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Ed Hartouni
Trad climber
Livermore, CA
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May 12, 2013 - 02:04pm PT
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RE: middle figure in Steve's post Fig. 6-46
well, like I said, I get this stuff wrong all the time, funny... actually rgold does a better job.
one way to look at it is by the tensions in each of the lines, there are three in lines, one to the pig ("the load") which is directed over the first pulley...
the second line goes to the the second pulley,
and the third line to the attachment point...
so let's look at the "static" forces...
if nothing is moving ("static"), the tensions in these three lines is equal. The tension in the first line is the weight of the pig.
the force that the first pulley exerts on the attachment is twice the weight of the pig.
the force on the jumar attaching the end of the line is the weight of the pig...
interestingly, the force exerted on the second pulley is twice the weight of the pig, so yes, in this analysis you have to put more force to lift the pig then the weight of the pig...
But there is a bright side to this... for every meter you push down the 2nd pulley, 2 meters of rope have to be drawn in (there are two lines "connected" to that pulley), so the pig gains 2 times the extension of the 2nd pulley.
For small loads, e.g. < ½ body weight, this system would be faster than the one-to-one pull, at least in principle.
FULL DISCLOSURE CLAUSE: I've only ever hauled stuff up hand-over-hand, or with a 1-to-1 ratchet... and never had to resort to any of these rigging shenanigans... my loss which I hope to amend someday (soon). Consider me, for the purposes of these discussions, to be a "theoretical big wall hauler"
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Steve Grossman
Trad climber
Seattle, WA
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May 12, 2013 - 03:03pm PT
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Ed- I have never found the need to use anything more than a single pulley system while counterbalance-hauling with a third Jumar to gut haul on anything that I have done on El Cap.
Keeping the weight down always did the trick. That folks insist on tackling FA sized loads on every vertical battle of attrition is pretty mind boggling.
I didn't post the hauling diagrams from Aleith's book because I champion his methods. I simply see a lot of twisting, cinching and stretching in the systems shown starting from the powerpoint on down. I agree with Werner that using double pulleys and a mini block and tackle might be a cleaner system if weight and speed aren't a concern.
With a Protrax or something sturdy as the principal catch point it would be interesting to see how light you could get a triple pulley set up from a yachting supply if you dropped the cord diameter.
The load table that Aleith provides is interesting in that he provides some empirical data using both carabiners and pulleys. He was a technical illustrator at a large engineering firm and heavily involved with Search and Rescue around Phoenix. I will post more of his manual at some point on a dedicated thread.
Pete proudly bellowing STUPID from the bottom of the academic barrel is rich indeed.
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madbolter1
Big Wall climber
Denver, CO
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May 12, 2013 - 04:20pm PT
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Totally agree, Ammon. Leg-hauling is useless.
Hey, how's the leg? I hope you're doing well and not suffering lingering effects.
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chappy
Social climber
ventura
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May 12, 2013 - 09:17pm PT
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I was wondering if a 2/1 could be rigged without using an auxiliary cord--by using the haul line itself. Its easy of course to rig a 1/1 and the 3/1 is pretty obvious as well. A 3/1 one is a lot action for very little traction and a 1/1 can be a ton. Of course the middle drawing a few posts back was a 1/2 boo boo. Here is what I came up with: I realized in the 3/1 if the middle pulley was replaced by a knot it became a 2/1. Photos and a drawing to come on the next post as this computer won't let me download pictures!
Chappy
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Ed Hartouni
Trad climber
Livermore, CA
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May 12, 2013 - 09:38pm PT
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I was wondering if a 2/1 could be rigged without using an auxiliary cord--by using the haul line itself.
I think not... here are some images from http://www.swe.org/iac/lp/pulley_03.html
1:1 with pulley (the other 1:1 doesn't have a pulley, it is just pulling the load up by the rope)
2:1:
3:1
4:1
what you notice is that for an "even" advantage system, 2:1, 4:1, etc... the pulley attached to the weight is "free," where as in an "odd" advantage system 1:1, 3:1, etc.. thy pulley is attached to the same rope... or to the anchor point...
if that second pulley is "free", there is no way to implement the rigging with the single rope connecting the load.
