Today’s "Trains News Wire" had a note about a ‘tagger’ that got hit by a Brooklyn subway train and lost a leg. Tough. A cop (spokesman?) said something to the effect that “the graffiti ‘artist’ was lucky, for if he had been touching metal when the third-rail shoe hit him he would have "burst into flames”. I have never heard of such a thing from 600V. DC. Maybe if he was wedged between the third- and running-rail for a while… Dunno. Anyone have any true anecdotes?
Hays
If contact with a third rail shoe is what cost him his leg, the, “Burst into flames,” comment was probably a, 'Let’s scare ‘em good,’ toss line.
One thing I’m sure of. If he had been gripping any kind of grounded conductive material (pipe, metal fencepost, etc) he would have left the scene in a body bag. 600VDC can and has killed, and will undoubtedly claim victims in the future.
Chuck
Supposedly there’s a legend from around a hundred years ago wherein a motorman opened the outside side door of his cab and proceeded to relieve himself. Because his bare hand was touching the brass controller, when the stream touched the third rail of an adjacent track, that’s all it took to complete a high voltage circuit. As a result, his “spigot” sustained quite a jolt. I heard the guy survived, but apparently his old lady was none-to-happy with this experience.
Similar things have happened along Pennsylvania’s electrified system. With 10,000 volts it is deadly. More than one person has been found on an overpass very dead holding his plumbing. Electricity travels faster upstream than fluid flows downstream.
I suspect that’s more of an ‘urban legend’ than fact, although I suppose it has happened a couple times over the last 95 years or so. I have no doubt of the electrical effects - the ‘fluid’ is very ionized and hence conductive, I believe - but both the PRR and RDG bridges usually had very high solid metal panels along the portions of the sides over the tracks and catenary, to something like 6 to 8 ft. above the sidewalks, to prevent all kinds of stuff from going over the side and onto either the tracks or the catenary.
I’ve lived in the area for over 50 years now, and had not heard that story before - and some of the railfan circles I hung out with as a teenager had members who were bizarre enough that they would have known and joked extensively about such a thing. I’m sure that the usual news reports would omit those details out of respect for the deceased and his family, and to maintain dignity and decorum. But had it occurred, I would think that such a thing would have been recorded in some official report someplace, or even made a part of attempted litigation against the railroad for negligence for failing to prevent it - after all, if McDonald’s can get sued for hot coffee . . . [sigh]
Third-rail voltage is relatively low but the amperage is high. If the circuit was completed but the contact was not good, the resulting arc could ignite clothing or anything else that was flammable. There have been more than enough botched executions which demonstrated the principle.
Sounds like a good segment for Mythbusters!
Mythbusters already tackled the, “Urinating on a third rail,” myth, and discovered that the stream was individual droplets, not a solid column of liquid. Individual droplets didn’t conduct electricity. Busted.
As for the targetshooters on overpasses hitting the 11,000VAC catenary, the probability is a little higher - the stream could possibly create an ionization path, but I wouldn’t bet on it.
Chuck
Here’s a link to a photo of a modern example on Amtrak. I’ll see if I can find some photos of older ones on the PRR and RDG - for some reason they seem to not have been photographed very often . . . [:-^]
http://www.railpictures.net/viewphoto.php?id=15372
Here’s one on the PRR from 1954 on the ‘Port Road’ line - except that note that the metal guard sheet slopes out and down over the single-track catenary, instead of vertical from the side of the bridge as I had stated earlier:
I’ve also driven on several overpasses where I-95 crosses over the NEC main line and the overpasses have those guard sheets in place, even though pedestrians are not allowed.
Sorry, but peeing on the third rail is definitely dangerous. Pee may consist of individual droplets, but the distance between them is small enough for electricity to bridge the gap. You will be hurt but will survive if you aren’t otherwise touching anything metal that is grounded, and if the weather is dry. If the gound is wet and your shoes are wet, your chances of survival are reduced considerably. This is 600 or 750V, DC.
