3 ms·
As an aside, as trivia ... It may interest HN readers to learn (it interested me) that if you are standing near downed power lines (for instance, your car cras
by rsync 9y ago
As an aside, as trivia ...
It may interest HN readers to learn (it interested me) that if you are standing near downed power lines (for instance, your car crashed into a pole and it fell, or a storm, whatever) you need to jump away from those downed power lines.
You need to stay in one fixed place and then jump, up in the air, to the next place, and continue to "bunny hop" away from the downed power lines.
The reason is, depending on the amount of moisture in the earth, or cracks in the asphalt, or dirt, or water or whatever, it is possible for there to be a spot where there is more resistance in the ground between your two feet than there is in your two legs and so (if you are walking) the electricity will arc out of the ground, up one leg and then down the other.
- Nadya 9y agoTo expand on what you said, since you used crashing into a pole as an example... If you crashed your car into the pole the safest place for you to be is in the car. Unless your car catches on fire do not leave the car. If you must leave the car do not touch the car and the ground at the same time. Open your door and jump out of the car with your feet together. Then do as rsync said: bunny hop away.
- devrandomguy 9y agoThis reminds me of an incident report I saw back when I used to work in a warehouse. A forklift driver raised the boom too far, and smashed it into a high power lamp. He immediately let go of the controls, and decided to get away from the forklift, rather than lower the boom, concerned that the metal levers might electrocute him. As soon as he stepped on the ground, he completed the circuit that was preciously blocked by the rubber tires, and paralyzed himself from the waist down. The report recommended jumping clear, and then using this hopping escape strategy. It did not recommend or countermand moving the vehicle to break a potential circuit; I guess that situation is too complicated for a blanket policy.
- zkms 9y ago> and decided to get away from the forklift If you're not currently being electrocuted and there's no imminent risk of the situation worsening (or high voltage wires moving) there's little need to put yourself at risk by moving. There's no guarantee that jumping clear/hopping will be safe -- electrical potentials can't be visualised with the naked eye. Even if the power line is touching the ground, the ground isn't perfect and there's still a gradient: https://ehss.energy.gov/sesa/Files/corporatesafety/advisory/SA_2010_05.pdf https://ehss.energy.gov/sesa/Files/corporatesafety/advisory/... , https://en.wikipedia.org/wiki/Earth_potential_rise https://en.wikipedia.org/wiki/Earth_potential_rise Stay put, call for help, tell people not to get close to the vehicle or the high voltage conductors, and wait until someone de-energises the offending high voltage circuits. https://www.osha.gov/OshDoc/data_General_Facts/downed_electrical_wires.pdf https://www.osha.gov/OshDoc/data_General_Facts/downed_electr...
- malandrew 9y agoWhen bunny hopping does the distance between your feet matter? i.e. Is it better to keep your feet closer to one another as you do it?
- sliken 9y agoAlso keep in mind that with a down line always treat the line as live. Apparently if a line is down or shorted the power is cut automatically at a certain point. But afterwards test pulses are sent out to measure the line. Said pulses can easily kill if you happen to be completing the circuit at that time.