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chappy
Social climber
ventura
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May 12, 2013 - 09:48pm PT
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chappy
Social climber
ventura
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May 12, 2013 - 10:07pm PT
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Ed,
What I designed (in a sense)is the 2/1 in image number three of your post. It is in fact a 2/1. 1/2 the load is carried by the knot anchored to the wall hauler biner and the other 1/2 load is attached to your harness. One thing I realized a long time ago is that in an odd system (1/1 3/1 etc.) the line is always dead tied to your load. In an even system (2/1 4/1 etc.)the dead tie is at your pick point or anchor and only pulleys are attached to your load (as in the case of this system)
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Mark Hudon
Trad climber
Hood River, OR
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May 12, 2013 - 10:19pm PT
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Ha! Good work, Mark!
I carry my "hauling kit" all set up in a medium Fish Beef bag and be set up and ready to haul in seconds.
Simply understanding how to set up a mechanical advantage on the fly, using what ever gear is available is a great trick for climbers to have.
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chappy
Social climber
ventura
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May 12, 2013 - 11:45pm PT
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Mark,
It's fun to play around with variations of parted systems. It's probably easier to use your kit but it's nice to play around with variations. It was a fun little puzzle. When one understands the basics you can always design something that works with what is available. I get to play with puzzles like this a lot with my rigging work.
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Mark Hudon
Trad climber
Hood River, OR
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May 12, 2013 - 11:51pm PT
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That's what I figured.
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Mark Hudon
Trad climber
Hood River, OR
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May 13, 2013 - 01:59pm PT
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Keeping the weight down always did the trick. That folks insist on tackling FA sized loads on every vertical battle of attrition is pretty mind boggling.
You guys continue to not to get the point. Its some sort of ego thing I guess. It's not so much the ability to haul more, as it is to haul it with less effort. Do you really think that everyone who chooses to haul via 2:1 is taking monster loads? Really? Don't you think that some of those people are taking the average, everyday loads that most climbers would take?
On my Zenyatta Mondatta solo for example, I found that hauling via 2:1 was very easy but when I tried to haul 1:1 it took simply more effort that I cared to give it.
I simply did not want to work that hard!
Get it?
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Mark Hudon
Trad climber
Hood River, OR
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May 13, 2013 - 02:15pm PT
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As a side note, I wish I had a photo of this, I was hiking back to the road after humping a load to the base of El Cap and was walking behind a woman who had blisters larger than half dollars on each hip! The skin had broken off and everything. I'll bet she would have appreciate some 2:1 hauling information!
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Ed Hartouni
Trad climber
Livermore, CA
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May 13, 2013 - 04:33pm PT
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I simply did not want to work that hard!
Get it?
ah, ya, but like, you're climbing a wall...that work is supposed to be hard.
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Mark Hudon
Trad climber
Hood River, OR
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May 13, 2013 - 04:47pm PT
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You mean I'm doing wrong? It's supposed to be hard? You mean I can't use all these little tricks I've developed to make things easier?
Dang!
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julton
climber
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May 13, 2013 - 05:19pm PT
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Would one imagine Sisyphus even happier with a 2:1 ratchet?
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Reilly
Mountain climber
The Other Monrovia- CA
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May 13, 2013 - 05:48pm PT
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Sisyphus shoulda waited for SuperTopo and the reinvention of the wheel.
I can see yous guys standing around the base of the Great Pyramid arguing
with the construction foreman.
"Ho, man! Yer doin' it all wrong!"
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guyman
Social climber
Moorpark, CA.
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May 13, 2013 - 06:34pm PT
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Matty.... you have some fun, OK.
C-ya when you return.
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Moof
Big Wall climber
Orygun
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May 13, 2013 - 08:39pm PT
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I second Mark on the whole not wanting to work hard.
Most of my previous walls were with very similar loads, most done with 1:1 hauling. Zodiac last week was the first time I didn't feel destroyed after each haul. Just slightly worked. For the top third of the route I was able to clip the Zee cord to my russian aider cuff and 2:1 leg haul. Especially at hanging belays I found the 2:1 leg haul to be a huge improvement, saving the arms and body for leading. Thankfully we were slow slugs, so I could almost always haul and dock the pig by time my partner got to the belay,
At the top I was able to just lean away from the haul tree to haul, it was great, getting 18" strokes out of a 3' lean. Then the bags got stuck. I switched to 1:1 hauling to try to bounce the bags over the lip, and boy was that miserable. So I went back to 2:1 and tried bouncing the bags again, and it was night and day better, and soon the bags were free and up over the summit with record low effort.
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Mark Hudon
Trad climber
Hood River, OR
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May 13, 2013 - 08:44pm PT
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MOOF!!!!! Do you realize that you're giving up Manliness Points by posting that!
We're talking Manliness Points, Moof, do you want to take a moment and think about it?
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