Root ball torque

[ArtB]

Has anyone ever seen a table that lists the torque needed to pull a root ball out of the ground by species and DBH, with possibly a sol type also in the mix ?

Interested in what the torque due to wind blow down would be for different species and sizes in various soil types.

Only personal experience with crawler and cables with 'eyeball' dynamometer (cable stretch) is roughly 2,000,000 ft-# to pull a 42" DBH black cottonwood; 1,200,000 ft-# to pull a D-Fir 20" DBH; and under 100,000 ft-# to pull a 10" alder.
All pulled from 3 ft of damp topsoil overlaying clay/gravel mix

Years ago, got a kickout of a neighbor trying to pull a 12" alder stump 3 ft high with a Ford 4x4 - stump did not budge.

 

[Zale]

I doubt any table exists. Sounds like a good doctoral thesis.

 

[CanopyGorilla]

Sounds like too many variables

 

[BC WetCoast]

Many years ago I got some copies of the Journal of Arboriculture. I seem to remember an article in it on this subject. I think what they did was compare same species, same soil type and just varied the tree size. Trees were from a plantation or nursery. Probably a masters or Phd thesis, so lots of math, not a lot of practical advice.

 

[ATH]

I vaguely recall a professor talking about and showing us pictures of "whole tree harvesting" (much more literally than applied now-a-days) somewhere in Scandinavian counties. They had a machine that would pull the tree out of the ground. The idea was they would get more tons of fiber per acre. Not sure how they thought that made sense to burn that much extra fuel to get dirty chips...but it was at least tried. There is probably data out there somewhere about the force it took to pull those trees...

 

[ArtB]

Thanks for the Journal of Arborculture hint.

Found this, but just for 4 year old saplings.
https://www.google.com/url?sa=t&rct...sg=AFQjCNF1iwSyFuyTN2yB7iVU-GVeAIAt8g&cad=rja

Also, this may be the thesis paper you referenced:
https://www.warnell.uga.edu/outreach/pubs/pdf/forestry/Root Strength Pub 10-19.pdf

pretty simple math, will have to see how it compares to my old data.
BTW, there was an old link on this site where I'd asked the questin a few years ago also - I had a typo (left out a zero or 2) in that post.