Letter box

Burnham

Woods walker
Joined
Mar 7, 2005
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Western Oregon
When Pete McTree joined me to observe the USFS treeclimbing instructor's workshop last week, he pointed out a butt cut in a pile of wood set aside for firewood permit holders. He said something like "Look at that, a classic letter box felling cut".

I laughed and told him that was a stem I felled this spring during the FS EC-4 heavy rigging/large wood removal training/cert. course. He said I was doing it European style, using a short bar :D. I told him that it was a normal "gut the hinge" felling cut to ease pulling the short spar over :).

I was using the 200 rear handle, so the bar was just a smidge shorter that the Oregon ash was across.

I decided to take a pic or two, and then hunted down the stump as well.

Here they are.
 

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I believe it's for when your bar is less than half the diameter of the stem, and so you don't have enough bar to get to the middle of the stem when you do your back cut. So instead you bore into the middle of your face cut to get that wood before you even begin your backcut. At least that's the only reason I've ever had to use it.

EDIT: Just reread Burnham's original post and see he's using it to make it easier to pull a short spar over. That makes sense too.
 
I probably should have used that on a stem I dropped today. I had a heck of a time getting it to wedge over even though I had cut my hinge down to 1/4". If I had bored out the middle, I could have left 1/2"+ of hingewood and still wedged it over easier.
 
I did it today on a 40" walnut stump with a 36" bar. Tree had a bunch of back weight and we were pulling with a 3 to1 and the dingo. Hinge was about 4" thick and thats alot of work pulling on so I gutted the hinge.
 
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  • #6
Yup, I did it to make the hinge flex over easier. With a short spar, little weight up top, it makes a pull sooooo much easier.

And with a full crown, but some back lean that you are wedging to force the tree to commit to the face, gutting the hinge eases the wedging effort.
 
Never heard it called that before. 'Round here, it's a "bored face". Among other things, it's used to eliminate fiber pull in good veneer logs.

Also helps on smaller diameter trees, so the wedge can pass through without bottoming out in the back cut.
 
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  • #10
Exactly, Erik...before the back cut, the slot looks like the mail slot in a front door.
 
I teach folks that technique for dropping spars, even tops. There is less hinge to break, the corners are still intact. Works like a charm. After talking with Pete, one thing I want to do is go to the UK and learn the different way they fall trees. I've always been comfortable "doubling up" when falling, but it seems they cut that way as a matter of course.
I learned alot from Pete in the short time I got to talk to him.
 
I first saw that cut being used here on the large valuable Zelkovas, for as NeTree explains, to help eliminate wood pull that would decrease the value of the log at auction. That was especially true with trees that were being pulled by a powerful implement, with the likelihood of the tree going over before the back cut was sufficiently completed. The Zelkovas get enormous and very heavy, so just the right amount of pull can get tricky. I find that most people pull too hard, and there is that big cracking sound.
 
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  • #17
sorry to be thick, whats the list of steps to that cut Burnham? :)

Make the face with a horizontal and a sloping cut, per normal. Then bore the center out of the hinge, either from the face side or the rear (bar length relative to tree diameter can govern the choice), at the same elevation relative to the horizontal cut of the face as you intend to place the back cut. Then make the back cut per normal.

It's not vital to exactly match the kerf of the gut and the back cut...it'll break out along the vertical fibre line of an overlap with little effort.
 
The old hand who taught me most of my clear felling knowledge, said you could cut out upto half the length of the hinge out of the middle without compromising hinge reliability, even on side leaners.:O

Never tried it in a crucial situation though!
 
In goose pen trees all you have to rely on is the corners. Ultimately they are the guiding force of any tree, but by themselves not strong enough to hold a tree for very long. Especially a side leaner.

There lot's of times you can get away with less hingewood and even more times that you can't. It's one of those variables that takes falling many trees,, and observing how and why things end up the way they do.

I think I'm getting the hang of it.
 
You can also "swing" the tree with that cut. Once it starts in motion, cutting off the hinge on one side or the other gets some pretty interetesting sideways movement going. :)
 
Intentionally, absolutely. I had an old master teach me that trick many moons ago for clearing protruding limbs on the edge of lots, etc. Let it drop down past the limb, then swing it in line with the skid trail. Newfie (Mike) just about shit the first time he saw me do it. :lol:
 
That will do it every time. I'll never forget learning to use a Dutchman and cutting corners off.

I certainly don't recommend doing it, unless you have a lot of room for error,, and stand way back.
 
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