Third Rail Hazards

[MattAmity90]

When I was about that age I stuck a knife in the toaster (the pound cake I was toasting was stuck). No burns, but the jolt threw me across the room slamming me into the opposite wall. I remember sliding down the wall, wondering how I got there! Don't Do That!

I know we should be focusing on the hazard issue, but my Dad stuck knives in electrical outlets when he was a kid. I use a sleeping bag as my blanket for my bed where I'm all zipped up and tucked. My cat went into it the other night, and as soon as she came out, she looked like the top of bumper cars, or when the third rail arcs when a train goes over one when it is ice-covered with all the static electricity built up. Looked like an M8 after switching from third rail to catenary wires with her tail and backside being the pantographs.

[Triaxle]

Back when I was around 9 or so I touched the third rail on the West Hempstead Line with the knuckle of my thumb. On purpose, because I reasoned it couldn't be really be THAT bad, because if it were, people wouldn't be able to touch it, right? (kid reasoning). I got a little burn on my knuckle, but that was it. I still wonder to this day why it wasn't worse.

Don't do that, and I hoped you learned your lesson. Only reason you got burned was because you weren't touching a running rail and you tapped it. Probably the fact that the third rail on the West Hempstead Branch doesn't have that much juice. DON'T TOUCH!

"doesn't have that much juice" Nooooooo!
ONE ampere at 750v is lethal if you are the path to ground. The saving grace here may have been a combination of:
1. A dry hand.
2. Dry feet. 9 year olds don't sweat as much.
3 Sneakers with rubber soles
4. Standing with both ankles well clear of either running rail.
5. Kids don't go into cardiac arrest as easily as us oldsters.

Somehow, instead of being electrically clamped in place and then arced/cooked, he got only a stern message, some small fraction of an amp made its way from hand, through thorax, to ground. Also fortunately, his other hand was in free air, so no path across the chest, that's a killer.

What Matt doesn't say is what happened when he tried that experiment. I suspect it was not pleasant.

[Head-end View]

A friend told me a story years ago about his young teenage daughter and her girlfriend walking along the tracks with tennis rackets in hand. And my friend's daughter touched the third-rail with the racket and supposedly nothing at all happened. Except that my friend almost had a heart attack when his daughter told him the story..............

[Morisot]

My Dad was furious about my carelessness with electricity at the toaster --- but I saw him cry that day. He was a lineman for Con Ed.

[MattAmity90]

Back when I was around 9 or so I touched the third rail on the West Hempstead Line with the knuckle of my thumb. On purpose, because I reasoned it couldn't be really be THAT bad, because if it were, people wouldn't be able to touch it, right? (kid reasoning). I got a little burn on my knuckle, but that was it. I still wonder to this day why it wasn't worse.

Don't do that, and I hoped you learned your lesson. Only reason you got burned was because you weren't touching a running rail and you tapped it. Probably the fact that the third rail on the West Hempstead Branch doesn't have that much juice. DON'T TOUCH!

"doesn't have that much juice" Nooooooo!
ONE ampere at 750v is lethal if you are the path to ground. The saving grace here may have been a combination of:
1. A dry hand.
2. Dry feet. 9 year olds don't sweat as much.
3 Sneakers with rubber soles
4. Standing with both ankles well clear of either running rail.
5. Kids don't go into cardiac arrest as easily as us oldsters.

Somehow, instead of being electrically clamped in place and then arced/cooked, he got only a stern message, some small fraction of an amp made its way from hand, through thorax, to ground. Also fortunately, his other hand was in free air, so no path across the chest, that's a killer.

What Matt doesn't say is what happened when he tried that experiment. I suspect it was not pleasant.

Valid point, never thought of that. I was referring to the fact that M3's are not that common on the West Hempstead Branch because they overload the third rail. A friend told me that, but hey 750 volts and just one amp is 750 volts and one amp that will kill you.

[scopelliti]

When I was about that age I stuck a knife in the toaster (the pound cake I was toasting was stuck). No burns, but the jolt threw me across the room slamming me into the opposite wall. I remember sliding down the wall, wondering how I got there! Don't Do That!

