Tree Felling - Leaners

So far in this series on

tree

felling

we have covered techniques where the main danger is simply mishandling the chainsaw. When it comes to cuts, we are dealing with a

tree

that can be very dangerous just because of the cutting sequence that is defined as a cut. Like any tree that does not have its weight centered on its stump,

leaners

can be further classified based on how much lean they have and how the lean is oriented in relation to the direction we want the tree to fall, while There are no established ranges for The classifications in this illustration show nomenclatures for slopes along the line of the desired fall direction, depending on the amount of slope, some very different techniques may need to be used to fell those who are lean back, anything more than a slight lean will require tackle to pull the tree.

We will discuss the desired direction of fall in the next video in this series. A tree can have a component leaning either to one side or in line with the direction of fall or can have both components simultaneously as mentioned in the introduction. Slanted hinges can be extremely dangerous. A key point to remember is that, while a narrow hinge will easily bend and fail as desired, a hinge that is too thick or incomplete will not bend and is likely to cause shear failure in the log. In this illustration, our the feller has already made a notch and is in the process of making the subsequent cut when disaster strikes the tree has a significant bending moment due to the encumbrance the stump attempts to counteract the overturning moment by strongly pulling down on the left side of the unfinished hinge above the posterior cut, the fibers running toward the trunk, just to the right of the progressive posterior cut, are pulled forcefully downward.

All the fibers just to the left, which are being pulled forcefully upward, when the forces are large enough, can overcome the shear strength between the fibers. Fibers and a split can develop, that split can move up the trunk very quickly if the bending moment is initially high and the wood is somewhat brittle. The crack can travel 20 feet down the tree in just half a second if the tree is more elastic. and the bending moment is smaller, the crack may move only several feet per second and reach the point where additional cracks are driven by the stresses generated by the falling tree rather than the initial stresses released from its connection to the side. right of the trunk. the left side will be freed, since with the speed of the split, the movement of the left half of the trunk can vary from walking speed to as fast as the swing of a baseball bat.

A guy standing with some vital organ behind his trunk could die. by a quick and powerful backward movement of that part of the trunk, here we have an example of a leaning northern red oak, it is leaning to the right about eight degrees and that is probably not much of a burden, however, we have to consider others factors instead of just what the trunk does what we see is that on this side there is a wide open field that normally receives a lot of good sunlight, but on the other side we enter a deep and dark forest, as a consequence this tree has grown with almost all of its It can be seen that the branches that face the sunlight, there are essentially none that grow back towards the shade, as a consequence of the fact that all these branches leaning outwards significantly affect the center of gravity of the tree and make it a much slimmer weight.

Smarter than just the leaning of the tree would tend to indicate now that it could have been much worse, but now you see the problem this leaves us: we have all this weight of tree on top of where we need to work and it becomes a dangerous place. I'm trying to decide how to do this because it has a big spring and will want to come back up, so the cutting sequence for this will be very complicated. What I'm going to do is cut off pieces so that there's nothing to hit against it and then I'm going to nibble on it from the sides and now that the tree is down it's easier to see that all the branches are actually on the side facing the sun, essentially nothing comes out the top of this tree as the split goes up the trunk it tends to migrate towards the part experiencing the bending in our example meaning the split will move to the right thinning the part that is still connected to the stump.

What happens next will vary with elasticity. of the tree and the amount of initial lean in some weak and elastic trees, the split may not move much towards the bending side and everything will simply stop once the crown is on the ground, this leaves a very dangerous which we will discuss in a future video, the other possibility is that the thinned connection breaks and the upper part of the trunk falls off. Note that the left end of the butt now extends several feet beyond where the feller was standing. If the connection breaks, the trunk will most likely fall.

Hopefully the feller has already left the area at high speed, the part of the trunk connected to the stump was strongly bent and wants to jump to the left, if he does so, when the connection breaks, he can kick the falling part several times . feet aside the reasons are shrouded in history, but the lumberjacks nicknamed the part of the tree that remained a barber's chair, so for those of you wondering how to avoid a barber's chair incident, how should you plan your cuts for that dangerous inclination? Plan your cutting sequence to get the hinge to the desired thinness before the tree can begin to fall.

