Chockstone Forum

      Sponsored By
      ROCK
   HARDWARE

Chockstone Photography

Australian Landscape Prints

Chockstone Forum - Gear Lust / Lost & Found

Rave About Your Rack Please do not post retail SPAM.

Author

Comments sought on natural anchor design


IdratherbeclimbingM9

26-Jul-2012
1:37:00 PM

On 25/07/2012 Tim_1964 wrote:
>M9 - I dont suppose you could sketch it out?

Sorry, no.
My 'putersmarts (and time to devote to it), has limits!

The issue of knots and adjustments to slack in the system is no big deal (as long as appropriate knots correctly tied are used), and I am pedantic so was pointing out that it is easier to make the adjustments from the location of where the three anchor strands converge, than running backwards and forwards x 3 to do the same job...
~> A giant cordelette style anchor system does the same thing!


pmonks

26-Jul-2012
2:18:02 PM

On 26/07/2012 tnd wrote:
>Do you always climb facing out Pete? ;-)

No silly - it's a glass cliff and the diagram is drawn looking out. ;-)


IdratherbeclimbingM9

26-Jul-2012
2:30:49 PM

On 26/07/2012 pmonks wrote:

>>On 26/07/2012 tnd wrote:
>>Do you always climb facing out Pete? ;-)
On 26/07/2012 pmonks wrote:
>No silly - it's a glass cliff and the diagram is drawn looking out. ;-)

... There he goes throwing people off the scent again!
~> It's a tatt on the back of his head to stop the ~~ODH chockypost~~ magpie attacks, while elaborating on training techniques...
☻

One Day Hero

26-Jul-2012
3:05:56 PM

Here I was thinking that 'backs to the wall' might be a special technique developed by San Fran climbers

uwhp510

27-Jul-2012
9:56:29 AM

On 26/07/2012 egosan wrote:
>Can someone gives us a little curve of peak force against the length of
>the slump on a "theoretically static"top rope?

Here you go.


muki

27-Jul-2012
2:40:21 PM

On 26/07/2012 pmonks wrote:
>On 25/07/2012 muki wrote:
>>I would stick with a totally static system
>
>I wouldn't - even short slumps on a static rope can generate dangerous
>loads on your body and the anchors.

think of the shock loading a base or skydiver gets when they open their canopy, I would call this a severe shock load, but every part of the system is a static component.
and yet they suffer no injures as a result of this?
it would take a fall of 1 metre to get your "dangerous loads" so the myth of slumps onto static rope resulting in one is one I have put to the test often and found no evidence that it is in any way true, sure your dynamic is spongier on falls and thats nice cos you get to do the move you fell off again, but often when working the moves the ability to stay at the holds your falling of is an advantage, so as to be able to try another sequence, without having to climb back up to do so.

>The only potential problem with this setup is that I'm using the same
>device on each strand of the rope. I'd originally tried using a grigri
>on one of the strands, but having to stop every other move to feed rope
>through the device sucked.

due to the Gri Gri not being modified to run on the rope, It would make as much sense as putting an auto locking stitch plate on the rope!


muki

27-Jul-2012
2:46:51 PM

On 25/07/2012 Stugang. wrote:

>Would you use a rope log for your ropes in that situation?

Im using an online rope log now so much cheaper than paper version

One Day Hero

27-Jul-2012
2:48:20 PM

On 27/07/2012 muki wrote:

>think of the shock loading a base or skydiver gets when they open their
>canopy, I would call this a severe shock load, but every part of the system
>is a static component.......
......except the canopy/air combo which is most certainly not static and performs all of the energy absorption. Bad comparison.

Don't forget that static ropes are still almost half as stretchy as dynamic ones, plenty enough stretch for little toprope slumps. I just use my old dynamic ropes for this sort of crap, it's fine as long as you pad all the edges and you're not trying to dog a hard sequence.


IdratherbeclimbingM9

28-Jul-2012
11:09:18 AM

On 27/07/2012 One Day Hero wrote:
>Don't forget that static ropes are still almost half as stretchy as dynamic ones,

?
I haven't looked up the stats recently but I thought 11 mm statics generally have less than 2% stretch under bodyweight, while equivalent diameter dynamics typically have 8% to 10% under similar loading.


muki

29-Jul-2012
1:39:47 PM

On 27/07/2012 One Day Hero wrote:

>......except the canopy/air combo which is most certainly not static and
>performs all of the energy absorption. Bad comparison.

if it performed "all the energy absorption", then when you deployed the shute you would feel nothing, as this is definitely not the case, then the static elements in the harness, leaders, and strands, etc do shock load the occupant, do you think this is a gentle shock loading ? how much force is generated in terms of G force ? this loading is way higher than a slump onto a top rope which is being touted as severe and dangerous by others here on the forum @ pmonks, which is untrue,

>Don't forget that static ropes are still almost half as stretchy as dynamic
>ones,

static "half as stretchy" bad comparison.

