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Catalystic Productions
Boulder climber
Arcata, CA
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Topic Author's Original Post - Dec 17, 2009 - 03:06am PT
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For the first time in the known history of slackline, a catastrophic highline failure has occurred. Had it not been for the backup implemented into the system someone most likely would have died. Luckily only a minor injury occurred.
Please take the time to read this article on slackline.com and learn from this mistake.
This is a prime example of why you ALWAYS use a back up and why you always place your back up on a separate anchor. Every highlines requires different rigging measures and always use your common sense and best judgment when rigging!
-Shaun
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enjoimx
Big Wall climber
SLO Cal
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Dec 17, 2009 - 03:26am PT
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Your always doing things "First" Andy!!!
Good thing nobody got hurt, and SCARY
Rope backups are super important. I remember my first highline was a single piece of webbing, 70 foot line. The webbing was actually messed up and was bottlenecking for a couple inches. We backed it up day 2, thank God.
Rob
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Mungeclimber
Trad climber
sorry, just posting out loud.
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Dec 17, 2009 - 03:43am PT
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"constant element of guessing, and trusting"
really? why guessing? I don't slack, so not sure I follow this idea.
calculated yes, but not guessing
good to learn
like in soloing, be ready to walk away from the set up in the first place allows good choices, eh?
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Catalystic Productions
Boulder climber
Arcata, CA
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Topic Author's Reply - Dec 17, 2009 - 04:31am PT
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What he means is that you don't always know how much force your applying to your anchors and line. When you're using bolts it's not that big of a deal but when using trad gear and natural protection such a slinging boulders it does matter. When you're trad climbing it's easy to say "oh yeah this cam or nut is bomber" but that same cam or nut might be the weakest point in a highline anchor. So there is a constant element of guessing and trusting when using natural pro in highline rigs.
-Shaun
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Scared Silly
Trad climber
UT
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Dec 17, 2009 - 09:04am PT
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Actually, it does not matter whether your anchors are trad gear or bolts. Both will and have failed. People falsely thinks bolts are automatically bomber. Well they might be and they might not be. All depends on the rock and the knucklehead who put them in. IMHO the vast majority of people rigging use PIROMA techniques.
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pFranzen
Boulder climber
Portland, OR
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Dec 17, 2009 - 12:31pm PT
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really? why guessing? I don't slack, so not sure I follow this idea. When you see 3 people yarding in on a slackline with a 3:1 pulley ratio to get it tight there is likely a fair amount of old-fashioned assumptions going on. I'm sure there are plenty of people out there who have done the math and can tell you off the top of their heads how much force is being put on an anchor for a given line, but I would say that most of the time a slackline is installed it's just 2 "bomber" anchors and a lot of tension.
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WBraun
climber
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Dec 17, 2009 - 12:47pm PT
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Without any photos or diagrams of the actual setup there's not much to go on for understanding this completely.
Even if you have a backup and the slack line goes slack the slacker walking the thing can pop off.
Then the slacker trying to grab the line with slack in it can cause a shock bounce and the slacker loose grip falling to the ground (if they are soloing).
You got anything we can see on your failure?
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Clint Cummins
Trad climber
SF Bay area, CA
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Dec 17, 2009 - 01:15pm PT
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The block/boulder sliding failure sounds a lot like when Todd Skinner and Paul Piana almost died on top of the Salathe' Wall. Their boulder slid also when they were hauling a lot of weight. It cut parts of their anchor and shredded ropes, but somehow they survived.
It sounds like the testing of the highline was inadequate.
Shouldn't there be a test where a guy goes out onto the line and jumps up and down on it? (He should have a belay rope that goes to a separate anchor).
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neebee
Social climber
calif/texas
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Dec 17, 2009 - 02:28pm PT
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hey there say, all.... bump for all this info to get seen now...
keep learning all....
god bless...
edit: oooopssss, just remembered, clint: please EMAIL me, got a question...
thanks so very much! :)
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Catalystic Productions
Boulder climber
Arcata, CA
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Topic Author's Reply - Dec 17, 2009 - 02:31pm PT
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I wasn't there so I can't really answer too many of your questions but what I can say is that highline rigs are not like janky lowline rigs with a couple of carabiners and some webbing. You need first hand experience to rig highlines safely and in this event we can see that experience didn't exactly pay off.
What I can say about the rigging used in this case is, the backup that saved the guy was the line he was walking on. It was a double threaded line with 2 pieces of 9/16" on the inside. On both ends the longer piece of 9/16" came out of the line and was linelockered and attached to separate anchors. This is a system Andy came up with over the past year and has been using pretty regularly. I personally do not use this system and would rather have a nice separate climbing rope attached to my line so that if something like this were to happen to me, the back up would not be shock loaded by the tension that was in the line. Anyways, I'll try and get Andy to post up some more details.
