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Shockloading is bullshit

Olbert

29-Apr-2020
8:00:36 AM

https://www.youtube.com/watch?v=nr3YBDnOI8Q

I've always thought shockloading in practice was pretty bullshit - especially when they test factor two falls on a dynema with a 80kg weight. If a climber were to factor two onto a dynema there is plenty of stretch in the system which means the dynema would not break. Unfortunately, that stretch is the climber and therefore, it is the climber who will break.

I do wonder about holding ability of marginal gear when there is dynamic loading dynamic loading (ie loading with a bit of movement). And then add to that the change in direction of the loading.

capt_planit

29-Apr-2020
10:09:54 AM

Glad to hear it! I always spend so much time faffing about at anchor on other tasks that I have to skip most of the equalization anyway.

gordoste

29-Apr-2020
12:22:37 PM

I always thought the concern with shockloading was ripping the gear through higher forces, not breaking the dyneema or the climber.

It does sometimes happen that you set up an anchor without any rope in it - personally I avoid clipping my harness direct to this type of anchor. If you clip with the rope that's fine but many people are using PAS these days which gives me the heeby-jeebies.

Personally I decided to get a Kong Slyde with a short piece of dynamic rope to make a dynamic version of a PAS.

IdratherbeclimbingM9

1-May-2020
2:18:24 PM

>Shockloading is bullshit

No it's not. It's real and can have real consequence/s.

I watched the Youtube video that is linked within the original post; and all I learnt from it (re-affirmed actually, because I already knew somewhat from personal experience), is that these things are usually a matter of degree...
The Youtube vid simply put numbers to the real-life scenarios that it portrayed.

I have taken FF2's on a spectra daisy chain while aid climbing (once twice in quick succession!), and I have also accidentally taken greater than FF2 on a fifi hook during an aid-climbing fall. Neither the daisy, nor the hero loop attaching my fifi broke in those incidents. I did however suffer considerable bruising from my harness at the time/s...

I agree with gordoste in that the primary concern is how secure the gear or belay is under such loading.

Regarding equalisation of belay components, this too is important in mitigating cascade failure of a belay or critical piece of protection... which touches on Olbert's query of;
>I do wonder about holding ability of marginal gear when there is dynamic loading dynamic loading (ie loading with a bit of movement). And then add to that the change in direction of the loading.

Without good equalisation marginal gear WILL rip, though it can often be finessed into acceptable protection by careful attention to equalising potential loads and loading direction/s on the individual components.
~> Cue for egosan to comment here about how his hide was saved by an equalised matrix of a number of very suspect components of protection that were combined into a single unit, during his ascent on one of the Aidfest weekends a while back...

Edit: I was going to put a link to the relevant post of the fifi arrested fall, but my Trip Report (Buffalo Oysters) from it has lost the second half of its content during the subsequent Chockstone hack-attack preventative measures. Disappointingly my backup USB stick containing the original report seems corrupted and won't open...
There is a slim possibility that I have a paper copy of it somewhere, but if that exists I'm unlikely to find it any time soon!

Second Edit:
Here is egosan's TR from March 2010, that also has been shortened by the hack-attack preventative measures, though luckily it still contains his version of the matrix event...
http://www.chockstone.org/Forum/Forum.asp?ForumID=2&Action=Display&MessageID=5851&PagePos=0&Sort=
(Further clarification of that matrix by myself is in a following post on that thread).

PeterW

1-May-2020
3:12:54 PM

On 1-May-2020 IdratherbeclimbingM9 wrote:
> I have also accidentally taken greater than FF2 on a fifi hook during an aid-climbing fall.

My first thought was, "How is more than FF2 possible?"

My second was to guess that the hook caught on something as you fell past?

IdratherbeclimbingM9

1-May-2020
4:04:39 PM

On 1-May-2020 PeterW wrote:
>On 1-May-2020 IdratherbeclimbingM9 wrote:
>> I have also accidentally taken greater than FF2 on a fifi hook during
>an aid-climbing fall.
>
>My first thought was, "How is more than FF2 possible?"
>
>My second was to guess that the hook caught on something as you fell past?

Your second guess is correct.
It would have been a non-event (read 'routine clean-air on vertical wall type') fall of about 3 metres, except that my fifi snagged gear lower down while I was falling and statically arrested the fall before the lead rope took any loading.
The fifi was on a 20 cm loop girth hitched to my harness, and the fall length was probably a metre or so before the fifi snagged. It snagged on the pro that would have held the lead rope under belay tension!
I was somewhat baffled by it at the time and didn't get out my tape measure to get the exact numbers(!), but I know that last piece was below my feet at the time.
I marveled as much that the fifi didn't cut through the wire of the passive pro that arrested the fall!
;-)

One Day Hero

1-May-2020
4:45:19 PM

I can't understand why people are still rigging belays with slings and cord. Rigging with the rope seems to fix all of these made up problems.

Olbert

2-May-2020
8:55:50 AM

On 1-May-2020 One Day Hero wrote:
>I can't understand why people are still rigging belays with slings and
>cord. Rigging with the rope seems to fix all of these made up problems.

