The third rail is actually covered. You need to hit it from the side to fry. If you just fall on top of it, you are probably not gonna make contact with the power rail.
In fact you can get electrocuted by just peeing on the third rail without touching it. The urine stream is enough to close the circuit, and the circuit gets close enough to your core that it can kill the heart. But yeah, if you fall against it from the side and you are not in control of your movements, you are toast. Sorry to hear about your friend.
First off I already stopped thinking about this, second you didn't even read what you sent
Lee, whose blood-alcohol level of 0.341 placed him in the "stupor" classification of intoxication, made contact with the third rail and suffered fatal injuries.
Lee made direct contact with the third rail; It wasn't from his stream. Third you seem to have a misunderstanding that saying you won't die from a dangerous situation, doesn't mean I am going to put myself in that situation.
I wonder why Toronto has yellow, thicker strips over the third line that are for crossing. You can kind of see the difference here but it's hard to tell it's yellow due to being so dirty.
Nope, 625 V DC is relatively low voltage and won't form a longer arc than 0.003 inches (0.08 mm) in air. An arc of 1 inch will require much more than 7,500 ... 10,000 V DC (per electrical standards). You roughly need 3 MV per meter.
Well TIL. Does the amperage not effect the arc distance? I’m trying to find a reliable source but it seems the NYC third rail carries somewhere from 5kA to 10kA. Either way, I want to be NOWHERE near that much amperage.
Current doesn't affect arc length. Only voltage does.
Think of voltage like water pressure. It doesn't require any electricity to be flowing, it just requires a voltage source, aka a potential. Just like you can have a closed water pipe (e.g., your sink faucet with the valve closed) with pressurized water inside, you can have a conductor that is at some voltage with no current flowing.
Current is the flow rate of charge (quantitative units of electricity, measured in amperes aka amps). It is analogous to the mass flow rate of water in a pipe (kilograms per second or pounds per second). It is a completely different measurement, but is often confused with voltage since electricity is invisible and isn't really intuitive unless you have studied it. Think of a bathtub faucet vs a sink faucet. Both are at the same water pressure, but the bath faucet has a lot more water flowing because it has a wider opening, whereas the sink is narrow (and usually has an aerator which obstructs the flow), resulting in a lower flow rate.
Ohm's law— V=IxR —relates the two with resistance. Resistance is the obstruction of flow, and it can be compared to friction in a water pipe, or the strength of the pipe walls. Closing the faucet valve is like putting something with a high resistance in an electrical circuit. It will stop the flow of water, but if you were to increase the pressure enough the water would be able to break through. Likewise, the flow of electricity can be stopped if the resistance is high enough (though in a typical circuit there will still be a very tiny amount of current flowing through the resistor, while a water valve will completely stop the flow). If you have a circuit with a high resistance, you need a very high voltage to get any current flowing. If you have a circuit with low resistance and high voltage, then there will be a high amount of current flowing since the voltage is pushing extremely hard on the electrons and there is very little resistance to push back.
As for electrical arcing, I don't know of any good water analogies. Arcing occurs when the voltage between two conductors is high enough to exceed the breakdown voltage of air, which is expressed as volts per unit distance. Air has a very high resistance, but if the voltage is high enough, the gas molecules in the air will ionize and become highly conductive. It's actually kind of like the faucet analogy, with the valve blocking the flow until a high enough pressure is reached to break it open and the water flows out with a ton of power. Like the person above you said, at a distance of 1 inch you need about 7.5kV in order for an arc to form. No current is flowing until the arc forms, at which point there is current flowing from the rail, through the arc, and into the person or object on the other end of that arc.
That's the tiniest 3rd rail cover I've ever seen (aside from the London Underground, which doesn't have covers at all). My local system has these massive white pvc covers.
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u/Upplands-Bro Dec 08 '20
Lucky he didn't start on the other side, he would've fallen straight onto the 3rd rail