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linuxxpert
Mar 30, 2010, 2:40 PM
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So here goes:
I have this crazy idea about spanning a 400 feet wide 100 feet deep canyon with a rescue highline setup. Since these are big numbers (at least for me) I am doing a lot of researching into the forces that may be at work here and there are a few twists to the setup. I know that this a a slacklining forum but the same principles apply as far as I know.
This is what I'd like to use:
2 - 200 feet 10.5mm bluewater static lines tied together with a double figure eight with fisherman backup. (triple fisherman's would be better but I'll never be able to get it apart.)
3 anchors on each end using 3 good trees, each anchor will use a locking carabiners.
I've used the slack lining calculator and calculated about 1000 lbs force with a hand tightened 20 feet sag. This seems to be well in range with the 7000 lbs rated line even with the tied knots. (the sag can be increased if required)
Is this a bad idea? Will this work? Please only serious answers please.
Thank you in advance for your advice.
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soNVclimbing
Mar 30, 2010, 3:28 PM
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Every year I/we set up a 400ft zipline 400ft. off the canyon floor. It has been going on for about 15 years. We use two (parallel) static 7/16 (11.11mm) new england ropes. In the beginning before we had long enough ropes we spliced two together with a tracing 8 with the ends and the knot taped to allow our kutinee carriage to Zip right over. Never a problem. You will be amazed how much the ropes stretch once the first person zips across requiring tightening every so often. On occasion people freeze and don't grab the rope once they reach the other side and glide back to the middle of the rope. I have seen some tough guys barely make it back to the low side doing it hand over handdue to the steep sag in the ropes. I am not exactly sure what your setup will be but since your setup will be more of a tyrolean traverse I definitely recommend the first to bring gloves and an ascender of some sort. Your gonna need one to tighten the lines anyways. We use a petzl swivel to untwist the lines before tieing them off. High side is tied off and the low side has rigging plate with 6:1 advantage for the sometimes constant tightening we have to perform to keep the landing perfect. We have sent a couple hundred people across and never had a problem. Oh ya girls with long hair must were a hat.
safe traversing
(This post was edited by soNVclimbing on Mar 30, 2010, 3:31 PM)
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tyrolean.gif
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linuxxpert
Mar 30, 2010, 4:11 PM
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soNVclimbing wrote: Every year I/we set up a 400ft zipline 400ft. off the canyon floor. It has been going on for about 15 years. We use two (parallel) static 7/16 (11.11mm) new england ropes. In the beginning before we had long enough ropes we spliced two together with a tracing 8 with the ends and the knot taped to allow our kutinee carriage to Zip right over. Never a problem. You will be amazed how much the ropes stretch once the first person zips across requiring tightening every so often. On occasion people freeze and don't grab the rope once they reach the other side and glide back to the middle of the rope. I have seen some tough guys barely make it back to the low side doing it hand over handdue to the steep sag in the ropes. I am not exactly sure what your setup will be but since your setup will be more of a tyrolean traverse I definitely recommend the first to bring gloves and an ascender of some sort. Your gonna need one to tighten the lines anyways. We use a petzl swivel to untwist the lines before tieing them off. High side is tied off and the low side has rigging plate with 6:1 advantage for the sometimes constant tightening we have to perform to keep the landing perfect. We have sent a couple hundred people across and never had a problem. Oh ya girls with long hair must were a hat. safe traversing
Thats an awesome picture! We've actually used a grigri for tensioning on shorter lines but I'm quite sure that the high loads of a longer line are probably too much for a grigri since it was rather difficult to unlock on the shorter setups already.
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soNVclimbing
Mar 30, 2010, 4:58 PM
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The picture looks a little better under my profile. It was a scanned 35mm. I hope to get some more up soon.
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areyoumydude
Mar 30, 2010, 5:13 PM
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linuxxpert wrote: Is this a bad idea?
Yes
linuxxpert wrote: Will this work?
No
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trenchdigger
Mar 30, 2010, 5:20 PM
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Here's a basic highline tension calculator I made in Excel for STATIC loading of a highline.
As a side note, this doesn't sound anything like a rescue highline setup to me, and I strongly encourage you to question your own judgement and rigging skills here. Have you ever rigged a highline? Are you experienced with rescue rigging and high-strength anchors?
The old cliche seems to apply here: If you have to ask...
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linuxxpert
Mar 30, 2010, 6:32 PM
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trenchdigger wrote: Here's a basic highline tension calculator I made in Excel for STATIC loading of a highline. As a side note, this doesn't sound anything like a rescue highline setup to me, and I strongly encourage you to question your own judgement and rigging skills here. Have you ever rigged a highline? Are you experienced with rescue rigging and high-strength anchors? The old cliche seems to apply here: If you have to ask...
