How to Safely Drop Large Trees with a Chainsaw
How to Safely Drop Large Trees with a Chainsaw
One of the most common ways I see people mis-using a
chainsaw is when they are cutting down large trees. Hinge-cutting is a popular
technique for enhancing deer habitat, but this technique is best for small
trees that you can easily handle. It’s not safe to attempt to hinge-cut large
trees, for reasons I will explain. The trouble is, it’s tough to define “large”
in terms of trunk diameter, because tree species vary in density and other
characteristics that make them handle differently when cut, and even “small”
trees can hurt you if you aren’t careful. Err on the side of caution: If in
doubt when studying a particular tree, consider it “large.”
Here’s what people tend to do WRONG: They walk right
up to these large trees and make a single felling cut, right into the trunk of
the tree, and saw until the tree falls. Often this works, and no one gets hurt,
and nothing valuable is destroyed. But these people should consider themselves
lucky. They avoided several potentially bad outcomes of a cut like this.
First, when you cut a large tree like this, you have
little control over the direction in which the tree will fall. Enough said.
Second, unless the tree has an obvious lean, you can
sometimes end up with the weight of the tree squatting on the saw bar and
pinching it. Now you’re in a mess. You’ll need wedges and an axe, or rope and a
come-along, to open the cut and free your saw. Obviously, rescuing your saw
when it’s pinched in a large tree is a risky operation on its own that is
better avoided in the first place.
Third, and most significant, large trees cut down
this way can perform a number of unexpected stunts as they fall, many of which
can result in your being injured or even killed. One example is what’s known as
a “barber chair.” Instead of leaning and falling as you saw through the trunk,
the tree splits vertically until it snaps at some point above the ground, and
the half-trunk and top of the tree fall straight to the ground. This often
happens extremely fast, so fast that the chainsaw operator might still be
standing at the base of the tree when it collapses.
To see a classic barber chair, watch the video
below. The saw operator was lucky that he heard the tree splitting and had
removed his saw and backed away before the tree collapsed. He had time to get
out of the way, but that is not always the case.
Even if the tree begins to lean and fall like you
want, the butt can still split as the tree is falling, and usually the top half
of the butt kicks back violently in the general direction of – you guessed it –
the person holding the chainsaw.
There’s a much better method for felling large
trees, and it’s shown in the diagram above, which is based on guidance QDMA
received from the Game of Logging training program. Following the
instructions in the diagram, you make a “notch cut” first and you make this cut
on the side of the tree that faces the direction you want the tree to fall.
Then, you make the felling cut, leaving a hinge. The hinge holds the tree to
the stump during most of the tree’s fall, and it guides the tree in the
intended direction.
The length of the hinge should be 80 percent of the
diameter of the tree. For example, on a 20-inch diameter tree, the hinge should
be 20 inches x 80% = 16 inches. The thickness of the hinge should be 10 percent
of the diameter of the tree. For example, on a 20-inch diameter tree, the hinge
should be 20 inches x 10% = 2 inches.
Not only does this method help ensure the tree falls
where you want it to, it greatly reduces the possibility of any surprises, like
splits, butt-kicks and barber chairs. In the photo in the Gallery below, you
can see images of a large white oak that died at QDMA Headquarters. I used the
notch-cut method to bring it down safely.
It should go without saying that you don’t ever
crank your chainsaw, no matter what you’re going to cut, without putting on
your helmet, eye protection, gloves, and safety chaps. But I’m saying it
anyway.
So, the next time you, or someone you know, needs to
drop a large tree, don’t give it the old Jedi light saber chop. Take your time,
plan your cuts, and use the notch-cut method to bring the tree down safely.
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