One Day Hero

30-Jul-2012
10:19:42 AM

On 29/07/2012 muki wrote:
>
>do you think this is a gentle shock loading ? how much
>force is generated in terms of G force ?

Fuch knows? 2 or 3g I'd guess, not nearly as much as you probably think.

>this loading is way higher than
>a slump onto a top rope which is being touted as severe and dangerous by
>others here on the forum @ pmonks, which is untrue,

Yeah, I don't disagree with you there.

> static "half as stretchy" bad comparison.
>
Well, maybe I'm exaggerating a little. I'm sure when I first started buying climbing ropes the stated static elongation with 80kg was only 4 or 5%.

One Day Hero

30-Jul-2012
10:26:59 AM

On 29/07/2012 muki wrote:
>
>if it performed "all the energy absorption", then when you deployed the
>shute you would feel nothing.................

Nope, that's wrong as. However, I don't feel like going on a rant about the difference between energy and force, so you'll have to take my word for it.


muki

30-Jul-2012
10:42:14 AM

True, 3% to 5% elongation is a generalism for most 11mm static ropes but can be higher if a skinier static or dynamic rope is used.
I use a 10mm static or an old dynamic, and have never had a bad shock loading on a slump onto these systems.
But I also recomend no exesive amounts of slack be allowed to enter the sytem
Whatever system is used, this is the most important to reduce any high loadings.


pmonks

31-Jul-2012
7:50:38 AM

On 29/07/2012 muki wrote:
>a slump onto a top rope which is being touted as severe and dangerous by
>others here on the forum @ pmonks, which is untrue,

A slump may not be dangerous, but how about a 50cm fall? A 1m fall? A 3m fall?

I've experienced all of these while top-roping, for a variety of entirely normal reasons, and I'm fairly certain I wouldn't want to have taken any of them on a static rope.

An example from just this weekend: I was solo top-roping a route (the one in the background of this photo, for anyone who gives a crap), and didn't have enough weight on the bottom of the rope. As a result I needed to pull rope through the mini-traxions from time to time. The route is a sustained slab for the top 3/4 though, so the only stances where I could stop to pull slack through were where there were (infrequent) edges. As a result there were a few sections where I would have fallen (slid) a metre or two before the rope would have taken.

Thankfully (a) I didn't fall and (b) the traxions started feeding themselves (due to rope weight) about halfway up the slabby section, but I would have been a lot less happy if I'd been on a static rope (which I wasn't). And I learnt my lesson: ensure the weight on the rope is completely off the ground, including rope stretch, before leaving the ground.

Now with all that said, I expect you'll continue doing whatever the fark you want and I wish you the best of luck with it. All I can do is point out the dangers of climbing on a static system so that others who are less informed don't jump in without understanding the risks and risk ending up in a body bag.

PDRM

31-Jul-2012
8:28:26 AM

On 31/07/2012 pmonks wrote:

>An example from just this weekend: I was solo top-roping a route (the
>one in the background of this
>photo, for anyone who gives a crap),

Pete,

What weird looking rock. Looks like crazy paving.

P

uwhp510

31-Jul-2012
9:56:37 AM

On 31/07/2012 pmonks wrote:
>On 29/07/2012 muki wrote:
>A slump may not be dangerous, but how about a 50cm fall? A 1m fall?
>A 3m fall?

Don't forget that fall factors work for top-rope falls as well, except that they are usually WAY lower than for lead falls. It makes absolutely no sense to talk about the length of fall that is acceptable, without talking about the amount of rope you've got out. The moral of the story is that you can fall as far as you like on your static rope, provided you make sure that your fall factor is low enough.

Given that dynamic ropes, plus all the other gear that we use... (maybe not mini-traxions though but grigris for sure)... are made to deal with at least one factor 2 fall, and assuming you've got a reasonably low stretch static (3% extension under body weight, ie 3 times as stiff as a normal dynamic rope) you could fall 3m, provided you've got 3 x 1.5m = 4.5m of rope above you, and generate roughly same force as your 3m factor 2 fall on a dynamic rope. I think that we can all agree that if you're falling 3m when solo top roping, you're doing it wrong, but if you really want to fall 3m, then put your anchors more than 4.5m above or back from the top of the route and you'll be (mostly) fine.

Now say you've got a super stiff polyester rope, with only 1% stretch under body-weight (ie 10 times as stiff as a dynamic rope). Then you can fall 3m, provided you've got 10 x 1.5m = 15m of rope above you. Not ideal, but probably not likely to lead to imminent death, provided you manage your system well.


muki

31-Jul-2012
10:11:56 AM

On 31/07/2012 pmonks wrote:
>On 29/07/2012 muki wrote:
>>a slump onto a top rope which is being touted as severe and dangerous
>by
>>others here on the forum @ pmonks, which is untrue,
>
>A slump may not be dangerous, but how about a 50cm fall? A 1m fall?
>A 3m fall?

as I said a slump is not dangerous..... 500mm 1m 3m these are not slumps and as I said do not allow slack to enter the system.

