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hans
Feb 5, 2003, 9:10 PM
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I've been doing some thinking about 1:1 vs. 2:1 hauling systems, and trying to figure out which is the better way to go for certain situations.
Although I've rigged a (as yet untested) Chongo 2:1 system in my garage, to date 1:1 hauling is the only system I have practical big wall experience with, so any conjecture I might make about 2:1 hauling should be taken as Theory.
When I first read about 2:1 hauling, it seemed like a great idea. You have to exert half as much force on the Z-cord, which means less pressure on your hips.
However, you are paying for halving that force by doubling the distance you have to pull the Z-cord. Nothing's free, especially when it comes to the Law of Conservation of Energy.
Since you are using your body weight as a counterweight to pull the Z-cord (unless leg-hauling), you are moving your body up and down twice the distance that you would in a 1:1 haul.
So by my logic you are exerting twice as much energy per vertical unit of pig rise when you haul using a 2:1 system!!!
I can see why you would have to haul 2:1 when your pig weighs more that you do, but is there any advantage otherwise?
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flamer
Feb 6, 2003, 1:51 AM
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Twice as far?
Please clarify! If you use the 2:1 rachet you pull the same distance, but the force needed is reduced! Maybe I'm misunderstanding what you are saying?
josh
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davidji
Feb 6, 2003, 2:16 AM
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The original poster is correct, there is no magic in hauling systems. To reduce the force per the distance you pull (ignoring friction), you have to reduce the distance the hauled object moves per the distance you pull. Pull harder or pull farther, your choice.
[ This Message was edited by: davidji on 2003-02-05 18:17 ]
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flamer
Feb 6, 2003, 2:39 AM
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Look at the chongo 2:1 Tell me how you pull more? Please!
josh
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baywolf
Feb 6, 2003, 3:32 AM
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when ever you work with ratios you change the distance that you can pull. I would ask pete for the expert advice, but the way i understand it, if you have a 2:1 hauling system, you move your gear up half as far for every pull based on a 1:1. you can check into mechanical advantages through rope-rescue books and manuals.
good luck
Jared
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flamer
Feb 6, 2003, 3:56 AM
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I understand how a basic 2:1 works...but the way the chongo Ratchet works is different. You Essentially rig 2 separate hauls. By doing this you eliminate the need not only for a 400ft haul line(as you would need for a standard 2:1) but also eliminate pulling the haul line twice as far(ok maybe that's the same thing)...Someone with experience using the Chongo method please chime in here.
josh
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twrock
Feb 6, 2003, 4:11 AM
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"By doing this you eliminate the need not only for a 400ft haul line(as you would need for a standard 2:1)"
What? You can do a 2:1 with a single 200 ft line. You don't need a 400 ft. line.
The haul ratchet has the advantage of being added or removed from your 1:1 at any time because it is "independent" of your 1:1 haul pulley setup. But you certainly can rig a 2:1 with a single 200 ft. line.
(edit-actually Chongo's 2:1 system does rely on the 1:1 haul pulley setup, but I hope you understand what I mean)
[ This Message was edited by: twrock on 2003-02-05 20:22 ]
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hans
Feb 6, 2003, 4:37 AM
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When you're hauling using a 1:1 system, for every 1 unit of distance that you move down, the haul bag moves up by the same amount.
In a 2:1 system, the pig moves one unit up for every two units that you move down.
It's the same whether you're using a 400 ft line or a Chongo ratchet.
Sure, you're only pulling half as hard each time you move down on the 2:1, but you have to lift your body weight back up again. And you have to do it twice as many times.
Therein lies the inefficiency.
-Hans
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hans
Feb 6, 2003, 4:38 AM
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When you're hauling using a 1:1 system, for every 1 unit of distance that you move down, the haul bag moves up by the same amount.
In a 2:1 system, the pig moves one unit up for every two units that you move down.
It's the same whether you're using a 400 ft line or a Chongo ratchet.
Sure, you're only pulling half as hard each time you move down on the 2:1, but you have to lift your body weight back up again. And you have to do it twice as many times.
Therein lies the inefficiency.
