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Post links and comments about your favourite climbing flicks

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Climbing and highlining the Totempole HD


shortman

11-Apr-2013
5:48:46 PM

On 11/04/2013 egosan wrote:
>That is kind of cool. Webbing made from Dynama/Spectra/Whatever/Ultra-high-molecular-weig
>t-polyethylene. You pay for it though. 10 bucks a meter. Gonna need a
>grant to rig that line from the Bluffs to the Organ Pipes. Hell even that
>line from Dunes to Missing Link was at least 500.

Friggen weird/hard demonic hybrid between slacklining and wire walking those type of lines. I've got halfway across a 45 m line. Struggled like all f*ck the whole way.


shortman

11-Apr-2013
5:56:27 PM

On 11/04/2013 One day Hero wrote:
>I have no idea, but I'm sick of people attempting to math geek things which
>are very easily measured, despite the measured values consistently coming
>in well below the geeked values. Someone will have tried a long line with
>a fat prick and a load cell and will have the results up on the interwebs.
>Go look and tell us what you find.

Alot more than 465kgs. I think we would both agree on that.

One day Hero

11-Apr-2013
6:04:46 PM

On 11/04/2013 shortman wrote:
>Alot more than 465kgs. I think we would both agree on that.

Put a load cell on one and measure it! I promise I'll agree with that.


shortman

11-Apr-2013
6:13:05 PM

Fark. I'll take the 'find it in the web' option then. Unless you supply the measuring device?

alpinejoy

12-Apr-2013
10:03:05 PM

Um, I'm not a physics geek nor have I ever high-lined but it seems pretty clear that it's going to produce huge amounts of force, especially if you whipper on to lanyard in the middle. That's basically a fall factor 2 onto a line which is going to multiply the force something like 550% compared to a regular fall on lead. (http://www.ropebook.com/information/vector-forces).

And I don't think this video is very good example of what should be acceptable level of risk for regular folk. Daniel Ahnen, the guy on the line is someone who pushed it at a different level to most (he died in the Himalayas a couple of years ago).

One Day Hero

12-Apr-2013
11:27:11 PM

On 12/04/2013 alpinejoy wrote:
>Um, I'm not a physics geek..........That's basically a fall factor 2 onto
>a line which is going to blah blah the blah blah
>
If you were a physics geek you'd know that talking about fall factors with regard to slacklines is utterly meaningless.

One Day Hero

12-Apr-2013
11:32:02 PM

On 11/04/2013 sliamese wrote:

>found that, WLL of 13.4kN suggests anchors with ultimate design load of
>65kn.

So all your rigging has a 5x safety factor? Apparently the theoretical maximum force from a factor 2 fall onto an anchor is about 15kN..........do you rig your hanging belays for 75kN? (8 wires or 6 cams, hehehe) If not, why do you demand a higher safety factor for slackliners than for climbers?

alpinejoy

13-Apr-2013
6:06:57 AM

http://photography.nationalgeographic.com/photography/photo-of-the-day/highline-gavea-stone-brazil/

Note the lanyard in the image. Now imagine him falling.

Are you saying that because it's attached to a slackline instead of a belayer that it's not just shy of a fall factor 2? At least a belayer can give out some extra slack.

uwhp510

13-Apr-2013
11:00:10 AM

On 13/04/2013 alpinejoy wrote:
>Are you saying that because it's attached to a slackline instead of a
>belayer that it's not just shy of a fall factor 2?

The slackline is the stretchy bit, not the lanyard.

𝄇⥀.⥀𝄆


sliamese

13-Apr-2013
7:01:03 PM

Hmm fall factors are entirely irrelephant. 2m fall on 2m lanyard plus 20m line means FF of 0.09 anyway...

15kN generated by a climber? Bull shit. Maybe in theory but given your body breaks at around 6kN im more worried about your spine. 5:1 is a fairly standard safety margin, used to be 8-1. The reason is stuff gets stressed abd damaged if loaded to just below breaking strain, cyclic loading makes it go snap. Hence safety margins and working load limits(Safe working load)

alpinejoy

14-Apr-2013
4:53:01 AM

Ok fair enough the stretch in the slackline is going to absorb some of the force "2m fall on 2m lanyard plus 20m line means FF of 0.09 anyway.." So the longer the slackline the lower the force?

Paul

14-Apr-2013
5:55:24 PM

On 13/04/2013 sliamese wrote:
>Hmm fall factors are entirely irrelephant. 2m fall on 2m lanyard plus 20m
>line means FF of 0.09 anyway...

Wouldn't the fall be more than 2m, lanyard attached to slackline at foot height and harness at waist height? surely that would be about 3m fall? However the slackliner would probably be falling to one side rather than droping straight down so it could be more of a swing than a straight drop?

>15kN generated by a climber? Bull shit. Maybe in theory but given your
>body breaks at around 6kN im more worried about your spine. 5:1 is a fairly
>standard safety margin, used to be 8-1. The reason is stuff gets stressed
>abd damaged if loaded to just below breaking strain, cyclic loading makes
>it go snap. Hence safety margins and working load limits(Safe working load)


ajfclark

14-Apr-2013
6:35:39 PM

On 14/04/2013 Paul wrote:
>Wouldn't the fall be more than 2m, lanyard attached to slackline at foot height and harness at waist height? surely that would be about 3m fall?

Your waist is 1.5m from your feet?

One Day Hero

14-Apr-2013
6:47:31 PM

What happens to the line the instant you fall off? Hmmmm, that's right, you don't go as far as you think.

alpinejoy

15-Apr-2013
6:22:54 AM

"15kN generated by a climber? Bull shit. Maybe in theory but given your
body breaks at around 6kN im more worried about your spine."

I don't know about 15kn but you are missing the point. The force at the anchors on a slackline is many times greater than the force initially generated by the person falling onto the lanyards. You can try it yourself, attach a tight cord between two 5kg weighted things, then hang 1 kg weight in the middle. Watch as the 1 kg pulls the two 5kg weights over.

https://www.youtube.com/watch?v=8gzZGHyuV7c

Olbert

15-Apr-2013
7:04:38 AM

On 15/04/2013 alpinejoy wrote:
>stuff

I'm not sure why you are arguing. ODH isn't arguing against the theory, he's arguing that you should actually cite some results to confirm the theory.

Also some of your physics makes me angry.


shortman

15-Apr-2013
7:17:29 AM

On 14/04/2013 ajfclark wrote:
>On 14/04/2013 Paul wrote:
>>Wouldn't the fall be more than 2m, lanyard attached to slackline at foot
>height and harness at waist height? surely that would be about 3m fall?
>
>
>Your waist is 1.5m from your feet?

Almost, :)

alpinejoy

15-Apr-2013
5:10:21 PM

Sorry didn't mean to sound so argumentative.

Ok here are some results:

36 meter highline on some new product called "Vectran webbing". It's a low stretch webbing for longer lines so obliviously higher forces than most slacklines.

54 kg weight dropped on dynamic rope lanyard from 30cm above the line.

19 kn recorded at anchor:

http://www.youtube.com/watch?feature=player_embedded&v=V83otceITf8

http://www.balancecommunity.com/Slack-Science/gear-test-leash-fall-simulations

OK so this isn't just regular webbing, but people seem to be using these low stretch lines. Dean Potter makes a 24kn rated pulley explode just tensioning his low stretch line:

http://www.youtube.com/watch?v=CPkioA0VFf4

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