I often don't use the rope because I'm the one leading all the pitches. Having a partner comfortable with leading solves this but it's not a luxury I enjoy that often when at Arapiles...

Then again, it is a rare event for me to have to worry about anchor gear pulling. I steer well clear of death aid routes on granite.

phillipivan

2-May-2020
9:09:25 AM

Block leading and the possibility of rope stretching pitch lengths (to and past the point of necessitated simul climbing) are the reasons to not use the rope in the anchor. Admittedly not reasons that have a lot of applicability for Australian rock climbing.

Olbert

2-May-2020
9:10:36 AM

On 1-May-2020 IdratherbeclimbingM9 wrote:

>I have taken FF2's on a spectra daisy chain while aid climbing (once twice
>in quick succession!), and I have also accidentally taken greater than
>FF2 on a fifi hook during an aid-climbing fall. Neither the daisy, nor
>the hero loop attaching my fifi broke in those incidents. I did however
>suffer considerable bruising from my harness at the time/s...

Exactly - the gear didn't break - you absorbed the impact! Although I'm surprised you weren't more damaged by the incident.

>I agree with gordoste in that the primary concern is how secure the gear
>or belay is under such loading.
>
>Regarding equalisation of belay components, this too is important in mitigating
>cascade failure of a belay or critical piece of protection... which touches
>on Olbert's query of;
>>I do wonder about holding ability of marginal gear when there is dynamic
>loading dynamic loading (ie loading with a bit of movement). And then add
>to that the change in direction of the loading.
>
>Without good equalisation marginal gear WILL rip, though it can often
>be finessed into acceptable protection by careful attention to equalising
>potential loads and loading direction/s on the individual components.

Yeah - I don't disagree that sharing the load is important. It's just that as the stretchiness of the system descreases (ie the amount of dynamic rope is less or the lanyard is not dynamic), the less the fall factor matters. That is, if you were attached to a bit of pro by a one foot fifi hook whilst leading and fell two feet (FF2) you'd generate almost exactly the same amount of force on the pro as if you you took a took the same two foot fall on a two foot fifi (FF1). In this type of scenario the "stretch" in the system is you, not the lanyard.

The fact that your fall was more than FF2 has very little to do with the force generated. The length you fell does. You'd generate twice the force from a two metre fall as on a one metre fall regardless of the length of your fifi.

>~> Cue for egosan to comment here about how his hide was saved by an equalised
>matrix of a number of very suspect components of protection that were combined
>into a single unit, during his ascent on one of the Aidfest weekends a
>while back...
>
>Edit: I was going to put a link to the relevant post of the fifi arrested
>fall, but my Trip Report (Buffalo Oysters) from it has lost the second
>half of its content during the subsequent Chockstone hack-attack preventative
>measures. Disappointingly my backup USB stick containing the original report
>seems corrupted and won't open...
>There is a slim possibility that I have a paper copy of it somewhere,
>but if that exists I'm unlikely to find it any time soon!
>
>Second Edit:
>Here is egosan's TR from March 2010, that also has been shortened by the
>hack-attack preventative measures, though luckily it still contains his
>version of the matrix event...
>http://www.chockstone.org/Forum/Forum.asp?ForumID=2&Action=Display&MessageID=5851&PagePos0&Sort=
>(Further clarification of that matrix by myself is in a following post
>on that thread).
>

My original contention is that the amount of force generated in a "shock loading" situation, is very much smaller than the amount of force generated in any drop test done by DMM where they recommend never to attach to an anchor with dynema. I think a much more apt test would be doing an FF2 on a recent cadaver...though that might be a bit grizzly/unethical. Maybe someone has invented crash test dummies which mimic the human body?

One Day Hero

3-May-2020
12:24:46 PM

On 2-May-2020 phillipivan wrote:
>Block leading and the possibility of rope stretching pitch lengths (to
>and past the point of necessitated simul climbing) are the reasons to not
>use the rope in the anchor.

Could you clarify how A leads to B here? Whenever I've ended up simulclimbing, step 1 is to disassemble the belay (regardless of the anchoring method). The block leading thing is a bit more valid, but you can just switch rope ends.

It's not like I've never experimented with this stuff. Briefly tried a cordalette (hated it), rocked a couple of pre-assembled sliding-x "instant double bolt rig" things for a few years too. You can make any method work, but I've gone back to rigging with the rope. It's simple, adaptable to any situation, as fast or nearly as fast most of the time, don't have to carry big lumps of slingage like some bumbly, and you have built in shock absorption through the whole system.

Mr Poopypants

3-May-2020
6:56:33 PM

On 2-May-2020 Olbert wrote:
Maybe someone has invented crash test dummies which mimic the human body?
>

Ummm ... Ollie, they have - they call them "crash test dummies". Too many late nights walking up and down the hallway rocking you both to sleep???? :-)
Raspberries to the bub.
PP

gordoste

4-May-2020
9:07:21 AM

On 2-May-2020 Olbert wrote:
>My original contention is that the amount of force generated in a "shock
>loading" situation, is very much smaller than the amount of force generated
>in any drop test done by DMM where they recommend never to attach to an
>anchor with dynema. I think a much more apt test would be doing an FF2
>on a recent cadaver...though that might be a bit grizzly/unethical. Maybe
>someone has invented crash test dummies which mimic the human body?