Start the sequence by making one of the two notched cuts, but not this way, the bottom of the tree will be under a lot of pressure and its blade could easily get caught and forced to remove weight with another saw. The first measure to avoid this pinch is to make the first cut with a pronounced inclination. The thin wooden wedge on the outside of the saw cannot tighten the blade too much if it catches. A plastic shim can usually be placed just above the teeth to open the cut enough to free the saw. The second measure is not to try to tie the knot too deep; if it is important to prevent the tree from falling to the sides, you will have to do so. make the knot deep enough to obtain a fairly wide hinge;

Otherwise you can limit the depth of the notch to perhaps 1/6 of the diameter of the log. However, the next step is to start the back cut instead of starting at the back of the tree. The cut should start near the finish line of the back of the hinge. The way to do this is with a plunge cut which is done by essentially pushing the saw lengthwise through the center of the tree; however, care must be taken when beginning such a cut. The chain at the tip moves perpendicular to the length of the saw and if the tip makes contact, the blade will be thrown in the direction that the chain is moving.

Fortunately, although alarming, this error rarely kicks the blade enough to make contact with the feller. Of course, it's a very bad thing when it happens. The correct way to start a dive is to contact the tree at an angle of approximately 45 degrees using the return or pull portion of the chain once a groove has been made that is deep enough. To cover the curved end of the blade, the angle of attack can be changed to perpendicular and the plunge cut can be advanced across the trunk. Ideally, the plunge cut should be kept about an inch away from the final hinge location when the saw emerges at the far end.

On the opposite side, the position of the plunge cut can be compared to the location of the notch to determine how much cutting is needed to finish the hinge. If the tree is still well supported, you can lean under the trunk to look the other way; However, if the entire support appears suspicious, the saw should be removed from the plunge cut and the distance should be evaluated by palpating the area under the lien. Once the evaluation is completed, the hinge with the hinge established, the subsequent cut advances in the direction opposite to the uncut part is commonly known as the strap or the trigger the tension in the strap will be all that prevents the tree from falling at some point the strap will become so thin that it will fail almost instantly without warning, fellers should approach the final cut cautiously by reaching To make the cut and be prepared to jump, in some cases the tree may have a small diameter but still large enough that the reaction of a barber chair is a safety issue if the center of the saw blade is such that the belt or hinge will be a hazard when making the plunge cut.

The problem can be addressed by doing a slanted back cut. Let's move on to the least dangerous situation. Slightly leaning trees In general, these trees can be safely felled with a normal notch and backcut, regardless of the size of the tree. You should consider before making that decision. The larger the tree, the greater the stress on the tree as cuts are made. This means that a more cautious approach may be warranted for a large tree than for a small tree. Size is also important for how quickly the back cut can be advanced to reach the final hinge thickness with a large tree, once the tree starts moving there may simply be a lot more cutting to do on Back cutting before you can get to the hinge with a medium to small tree, it will be quite easy to continue sawing quickly to complete the hinge before the trees lean, may cause enough shear stress to split the trunk if the cut stops or is too slow, the tree may be a barber's chair To close the information on the danger of lean, there are several potential defects in the structure of the trunk that could increase its susceptibility to splitting.

Unfortunately, these may not be visible until after the tree is cut down. There may be weaknesses due to insect attack or sometimes rot, this damage can be easily seen on the trunk. Look for old wounds on the top of the trunk, as they may have allowed regular water entry into a cavity, allowing rot to advance up the trunk behind a healthy facade. Another phenomenon is what is called Wind Shakes of Trees, as defined by the World English Dictionary, are cracks between the annual rings of wood caused by strong winds bending the trunk of the tree. Unfortunately, there is no external clue that such shaking may exist, although they are more likely in conifers.

Less common are trunk cracks. These are radial cracks that are significantly deeper than the more familiar frost cracks that only split the crust and part of the cambium. I recently found a crack in the trunk of a northern red oak. The crack had no discernible surface expression, but extended from the center to just below. the bark on the southwest side of the tree the crack extended from the ground to a height of about 4 feet while the crack had some discoloration there was no rot to summarize the thinner ones can be very dangerous but if the proper techniques are followed they will be can handle According to the most competent lumberjack, the same is not true for lean-backs, which can require much more than a simple chainsaw, especially as the size and amount of lean increases.

The issues involved will be covered in the next video in this series.