I know we should be focusing on the hazard issue, but my Dad stuck knives in electrical outlets when he was a kid. I use a sleeping bag as my blanket for my bed where I'm all zipped up and tucked. My cat went into it the other night, and as soon as she came out, she looked like the top of bumper cars, or when the third rail arcs when a train goes over one when it is ice-covered with all the static electricity built up. Looked like an M8 after switching from third rail to catenary wires with her tail and backside being the pantographs.

There are two facets of electricity: voltage and current. Think of voltage as pressure of water and current as the amount of water in motion. Yes, i stuck knives in outlets as a kid... not very high voltage (110) and your body has a fairly high resistance to current flow at that voltage. So it will sting and hurt but usually not fatal (no,don't try it on a lark... touching 110 volts with one hand and having the other hand on a water pipe puts the current flow through your chest which can cause heart arrhythmia). A tiny pinhole in a pipe will give a high pressure water stream (similar to high voltage like your cat - perhaps 50,000 volts) but there is very little water flowing (low current) so you're pretty safe too.

But combine high water pressure and a large flow of water (in our analogy high voltage and high current) and you'll get knocked across the room or worse. One other item.. at around 200 volts the body's resistance to electricity drops which results in much higher current flow - and that will be fatal or produce serious burns.

Obviously, this is not a joking matter... be very careful around railroads.

[collin7]

There are two facets of electricity: voltage and current.  Think of voltage as pressure of water and current as the amount of water in motion...

 Which, of course, is why the 3rd rail needs to be so thick & heavy at 750 volts & sometimes may be just bearely adequate, whereas when you get up to 11,000 volts (or higher) the catenary appears to be only about a half inch (or less) in diameter...tho both can develop enough power to run a train, AND either one can kill you JUST AS DEAD!!

[artman]

Back when I was around 9 or so I touched the third rail on the West Hempstead Line with the knuckle of my thumb. On purpose, because I reasoned it couldn't be really be THAT bad, because if it were, people wouldn't be able to touch it, right? (kid reasoning). I got a little burn on my knuckle, but that was it. I still wonder to this day why it wasn't worse.

Don't do that, and I hoped you learned your lesson. Only reason you got burned was because you weren't touching a running rail and you tapped it. Probably the fact that the third rail on the West Hempstead Branch doesn't have that much juice. DON'T TOUCH!

"doesn't have that much juice" Nooooooo!
ONE ampere at 750v is lethal if you are the path to ground. The saving grace here may have been a combination of:
1. A dry hand.
2. Dry feet. 9 year olds don't sweat as much.
3 Sneakers with rubber soles
4. Standing with both ankles well clear of either running rail.
5. Kids don't go into cardiac arrest as easily as us oldsters.

Somehow, instead of being electrically clamped in place and then arced/cooked, he got only a stern message, some small fraction of an amp made its way from hand, through thorax, to ground. Also fortunately, his other hand was in free air, so no path across the chest, that's a killer.

What Matt doesn't say is what happened when he tried that experiment. I suspect it was not pleasant.

From my recollection, all five of your points were true that day.

[litz]

You were one very lucky 9 year old.

It's all a question of power which (in watts) is defined as Voltage x Amperage.

*one* amp at 750vdc = 750watts. Think about that ... that's basically 1/2 of a microwave oven.

Very luckily for you ... voltage is potential difference ... e.g., it's a definition of the amount of power (defined by current load) that could flow.

The actual flow is defined by the amount of resistance presented ... lower resistance = higher current = higher amounts of power transferred.

In your case, you presented a very small path, with high resistance, for current flow (due to the 5 items noted above), and therefore very little power transferred.

(as compared to a train with a traction motor presenting a low resistance path for very high current flow, therefore a tremendous amount of power transferred)

[JamesRR]

A friend told me a story years ago about his young teenage daughter and her girlfriend walking along the tracks with tennis rackets in hand. And my friend's daughter touched the third-rail with the racket and supposedly nothing at all happened. Except that my friend almost had a heart attack when his daughter told him the story..............

Was it a wooden racket? That might explain it. The wood might not have conducted enough of the electricity to notice.

[DutchRailnut]

just for slow readers, he mentioned tennis rackets ?

[nyandw]

Did I miss something? Wooden rackets, a non-conductor... I read at normal speed??

[Head-end View]

I don't get what Dutch said either........