Now he'll pull the " that doesn't matter to an arborist" card.
Just like being able to set a fast and precise face cut apparently doesn't matter to an arborist.
Apparently learning the basics of treefalling doesn't matter if you are an arborist, they only fell a few trees, so speed and precision isn't important.
Be like me teaching karate and not being able to do high kicks: " but I only fight dwarves, so that doesn't matter".
It is the minority of scenarios that don't require some stump shot. Thinking about it, It may be easier to wedge/tip without, but I don't know of any occasion where it is safer.
It is the minority of scenarios that don't require some stump shot. Thinking about it, It may be easier to wedge/tip without, but I don't know of any occasion where it is safer.
I would love it if someone could explain in detail the physics and forces involved, and how they make stump shot safer per your above statement. When you say safer, do you mean safer to the faller or to property? I can assure you that with a nice fat hinge and a high pull line on a machine, that leads to a scenario where the faller is nowhere near the stump at the time the tree begins to move, stump shot is NOT safer for the faller. And in cases where precision is needed, no or very little stump shot is safer for the property.
The majority of cuts I make stump shot is not safer, nor is it needed.
Now he'll pull the " that doesn't matter to an arborist" card.
Just like being able to set a fast and precise face cut apparently doesn't matter to an arborist.
Apparently learning the basics of treefalling doesn't matter if you are an arborist, they only fell a few trees, so speed and precision isn't important.
Is it that hard to understand that one of the main differences between arborists and loggers is the number of falling cuts that are made in a day?
I can prune trees or rig trees from the bucket truck all day long and only make one or two falling cuts over the course of that day. Does it matter if I spend an extra 20 seconds on the face cut? Do I need a worked saw and super sharp chain, or chaps when I'm only making a falling cut or two and walking away.
Then there is the other side of the coin, where a tree has front lean in an open drop zone which doesn't require directional control from the hinge. You still waste time by making notches you are so proud of when they aren't needed.
In this video (which BTW does show a slight bypass in the face cut, though it's not enough to affect the fall in any way). It takes you 2:20+ to get this tree moving. That tree had a little front lean. If it had even more front lean you still would have used a notch and created a hinge. It would have been no faster, and maybe even take more time to plunge and set up a back release.
I have a video of falling a similar-sized ash in 1:30 with an older stock 460 or 440 that isn't cutting nearly as well as yours. Probably could have been 20 seconds faster (or more) using your saw. So roughly twice as fast as you.
I AM happy to spend an extra few seconds setting up a better hinge with some height to the fibers on the front of the hinge, especially when I need all the control I can get from that hinge. And when I don't need control from the hinge I can cut twice as fast as you.
The saw hits the wood at :09 and the fall starts at 1:40
As just one example, any time you have twisted grain stump shot can cause the hinge to thin out on one side and get fatter on the other. In this Norway maple there appears to be no more than 1" of stump shot and quite a bit of hinge loss from the twisted grain in the wood.
Don't you still control that by how much you cut? I get that a slightly higher force is required to get it to tip, and if you keep cutting you will thin your hinge to nothing, but that is the same as no stump shot. I'm trying to visualize how twisted grain could change the thickness rather than the cuts controlling it, but i simply can't see it.
The placement of the bottom, the diagonal, the hinge, the back cut, be it in one go or quartered or bored...all of those are constantly discussed and analysed before and after each fall, hence, height of back cuts is an intrinsic part of the discussion
Don't you still control that by how much you cut? I get that a slightly higher force is required to get it to tip, and if you keep cutting you will thin your hinge to nothing, but that is the same as no stump shot. I'm trying to visualize how twisted grain could change the thickness rather than the cuts controlling it, but i simply can't see it.
It's not that hard to understand. The hinge has to connect the falling trunk to the stump. ANy weakness in those connecting fibers is going to reduce the effectiveness of the hinge. So any imperfection such as a knot or decay or squirrelly fibers is going to make a difference. If the grain is twisted in the differential, the hiigher the differential the more of the hinge can be altered unintentionally. And no... thinning out the hinge is not the same as no stump shot.
