THE OPEN-FACE DIRECTIONAL FELLING NOTCH

When people first stopped felling trees with axes and turned to chainsaws, they kept using the same technique: basically, making a 45° notch on the side of the tree towards which they wanted it to fall, then making a level cut from the back of the tree. Called the back cut, this is 2.5–5 cm up from the point of the felling notch (see diagram). The wood that’s left between the 45° felling notch and where the back cut ends is called the hinge, and it helps guide the tree safely to the earth.

But this method can still be dangerous, with the potential for the butt of the tree (the part closest to the ground) to launch up backwards, injuring or even killing an unwary tree feller.

So a few decades ago, Swedish logger and chainsaw instructor Soren Eriksson pioneered and perfected a method that takes advantage of a chainsaw’s unique ability. It’s called the open-face directional felling notch. It’s more complex, but it’s also safer, and it gains that safety from giving the wood cutter far more control of how and when the tree falls.