Rigging Pull Tree

Hey guys, I was going through some of my old posts and realized that I did not let you know how the finish of this job went.

It turned out to be a piece of cake. I used Kevin and Dave's line pull calculator from the Forestry Forum site and calculated the tension to be around 6000-8000lbs on a straight pull, which I did not want to use.

So, I set a block in the pull tree, used a tailhold and spar pole tree down to my rope come-along. I used a Samsom tree-master 1/2" line to pull the tree Over after the hinge was cut up. I have a bunch of pictures of the job that I need to put on a disk to show you guys.

Chris
 
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PULL TREE

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Way to be creative!

Chris, about your sketch. I assume you used Paint (or similar). Current versions of that program offer to save in PNG format. The one you'd sent was in BMP, which is uncompressed in any way. PNG compresses these types of images astoundingly well. JPEG compression is not really good at all for them, and yours was obviously saved as a JPEG file at one point. See the notes in orange in the attached copy. Since this file was at least once a JPEG it's quite a bit larger (in bytes) than it would have been otherwise; those artifacts are expensive. I'm guess the 200KB it is now would have been more like 50KB without the JPEG step. Certainly much less than the 1.7MB of your original!

On a technical note, see the notes in red. In practice it's usually close enough, but if you're trying to figure precisely you should take it into account. One thing I didn't mention in the notes is that a 90° wrap provides 1.4:1 MA.
 

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Sorry for the spelling of know, I ment No.

When I fell the tree, it was over a leach field, and the top landed over the edge of it.

My daughter corrected me in my spelling. Ha, Ha.

Chris
 
yet another time the answers to my question lay sleeping in the archives...

along with this nifty calculator:

Leaning Tree Force Calculator

shagbarkfarms.com

I've been using a pair of blocks from a Marine consignment shop to build 5:1. They are for boats, so look strong, but they are old and used. Has got me wondering just how much force comes from pulling a tree.

Short answer is that a generally "easy" pull may be running up to 600 lbs of tension force, where a "major" pull, may be maxing around 1200lbs. (results may vary) The calculator is pretty fun to assess some recent pulls and see what kind of forces were at play.
 
Dan Cobb said:
@dspacio, I like the Calculator. However, I think you have to add some amount of force for bending the hinge.
Click to expand...
Yes it's true. If you enter 90 degrees, tree from ground, it says it will take 0 pounds of force, which we all know aint true..
we were hauling an oak over the other day and I Was shocked at the holdnig power! I bored out the center of the hinge before it would come down. (it was sideleaning a bit so needed strong guides)
 
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