As recent events in upstate New York have proven, the late autumn and early winter weather patterns have begun arriving with a vengeance, and with winter’s blustery weather comes new challenges and hazards for tree care professionals.
Not only do cold temperatures, snow and ice add complexity to the typical tree care industry tasks of pruning, tree removal and cleanup, but their presence can also generate work of an urgent nature at all hours of the day or night under less than ideal conditions.
Storm work or cleanup is difficult enough in the warm and humid aftermath of hurricanes, microbursts and thunderstorms in the spring and summer. Add in the driving/traction problems of snow and ice, frigid temperatures, recalcitrant equipment, and the forces generated on trees by winter winds and precipitation, and seemingly simple tree care operations become much more complex.
While a written explanation of the hazards and challenges of tree care in storm scenarios is certainly no replacement for training, experience and education, it’s a start toward assisting tree care personnel in being aware of the unique dangers of storm work, and some of the basic methods/techniques that can be employed to mitigate the hazards.
The most common, and perhaps the most dangerous, hazard when carrying out tree care in storm scenarios is downed, energized conductors, or electricity. The snow, ice and winds that accompany winter storms are just as happy to bring down utility lines as they are to bring down trees and branches, and often bring down both at the same time.
Training in electrical hazard awareness should be a key component of any tree company’s education program, and tree crews should make the identification of electrical hazards part and parcel of their normal daily operations, but the singularity of storm situations and their heightened probability of electrical hazards make the identification of electrical hazards even more vital.
A prework scene assessment must be done prior to beginning any storm cleanup, and while the work plan is a goal of this assessment, in storm scenarios identification of any possible downed energized conductors is a key component. Tree crews should keep in mind that the chaos of a storm can cause normally benign lines, such as phone or cable, to come in contact with power lines, possibly energizing them, along with more hidden dangers such as energized metal fencing, curb edging, or even, with the right soil conditions, fatal voltage in the ground itself.
In short, the presence of downed, energized conductors in the work area is a game changer, and the crew must contact the utility company to shut off the power prior to any work going forward. Identifying electricity’s presence early is the only way to make sure the crew goes home with all the folks it started out with.
Storm situations rarely result in ideal working conditions for tree crews. Not only are the temperature and environment quite challenging, requiring changes in work practices and clothing, but often issues such as visibility and footing are also problematic.
Clothing with a synthetic outer layer to protect against rain, snow and ice will help keep the crew more comfortable in these situations. Dim and even dark working conditions will require the use of headlamps on helmets or portable work lights. And while high-visibility or reflective clothing is always useful in tree work, it is imperative for storm cleanup. It will not only ensure that crew members can identify one another in the often chaotic work space of storm cleanup, but also that passing vehicles or non-tree care personnel can identify them.
Wet, icy or snowy conditions coupled with tree pieces and parts on the ground can make movement and footing extremely difficult while working in storm situations. Crew members should move carefully and make sure their footing is secure prior to making any cuts, as falling with a running chain saw is a recipe for an emergency room visit.
Forces: The wind, ice and snow of a winter storm can often create forces in downed trees and limbs that are more dangerous than what’s typically encountered in standard tree care operations. Once again, just as with electrical hazards, every downed tree or limb needs to be evaluated and examined prior to work being started. The two most common forces a tree crew member will encounter during storm cleanup are compression and tension.
While these forces are always present to some degree in wood fiber, they become even more dangerous in downed trunks and limbs, making their identification a key part of safely completing the work at hand.
A compression force is present in the wood when it is under pressure and being bent, basically compressing the fibers together. A saw cutting into these compressed fibers will reach a point where the wood will “squeeze” against it, pinching, stopping and catching the blade of the handsaw or bar of the chain saw. A tension force also involves bending of the wood fiber, but in the opposite direction, attempting to pull the fibers apart. A saw cutting into these fibers under tension can release them too quickly, causing the fibers to pull and release very quickly, often with violent reactions.
While each trunk or branch will possess these two forces in varying degrees, their location will vary according to the orientation of the piece of wood. For example, a wind-thrown trunk lying on the ground with the top still elevated above the ground will typically have compression forces on the underside of the trunk and tension forces on the top. Conversely, the same tree with the top caught in another tree or otherwise supported will typically have tension forces on the underside of the trunk and compression forces on the top.
Regardless of orientation, crew members need to look carefully at each tree or branch to identify tension and compression prior to cutting.
Dealing with the forces present in storm cleanup does not necessarily require storm-specific cutting techniques; many of the techniques used in standard tree care operations are perfectly suitable. However, the hazardous nature of storm cleanup does require that the techniques be used slowly and carefully, with a vigilant eye on the movement of the trunk or branch being cut.
CUT: While “CUT” may seem to be what tree folks do every day, in this case it is a handy way to remember how to deal with compression and tension forces in wood. Developed by the trainers and educators at Arbor Canada, the letters of the acronym not only help the chain saw operator remember the forces present, but also the proper sequence to releasing them under control. The “C” stands for compression, the “T” for tension, and “U” are in the middle.
The side of the piece with compression forces present should always be cut into first, but with care taken to not cut too deeply and get the saw stuck or pinched. This will create an opening for the wood fiber to move or bend into. The tension side is cut into last, but as slowly as possible while watching the piece for movement, the intention being to gradually release the tension forces as the wood moves into the opening created in the compression side.
Spring poles: Spring pole refers to any piece of wood bent down by the weight of another tree, branch or ice/snow load. There’s a great deal of energy stored up in the wood of a spring pole, and it will certainly “spring” free violently if released incorrectly by an inattentive crew member. The use of the CUT acronym will assist in the safe release of spring poles, but some additional techniques are also helpful.
The shaving technique uses the edge of the chain saw bar to “shave” out a shallow notch on the compression side of the spring pole, creating an opening for the wood to move into when the tension side is slowly cut. The kerf technique uses multiple shallow small “kerf” cuts in the compression side to create openings for the same purpose. Both techniques should be used at the point of maximum forces in the spring pole and carried out slowly with the operator watching the pole for any signs of movement. Crew members attempting to release spring poles should have a clear escape route and begin moving down it rapidly at the first sign of movement.
Tree care operations are challenging and hazardous in the most normal and benign of weather conditions, but the addition of poor weather conditions and the nature trees downed by storms increases those challenges and hazards exponentially.
Training, education and experience are essential to be properly prepared for the unique challenges and hazards of storm cleanup, but the basic principles and techniques discussed here are an excellent introduction to the nature of tree work in storm scenarios.