3 to 1 hauling

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mucci

Trad climber
The pitch of Bagalaar above you
Mar 1, 2011 - 08:01pm PT
Using a pulley and jumar hauling system, or a block roll, or a pro trax is 1:1.

but a Yates Adj daisy, (think of the buckle as a pulley) is 2:1?

Hard for me to see that. Pete can you explain the difference?

'Pass the Pitons' Pete

Big Wall climber
like Ontario, Canada, eh?
Mar 1, 2011 - 08:46pm PT
You guys gotta go back and read my analogy about hanging on the toprope in the climbing gym. You know you can pull yourself up by pulling down on one rope quite easily, but if you pull down on the other rope you can't even move. Why? One way offers mechanical advantage, the other doesn't.

Yes, hauling a pig with a Kong Block-Roll is 1:1, if you are pulling down on the unweighted end of the rope.

Now, go to that same Block-Roll hauling system, but instead of you being up at the station, you are down actually sitting on the pig, attached to the pig by a quick-draw so you and the pig are one. If the pig is empty, you can probably easily haul yourself plus the pig by pulling down on the free end of the rope. If the pig has more stuff in it, you will still be able to haul yourself plus the pig by pulling down on the free end of the rope coming out the opposite side of the Block-Roll.

In the adjustable daisy 2:1 setup, the buckle is analogous to the Block-Roll. Obviously the adjustable daisy buckle has a lot more friction than a Block-Roll [which by comparison is virtually frictionless] but it is still a 2:1 mechanical advantage.

Why?

In the 1:1 hauling using a Block Roll, one end is attached to the pig, and one end is attached to you. You pull down with a hundred pounds, and the rope on the other side plus the pig is pulled up with a hundred pounds.

Now imagine the pig having little arms and legs, and he is capable of hauling himself. [Don't we wish!] So now in this situation, the pig itself pulls down on the free end of haul line, not you. If the piggy pulls down with fifty pounds, at the same time he is also pulled upwards with the same fifty pounds, giving him a net upward pull of a hundred pounds, a 2:1 mechanical advantage. This is analogous to the adjustable daisy.

What's the difference?

In 1:1 hauling, one end of the rope is attached to the load, the other end of the rope gets pulled down on.

In the 2:1 situation [piggy with arms, guy dangling on a toprope in a gym, adjustable daisy] the free end of the "rope" [or adjustable daisy] isn't hanging in space, it is actually attached to the load itself. The load itself is pulling down on the free end. For every pound the load pulls down on the free end, it is also pulling itself up with the same pound.

Certainly it is less intuitive using an adjustable daisy with a friction-y buckle than say a piece of cord and a mini-Trax or one of Kate's Ushba beauties, but it is indeed a 2:1 mechanical advantage.

Maybe there's a physicist out there who can explain it better?




And here's another question for you, one which I have posed before, and could not figure out except by trying it out. Once I figured HOW to make it work best, I then was able to explain WHY. But it is somewhat counter-intuitive as well.

You have a 2:1 hauling ratchet with your zed-cord, and your zed-cord runs through two pulleys. You have a "good" pulley that is big and has nice bearings, and you have a "bad" pulley which is nowhere near as frictionless. To make it work best, do you put the good pulley on top, and the bad pulley on the bottom, or vice versa? And why?

HINT: Try this at home, using one real pulley as your "good" pulley and just a carabiner as your "bad" pulley. It will very quickly - with about one pull - become apparent where you want each pulley!
mucci

Trad climber
The pitch of Bagalaar above you
Mar 1, 2011 - 09:18pm PT
Now that made cents....

Thanks Pete!
hoipolloi

climber
A friends backyard with the neighbors wifi
Mar 1, 2011 - 11:07pm PT
I suspect good pully on bottom...


Mighty Hiker

climber
Vancouver, B.C.
Mar 1, 2011 - 11:12pm PT
Perhaps a pushmi-pullyu ought to be employed. One of Dr. Seuss', that is.
Morgan

Trad climber
East Coast
Mar 2, 2011 - 04:53am PT
Wouldn't distance prove the point? With an adjustable daisy you raise yourself 1 foot for every 1 foot you pull down on the other side (1:1). With the 2:1 hauling ratchet, grigri/ascender/redirect ascending method, far-end hauling, you are moving the load 1 foot of distance for every 2 feet you pull down.

This is more about effort than distance: Say you had a 200 lb. crate on a concrete floor and you wanted to move it. (Kind of like hauling to Mammoth, but smoother and less steep). I guarantee it would be easier to move that crate hauling from an eye bolt fixed to the wall, going through a pulley on the crate, and the free end of the rope going to you, than it would be to have the rope tied to your waist, going through a pulley on the crate and the free end coming back to you.

