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thinksinpictures
Oct 28, 2003, 3:34 PM
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Disclaimer: this question is asked out of nothing more than curiosity. I have no intention of getting on a highline.
So I've seen how people set up a safety line when on very high slacklines, but I'm curious what sort of guarantee you have that the safety will hold. I know webbing is way strong when loaded parallel (as in a climbing anchor), but I imagine that it's much weaker when loaded perpendicular (when it's stretched horizontal and your safety line pulls vertically).
Anyone know what sort of force webbing can handle when loaded this way?
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rrrADAM
Oct 28, 2003, 3:42 PM
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Highlines tend to be three pieces of webbing not just one, so there is tripple redundancey. Look at pics of highlines, and you will see tape holding these lines together. There are also usually two lanyards connecting the person to the line for redundancey also.
Just as in climbing... Never trust your life to just one piece of anything. Always build redundancey into your systems.
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thinksinpictures
Oct 28, 2003, 3:48 PM
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Well, I suppose I just revealed myself as a highlining n00b. Pre-n00b is more like it, since I've never done it, never seen it done, and never really plan to. I'll stick to walking between the two maples at the local park, thanks :wink:
Thanks for the info though!
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piton
Oct 29, 2003, 1:56 PM
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what raddam left out is about the 3 lines Tension one just like you would on the ground. Tension the second on only half as tight.... and then hand tighten the third line.
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overlord
Oct 29, 2003, 2:19 PM
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^^^this could work. since the force on anchors (and line) is in relation with the angle of the line (straighter the line, bigger the force), you could get away with it (the first line is slack, so it has a bigger angle, meaning less force on the line and anchors).
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hikerken
Nov 15, 2003, 5:21 AM
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Registered: Nov 7, 2003
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Now wait a minute, guys.
The original post asked for specific information, that was not supplied.
This setup bears some serious analysis. First, the fall is more than a factor 1 fall, always serious. Second, the angle of the webbing means that there is approximatly 180, meaning that each anchor will experience about 600% of the force generated by the fall. Assuming that 1,000 # of force is generated, this is 6,000 lbs, on EACH anchor, and on EACH side of the webbing. 1" mil spec breaks at about 4,000, not counting knots.
Triple redundancy should provide adequate protection (might want to triple those biners, and be sure EVERYTHING is triply redundant.
I'm not sure what the effect of differential tighness would be on the three sections of webbing, but I don't think I'd want to just guess.
This, of course, is an "armchair" quickie analysis, but even if off a bit, there are SERIOUS forces at work here.
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