-Hans
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flamer
Feb 6, 2003, 4:59 AM
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Ok when I said the 400ft thing I was refering to the amount of rope you would need to do a standard 2:1 haul IF that haul (IE a pitch) were 200ft long. With a standard 2:1 haul you have to rig a pulley on the load that is being hauled and the rope is essentially doubled. I understand the doubling of the distance, you have to pull, in this case. However due to the fact that you do not use the haul line itself for the Chongo method It seems that this "distance doubling" is affectively midigated(sp?). Yes you may pull twice as far on the ratchet but this does not seem to translate into the haul itself. Taking into consideration the distance you pull down on a standard 1:1 Vs. the distance you pull down on the Chongo ratchet, as it relates to the distance the haul bag itself moves up- with each pull.
josh
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flamer
Feb 6, 2003, 5:13 AM
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Ok here's a better explaination, as to why I think this- and this only relates to the Chongo method!
Look at it like this the haul itself is still rigged up as a 1:1 haul. The Chongo ratchet provides a seperate system to assist with this 1:1. So for every foot you pull up on the Chongo ratchet the bag moves up a foot. The ratchet seems to be more of an extension of you then the hauling system itself. All it does is assist a basic 1:1 system- it does not replace it there for It does not change the distance you actually have to pull. Maybe there is magic?
josh
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twrock
Feb 6, 2003, 5:13 AM
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Josh, I'm still not sure if I understand your point on the rope length. But I did realize that I was imagining a 3:1 system when I said you could just use the 200 ft. haul line. (I gotta run, otherwise I'd spend a little more time right now figuring it out; I'll work on it later.)
(edit-noticed you posted just before me with another reply.) Check out the pic of the ratchet again. For every foot you pull down on the ratchet cord, the bag will move up 1/2 foot. It's a 2:1.
[ This Message was edited by: twrock on 2003-02-05 21:20 ]
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passthepitonspete
Feb 6, 2003, 5:40 AM
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Poor flamer. He is puzzling over this til he turns blue in the face.
I wish I were there in person - a few pictures, or maybe some slings and pulleys and crabs - and he'd be nodding, "Oh, NOW I 'get it' - why didn't I 'get it' before?"
At times like this, you need to take a break. You can go crazy analyzing this stuff in your head.
The Better Way is to grab the stuff, follow the instructions, and actually build the thing. You can go to the crag and haul a bag of rocks, or you can do like mojo, and pull down your video shelf. But go play with the thing, and figure it out for yourself.
Honest to goodness, it is a 2:1 mechanical advantage with Chongo's Hauling Ratchet. However these things are commonly mixed up!
One time in Camp 4, a BWT showed me his version of the 2:1, but it was really a 1:2!
Another time, Climbing Magazine published a 3:1, but Duane later told me he goofed and it was described in the magazine as being 2:1.
So you are not alone.
My beer glass is half empty. Were I to double the amount of beer, it would be full. However if I tripled the amount of beer, then I would have to drink a third of whatever is left, in order to avoid spillage. Which is really half a glass, the very same amount I had at the beginning.
[In the case of beer, it is probably better to make your own empirical observations. You should not always take your Wall Doctor's word]
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hans
Feb 6, 2003, 5:40 AM
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Let's look at the pig and 2:1 hauling ratchet as our combined system.
Assmuing that the system is not generating or absorbing a significant amount of heat, and that it is initially at rest, and that it ends its journey at rest, the amount of work done on (or by) the system must be equal to the potential energy gained (or lost) by the system. This is the First Law of Thermodynamics, and will prove true in all cases. The equation is W = deltaE.
The work done on the system will equal the force applied to the system multiplied by the distance that force is applied, or W = F X d.
The potential energy gained by the system will equal the weight of the pig multiplied by its increase in height, or deltaE = W X h.
Whatever your mechanical advantage, it's clear that the pig will travel the same height. This means that the same amount of potential energy will be gained by the system any way you slice it.
It follows that you have to put the same amount of work into the system to achieve this gain in potential energy. So we can assume work to also be a constant.
Now looking at the equation for work, it can be seen that if we halve to force we need to double the distance to keep W the same.
Note that this work is work done ON THE SYSTEM, not the work you have to do to work the system, which is a similar analysis but involves the generation of heat.
It is left as an exercise to decide whether you would rather do 3000 deep-knee bends or 6000.
-Hans
(message edited for clarity)
(and spelling)
[ This Message was edited by: hans on 2003-02-05 21:42 ]
[ This Message was edited by: hans on 2003-02-05 21:42 ]
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flamer
Feb 6, 2003, 5:50 AM
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Ok I have rigged this up and hauled with it!
And I LIKED IT(ala' mikey)! And I have 1 question and one statement. First is are you sure that the Chongo 2:1 isn't actually the Chongo 3:1? Second is (and maybe I just figured out where I over thought) For every foot you pull down on the ratchet the "pulling" ascender moves up a half foot right? Thus the bag also moves up a half a foot--and VOILA!! I'm an idiot!!
