Williamd got it right when he wote:
It looks like to me that gutting the hinge on a heavy backleaner has a purpose. You're giving yourself a holding hinge of pre determined width. Even if the tree is hollowed out to some extent there should still be enough holding wood on either side of the hollow for the tree to still be standing in the first place. I think it would help when you have to do the extra task of uprighting a back leaner before it falls over. It's more time the cutter is in the danger zone. By gutting the hinge and getting the proper tension on the pull line the cutter just needs to sever the wood on the compression side and get out of the way. If done right it seems like a reasonable approach.
Why did you delete that post williamd?
There are 10 alturnamats in the back of that bucket truck at all times... the skid steer has tracks that were designed for golf courses.. being the middle of a dry summer, the lawn was hard as concrete, and the lawn was in rough shape to begin with.. zero lawn damage..
I was running the bucket, pruning trees in the backyard.. and came down to make that falling cut.. It was waist level.. do you really think that chaps were going to make that cut safer? That said, I agree its a bad idea to show a video of operating a ground saw, without wearing chaps.. sets a bad example..
as far as the center plunge used to gut the hinge, my excuse is I learned how to do tree work on the east coast, where your average arborist doesn't even understand the basics of hinge mechanics... Arbormaster has been teaching this cut for years, and for the reasons described above by williamd.
Now let's take a step back and look at the situation of this industry: we have an arb from Bend, Oregon, that probably learned gut hinges on backleaners from his grandfather when he was 12 years old, and another arb form Ontario that learned to use the cut when he was in high school.. and when TCI mag got letters questioning its appearance on the cover of TCI Magazine, in 2004, they realized that they had no one on their staff that was familiar with the cut or its uses..
That is what's wrong with this business... the internet is just beginning to bring us out of the dark ages... and there is still a huge vacuum of good, practical training and education material that is reasonably priced and readily available..
PS... Tom.. why was this thread moved to "tree free" zone..