The placement of the bottom, the diagonal, the hinge, the back cut, be it in one go or quartered or bored...all of those are constantly discussed and analysed before and after each fall, hence, height of back cuts is an intrinsic part of the discussion
You already said.. what specifically is the information or training about the height of the back cut relative to the floor of the notch (stump shot). What are they saying about it?
If they think my back cuts were too low, please tell me why? You already mentioned that the tree can slide back off the stump. Did they give any more variables that might be involved (particularly size). I've heard that the hinge fiber in tropical trees (trees that grow without growth rings) is much less trustworthy than northern hardwoods. Is that or species a factor?
It's only when you get into big trees and thin hinges or the potential for big trees to hang up that there is much of a chance that buts are going to slide back over the stump from the forces generated during the fall. If you look at the photos of my hinges in post 44-46, you'll see there is ZERO chance that trees of that size will have back slipping forces anywhere near strong enough to break those fat hinges, with all that long holding wood. It's a NON-ISSUE in virtually all suburban tree falling scenarios. If your instructors don't know that, they won't pass my tests. You have to get into massive trees for back-slip to be a force worth considering.
Yes, big trees, and we were falling big trees, and trees with mush for middles, and dead trees, some with mush for middles.
The smaller the tree, the more open the falling area the lower the back cut cut can be but not less than 2".
'kay, done now, you obviously go home alive at the end of every day, back cuts low or not, good on ya.
Just one more question do you use or recommend that 2"minimum guideline for falling your suburban trees?
That was something I heard regularly in training for many years. Never heard the why of it though. I think that guideline has changed here in the states.
Clarifying, smaller trees in the bush are still big so 2"...residential, I always fall my trees with a back cut higher than the face, but if it's a tiddler tree the back cut will be commensurately lower than 2"
massive trees are a game changer. up to 4 or 5 feet there just isn't enough force to push the but back off the stump assuming a reasonable hinge.
I don't really know where the cut off is because I don't handle anything bigger, and even the 4 foot plus are more of an exception these days.
this is one of the problems with the standards. there are just so many variables, and the lines between them separating what works from what could kill you are not clear.
There's no need of an hang up in other trees to get a deadly shot back. You get one easily even in a fully open area with the massive limbs of a wide crown/short trunk grown in full light. These strong limbs make a prop for the trunk instead of being crushed flat by the fall's energy.
An embankment, a boulder or a hight stump closely in the way can do it too.
Kyle, the thickness is the same but not the actual holding fibers in the hinge. On one side with a twisted grain, the first intact fiber at the back of the hinge goes deeper back in the stump (so you get a fatter hinge than it looks like), since on the other side the same goes toward the front and come short of the front of the hinge, maybe even it's cut by the notch (so you get an actual thiner hinge or even no hinge at all). That with the same overall hinge's thickness on each side. The more angle of the twisted grain and the more high of the stumpshot, the more likely you get screwed, as if you cut truly through the hinge on one side.
It's the same effect to not take in count the back-lean of the trunk when setting the hinge. You can easily end up with no real hinge at all and lost the tree.
Offering no direct on-topic hinge expertise, I'll just throw out a refresher on two odd physics things. One is the classic brick chimney snapping in half part way down being "felled" - because the CofG is accelerating at one rate and trying to make the top tip accelerate at a higher rate, makes bending stress and tries to snap the trunk in half - matters for a rotten trunk. Other is trunk CofG wants to come straight down into the root plate, we make it accelerate more sideways most forcefully in the early part of the fell and that dwindles a bit when the trunk is nearer to the ground, but mid-fell-ish there is always side force across the stump because the CofG really wants to just come straight down, where ever it happens to be, but maintaining ("coasting") its horizontal component if it has achieved some up to that moment. This kind of falls out of the max horizontal velocity / horizontal throw calculation. Odd thing is if you think about it, any shape, size be it bean pole or super spreader have a CofG doing the same thing.
If you impart the horizontal acceleration with a pull you exactly directly reduce the hinge horizontal reaction force by that much.
Enjoying reading the knowledge here. Like the little gotchas like twisted grain, imperfections, rot etc that are often glossed over.
You'll just have to trust me... my tree left the stump in 90 seconds from the time the saw hit the wood. using a stock saw 461 stihl and chain.. Stig isn't even close..
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