>I've experienced all of these while top-roping, for a variety of entirely
>normal reasons, and I'm fairly certain I wouldn't want to have taken any
>of them on a static rope.

bad habits need breaking pete, you should never allow this to happen using a solo top rope system for a variety of very good reasons.

>An example from just this weekend: I was solo top-roping a route (the
>one in the background of this
>photo, for anyone who gives a crap), and didn't have enough weight
>on the bottom of the rope.

classic beginners mistake number one.

> As a result I needed to pull rope through the
>mini-traxions from time to time. The route is a sustained slab for the
>top 3/4 though, so the only stances where I could stop to pull slack through
>were where there were (infrequent) edges.

at the point of noticing the problem,you should have stopped, and taken the time to rectify the problem before it was too late, classic begginers mistake number two.

> As a result there were a few
>sections where I would have fallen (slid) a metre or two before the rope
>would have taken.

this would create the high loadings (even on a dynamic system) that you are trying to warn other about.

>Thankfully (a) I didn't fall and (b) the traxions started feeding themselves
>(due to rope weight) about halfway up the slabby section

shock loading traxions on a rope is quite unhealthy for said rope due to the teeth inside a traxion, infact it is a major concern to all rope access profesionals and as such is regarded as an instant fail in testing tthe competancy of profesional rope access personel....... I would not like to do this to a rope regardless of dynamic or static as sheath seperation from the core can be the result.

>but I would have
>been a lot less happy if I'd been on a static rope (which I wasn't). And
>I learnt my lesson: ensure the weight on the rope is completely off the
>ground, including rope stretch, before leaving the ground.

well even this late stage in the game it is good to see you learning valuable lessons that might save your life and the lives of the people you choose to climb with.

>Now with all that said, I expect you'll continue doing whatever the fark
>you want and I wish you the best of luck with it.

sounds to me that with your near miss the other day, you could do with some of that yourself !

>All I can do is point
>out the dangers of climbing on a static system so that others who are less
>informed don't jump in without understanding the risks and risk ending
>up in a body bag.

the things you mention that you did wrong recently are a great example and im sure that it will help others stay safe in the future, thanks pete.

One Day Hero

31-Jul-2012
11:07:15 AM

Btw, I don't really see the point in getting fired up over this one. I use an old climbing rope for this sort of nonsense, the stretch doesn't matter because I pad the top edge and I'm milage training, not working hard routes. If I owned a static I'd be happy to use that too, would just pay a little more attention to not letting slack build up. Also, the devicy things run a lot smoother on vertical walls than on slabs.

Just remember, it's only toproping (not proper climbing)...........if things are getting sketchy, then you're doing it wrong!


pmonks

31-Jul-2012
2:04:08 PM

On 31/07/2012 muki wrote:
>bad habits need breaking pete, you should never allow this to happen using
>a solo top rope system for a variety of very good reasons.

Who said anything about these falls occurring while top rope soloing? All I'm pointing out is that I have experienced bigger falls while top roping (traditionally, as it turns out) than I might have expected when I started out.

Ultimately climbing isn't a game of absolutes or simple single-factor failures. It's about a whole slew of semi-dependent variables that (if enough of them line up the wrong way) mean you're facing a one way trip to the morgue. As a first year apprentice on the top rope soloing path, this is part of the reason I'm going to the lengths I am - two ropes down the cliff, highly redundant anchors (more bomber than I'd bother with when traditionally top roping), doubled locking carabiners, testing the setup before leaving the ground, carrying sufficient gear to anchor myself to the cliff halfway up if needed etc. etc. blah blah ad nauseam. It's all about making the safety envelope is big as possible (leveraging my existing climbing experience) while I'm learning the specifics of top rope soloing.

However your continued insistence that a static rope used for top roping is just as safe as a dynamic rope is flat out bullshit. Static systems reduce the safety envelope to the point that they constitute a risk I wouldn't accept (for any type of climbing, let alone top rope soloing). Given that newcomers to the sport do frequent this site, I feel compelled to warn others about that risk too.


pmonks

31-Jul-2012
2:07:00 PM

On 31/07/2012 PDRM wrote:
>What weird looking rock. Looks like crazy paving.

It's granite, but did look weird from a distance - I actually thought it looked a bit like old-skool reinforced concrete! Shame the inclusions didn't actually form features - the slab was a lot blanker than it looked (as is usually the case for granite, I've found!).

This is one of the top roping areas at Donner Pass near Lake Tahoe, fwiw.

There are 52 messages in this topic.