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Aerial Chain Saw Operation and Safety

By Michael “House” Tain


While the increasingly lighter weight more efficient modern chain saw is an excellent tool that allows tree crew members to fell and prune trees efficiently, it is a tool that can “bite” its operator most severely if used inappropriately or in an unsafe manner. An additional complication to chain saw operation, one encountered hourly by most tree crews, is the difference when operating a chain saw aloft — either when climbing or from some form of aerial platform. Not only does this location isolate the chain saw operator from fellow crew members and assistance in the event of an injury or accident, but it also severely limits the operator’s options for a safe escape route in the event the cutting does not go as planned. Additionally, operating a chain saw while aloft, particularly during climbing operations, exposes the operator to additional dangers and challenges in regard to stable body positioning and the fact that they are suspended aloft by a system of ropes and cordages quickly and easily cut in a moment of inattention. Aerial chain saw operation does present specific problems and hazards not necessarily present during ground operation. But well-trained, knowledgeable operators have several guidelines they can follow, along with specific techniques and methods that can make cutting in the air as safe and efficient as possible.


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A mismatch cut on a vertical piece or spar (note that the mismatched cuts overlap or bypass one another). The distance between cuts will vary with diameter and species. Photo by Michael “House” Tain

The “basics”

Chain saws are designed and engineered to be used with both hands, whether on the ground or high in the canopy. In addition, the right hand is intended to be on the rear/top handle (dependent on saw design), and the left hand on the forward handle with thumb “locked” around it. Personal experience has shown that despite years of operation, strength, or speedy reflexes, a chain saw being operated with one hand cannot be adequately or consistently safely controlled. The continued one-hand operation of a chain saw, on the ground or in the air, is steadily increasing the odds of a bad accident or injury. The standards require that persons operating a chain saw aloft be secured in two ways — for example, a work positioning lanyard and climbing line — in the event the saw severs one of the systems. While not yet required by standards, and not necessarily germane to this column, climbers aloft should consider the sharpness and efficiency of modern handsaws, and would also be well served to have two methods of attachment during their use. That favorite wire-core lanyard should also not be thought of as chain saw proof in saw operation aloft as, particularly when under tension, wire-core lanyards have been cut by chain saws. Lower-body protection, chain saw pants or chaps, are not currently required by federal standards when operating a saw in the canopy, although some states and municipalities do require them. Regardless, progressive climbing arborists would be well served to always wear lower body protection when operating a chain saw — no matter their location. After all, a bleeding laceration to the lower body is certainly not going to be any easier to deal with 45 feet up in a pin oak than it is in Mr. Jones’ neatly trimmed backyard.


“This is kickin’!” isn’t always a statement of good things

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The completion of a properly executed spar mismatch cut in which the climber is able to put the chain saw away, and, using both hands, snap off and throw to the desired landing area the severed piece of wood. Photo by Michael “House” Tain

One of the key thoughts to entertain when operating a chain saw is where is the path of kickback. This is extremely important when running a saw while climbing or from an aerial lift, as, besides the operators’ obvious isolation from ready assistance, there are simply very few options with regard to footing, body placement and movement. These limitations, coupled with the fact that the operator is less likely to be in a “position of power” to absorb and counter the force of a kickback, all mean the operator needs to focus on the path of kickback. Knowing and recognizing the causes of kickback and avoiding them will eliminate the majority of the risk of it occurring. However, often some thought put into the positioning of the chain saw while cutting in relation to the operator can radically limit the possibility of a kickback striking them or their climbing system. For example, operators cutting with the bottom of the bar with the saw held directly in front of their face is setting themselves up for some brutal cosmetic surgery in the event of a kickback. A quick examination of the situation will often offer better positions or options, such as cutting from the side with the top of the bar, making any kickback that might occur likely to go out and away from the operator. Climbers and aerial lift operators should also consider the location of their equipment in the path of kickback, as a saw can just as easily take out a climbing or hydraulic line.


Old school

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A mismatch cut on a horizontal branch in which the cuts are to either side of the branch, not the top and bottom. The distance between cuts will vary with diameter and species. Larger diameters and species with stronger wood will require the cuts be closer together, while smaller diameters and species with weaker wood will need to be farther apart. Photo by Michael “House” Tain

Though often left on the ground, or even in the truck, during aerial chain saw operation, a hand saw can be an excellent complement to its motorized progeny. A great many cuts can be carried out almost entirely with the chain saw, saving time and energy, then quickly and safely completed with a few strokes of a modern sharp, efficient hand saw. The use of a hand saw with a straight blade will allow users to evenly “thin” the hinge in a felling cut while aloft, unlike a curved blade, which will remove material from either end of the hinge, leaving a thick portion in the middle.


Oh snap!

The mismatch or snap cut is a great technique when cutting aloft, as it allows the operator to cut the piece while leaving it in place, safely stow the chain saw away, and snap the piece off to hurl it handily towards the right place — all while avoiding one-handed chain saw operation. This technique can be used for either horizontal branches or vertical spars, though the location of the cuts will vary with orientation, species and diameter. For example, more brittle wood and smaller diameters will require the cuts be made further apart, while stronger woods and larger diameters will necessitate the cuts are closer together. The technique uses two staggered cuts, and the cuts should overlap each other in the middle of the piece, as can be seen from the accompanying photographs. The piece is now technically severed, but the remaining fiber in the vertical plane (if the cut has been done correctly) will keep the piece in place until the operator can stow the saw, and snap the piece off.


Notches are notches

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The completion of a horizontal branch mismatch cut, note the importance of the cuts overlapping or bypassing one another, as this is typically where the piece will separate. Photo by Michael “House” Tain

Felling notches, familiar to many an arborist in ground chain saw use, are just as valuable when up in the air — particularly when the branch, piece or top needs to fall into a specific spot or direction. Operators should use the same process to determine lean, size of hinge, desired direction, etc., that they would use during ground felling operations. Open-face notches are highly recommended with the caveat that the operator always needs to consider what arc of movement is needed for the piece or top being felled. For example, in a top that is vertically true, straight up and down, a notch of greater than 90 degrees will make the hinge keep working while the top is heading toward the ground, often “snatching” the spar forward and down — exposing the climber to some funky ‘80s disco movements. A good guideline for top removal is to open the notch to an angle that will cause it to close when the top is almost parallel, or parallel, to the ground, thus lessening forward movement of the remaining tree. Notches may also be used when tip tying and lifting branches in rigging operations, the only difference is that the operator is “felling” the branch upward. The size of the notch is determined by making one cut parallel to the ground/horizon and the other perpendicular to the branch orientation. This will form a notch that will close when the branch is vertical; assuming the block lifting the branch is located as close to directly above the face notch as possible. Closing the notch slightly, making its angle narrower, will lessen the likelihood that the climber will have to come back in and sever the still-attached hinge to free the branch.


Running a chain saw up in the air, whether climbing or from a lift, is certainly more complicated than operating one on the ground. But this valuable tool can be even that much more effective and efficient by employing some of the methods and techniques discussed here. In addition, an understanding of the forces and concerns of aerial chain saw operation will aid in safer use — an outcome that is more important and positive than any other.


Michael “House” Tain is a contract climber, splicer, educator and writer associated with North American Training Solutions www.northamericantrainingsolutions.com and Arbor Canada Training and Education www.arborcanada.com. He is currently located in Lancaster, Ky., and can be reached via e-mail at house@houseoftain.com.

Main photo by Thor Clausen.

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