Hazards Of Felling Storm-Damaged Trees-Part I

Perhaps the most difficult and dangerous trees to cut are ones that have been damaged by storms.

These trees should be tackled only by the most skilled and experienced tree cutters, for they are, in a word, unpredictable. This is primarily due to the tremendous compression and tension forces exerted on the parts of the tree under pressure. It is critical that release cuts be made correctly in order to avoid injury. The methods for making these cuts, and the principles behind them, are the same as those for bucking logs. There are countless scenarios of storm damage to trees, but the ones my crew and I most frequently encounter are of two general types: trees that have been uprooted (partially or completely), or trees that have broken off but remain attached to the trunk.

Felling partially uprooted and/or tipped trees requires an understanding of the various stresses exerted on the trunk as well as the possible reactions of these stresses to an arborist’s cutting technique.

Uprooted trees (or windfalls)

Strong winds often uproot trees, leaving them in one of three conditions:

1. Hung-up in another tree (or perhaps lying on a structure, such as a house)
2. Partially uprooted and severely
3. Uprooted and lying on the ground.

Hung up trees can be safely felled using various bucking methods, and the latter two conditions can be addressed using the following methods. 

Safety is important; never stand on or straddle the trunk of an uprooted tree while cutting to sever the root mass from the rest of the tree.

Partially uprooted and severely tipped trees

At first, felling partially uprooted and tipped trees appears simple until you consider, or experience, the dangers involving the tremendous pressure being exerted on the trunk, and what happens when the remaining root mass slams back down after the trunk is cut. To minimize some of the risk, do not attempt to make the following felling cuts above your shoulder height.

• Cut an open-face notch on the compression side of the tree (the bottom side of the trunk) to a depth of about one-quarter of the trunk diameter.
• Make the back cut on the tension, or top, side of the trunk. Be prepared for a potentially explosive response as the tree falls down and the root mass tips backward as pressure is released when the trunk is cut.
• When cutting larger-diameter trees, consider using the bore cut method that’s used for trees with a heavy forward lean, or securing the trunk with a chain or strap to prevent the trunk from barber chairing.

To avoid being injured by the sudden upright shift of the root mass, remove sections of the trunk incrementally; this will allow the root mass to counterbalance the tree gradually.

Jeff Jepson is an ISA Certified Arborist with more than 25 years of experience in felling trees. He is the owner of Beaver Tree Service in Longville, Minnesota and author of “The Tree Climber’s Companion” (1997).

Editor’s Note: This article is an excerpt from “To Fell a Tree: A Complete Guide to Successful Tree Felling and Woodcutting Methods” (2009), printed with the permission of Jeff Jepson. For more information regarding methods and techniques for cutting large-diameter trees, rope installation methods, and more as they relate to working on hung up trees, Jepson’s book provides many examples.

(Article courtesy of Tree Services Magazine: http://www.treeservicesmagazine.com)