You to much thinking, turn mind into mush!!
to much of this made me feel like this ...But it's ok because now I'm like this
josh
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passthepitonspete
Feb 6, 2003, 5:54 AM
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If you want the honest-to-gosh truth, you should AVOID using a 2:1 Hauling Ratchet whenever possible!
It is much faster, and much easier, to split your loads into two, and haul two 1:1's. If you have the superb Kong-Bonatti Roll Block, you will be able to do 1:1 hauls with far heavier loads than if you have a Wall Hauler, because the Kong device is so much more efficient.
If you don't have a static haul line, you can forget about the 2:1 because it WILL NOT WORK. [Why anyone would venture on a big wall without a static haul line is beyond me - its extra expense is negligible compared to the effort it saves]
About the only time you need a 2:1 is when you are soloing - in theory you could bring two haul lines, but I wouldn't bother when climbing on my own. Besides, I would then need to set up two Far End Haulers.
But even with a heavy load when climbing with a partner, a space haul [two guys hauling at the same time] is hugely faster than a 2:1.
Now if you're Leading In Blocks, then you won't want to piss around waiting for your partner to help you haul, so you might want to have your 2:1 handy in this instance.
One other situation I needed to use a 2:1 was when we hauled our pigs up to Lay Lady Ledge on Reticent Wall. The friction across the front edge of the ledge was abysmal, and we used the 2:1 with Space Hauling - meaning one guy jugged on the free end of the haul line while the other guy operated the zed cord.
In summary, you should avoid the 2:1 whenever possible.
But it is an important arrow to have in your quiver.
Understanding when to use which system is the key to avoiding having to do any extra work.
I am Dr. Piton,
and I never work any harder than I have to!
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timpanogos
Feb 6, 2003, 11:55 AM
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Josh,
I forgot my dedicated 2:1 ractchet line last time out, and used the free end of the haul line, you just need enough free to triple your zed pull length and get the free end of all this started into your rope bucket.
The 1st anchor on Prodagal Sun allowed for a nice long 3' zed pull (which would only raise the load side of the toohed cam 1.5') so I needed at least 10' of free line to set it up.
Chad
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mojorisin
Feb 6, 2003, 3:49 PM
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The way I look at it,, if I got two 50 pound boxes to go up 10 flights of stairs,, I am making two trips.
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hans
Feb 6, 2003, 4:52 PM
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mojorisin,
That's an excellent analogy, but not exactly a valid way of looking at it, because you're not carrying the box(es) up the stairs.
You're attaching the end of a pulley system to the box, carrying yourself up the stairs, and then jumping off the top of the stairs while holding the rope.
If you haul 2:1, you have to go up the stairs twice to get the boxes up to the top.
(message edited to emphasize the excellence of mojorisin's analogy)
[ This Message was edited by: hans on 2003-02-06 08:54 ]
(edited again for clarity)
[ This Message was edited by: hans on 2003-02-06 15:34 ]
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mojorisin
Feb 6, 2003, 11:19 PM
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You are right Hans,, but Im climbing the stairs with ALOT LESS effort.
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hans
Feb 6, 2003, 11:32 PM
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How so?
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mojorisin
Feb 6, 2003, 11:46 PM
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because Im only carrying half the wieght. It will take twice as long, but the energy conserved will come in handy later. There are two ways of looking at it.
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hans
Feb 7, 2003, 12:15 AM
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Now I think I see where you're coming from.
Are you saying that instead of getting upside down and burning your energy anaerobically trying to 1:1 haul a load near your body weight, you would rather do it more aerobically with a 2:1 system and not burn out, even though you would need to bring twice as many power bars?
If we use a running analogy, are you saying that difficult 1:1 hauling would be like sprinting, whereas 2:1 would be more of a marathon-type of pace?
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mojorisin
Feb 7, 2003, 12:34 AM
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That is exactly it, If Ive learned anything from carrying 50 pound plus packs thru 3 feet of snow is to conserve your resources. If you are talking about multi day activitys you need all you can get. I know if your on a one day climb,,who cares as long as everything goes right, you will be sleeping in your bed that night anyway.
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mojorisin
Feb 7, 2003, 12:40 AM
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I have to say tho Hans,, after looking at your list of climbs,, if we ever went climbing, we can do it any way you wish.
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