I was on YouTube searching around and noticed a lot of people plunge cut their back cut and leave a trigger on the backside. Supposedly this lessens the chance of a barberchair as your hinge is already setup. Assuming that the hinge is setup and I plunge cut and leave that trigger is this a safe way to fall a tree wether it is likely to barberchair or is not?
Regards-Carlo
Carlo,
I am a USFS and S212 trained volunteer sawyer. I do trail construction and maintenance. Here is what I have been taught and slightly modified to increase my safety when falling trees. This is especially useful in situations with trees with high lean, weight, or ice storm damage.
1. Use an open face notch. An open face notch is 90 degrees or greater. An open face notch CANNOT close and cause the trunk to shatter before the trunk is on the ground.
2. The notch depth should be 20-25% of the trunk diameter. Cleanup any "dutchman" (cut mismatch) that was formed while cutting the notch.
3. The hinge width should be about 10% of the trunk diameter.
4. Construct the hinge by bore cutting behind the CENTER of the notch. A swamper observer is useful to make sure that the bore cut is level with the notch. You can TAKE YOUR TIME doing this as the tree is still supported by the hinge and the remainder of the trunk. Unlike a conventional back cut the tree goes nowhere... yet.
5. Once the hinge width is properly set I will cut the holding wood from the inside (hinge) straight back. Eventually there will be enough room to insert wedges on each side of the cut to prevent any sit-back.
6. Cut most of the trunk but leave about an inch of what is called "holding wood". Withdraw the saw from the cut and re-position wedges as necessary.
7. Now cut the holding wood from the outside. If the tree has any weight or lean it should start falling. If not start hammering wedges.
The beauty of this method is that the hinge is COMPLETELY constructed first so that even if the holding wood pulls out before you have a chance to cut it, the trunk itself should NOT split and the tree will just fall in its intended direction.
This method works great for trees that are smaller diameter than the length of your bar. If the bar is almost long enough you can slab both sides of the trunk to fix this. For trees much bigger than your bar length you have to use techniques that were shown in a previous post in this thread. The main idea is to ALWAYS construct the notch and hinge FIRST!
Stay safe out there... Know when to walk away!
Steve