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TRAINING TRAINING & EDUCA& EDUCATION Tree Work Electricity and A common but often unseen danger By Michael "House" Tain Regardless of where a tree crew is working, electricity is probably part of their work environment,either aloft or underground.Sadly,some- times tragically, tree workers who don't specialize in line clearance often don't even recognize that this danger is lurking.Whether it's willfully, meaning Johnny knew the line was there and got too close anyway,or ignorantly,meaning Johnny fell into the trap of misinformation and lack of knowledge about the insulation of utility lines or how close one can get,the end result is the same — a spot in Dr. John Ball's regularly updat- ed statistics on tree work accidents and fatalities. Electricity is a fickle beast,and,in a sense,a force of nature,it really does not care whether a crew member knows it's there or not, or if the person knows safe working practices around it.All electricity cares about is getting back to the ground as fast as it can; and a climbing arborist or ground person with a pole- saw will work just as well for that purpose as a copper line. Safe working practices around electricity are fairly straightforward, and don't require a great deal of effort to comply.But as every industry member knows, there are a lot of safe practices, regarding almost every facet of the industry,that get ignored or skipped "just this one time"every day.All safe practices have value and are important, but when one talks of electricity one is discussing a force that will stop a heart or send it into a fatal rhythm,blow holes through flesh,and heat skin to the point body fluids boil and smoke.As is said in my neck of the woods,"The electric ain't something to mess around with." Arborist versus Line Clearance Arborist This is a pretty simple principle and standard, yet one that a lot of members of the industry see violated,or even perhaps violate knowing- ly, everyday. It's simple, personnel that have not received the required training, education, and evaluation that comprises a Line Clearance Arborist or a Line Clearance Arborist Trainee do not get closer to energized conductors than the minimum approach distance.This is not intended to make tree crew member's lives more difficult,nor is it intended to pre- 8 Arbor Age / September 2012 vent companies from bidding on jobs,it is meant to prevent the horrific wounds,burns and deaths that can occur from contact with electricity. Not how close, but how far The table below shows the previously mentioned minimum approach distance for arborists who are not line clearance certified.Line Clearance Arborists and Trainees have their own table that they work under,which allows them to be closer to energized conductors due to their training. Many tree personnel question the value of the table, saying they don't know how much "juice"is in the line,so how can they know how close they can get.This is fairly easily answered:first,no non-certified tree crew member should be within 10 feet of any line (as can be seen from the table); second,more insulators in general means more "juice, " thus stay further away fromthe line.Many utility and power companies are happy to give a quick class to tree crews on how to identify the rough voltage that a given line is carrying; and there are any number of tree industry seminars and classes that also address this knowledge. Electricity, given the right atmospheric conditions and voltage levels can easily arc through the air to a crew member who just wanted to get "a little bit closer. "Stay the proper distance away,or, if unsure,very far away;and the voltage will not have this opportunity to radically alter body chemistry and function. Kilovolts phase to phase 0.0 to 50.0 50.1 to 72.5 72.6 to 121.0 138.0 to 145.0 161.0 to 169.0 230.0 to 242.0 345.0 to 362.0 500.0 to 550.0 785.0 to 800.0 Feet 10' 10' 9" 12' 4" 13' 2" 14' 16' 5" 20' 5" 26' 8" 35' Meters 3.05 3.28 3.76 4.00 4.24 4.97 6.17 8.05 10.55 www.arborage.com