-Shaun
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the Fet
climber
Tu-Tok-A-Nu-La
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Dec 17, 2009 - 05:29pm PT
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Is it a catastrophic failure if the backup does what it's designed to do?
Does anyone know what the approximate forces are put on a slackline anchor?
A V-angle of 175 degrees puts 1146% of the downward force on each anchor. Plus add the pre-tension. That's some scary force.
180 lb slacker * 1146% = 2062 lbs on each anchor. Biners are good for about 5000 lbs properly setup (1350 to 1800 lbs open gate or cross loaded). 1" webbing is about 5000 lbs too(no knots) What force will a bouncing slacker generate? If its 2 Gs, that's 4125 lbs on each anchor.
Webbing will stretch a few percent limiting forces, but you take most of that out when you tension it.
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Catalystic Productions
Trad climber
Arcata, CA
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Topic Author's Reply - Dec 17, 2009 - 05:39pm PT
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It's considered catastrophic when the line or anchor fails. As stated this has never happened before.
The majority of highliners use steel carabiners, the ones I use and Andy use are 65kn Omega Pacific's. Slackers developed a method of removing all knots from the webbing by making linelockers (see picture where line is attached to pulley) which allows for webbing to break at it's MBS. Spansets are generally used because they're burly as all hell and pretty resistant to abrasion. A lot of people use shackles in powerpoints where triloading is occuring.
If you're interested in learning rigging techniques check out slackline.comand visit the forums.
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the Fet
climber
Tu-Tok-A-Nu-La
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Dec 17, 2009 - 07:05pm PT
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Thanks Shaun.
I haven't highlined, too many other activities and responsibilities taking up my time to get into it. But I do setup regular lines. And I may hook up with someone on a Rostrum or other highline at some point so it's good to see what a correctly setup system looks like.
It's easy to imagine a burly setup like that generating enough force to move a boulder.
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Mighty Hiker
climber
Vancouver, B.C.
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Dec 17, 2009 - 07:11pm PT
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I'm not a slacker, but wonder if anyone has done an analysis of the engineering and physics of slacklines? Just working from force triangles, it looks like a slackline could generate enormous forces, forces much greater than we usually encounter in climbing.
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Catalystic Productions
Trad climber
Arcata, CA
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Topic Author's Reply - Dec 17, 2009 - 07:52pm PT
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Actually there are quite a few folks in the slackline realm who have backgrounds in engineering and physics. I've personally done some force calculations on anchors. You can find my work on this page and a pretty decent discussion.
The stuff I was doing was more or less proving that by changing the angle or your anchor, changes the force upon your anchor and if you increase the angle you increase the force. A lot of folks have done tests with a dynamometer but are hesitant to share their results which is boogus in my opinion. Having real world numbers would actually allow slackers with engineering and physics background to figure out some true forces rather then just theoretical forces.
Calculations Page 1
Calculations Page 2
Calculations Page 3
Edit:
As far as what Fet said, that's a huge speculations and I've never heard of or seen someone create an angle greater then 90 in a slackline rig. So those numbers your posted a irrelevant for the most part, but it does point out the obvious, your anchors need to be bomb.com.
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GhoulweJ
Trad climber
Sacramento, CA
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Dec 17, 2009 - 08:36pm PT
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Let me know if your in Yosemite some time and want to borrow a dynamometer.
Happy to help.
Jay Renneberg
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Moof
Big Wall climber
A cube at my soul sucking job in Oregon
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Dec 17, 2009 - 08:49pm PT
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Free solo a slack line? Strange concept to me, as slacklining is inherently closer to aid climbing than free soloing.
Most of the "slack" lines I've witnessed were anything but slack. The stoners setting them up were anything but safety conscious, let alone capable of figuring out the forces (I saw one with about a 7:1 rigging and 3 dudes yarding on it, scary tight).
It will be a good day when this dud of a fad dies out.
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Catalystic Productions
Trad climber
Arcata, CA
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Topic Author's Reply - Dec 17, 2009 - 08:57pm PT
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Hate to break it too you Moof but slackline is approaching the 40 year mark pretty soon, so unfortunately for you it's not going away. Sounds to me that if you saw someone rigging 7:1 then they probably weren't the dumbass stoners you're making them out to be because rigging 7:1 is pretty complicated. Nice try though I applaud your effort to demoralize a sport you obviously know nothing about. Maybe you can go flame a topic which isn't related to life and death since you obviously don't have anything constructive to say. I also have no idea how you can connect slacklining to aid climbing... Free soloing means you don't have a leash which means if you fall and don't catch the line you die.
Ghoulwej I'll actually be in Sacramento this Sunday for the next week and half. If you have a dyno that can be used I would love to rig with you. My engineering buddy and I are both from Sac and we were planning on spending a good amount of time over break working some calculations so that we could maybe post up a solid slackline physics paper. Shoot me an email at catalysticproductions@gmail.com.
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