Loads thru Pulleys, Friction, Canopy and Basal Anchors

Richard Mumford-yoyoman

Richard Mumford-yoyoman

Been here a while
Location
Atlanta GA
I found some of these results interesting. After questioning the bounce check I wanted further information. It sounds like I'm beating up the traditional check but I found it interesting that in the natural crotch my 200# load only translated to 70 on the other side, after the bounce it went to 140.
In none of my test was I able to capture more than my weight to the other side regardless of the friction at the pulley/connection or crotch.



Capture.webp
 
...so if I just select a suitable basal anchor and set my line, smoothly climb without any bounce increased load I'll be putting 270# at that anchor (plus whatever addition from walking, hip thrusting etc)
If I bounce check, I'll start out with a load of 340 pounds on the anchor.
 
I broke out a redirect today. It was inconsequential and I knew it was likely to happen. I compounded the forces by using a revolver at a steep angle on a 4" oak branch about 3 ft out. I NEVER would have made that my primary TIP, but it was good to learn the limits of a redirect without any harmful side effects.

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Hey, @Toomuchsawdust! Thanks for your post. Is there any way you could post a drawing or a photo of a drawing in order to illustrate what your setup looked like?

Was it the 4" oak branch that actually broke out, or a smaller one later in the chain of redirects? Oak is so darned strong, it will be valuable to me to know that it was possible to break out a four incher.

I think it might have been the XMan that recently posted about sudden limb drop in trees during times of high heat stress.

Thanks in advance.

Tim
 
TimBr said:
Hey, @Toomuchsawdust! Thanks for your post. Is there any way you could post a drawing or a photo of a drawing in order to illustrate what your setup looked like?

Was it the 4" oak branch that actually broke out, or a smaller one later in the chain of redirects? Oak is so darned strong, it will be valuable to me to know that it was possible to break out a four incher.

I think it might have been the XMan that recently posted about sudden limb drop in trees during times of high heat stress.

Thanks in advance.

Tim
Click to expand...
It was a poor decision to begin with. But I REALLY wanted the perfect redirect. Lol. I just gently dropped a few feet. If it were in the crotch it would have been fine. I'll see if I can make a drawing. Or I'll take pictures next time I'm in the tree. It's in my yard.

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TimBr said:
Hey, @Toomuchsawdust! Thanks for your post. Is there any way you could post a drawing or a photo of a drawing in order to illustrate what your setup looked like?

Was it the 4" oak branch that actually broke out, or a smaller one later in the chain of redirects? Oak is so darned strong, it will be valuable to me to know that it was possible to break out a four incher.

I think it might have been the XMan that recently posted about sudden limb drop in trees during times of high heat stress.

Thanks in advance.

Tim
Click to expand...
27dae33cf190106665073b6b999d3e71.jpg


Just call me Picasso. The branch union was already questionable. But the "other branch" easily caught me.
 
A lot depends on the anchors, angles etc. If it is not a retrievable redirect that I use with pulleys etc, I may consider not using any type of friction reducing device, give it a static solid connection and lesson the multiplier of force, the pulley. Again, lots of factors, the more efficient a pulley is the more it will multiply the force if given the chance.
I pruned and dead wooded an entire oak yesterday, basal anchor. Ran a load cell at the base, maximum load the base anchor ever saw was 135 of my 200-215. ( I tried to capture the whole graph but it was lost in the email.)
 
Absolutely. I'm pretty sure it would have failed even with lots of friction at my redirect. It was an experiment. Lol. And it failed miserably. I have a few redirects I use to get more friction. One that uses one ring and a biner. If I need retrievable I'd use the M bight. If I had used the M bight on that, it would have been bad.

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My favorite canopy anchor. Retrieves smoother than a basal. Put a XSRE in the end of your rope and it looks right out. Connect a throw line to the XSRE and you can work it loose if it gets hung.

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Toomuchsawdust said:
Absolutely. I'm pretty sure it would have failed even with lots of friction at my redirect. It was an experiment. Lol. And it failed miserably. I have a few redirects I use to get more friction. One that uses one ring and a biner. If I need retrievable I'd use the M bight. If I had used the M bight on that, it would have been bad.

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Click to expand...
3X bad unless M Bight with ring.
 
Toomuchsawdust said:
My favorite canopy anchor. Retrieves smoother than a basal. Put a XSRE in the end of your rope and it looks right out. Connect a throw line to the XSRE and you can work it loose if it gets hung.

Sent from my SM-G920P using Tapatalk
Click to expand...
We can thank Doug for that, I love how it grabs a HC, Pinto or I use Omni block 1.1.
I use that redirect with basal or cinched anchor to get me offset on one side of the tree, then On Bight Redirect and or DdRT tail for others until I come back to center and reset for the other side of the tree.
 
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Toomuchsawdust said:
27dae33cf190106665073b6b999d3e71.jpg


Just call me Picasso. The branch union was already questionable. But the "other branch" easily caught me.
Click to expand...

Thanks for taking the time and going through the trouble to create and post this drawing. It gives a very clear idea of what was going on in this situation. I like all of the humorous embellishments within the artwork, too.

Thanks again.

Tim
 
The drawing rocks. It also demonstrates some really key rigging principles that many people dont think about. I do a lot of huge nasty willow oak removals that have been dead for a while and have hypoxilyn canker which makes them super brittle. I use many rigging rings and blocks to spead the forces as much as possible but the final redirect over the landing zone usually experiences some loads at wierd angles, especially if the rope man doesnt let the piece run well.
 
JeffOpar said:
The drawing rocks. It also demonstrates some really key rigging principles that many people dont think about. I do a lot of huge nasty willow oak removals that have been dead for a while and have hypoxilyn canker which makes them super brittle. I use many rigging rings and blocks to spead the forces as much as possible but the final redirect over the landing zone usually experiences some loads at wierd angles, especially if the rope man doesnt let the piece run well.
Click to expand...
I love fairleading the f$&# out of a tree with some ring slings. It makes me happy!
 
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