In answer to your other question (edited), best pulley closest to the person hauling. Theoretical Mechanical Advantage (TMA) of 2.76T vs. 2.67T for the other way around.
Silver

Big Wall climber
Nor Nev
Mar 2, 2011 - 02:52pm PT
All this chatter is why I choose to weigh more than the haul bag at all times.

Pete saw today that we Amerikans are 34% fat and you Canukians are only 24% fat. This is where your hauling really suffers more fast food,beer and TV should be added to your training program.

'Pass the Pitons' Pete

Big Wall climber
like Ontario, Canada, eh?
Mar 2, 2011 - 03:30pm PT
See? SEE?!

What can I say? Some people get it, and some people don't.
Alex Baker

climber
Portland
Mar 2, 2011 - 03:45pm PT
Adjustable daisy definitely gives 2:1. If there is 10 lbf tension on the daisy, there is 20 lbf tension on you, because it's fixed at 2 points, to you. Of course Pete already said that, in a lot of words. Yeah there's frictional "losses" and stuff that do matter, but you get the point I hope.
Moof

Big Wall climber
Orygun
Mar 2, 2011 - 03:57pm PT
Fish made a decent measure on one of his daisies a couple years back and concluded there are 60-70% friction loss for a net 1.3-1.4:1 mechanical advantage using Ankra buckles for daisies. Not worthless, but well shy of 2:1. In other words for a 200 lb climber to pull themselves up using only the daisy would require ~140 lbs of pulling on the strap.


Edit: Here is the link to the Fish test:

http://www.supertopo.com/climbing/thread.php?topic_id=92228

Conclusion was a 1.3:1 mechanical advantage using adjustable daisies, so 153 lbs of pull to move a 200 lb climber up. The real advantage is more around capturing progress and being able to use two hands (i.e. not needing a free hand to fifi into the daisy).
'Pass the Pitons' Pete

Big Wall climber
like Ontario, Canada, eh?
Mar 2, 2011 - 04:24pm PT
Ah, I had forgotten about that excellent post. Read what Karl Baba and John Middendorf have to say, and especially Klaus.

I guess if you want a near 2:1 adjustable daisy, use Kate's setup with the Ushbas or a piece of cord and a Mini-Trax.

Adjustable daisies really help me a lot. Their co-efficient of dynamic friction is less than their co-efficient of static friction, which means once you get 'em moving they are easier to keep moving.

However, adjustable daisies are indeed a 2:1 mechanical advantage less the friction in the buckle.
Morgan

Trad climber
East Coast
Mar 2, 2011 - 05:45pm PT
Thanks for posting the other thread Moof. Most interesting. In the third to last post. It sounds like Russ and Pete aren't that far off from each other, just defining things differently in theoretical and practical terms. In the real world, I guess it's somewhere between a 1:1 and 2:1.
Squeezo

Trad climber
Conifer CO
Jul 3, 2011 - 02:51pm PT
mark,
good luck on your adventure this june, , Im thinking on doing my first solo on, tangerine trip in september and know my pig will be heavy and was thinking on useing a 2;1, but have no really experance on anytinbg thing like that, Can you give me a quick run down of what i need and need to do to set it up? pictures? also im headed up the nose with a bussy and she is 130 lbs and think hauling wil be hard for her, so was thinking on setting up a 2;1 for her do you think thats nessary? any help would be great thanks
squeezo
Ed Hartouni

Trad climber
Livermore, CA
Jul 3, 2011 - 03:40pm PT
for your Archimedean pleasure:
http://www.swe.org/iac/lp/pulley_03.html
Melissa

Gym climber
berkeley, ca
Jul 3, 2011 - 03:53pm PT
Squeezo...if you're in a position to set up the pullies, you're ideally situated to haul the bags. ;-)

I hate having two people on the same end of the haul line (although when the bag is going to stick a lot it's still the most efficient way.) It's hard to sync, and when I'm the bottom hauler, I feel like a rat on a wheel. It's so demoralizing to jug away and just keep sinking down.

My favorite alternative, which works best when the bags aren't going to stick and there is room at the anchor for both partners to be side-by-side is to have one person haul 1:1 in the usual fashion and have the other haul 1:1 on the loaded line (i.e. Run a piece of spectra cord from their harness through a high pulley back to an inverted ascender on the loaded line. Use a munter mule to dial in the distance to the jug.)

It's so easy to haul in sync when you're side by side (especially important if both partners' peak impulse is needed to get the bag to move), and having someone haul w/ their full body weigh on the bag-side of the line seems to help break the bag's friction better too. It can also a quick and easy way to help your partner finish a haul when you arrive at the anchor after cleaning a pitch.

We started doing this when I dropped the 3rd pulley on "blast day" (doh!) making 2:1 and 3:1 single-hauler systems impossible for the entire route. Tip for idiots like me...If you're using a pulley system that involves accessory cord, don't let the pulley whiz off the end of the cord. :-(
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