Your calculator does not seem to be posted 
Thank you for your concerns, I have the same ones since I have never set up anything this big, thats why I am gathering information that will allow me to do this as safe as possible. It seems to be difficult to find good information on lines this big therefor I was hoping for some help on these forums from knowledgeable people who share the same passions.
I understand the math, have setup smaller lines and rigged many many anchors. If this was a 100 feet I would not think twice about it, but standing at the edge of this 400 feet canyon looking at the other side makes you think, ya know?
So please look at my proposed setup, I think it will work, the math adds up.
If you have any concerns I'd like to know about them and please explain them.
Thank you,
--Dutch
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linuxxpert
Mar 30, 2010, 6:38 PM
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areyoumydude wrote: linuxxpert wrote: Is this a bad idea? Yes linuxxpert wrote: Will this work? No
Wow, thank you for your wisdom, I've learned a lot. 
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trenchdigger
Mar 30, 2010, 6:44 PM
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Whoops... yah... here's the file. Forgot to click "Upload attachment" before posting.
Remember, this is intended for STATIC load calculations. You will be dynamically loading your line at least to some extent while you're on it.
Rescue highlines usually use dual track lines for safety/redundancy and to reduce sag. The fact that you're planning to tie two lines together to make a single track line further reduces your safety factor.
For what it's worth, I'm a SAR member with rescue rigging training and a climber, and I would not be willing to use your proposed highline.
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Highline Calcs.xls
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linuxxpert
Mar 30, 2010, 6:50 PM
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trenchdigger wrote: Whoops... yah... here's the file. Forgot to click "Upload attachment" before posting. Remember, this is intended for STATIC load calculations. You will be dynamically loading your line at least to some extent while you're on it. Rescue highlines usually use dual track lines for safety/redundancy and to reduce sag. The fact that you're planning to tie two lines together to make a single track line further reduces your safety factor. For what it's worth, I'm a SAR member with rescue rigging training and a climber, and I would not be willing to use your proposed highline.
That is worth something, thank you.
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Just-slackin-thru
Mar 31, 2010, 7:58 AM
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Do you know how rock climbers feel when, say, a drunk camper or some other NON-ROCK CLIMBER gets injured or killed trying to climb something they are not qualified to do, are not trained to do, or have no proper equipment for, and the headlines say "Rock Climber dies at .....". Or even better, when rock climbing by qualified real climbers is banned at that area because of that incident??
There has never been a death in the sport of highlining, and highliners (who walk on top of the line) have been carefully developing and testing materials and rigging configurations for years now making the sport even safer. Please don't think I am equating your endeavor to that of a drunk camper I know you are considering this carefully and I respect you for trying something so rad. I wish you the best of luck, just do not call it a highline.
btw, a standard highline rig consists of at least 2 webbing pieces (often stronger polyesters or beefed up nylons) with a static rope or amsteel underneath. So that is THREE seperate lines (triple redundant) with no splices/knots, etc... anywhere along their length - TAPED TOGETHER to be as one. The cumulative breaking strength (strengths arrived at by testing them in the exact rigging configurations of these lines as rigged in the field) of these tripled lines can often exceed 15,000 lbs. The rope you described may break at about 5000 lbs or less in the configuration you are describing. With that length line you are toying with some dangerously thin to non-existent safety margins. In other words start the plan over from scratch. I hope that helps.
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linuxxpert
Mar 31, 2010, 9:58 PM
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Thanks everybody that had intelligent and useful input, I've decided not to use this setup, while the numbers do seem to add up I am just not comfortable with the setup and if you don't think its bomb proof you shouldn't do it.
Maybe I should invest in a 400' 1/2" 10.000 lbs line :)
Anyways thanks for all the info.
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trenchdigger
Apr 1, 2010, 7:59 PM
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Just-slackin-thru wrote: ... I wish you the best of luck, just do not call it a highline. btw, a standard highline rig consists of at least 2 webbing pieces (often stronger polyesters or beefed up nylons) with a static rope or amsteel underneath.
Keep in mind that "highline" is common terminology for a "tyrolean" style rescue rig with one or more "track" lines and other lines to position and in some cases raise and lower the rescuer/litter package. I don't doubt that this type of "highline" (that the OP was referring to) has been around longer than the stacked webbing line you refer to.
At any rate, I too am pleased to hear that the OP has decided against attempting this rig.
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Davey
Jun 3, 2010, 6:09 AM
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Why don't you join your local Mountain Rescue or Search And Rescue and learn how to do this
http://mra.org/drupal2/
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just curious... who's gonna rescue you? nevermind @ 100 feet there should be nothing left to rescue. so what's the point of this?
wait a sec... so you're slacklining... who really cares!