Sorry I misunderstood your contention... basically you're saying that lab tests aren't realistic. Wait till you read about the UIAA testing...

https://sterlingrope.com/journal/232-fall-rating-really-mean

Olbert

4-May-2020
9:50:02 AM

On 3-May-2020 One Day Hero wrote:
>On 2-May-2020 phillipivan wrote:
>>Block leading and the possibility of rope stretching pitch lengths (to
>>and past the point of necessitated simul climbing) are the reasons to
>not
>>use the rope in the anchor.
>
>Could you clarify how A leads to B here? Whenever I've ended up simulclimbing,
>step 1 is to disassemble the belay (regardless of the anchoring method).
>The block leading thing is a bit more valid, but you can just switch rope
>ends.
>
>It's not like I've never experimented with this stuff. Briefly tried a
>cordalette (hated it), rocked a couple of pre-assembled sliding-x "instant
>double bolt rig" things for a few years too. You can make any method work,
>but I've gone back to rigging with the rope. It's simple, adaptable to
>any situation, as fast or nearly as fast most of the time, don't have to
>carry big lumps of slingage like some bumbly, and you have built in shock
>absorption through the whole system.

When swinging leads there is not much of a reason not to use the rope. When not swinging leads, untying and retying is pretty faffy and involves the use of slings anyway. Why not just use slings to build the belay and coil the rope in a way that won't snag when belaying the other direction?

I carry an extra sling or two - not a special cordelette. That way, I can use them during the pitch if I really need to (coping with the extra faff of a rope made belay) or use them to make the belay at the end.

One Day Hero

4-May-2020
9:23:13 PM

On 4-May-2020 Olbert wrote:
>When not swinging leads, untying and retying is pretty faffy and involves
>the use of slings anyway. Why not just use slings to build the belay and
>coil the rope in a way that won't snag when belaying the other direction?

You can just do that, but the situations where it doesn't work very well include;
-High anchor and you want to sit on a ledge rather than half hanging from your slightly too short slings.
-Belay placements spread out all over the place, and you can't reach with slings (common at Araps)
-Belay placements at the back of a wide ledge, and you want to belay at the edge where you can see your second (also common at Araps).

The situations where you can't rig with the rope include:
-61m pitch on a 60m rope and your second won't simulclimb.
-That's the only one.

I agree that in "multipitch guiding situations" rigging with slings is the way to go.

gfdonc

5-May-2020
9:48:24 AM

I'm a fan of rigging using the rope, but also often carry a cordalette.
Why? I'm a fan of redundancy - tied in via both. It's also easier to equalise. It's certainly easier if you're not alternating pitches, as I really dislike untying and retying in the middle of a wall.
If I was going light and fast, and alternating pitches, I'd leave the cordalette behind.

Olbert

6-May-2020
7:23:38 AM

On 4-May-2020 One Day Hero wrote:
>On 4-May-2020 Olbert wrote:
>>When not swinging leads, untying and retying is pretty faffy and involves
>>the use of slings anyway. Why not just use slings to build the belay
>and
>>coil the rope in a way that won't snag when belaying the other direction?
>
>You can just do that, but the situations where it doesn't work very well
>include;
>-High anchor and you want to sit on a ledge rather than half hanging from
>your slightly too short slings.
>-Belay placements spread out all over the place, and you can't reach with
>slings (common at Araps)
>-Belay placements at the back of a wide ledge, and you want to belay at
>the edge where you can see your second (also common at Araps).
>

Yup - and in those cases, I often use the rope. Occasionally, I deal with not sitting on the edge.

>The situations where you can't rig with the rope include:
>-61m pitch on a 60m rope and your second won't simulclimb.
>-That's the only one.
>
>I agree that in "multipitch guiding situations" rigging with slings is
>the way to go.

I often seem to be in 'guiding' mode when multipitching.

IdratherbeclimbingM9

9-May-2020
7:00:31 PM

On 2-May-2020 Olbert wrote:
(Snip)
>The fact that your fall was more than FF2 has very little to do with the
>force generated. The length you fell does. You'd generate twice the force
>from a two metre fall as on a one metre fall regardless of the length of
>your fifi.
And
>My original contention is that the amount of force generated in a "shock
>loading" situation, is very much smaller than the amount of force generated
>in any drop test done by DMM where they recommend never to attach to an
>anchor with dynema. I think a much more apt test would be doing an FF2
>on a recent cadaver...though that might be a bit grizzly/unethical. Maybe
>someone has invented crash test dummies which mimic the human body?
>
There’s a certain amount of logic to your contention, but I think that you’re minimising the role of time-factor involved in force attenuation.
This is where zypers (as gordoste uses), dynamic instead of static materials, and incorporating the lead rope into belays, etc, have huge benefits in saving broken bodies and buggered gear or belays!

There are 18 messages in this topic.