Forest Industry Safety & Training Alliance, Inc.

July 2014Ben Parsons, FISTA Training Coordinator

Whatta Biggun!

There seems to be the same few situational questions that come up frequently in chainsaw safety classes. One of these is how to deal with trees so large in diameter your saw bar doesn’t reach all the way through. While there are a handful of ways to deal with this issue, the following steps detail a common and widely accepted method of laying ol’ “fatty fatty 2x4” on the ground.

First, establish your “open face” notch (70 degrees or greater opening). Make sure the cuts do not bypass by more than 3/8ths of an inch (known as a Dutchman’s Notch). Set the hinge length at least 80%, and hinge thickness about 10% of the DBH.

Next, bore cut with the attack corner of the bar on the side of the tree deemed safest. Be sure the initial bore is parallel with the notch. The bore cut depth should be slightly beyond the halfway point of the trees diameter. To be sure your bore cut is deep enough, it is acceptable to go about two thirds of the diameter of the tree from either side of the tree.

Now go to the opposite side of the tree and make the second bore cut, again being sure that the bore cut is parallel with the notch, and the cut is deep enough to bypass your first bore cut. (To be sure your bore cut is parallel and level with your notch cut, it is critical that when you set the hinge, “square up” and position yourself so that you can see the entire length of your notch cut. Again, set your hinge thickness by keeping the bar parallel to the face of the notch.

It is not necessary to match the level of the bore cuts from each side, but rather that they bypass one another inside the tree to be certain all of the fibers are cut. Mismatching the cuts has very little effect on the remaining steps of your procedure, since vertical fibers separate when the tree begins falling. Remember, it is the hinge and holding wood that control the felling process.

The manner of release made will depend on the lean of the tree. Slight forward leaners will allow the sawyer to cut from the inside out if desired, after a visual check to make sure the target is clear. Back leaners or heavy forward leaners will require releasing the holding wood from the back of the tree.

Finally, remember that the saw cuts smoother at full throttle, so when using the boring technique, cuts should be made at maximum rpms.

If cutting trees larger than 2X the length of the bar on your saw, one additional step must be added to ensure that all the fibers inside the tree

Once the notch cut is made, bore through the center of the notch toward the back of the tree. In a pivoting motion, cut out the center portion of the tree without compromising any more hinge than the width of your bar. To do this, once the bore cut is made, pivot the saw so that the end of the bar is cutting in a pie-shaped motion, while the part of the bar near the powerhead shouldn’t be cutting anything. The inside of the tree will be cut, but the hinge will only have about a 4-½ inch void (bar width) where the bore cut was made. Preserve as much of the hinge wood as possible. After this process has been completed, resume cutting by following the above outlined steps.

Following these techniques when cutting large diameter trees, your ability to fall and control the tree, is greatly increased.

Ben Parsons, FISTA Training Coordinator, is originally from West “By God”, Virginia as they say in that part of the Appalachian Mountains. His family’s deeply rooted philosophy of living off the land was monumental in deciding to earn a degree in Forest Management from West Virginia University.  Throughout his career, Ben has had the opportunity to tackle a wide variety of assignments.  He measured Forest Inventory and Analysis research plots in Virginia and Georgia, been involved with urban and utility forestry operations throughout the Appalachian region, procured lowland hardwood timber in the swamps of South Georgia, managed logging contracts and harvest operations in Arkansas and specialized in water quality and harvest planning as well as fighting forest fires in Virginia. As FISTA Training Coordinator, helping to meet your safety and educational needs is the number one priority here at FISTA.  For more information, contact Ben at 800-551-2656 or