Dealing With Dangerous Trees
By Ben Hoffman, Maine
Always, before cutting a tree, carefully examine the tree, the trees around it and the ground where it will fall. Are there any dead limbs or debris in the tree (widow makers), or neighboring trees that may fall on you? Does the tree lean, or is the crown heavier on one side, or laden with snow that may affect its balance and direction of fall? Are its branches intertwined with other trees in such a way that it may hang up rather than fall freely? On a windy site, a tree may not lean but strong prevailing winds can create stresses that cause a growth reaction in the tree. A decided lean or unbalanced crown will affect wood strength—compression in softwoods, tension in hardwoods.
If a tree falls on a large rock or stump, it may break, or rebound. Cut any brush that may affect your work, and always create an escape path behind the direction of fall, at a 45-degree angle. This is your protection in case of kickback. It may also be wise to cut brush and small trees in the area where the tree will fall in order to make limbing easier and safer.
Trees that are straight, healthy, with balanced crowns, are easy to fall, but all trees are not that way. In fact, if you own a woodlot, the straight, healthy trees are the ones you want to keep. The candidates for removal are diseased, poorly formed, leaning or rotten. Are there any large wound scars or cat faces on the trunk? I learned to deal with problem trees the hard way, fortunately surviving, by the grace of God, some hairy experiences. Some of my friends were less fortunate and suffered severe injuries.
If you cut firewood to improve your forest, you will be cutting the worst trees—dead, dying, seriously injured, poor form, ratty crowns, partially uprooted leaners. Trees with decided lean or heavy crowns on one side or rotten and hollow butts present problems. Leaning trees produce reaction wood. With conifers, the reaction is weaker compression wood on the side toward the lean, rarely a serious problem, but be aware of it and leave a larger hinge. And be careful when cutting a soft wood with a dead top; pounding on a wedge may cause enough movement and vibration in the top that the wood breaks and drops on you.
Hardwoods that lean badly or have lopsided crowns often have reaction wood on the backside—tension wood that is brittle and weak. When cutting from the back, tension wood may break suddenly and the tree will fall before you expect it, creating a “barber chair.” The safest way to drop them is to bore into the trunk, parallel to and above the hinge, leaving the tension wood intact, then cut back through the tension wood. When that last inch is cut, the tree will drop quickly. Bore cuts are dangerous unless done properly—the tip of the bar can kick the saw back, hard, unless the saw is revved up. Unless you are experienced with a chainsaw, I strongly recommend having a pro show you how to make a bore cut. Poorly made bore cuts cause problems.
The objective is to drop a tree exactly where you want it so as to minimize damage to other trees, reproduction or to facilitate its removal. Often, a nearby tree crown may be in the way. The hinge is normally uniform in thickness but you can swing a tree to one side to avoid a nearby obstacle such as a tree crown. Make the notch so as to fall the tree free of its neighbor; then, on the back cut, leave more holding wood on the side toward which you want it to lie. The tree will begin falling in the direction of the notch, missing the crown of
its neighbor, but the extra holding wood will cause it to swing to that side. This is a good method to prevent hanging your tree in another (or damaging its crown).
Leaners are obvious, but rotten or hollow butts may not show up until you begin cutting. Wounds on the trunk may indicate rot. Old-timers pounded on the trunk to discern if it was hollow, but that doesn’t always work. You may not know until your undercut has started. If the rot/cavity is large, try another cut about 16 inches (firewood length) higher (butt rot often decreases as you go higher in the tree). If there is rot, a shallow undercut gives more hinge. I commonly cut firewood trees about 32 inches up—it saves bending over, holds the stem off the ground for easier limbing, and I can easily cut the stump off flat and close to the ground. Loggers make stumps as low as possible to maximize recovery of quality saw and veneer material.
Do not stand and watch as a tree starts to fall. Scram! I photographed a faller in British Columbia as he stood and watched a 90-foot lodgepole pine go down. About a month later one of the crew was seriously injured when the tree he was watching rebounded and smashed his upper leg. He died from loss of blood on the way to the hospital. If a tree does not begin falling when you expect, slowly pare away the hinge, maybe try wedges, and be ready to move quickly in case it kicks back or rolls after falling.
With hardwoods (deciduous trees), the side away from the lean is under tension and forms tension wood that is brittle, weak and likely to split. If a tree is leaning badly, when cutting in from the back, tension wood can break suddenly and the tree will fall unexpectedly, creating a “barber chair.” Hardwoods with a decided lean, or a very heavy crown on one side, call for much more care in falling. The easiest way to drop them is to bore into the middle of the tree, leaving the tension wood intact, then cut back, through the tension wood. When that last inch is cut, the tree will drop quickly. Starting bore cuts is dangerous unless done properly, as the tip of the bar can kick the saw back, hard.
You might also encounter a tree that is both leaning and hollow or rotten, and that calls for more care, especially with softwoods. A leaning conifer with rot or hollow butt will have compression wood on the lower side that is weak; hence the hinge must be thicker. In these situations, a shallow notch gives a thicker hinge and may require wedging.