Fast French Free Techniques?

NickMartel wrote:Sorry Ryan, Bills right, no diagram needed. its the same thing as being on top rope and putting ascenders on the belayer's side. You are pulling only 1/2 your weight (in reality 3/4 or so with friction) twice the distance, as in you pull down 1' on the ascenders and you rise 6". same as batman-ing up the rope after a fall.

Yup. Your hands are the other "pulley".

You're totally right. Man, it looks like I just felt like arguing this morning. Sorry about that. I did a mental FBD, and there's definitely an advantage when the leader him/herself is doing the pulling. Doh!

The free-body diagram with algebraic proof (was finished with this before seeing it is not necessary to make the point that leader pulling down 2 feet of rope raises him/her 1 foot)

Edit to add: I really think Kedron Silsbee's explanation was best ... if you pull on the side of the rope that's opposite the piece from you, then the rope pulls on your harness with the same force you pull on the rope (ignoring friction) so it's effectively 2:1 since your body is lifted both by the force on your arms, and also by the force from the rope on your harness.

I looked at the pics in that link. None of them are what we do when french free climbing on the lead end of things. WE are the weight, we are not standing to the side of the weight. So when I pull down on the cord it is twice as easy to go up as when I pull on the piece. Try it you will like it. :)

I admit that I don't know if this is really 2:1. But it is way easier.

Also, once you step up, or pull yourself up, as high as you can hold the bottom of the biner and the two strands of rope. The friction of the rope going around the biner combined with the mechanical advantage of holding the opposite side makes it nice and easy to hold your position. I know it sounds obvious but I often try to gain a couple of inches of height by grabbing the piece. Not usually a problem but if I am very tired this is much easier. :)

Wes

Oops I just saw the above. Good stuff.

Sorry but none of that is 2:1. It's a redirect of force. If you where standing at pitch 10 of a 15 pitch climb, hauling your pig through a single biner (ouch) would you call that a 2:1? The only difference is that you are the load. If you feel that you are acquiring some decrease in work this way it's only because you are shifting your weight from one side of the rope (harness side) to the other (hand side) when you pull. A 2:1 pulley system gains it's advantage by increasing the distance required to do some unit of work. If you pull on the rope x units of length and the object you are pulling on moves the same x units of length you are 1:1.

cfuttner wrote:If you where standing at pitch 10 of a 15 pitch climb, hauling your pig through a single biner (ouch) would you call that a 2:1?

No; because the pig isn't doing the self-hauling. Different scenario completely.

cfuttner wrote:If you pull on the rope x units of length and the object you are pulling on moves the same x units of length you are 1:1.

If it's 5 feet from your tie-in to a piece clipped above you, then there has to be 10 feet of rope running from your tie-in point to your hands at the same level. In order for you to pull yourself all the way to the piece, you have to pull all 10 feet of rope to travel up the full 5 feet.

If the belayer was doing the pulling, he/she would only have to pull 5' to pull you up to the piece.

cfuttner wrote:Sorry but none of that is 2:1. It's a redirect of force. If you where standing at pitch 10 of a 15 pitch climb, hauling your pig through a single biner (ouch) would you call that a 2:1?

No, I wouldn't. In this case the bag moves one foot for every foot of rope I pull. That is different from pulling yourself up (see below).

cfuttner wrote: A 2:1 pulley system gains it's advantage by increasing the distance required to do some unit of work. If you pull on the rope x units of length and the object you are pulling on moves the same x units of length you are 1:1.

I agree, but in the reference frame of whomever is performing the work. This is why it's different if you ARE the pig hauling yourself, vs. if you're just hauling the pig. Say I am x units below my piece and I start pulling up on the rope re-directed through the piece. There is length 2x of rope between me and where I'm pulling. When I get up to the piece, there is no rope between me and where I'm pulling, even though I've only ascended distance x. Relative to my body, my hands have moved distance 2x while holding the rope, even though the rope has only moved distance x through the carabiner attached to the piece at the top.

oops - Ryan beat me to it.

Ryan Nevius wrote:If it's 5 feet from your tie-in to a piece clipped above you, then there has to be 10 feet of rope running from your tie-in point to your hands at the same level. In order for you to pull yourself all the way to the piece, you have to pull all 10 feet of rope to travel up the full 5 feet.

Again, I find myself wondering if you (or Kedron) instruct or teach for a living. This is another great illustration for something that is not necessarily intuitive.

My mind is blown.

Good explinations and arguments every one.

Kedron's post paints a nice picture of exactly what my math can't. Kedron uses cfuttner's statement of the 2:1 fact, that you gain advantage by moving rope twice as far as the load , to prove that in fact it actually is 2:1. (There will be friction of the rope on a carabiner making things more difficult than if you used pullies, as in the pics.)

Weather or not you think it's 2:1 or 1:1 you can easily test this out in the real world next time you climb on a rope. You will find that it is much much easier to yard up, by pulling down on the belayers side of the rope (that is clipped to a piece/draw above you) vs pulling down on the piece alone. :)

Wes

Can somebody describe "batmanning" to me? I've heard it mentioned, but I'm not quite sure what it is...

cfuttner wrote:Sorry but none of that is 2:1. It's a redirect of force. If you where standing at pitch 10 of a 15 pitch climb, hauling your pig through a single biner (ouch) would you call that a 2:1? The only difference is that you are the load. If you feel that you are acquiring some decrease in work this way it's only because you are shifting your weight from one side of the rope (harness side) to the other (hand side) when you pull. A 2:1 pulley system gains it's advantage by increasing the distance required to do some unit of work. If you pull on the rope x units of length and the object you are pulling on moves the same x units of length you are 1:1.

The essential difference is that you are the load. When you are hauling something else over a pulley, the tension on the haul side of the line is applied to the hauler, not the load. When the hauler is the load, the tension on the haul side of the line affects the load with the same amount of force as the load side of the line, creating a 2:1 mechanical advantage. (In a world without friction, of course.)

Science, bitch!

Oh suck it Chuck..........you know I love you.

cfuttner wrote:Oh suck it Chuck..........you know I love you.

I love you too, man.

rockcarl wrote:Can somebody describe "batmanning" to me? I've heard it mentioned, but I'm not quite sure what it is...

It's homosexual slang used by sport climbers. As in "cfuttner and I will be batmanning hard tonight".

Batman!

Secrets out.......

Chuck Parks wrote: It's homosexual slang used by sport climbers. As in "cfuttner and I will be batmanning hard tonight".

So that's what those sport climbers have been doing!

In seriousness, they're just talking about pulling up on the rope? I expected something more exciting for the name

Not to be confused with Ambiguously Gay Duo'ing.

Ace and Gary

"ambiguously"