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Back cut below gob cut?


Georgesoton
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Don't reckon it makes a deal of difference personally, more problems come from people who can't read a tree, ie they don't take the time to look round the tree and decide if want it in that direction that if the gobs there it will go there, if you fell with the natural lean of the tree or in the direction it is most heavily weighted it will go that way, just make sure the gob is of a proportional size for the tree and how you want it to land and of course not so small that it won't come down in the first place.

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I think by the sounds of things he is doing it wrong, unless he is employing some of the more advanced felling techniques some of the guys are talking about. However if he is just 6 months out of the course and using it on every tree I doubt that he is.

 

Does anyone use it to try and 'jump' the stem? I heard about it in Canada, putting the back cut in 4" to 6" below the notch if the tree has a slight lean the way you want it to go. Mostly applicable to climbing and knocking out the head to clear an obstacle but have heard 'stories' of people jumping whole trees over fences. Putting sticks in the gob to give it more pop and other such wizardry!

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If you put a stick in the gob, doesn't that just lessen the size of the gob?

 

It creates a fulcrum . As the gob closes the top face meets the stick and snaps the hinge and pops it forward off the stump . ( In theory ) :001_smile:

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...I have never heard or seen anyone put the back cut below the gob. Is this something new? Or maybe for a particular situation, so slopes/leaners/splitty types? The fella reckons that's how he was taught by his instructor...

 

And got it past his assessor on his assessment? Really?

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There are times (flared buttresses) when back cut lower is safer. Back cut above with flared roots and even with an ideal hinge you can risk severing the fibers

 

You see here, the top cut, although good thicknes in hinge has no complete fibers. The bottem cut has the most complete fibers

 

When you fell at the level of the flared buttresses with a conventional notch and back cut (without cutting the buttresses off) the fibres at each side of the hinge tend to hold the tree in place as it falls over not only because the sapwood is more fibrous but also that the fibres at each side of the hinge are curving away at 90 degrees to the felling direction so they wont shear cleanly like in your pic.....all things being reasonably equal it'll will be a slow tearing shear on each side of the hinge giving more control of felling direction. Also most people would make a deeper notch into the straight grained fibres of the trunk which would avoid the type of shearing shown in your pic.

 

I get what the guy is saying but the pic example only tells half the story.

felling.jpg.6e97e0d280b58976b5644afd2cfe6337.jpg

Edited by scotspine1
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When you fell at the level of the flared buttresses with a conventional notch and back cut (without cutting the buttresses off) the fibres at each side of the hinge tend to hold the tree in place as it falls over not only because the sapwood is more fibrous but also that the fibres at each side of the hinge are curving away at 90 degrees to the felling direction so they wont shear cleanly like in your pic.....all things being reasonably equal it'll will be a slow tearing shear on each side of the hinge giving more control of felling direction. Also most people would make a deeper notch into the straight grained fibres of the trunk which would avoid the type of shearing shown in your pic.

 

I get what the guy is saying but the pic example only tells half the story.

 

Excellent post!!!:thumbup1:

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I think by the sounds of things he is doing it wrong, unless he is employing some of the more advanced felling techniques some of the guys are talking about. However if he is just 6 months out of the course and using it on every tree I doubt that he is.

 

Does anyone use it to try and 'jump' the stem? I heard about it in Canada, putting the back cut in 4" to 6" below the notch if the tree has a slight lean the way you want it to go. Mostly applicable to climbing and knocking out the head to clear an obstacle but have heard 'stories' of people jumping whole trees over fences. Putting sticks in the gob to give it more pop and other such wizardry!

 

Do canadians not put the gub in upside down?

So 4-6" below would be like us putting back cut halfway up gub

 

Must admit never really tried to make a tree jump over anything.

Generally if i have to fell a tree/limb over a fence i will cut a high open gub over fence hieght and try to leave hinge so it will hold the stem while i break it down.

But generally not a good idea to fell trees over fences u don't want to flatten

 

Anytime i've screwed up up and put back cut below gub cut it generally always sits back even if it wouldn't normally sit back if back cut was above and can be a pig to wedge over.

 

Can see the theory behind it for winching dead stems but not really a job for beginners

 

never heard of puting the stick in before, will that not be the same as cutting a vey acute small gub?

I experimented with cutting very small gubs when cutting for skyline to try and get every hinge to break, but found on quite small trees (less than 12-18") it would sometimes support the tree and not snap off at all.

 

For a begginner i'd say always cut above the gub, the nearer they are to level the stronger the hinge will be, but if u cut too low it well often sit back on ur saw.

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Canadians and those who also log the United States of America use the upside down "gob". Its known as the humboldt undercut. You guys want to check out some good falling, type up Worksafe B.C. falling on Google. The Humboldt is better for logging because the undercut comes out of the stump, not the log. Also, the tree cannot come back at you, like if it hits another tree on the way down. The backcut is always a bit above, the bigger the tree, the higher. On a tree that is 2ft at the butt, the backcut would be about 1"-2" higher.

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