Getting back from a limb walk.

[monkeylove]

I just did the simple experiment, if I am a climber using this system and I raise myself 2' I will have pulled 4' of tail through the pulley.

Really? Damn it, foiled again.

 

[Leroy]

 

[tc262]

2:1 3:1 4:1 I could really care less, I don't need the m/a. The biggest reason I really like the system I use is there is no need to tend slack. Just pull the line as you walk in.

 

[DSMc]

Levi, your tape mark is in the wrong spot. It needs to be at the BDB. Then you will have 6 feet as it is a 3:1 system.

 

[Leroy]

Dave, I disagree, it's about how much moves through the pulley. At least in the mind of this high school drop out.

 

[Leroy]

By that logic, if I were to pull on my tail up from bellow my system 180° I would have a 2:1 ma however, this is not the case.

 

[DSMc]

It is pretty much agreed that a typical DdRT system is 2:1. Try measuring it your way.

 

[Leroy]

Dave, look at the image showing the gun tackle. Does that look like a typical ddrt system to you?

 

[Leroy]

Mechanical advantage in order- 2, 3, 4, 5, 6

http://www.technologystudent.com/gears1/pulley7.htm

 

[Leroy]

http://www.technologystudent.com/gears1/pulley8.htm

 

[DSMc]

So what are you trying to say? That our DdRT is a 1:1 with no mechanical advantage? Block and tackle charts are calculated from a different perspective.

 

[DSMc]

Stop looking for answers in charts and put your harness on. Set a single leg of rope, grab hold and pull yourself up. That is 1:1. Feel it? Now a DdRT system and pull. Different right? Now set a haul back and do the same. Different still. Don't think just feel it.

 

[Leroy]

Ha! It's not a feeling or opinion, it's science. This video explains the whole concept...

https://www.khanacademy.org/science...nical-advantage/v/mechanical-advantage-part-3

 

[DSMc]

Everything you have posted is correct in the context they are describing. It all changes when you climb.

 

[Leroy]

How so?

 

[DSMc]

Reference point. They are standing on the ground. A climber is moving along the rope.

 

[DSMc]

The measurement of the rope that passes you as a climber is not the same.

 

[Leroy]

The climber is the load. The same legs of rope are being pulled on. I don't see how this changes the math.

 

[DSMc]

It does.

 

[Leroy]

It doesn't.

Earlier you said that the tape in the video I posted was in the wrong place. Do you still make that claim? Clearly it is false.