subject: Electricitiy lines and tree surgery [print this page] Electricitiy lines and tree surgery Electricitiy lines and tree surgery
If accident prevention fails and a tree or tree part falls on to a power line, it is trouble. The best course of action is to immediately call the emergencyservices and the operating utility company. Ensure everyone maintains minimum approach distances from anything that is, or could be, energized, including the tree,fences, tools, or other objects. In order to avoid the risk of step potential, do not violate minimum approach distances from the base of the tree, tree part, or other potentially energized object on the ground. If someone is in the tree, still alive and not being shocked, it is best not to move from the tree until a utility representative declares it safe, rather than run a gauntlet of electrical hazard to evacuate the tree.
On the other hand, if the person is electrified, there is not much anyone can do to mount a rescue without risking his or her own life. If there is enough energy present to threaten one person, it is a good bet there is enough to imperil others. Remember that an energized human body, tree, climbing ropes, and many nearby conductive objects are all indirect contact threats. Potential rescuers should not touch anything that is or could be energized. Electrical contact will thwart the rescue by injuring or killing the rescuer. That does not help the original victim and compounds the tragedy by increasing the number of casualties.
In nearly all cases where someone is energized, the only reasonable course of action is to wait for emergency crews and the utility to arrive and shut off power. Regrettably, they often arrive too late for the victim.
Downed lines are extremely dangerous, because they are
accessible to people on the ground and present direct contact risks. Lines can fall across and energize conductive objects such as fences, vehicles, or metal-sided buildings, expanding the threat of electrical contact exponentially. Moreover, live wires can arc and whip around, possibly striking bystanders and inflicting physical or electrical injury. Lines down across occupied vehicles are special cases. In these instances, people in the vehicle are usually safest if they stay inside. Electricity will flow like water off the vehicle to ground and, ordinarily, pose little danger to those within. Call the utility and emergency crews, and keep all others away. Do not let anyone touch or stand near the car or truck. Making contact with the ground and an energized object at the same time will provide a path to ground for electricity through the body.care to touch only one foot to the ground at any one time.
There are few circumstances where occupants of an energized vehicle are safer to evacuate than to stay inside. Fire is one of those circumstances. If occupants have to evacuate, they must jump well clear. They need to make sure to land without touching the vehicle, and to avoid step potential by landing with their feet together and without falling down. Then, they must clear minimum approach distances by shuffling,hopping (keeping feet together), or bounding, taking
Electrical contact is the most common fatal accident involving arborists, and tree high-voltage conflicts subject the public to electrical safety risks as well. Given the criticality of electrical exposure involving trees, it is crucial that arborists understand electricity.Power lines can carry industrial loads of electricity that can instantaneously kill most people who contact them.
