie

remember doing obsession fatale with charlie about 8 years ago after bumping into him at the roaches.

In reply to mark s: oh and forgot to say,good pics si

In reply to Tdubs:

Yeah, I too have noticed that. Obviously on short grit routes you may not have a choice, but I think there does seem to be a tendency to under extend, and I don't think it can always be a headspace thing Like Adrian suggests.

Well done to Mr Woodburn.

In reply to Tdubs:

Have another look at the runners, some of them are longer.

In reply to johncoxmysteriously:


He has had more comebacks than Tom Jones. Nice one Charlie.

Top effort, Charlie, well done!!

In reply to Tdubs: I basically agree with you.
After the leader chooses a stretchy rope and good belayer (vital!) and then arranges the gear available, what s/he can do to save marginal gear from popping out when weighed is limited: (1) extending each gear, (2) using load-limiting slings (aka Screamers) on marginal gear, (3) using DMM Revolvers in rope-side in almost all the gear, all to minimise the fall factor. It is not a rocket science, all one needs is A-level physics -- an old knowledge well established for hundreds of years.

As for (1), any bent in ropes by (QD of) gear increases the fall factor significantly, hence chance of the top gear popping out when weighed by a fall. Therefore unless it is a dead straight line, 10cm QD is not unlikely to be of no use in trad, where marginal gear is expected somewhere up there. The exception is when you (kind of) expect to fall onto that gear, namely for the last gear before the crux.
As for (2) and (3), there is hardly any reason not to use them (apart from cost!).

Having said that, there are of course some exceptions, as is everything else in climbing. An obvious one is they are marginally heavier than the normal gear (and bulkier for Screamers). It is up to a leader to choose to reduce the weight with sacrifice of the safety when things go wrong, in order to increase the chance of success. If one is that serious for the weight, though, I would say s/he should consider to use the lightest gear, such as, 6mm sling (Beal), Phantom (DMM) or Nanowire (CAMP), before making a risky trade of sacrificing the safety.

Masa

In reply to UKC News:
Good skills Charlie Brilliant effort. Fancy a swop, I'll jump on it and you can get on Muy Caliente! !
Fun times for 2011

T

In reply to UKC News: Nice one Charlie! Get in!

In reply to yesbutnobutyesbut:

Actually distance of fall does have something to do with it, or at least the fall factor does... Screamers reduce the peak impact force, but so does rope stretch. In principle, if the fall factor is low enough, the rope will already have done the job of the screamer, and the stitching won't tear.

In reply to UKC News:

That's a really impressive effort Charlie! Glad he's back on top form

In reply to Tim Emmett:

wanted to ask if you were going to jump on this at your spicy times talks!
good luck!!!

Good stuff Charlie Woodburn, and great to see the SW getting the media spotlight lately!

Sorry for the delay in replying.

I'd like to address comments on what I said re:screamers. Obviously I know how they are supposed to work - and the information I have been given comes from a third party who is immensely knowledgeable. I'm not a physicist and cannot verify this. The data comes comes from research by a manufacturer who then naturally did not pass this on.

Basic idea is this: a fall onto a screamer had two points of arrest. The first activates the release mechanism of the screamer, the second stops you. This is not a gradual process like ropestretch. The first point of arrest takes a lot of the rope stretch out of the process, so when the screamer rips and you hit it fully extended, the rope is actually quickly springing back to its shorter length - the inverse of what you want, so you're taking a fall onto a less than static rope, which actually increases the peak force.

I'm just the messenger here, and I won't reveal my source - they can come out should they choose to. It makes sense to me.

As for the other point re:quickdraws - the climber in question probably doesn't own long ones, just because someone is at the top of their sport doesn't necessary mean they have all the gear - I know one world-class climber who's rack is worse than most beginners'.

In reply to Adrian Berry:


Thanks Adrian - very interesting. It will be interesting to see if the more mechanically minded here are convinced or not.

In reply to TobyA:

I happened on this thread and think I can offer some insights without invoking too much of the underlying physics.

A rope provides variable resistance to elongation, and this gives it the ability to absorb high fall energies by becoming stiffer and stiffer as it elongates. In fact, resistance is proportional to percentage stretch, not to absolute elongation, and this translates into the fact that peak loads depend, ideally, on the fall-factor and not on just the height of the fall.

A Screamer is different in two ways. (1) When ripping, the Screamer offers a constant resistance---unlike the rope this resistance does not increase as the Screamer elongates. (2) The Screamer has a fixed length that does not increase as the climber advances up the pitch.

The consequence of these two conditions is that there is a fixed maximum amount of fall energy a screamer can absorb (equal to its full elongation times the resistance it provides). As the fall height gets bigger and bigger, the fixed amount of energy the screamer can absorb becomes a smaller and smaller portion of the total fall energy, and all the rest will still have to be absorbed by the rope. For this reason, the effect a screamer can have decreases as the height of the fall goes up; there is nothing like the relative effects of the fall factor that come from a scalable rope.

One way to view a screamer's effect on fall energy is that in terms of peak load to the gear, it essentially "shortens" falls by a fixed amount, which a back-of-the-envelope calculation suggests is a meter or so (depending of course on the weight of the faller). So if the height of your fall is two meters, the screamer absorbs half the total fall energy and your gear gets the impact of a one-meter fall, a significant lessening of the peak load. On the other hand, if your total fall is six meters, the screamer still only absorbs a meter's worth of fall energy, your gear gets the impact of a five-meter fall, and the effect on the peak load is negligible. For this reason, Screamers are only useful, in theory, for short falls.

In reality, all this may be optimistic. The CAI did a bunch of tests

http://www.caimateriali.org/index.php?id=27

that suggest that Screamers don't contribute significantly to peak load reduction in general.

In reply to TobyA:

The claim against screamers is based on timing, a dynamic situation. How long different parts of a process take to happen, and therefore what condition one thing's in when another gets going...

The humbler mechanically-minded might well therefore feel that without some high-speed photography or rather high-faluting numerical analysis (I mean numerical in the technical sense - running a bunch of computer models rather than writing a handful of equations) they're ill-placed to offer well-founded opinions.

Y

In reply to UKC News:

Awesome piece of climbing. Sparse and in-your-face venue.

Y