Hinge Thickness For Falling Large Diameter Trees?

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Hello,

Happy Thanksgiving everyone! Here is an interesting question to ponder over turkey and football.

The Forest Service guidelines specify a falling hinge thickness of 10% DBH as a maximum. The 10% number works out pretty good for trees under 20" or so. But what about a 48" tree? 10% is 5 inches which sounds like a near impossibility to wedge over, especially if the tree is dead and has no lean or weight. Think about trying to break a true to life 5" x 48" piece of wood. Think about a huge dead, dry piece of red oak.

Here is the situation: The tree in the photo is right next to a hiking trail and has been dropping widow maker limbs onto the trail. Due to this the trail section monitor has asked me to evaluate the safe removal of this tree. The tree was supposedly alive a couple of years ago until the town put a sewer line in the vicinity of the tree and damaged the root system.

As a disclaimer I have not laid eyes or hands on the tree as of yet. I do have it on good authority that the DBH was actually measured at a little over 48". The diameter tape was only 12 foot and that was the end of the tape!

For mitigating resources/measures we have access to rope rigging and a Tu-17 Griphoist so this could belay having to wedge the tree over.

Your thoughts?

View attachment 1222720
Can you rent a towable lift?
 
tree.jpg

Heavy rigging line as shown in blue the tree where there seems to be some decently strong trunk. I don't know whats to the right but pull to that direction to fall in what seems to be a field (?). With a long enough rope, maybe attach to a heavy piece of equipment or truck to pull it over? Or maybe if there's a sizeable tree, use a pully to offset the direction of the pull. With no lean and no offsetting weight to one side or the other, any pull from any direction will pull the tree to that direction.

1/3 notch, cuts the sides of the notch in from both sides to make sure they're free, pull on the rope and cut the backside. I do it all the time with long dead white and red oak that have died from gall wasp or gypsy moth damage/death.
 
Like you say, the target zone includes the use trail, then what ever you do when you touch it, it is best to finish it for creating a hazard to the public users of the trail.
Right now the trail is re-routed off of our ROW and away from this tree. We would like to put it back on our ROW but if we can't we can't.
 
In 50 years of tree felling, the only non-minor injury I've had was a dead branch detaching 80ft up as the tree started falling. I thought I was ready for it but it smashed onto my climbing helmet, ripping the ear defender off and compressed my neck by an inch or so. I was shaken but not injured longterm.
So pull it over or better still, walk away!!
 
Either fell it like any other tree as there looks to be enough lean, shouldn’t need wedges OR hire a bucket truck to take the top out of it.
I had to google what a grip hoist is, “come along” which in my opinion will be totally useless and there doesn’t appear to be any need to pull that over.
It sounds like it’s way out of your comfort zone as I don’t know your background nor experience so I would recommend hiring a professional feller. Just my 2 cents.
 
Either fell it like any other tree as there looks to be enough lean, shouldn’t need wedges OR hire a bucket truck to take the top out of it.
I had to google what a grip hoist is, “come along” which in my opinion will be totally useless and there doesn’t appear to be any need to pull that over.
It sounds like it’s way out of your comfort zone as I don’t know your background nor experience so I would recommend hiring a professional feller. Just my 2 cents.
While that tree doesn't LOOK like it, even the vibrations from sticking a saw into a highly compromised tree can cause it to let loose pieces or fail completely.


I do agree with you that the tree likely could be straight felled, but it would need thorough evaluation. Be bad if the heart was far to one side or the other and not anticipated as such.
 
But if it's not too far from the road, that griphoist is your ace in the hole. But I wouldn't want to carry it (or the rest of the rigging) very far at all. Good luck!

Isn't that what swampers are for??!
😉


You needed bullet points for that one!

Yes to the banana wedges, wedging sideways, and setting wedges before making your face; even on that row of smaller pines out Jaybee some years back.

5" hinge seems way too much. 3" sure, but still a lot. Block out if you feel the need.

Trunk weight looks in favor. Undermine gravity a little and have multiple escape routes cleared and well-practiced.

You need to get out of the zone of those branches if one decides to come backwards or sideways while in motion.
 

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