2:1 hauling system - why not make it simple like this?

Hey all,

I've always had 2:1 hauling systems explained to me (including the vDiff course) to use a separate cordelette for use with the pulleys in the hauling system, as illustrated by the graphic left. Haul up, and then take the slack to whatever progress capture device you're using. My question is, why not do away with the separate chordelette and anchor point, and use the actual rope for this (see graphic right)? Seems like less gear and only one rope to pull on. What am I missing?

Well the pic on the right is now a 3:1 instead of a 2:1.  This means your hauling work is 'easier' but it will take longer as you only progress 1 foot for ever 3 feet pulled.
Do you want speed or less weight to pull?

Full disclosure, I'm no big wall climber so I'm not sure about why certain techniques are preferred over others, this is just an observation about the two systems.

Yeah, that's probably it... there's no real way to do a 2:1 using the haul rope unless the pulley is all the way down at the bag with two ropes going back up... I think. That being said, the vDiff climbing course describes a 3:1 while still using a separate cordelette... but that's probably just another way of doing it.

Also not a big wall climber.  The setup on the right could easily be converted to 2:1 by fixing the strand coming out of the main line progress capture by clove hitching it to your master point.  One side of the clove is the slack you take in through the main progress capture, the other becomes what was the fixed leg of the cordelette.

I think the disadvantages are that you need the slack at the start of the haul, limiting your pitch length.  And there is also going to be more friction by nature of a larger rope diameter, lowering overall efficiency while hauling.

Unless I just haven't had enough coffee this morning, the right image is still 2:1--the top pulley is just a redirect to allow downward hauling force, so doesn't add any mechanical advantage. 

In my mind the advantages of using a zed-cord are 1) more efficiency using a smaller cord through the pulleys, 2) super-static zed-cord is better than any static main haul line and 3) avoiding everything getting bunched together, since you can spread things apart a bit. Might not sound that critical, but something you do like a thousand times on a wall benefits a lot from optimization (say it's even 1lb easier per pull and you're not fighting pulleys and ropes twisting together, that adds up to a lot of calories/bother over time).

Another one I just thought of, it's nice not to have to connect to your harness with another rope clamp--that adds one more operation for each pull and in general is a hassle and another metal thing flopping around.

ETA: Thanks for the correction, what I've been calling 2:1 for my 30+ years of climbing is actually 3:1. I guess that's why I'm an EE not an ME.

Ryan Franz wrote:

Unless I just haven't had enough coffee this morning, the right image is still 2:1--the top pulley is just a redirect to allow downward hauling force, so doesn't add any mechanical advantage. 

I believe that that frame of reference has switched in the right setup.  But I also have only had 1 cup of joe this morning.

This video helps explain how the frame of reference effects mechanical advantage in pulley systems.  On the right, 3ft must be taken in to get 1 ft of work since "the load is doing the work".  On the left, the load is not doing the work and 2ft must be taken in to achieve 1ft of work.

https://www.youtube.com/watch?v=93AX2aPibZc

Ryan Franz wrote:

Unless I just haven't had enough coffee this morning, the right image is still 2:1--the top pulley is just a redirect to allow downward hauling force, so doesn't add any mechanical advantage. 

let the caffeine soak in...

its a 3:1

Another disadvantage is that with the 3:1 you need to reset how you pull on the slack end of the rope. Using cord on the 2:1 allows you to have a fixed point that you pull on, usually by cloving the orange cord onto your belay loop. One less thing to reset with each squat.

There are about 1 billion different threads in this forum about hauling. Go read those by Kevin, Mark, Skot, Pete and the like instead of starting yet another one.

It will help you out way faster.

Look into the Drop C method of a 2:1. It is becoming more popular in simple crevasse rescue systems. I can't find a good image to share unfortunately. Here is a link to Alpine Saavy to look into it more https://www.alpinesavvy.com/blog//crevasse-rescue-simplified-drop-loop-21

Very simple and only uses the rope.

Rope, Cordelette, doubled shoestrings, girthed slings? Sure, you can certainly beat a deadhorse with a little extra rope.

The tidbits that come from asking questions give us something to think about when the needs arise.

I went to the Forum in Rome once, very quiet. I love a rowdy live place.

Your setup on the right is 3:1.

So, you haul up your load and now your two green pulleys are touching each other. Now, you have to feed that rope back into the system to push that ascender down. If you’re on a ledge, no big deal. If you’re hanging, you now have to clip yourself to the anchor, feed the rope, unclip and start hauling again.

3:1 is wonderful if you really need it but it is soul crushingly slow. The setup on the right has added a step that makes it even slower. 

99% of the time you'll come to the same conclusions that we're going to give you but you know what, you'll believe the answers from your own conclusions more because they'll be YOUR answers. You don't actually want THE answers, you want YOUR answers. So git out there and go find them because 1% of the time YOUR answer you bring back will end up becoming OUR answer too. 

This is the way!  
ignore what the threads say….  Rack your gear and go on a wall and find out for yourself what works best for you!   That’s the only true way to get your own answers.  

Listen to Skot and Kevin.