Sunday, December 2, 2007

Falling a Tree: The Open Face Cuts and Hinging

Falling trees and bucking logs are activities that have inherent risks. The methods you use when performing these tasks can dramatically increase or decrease your risk of being injured or killed. The most important step in preventing problems is committing to developing a plan for every tree you cut. If you don't have a plan, everything that happens becomes an accident; so here are your planning steps, and a slide show demonstrating the cuts to make in aiming a tree you are going to fall.

1. Look for safety issues around the tree you are cutting. Downed limbs, vines, brush, dead wood and widow makers overhead, power lines, and anything you can identify as a possible hazard. You have to mitigate your hazards before you start cutting. Sometimes you walk away and leave the tree for someone with a bucket truck.

2. Determine your aiming point. This is done by walking to the spot you want the tree to fall and looking back at the tree. If the tree is vertical in relation to you, you will aim straight on for this spot. You will need to change your aiming spot if the tree has side lean. Point up at a 45 degree angle into the tree and determine how much the trunk/crown lies off a vertical line from the center of the stump. You will move your aiming spot an equal distance in the opposite direction. Put a stick in the ground to mark the spot. The hinge will fail if the tree has significant side lean. If this is the case, find another direction to fall the tree and do this step again. You can handle more forward lean and back lean than you can side lean.

3. Determine your escape routes from the stump you are about to create. Your escape route should be on a line 45 degrees off of the fall line of the tree. (135 degrees from the direction the tree will fall.) Clear out any obstacles that might trip you or block you from making an efficient move away from the stump. You MUST get beyond a 12 foot radius as quickly as possible when the tree begins to fall. Ninety percent of injuries and deaths occur within that 12 foot radius, so distance is your friend. If you can dodge behind another tree, so much the better. Wood often comes raining down from the treetops when trees move, so get out of the circle, and stay out until things settle down.

4. Make your open face cuts to aim the tree. You aim the tree with the first cut, and your aiming aid is the line across the top of the saw. Line up your eye behind this line and point it at the stick you put at the aiming spot. Cut down on the face of the tree until the bottom of the cut is 80% of the tree diameter. If the tree has much side lean, you will want to make the hinge 90% or 100% of the tree diameter. A pocket size tape measure with a diamater scale on the back is a handy item to have in setting up this cut. Your second cut is made by cutting in horizontally and meeting the bottom of the first cut. Remove the wood and inspect the junction of your cuts. The cuts should meet exactly. If either cut passes the other by 1/2 inch or more, clean it up so they match. The angle between these cuts should be 70 to 90 degrees. This wide angle allows the tree to fall to the ground with the hinge holding the tree to the stump.

5. The final step is establishing a hinge, releasing the tree, and wedging if the tree is not balanced forward. Begin your back cuts on the bad side of the tree; that is the heavy side. You will complete your cuts from the good side of the tree. You start by determining your hinge thickness. The hinge thickness should be no more than 10 percent of the diameter at breast height. Begin the cut with the lower corner of the bar and bury the nose of the bar, then rotate your saw until the bar runs parallel to the open face cut. With the saw running wide open you push the saw through the tree while staying on track to make the hinge the correct thickness. When you have the saw all the way in you will then cut toward the back of the tree, but stop and leave a strap of wood holding the tree. If your saw did not reach all the way through the tree you will repeat this operation from the other side. Set a wedge in the back cut unless you are sure that the tree has forward weight. This will prevent your saw being trapped. When you are satisfied with your setup, make sure everyone is out of the way, cut the back strap, and make your escape. Use your wedges to tip the tree if it does not go on its own.

Remember when making these cuts that the hinge should be no more than 10% of the tree diameter in thickness, and should be at least 80% of the tree diameter in length. Boring cuts are always started with the bottom corner of the chainsaw bar. Stop and look around before you cut the backstrap. Make sure no persons or pets have wandered in while you had your head down making your cuts. Make your escape when the tree begins to go.

Always wear boots, chainsaw chaps or overalls, hard hat, ear, eye, and face protection when running your saw. Activate the brake if you are taking over two steps.

After watching this video, click on the "chainsaw" label to bring up other videos about using a chainsaw.

For Extreme Leaners, CLICK HERE.   And HERE.

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