Some many years ago, TRAINS ran a wonderful story “Pin’s Cushions.” All about George Pin’s private railroad cars, most of which are still in operation under other owners. He had to sell to cover his losses after a New Years party in Pennsylvania Station where a couple decided to “make out” on the roof of one of the cars. I understand the woman survived after falling to the platform, but the man did not after his head contacted the 11,000V overhead.
Sorry. My query was limited to 600 V. DC (even 750 V., at a stretch). I, for one, wouldn’t urinate on a 11,000 V. AC catenary, not even on a bet. Maybe I’m too modest, but I am still intact! Again, any news accounts, etc., of third-rail ‘zappings’? Tnx.
Hays
Filed under “didn’t actually happen.”
Sorry.
Well I don’t have any reports of that happening but my poor Siberian Husky only watered the electric fence along the bottom of the fence once.
New York Subways run on 600 Volts, 1000 Amps of current. Its not the volts but the amps that kill you, and 1000 amps will fry you to “EXTRA CRISPY”. Went to work in Manhattan on the Number 7 IRT line for years and saw thousands of sparks and heard lots of crackles as the shoes jumped over the third rail.
I just recalled that it takes way less current = amps than you think - the range in the publication below is from around 0.020 amps = 20 milliamps to 2 amps, which is way more than enough. From -
Part I. Electrocution-Related Fatalities - Overview of Electrical Hazards
Virgil Casini, B. S.
at - http://www.cdc.gov/niosh/docs/98-131/overview.html
" . . . few really understand just how minute a quantity of electrical energy is required for electrocution. In reality, the current drawn by a tiny 7.5 watt, 120-volt lamp, passed from hand to hand or hand to foot across the chest is sufficient to cause electrocution.1 The number of people who believe that normal household current is not lethal or that powerlines are insulated and do not pose a hazard is alarming. Electrocutions may result from contact with an object as seemingly innocuous as a broken light bulb or as lethal as an overhead powerline, . . . " [emphasis added - PDN]
I have read that 75 milliamps (.075 amperes) will cause the heart to fibrillate. Fibrillation is the fluttering of the heart during which no blood is pumped, and death ensues.
Of course, voltage - electrical pressure - is required for the amps to flow, but if the electrical contact to the body is good, like into the skin or blood vessel, very little voltage is necessary.
And, like Paul, am not in a hurry to personally check this out!
Art
Yep - in the NIOSH = National Institiute for Occupational Safety and Health reference that I quoted and linked above, Table 1. Estimated Effects of 60 Hz AC Currents says that -
| 100 mA | Ventricular fibrillation threshold |
|---|
And that -
* Contact with 20 milliamps of current can be fatal. As a frame of reference, a common household circuit breaker may be rated at 15, 20, or 30 amps.
And also -
When current greater than the 16 mA “let go current” passes through the forearm, it stimulates involuntary contraction of both flexor and extensor muscles. When the stronger flexors dominate, victims may be unable to release the energized object they have grasped as long as the current flows. If current exceeding 20 mA continues to pass through the chest for an extended time, death could occur from respiratory paralysis. Currents of 100 mA or more, up to 2 Amps, may cause ventricular fibrillation, probably the most common cause of death from electric shock.11 Ventricular fibrillation is the uneven pumping of the heart due to the uncoordinated, asynchronous contraction of the ventricular muscle fibers of the heart that leads quickly to death from lack of oxygen to the brain. Ventricular fibrillation is terminated by the use of a defibrillator, which provides a pulse shock to the chest to restore the heart rhythm. Cardiopulmonary resuscitation (CPR) is used as a temporary care measure to provide the circulation of some oxygenated blood to the brain until a defibrillator can be
Here’s an experiment you CAN try at home, but I don’t recommend it: Fill your tub. Get in. Have a friend throw in your cell-phone, cordless razor, a car battery, the i-Pod, your laptop, your digital camera, your videocam, your hearing aid, your vibrat… (no, you don’t have one. I forgot!), your Walkman, and, if there is any room, the ‘Segway’. Feel a tingle? No? Then have your friend throw in the clock-radio, plugged into 110 V. AC. Have him/her report the results on this Forum, please. We await the results, with 'bated breath!
Hays