Pennies on RR Tracks

I live near a set of RR tracks, and want to try something I’ve heard about since I was a kid. If I put a penny on the tracks, will I get a) a big-ass penny b) a derailed train or c) nothing at all?

Well you won’t get a derailed train just by putting it on the tracks that I can see. I’ve worked on those lines and there’s crap falling on them all the time.
The coin will probably get knocked off the tracks and lost.
Best you could hope for is a peice of bronze that looks like it’s been smacked about 700 times with a steel mallet.

Finally a question that I can reply to with the authority provided by a misspent youth! Ha-ha! I can quite positively say that, if you put a penny on a Railroad track, and a train just happens to run over it… one of two things will happen…
One: You will get a big, long-assed, flat piece of copper only remotely resembling a penny. Sometimes the face is still there, but it is all stretched out. Be careful about picking it up right after the train has gone by… the penny will be hot! Great laffs for kids!
or…
Two: The penny will go missing. I don’t know how many times this happened to my friends and I. Put penny down on tracks. Wait for train. Train goes by. Penny is gone. Where did it go? Did it stick to the wheels of the train? Nobody knows…
Oh. I almost forgot.
Three: The penny will fall off the track before the train gets there due to track vibrations. Best to use multiple coins for this.
I have never, ever heard of a penny (or a quarter for that matter) derailing a train. A train fully loaded weighs a few thousand tons or so. It would take a bit more than a cheaply-made US coin to throw it askew. I know I never derailed a train when I was a kid!

catmandu42, you forgot:

four: the penny will leave the track at incredible speed, narrowly missing your head, and imbed itself in the wall of a nearby building.

Observing such experiments from a distance and behind cover is advised.

When my friends and I started thinking about what a
razor-thin flattened penny would do to human flesh if shot out from under the wheels of a speeding train, we abandoned coins and tried ketchup packets instead. Not as interesting, and cover is definitely recommended.

I did this as a kid too. It’s pretty cool. We did pennies, quarters, half dollars, you name it. I think I still have some of the flattened ones. It works best if you do it near a station, so the train rolls over it slowly. Otherwise the coins tend to get knocked off.

Having lived in a time when a penny still bought something, I always thought it was a terrific waste of cold cash. Later as I became mildly more affluent I took to the practice.

Remember to place your coin directly above a marker like a railroad tie or near a splice in the rails. Point to that spot with a different colored rock or a piece of wood so that you may retrieve your artifact (or still spendable coin) afterwards.

There was this coin-operated machine in a truck stop near Terrell, TX (Rip Griffins) that would smoosh pennies, I believe it put some kind of impression in them too. I thought that would be illegal, destroying US currency.

I recall “pennies” in an eliptical shape, around four inches long and an inch and a half or so wide. The pleasure was immense at the time, and would probably still be. We set up three sided corrugated cardboard shields that stood just above the height of the tracks to contain any misfires. None were ever experienced. It was assumed that missing coins had cold forged themselves to the locomotive’s wheels.

      • I actually have one in my posession right now. ~ The penny measures 21 x 26 mm. (A regular penny is just about 19mm dia.) It is pretty close to perfectly symmetrical. It measures about half the normal thickness of (the edge of) a penny, with the ends along the longer dimension a bit thinner than the middle. Oddly enough, the “heads” side is completely flattened smooth, while the “tails” side is still clearly visible, though stretched a bit. I do not remember which side was facing up at the time. No trains derailed. - MC

As a teenager, I had heard that if you place a pile of coins of progressively smaller size on the tracks, the train will mash them all together, and the result will be a very cool series of embedded concentric circles.

I tried this with an Australian 10c coin on top of a 20c one (the larger one). Both are of copper/nickel alloy. The result? The ten cent disappeared to the same place all my odd socks go, and I had a 20c coin which was about 40 - 50% bigger than the original. It was misshapen, about half the thickness of the original - by no means razor sharp), and had a half-moon shape where one half of the ten had been impressed into the twenty. The half-moon impression was only slight.

And yes, I got the hell out of the way as the train went by.

Another question which may warrant its own post: is the train wheel microscopically flattenned where it touches the rail (much as a car wheel does on a visible scale)? Surely if the wheel is perfectly circular and rigid, the point of contact would be infinitely small? Is steel elastic enough to do this?

They have those machines at Disneyland too. And the thing about it being illegal, well, you arent actually “destroying” the coin, you’re altering it. An altering, I might add, that usually costs you at least a dime (although i think the ones at Disney cost like a dollar now). That’s anywhere from 10x to 100x the value of the original penny. It’s not neccesarily illegal to destroy US currency, its illegal to devalue it. In other words: if you mutilate a dollar and i give you $2 for it then its not illegal.

On a related note: It takes a lot of energy to flatten a penny. Therefore, the train must transfer some energy in the process. If one takes $100 worth of pennies and puts them down every foot on each rail for a mile, would the train lose noticible speed?

The steel does indeed deform, flattening out where is must contact the rail. The rail deforms as well under the weight of the wheel. It’s not even microscopic, that is, in that if one had a very finely graduated ruler one could potentially see the deformation with the naked eye.

You can thank the incredible elastic properties of steel with it’s limited “infinite fatigue life” under relatively small stresses for being able to withstand the constant flexing. (yes, given the strength of the steel and the size of the rails and wheel, you do get a pretty long fatigue life.)

Anyone remember the “Freedom Train”? As part of the U.S. Bicentennial celebration, the Liberty Bell (the bell, not the spacecraft :p) was taken around the country on a special train. It didn’t stop in my town, but it did pass through. Anyway, when I was a kid I put a penny on the track so the Freedom Train could run over it. I still have it. Had I really thought about it, I should have used a bicentennial quarter.

Well, it depends on how you define noticeable. The short answer is no, there is simply way too much inertia in a moving, loaded train to lose noticeable speed. It would lose speed, however, as the effective rolling resistance would be increased for the train.

But shoot - a typical 110 car coal unit train may have 100 tons of coal per car, and each car itself weighs a good chunk - 4 tons for an aluminum car possibly? Thus, you are talking about trying to slow down more than 11,440 tons, not counting the locomotives themselves, which IIRC weigh about 125 tons themselves.

One tip I remember from my youth - if you spit on the coin, it will stick to the track and not vibrate off when the train is approaching. They do still disappear altogether sometimes this way though.

Not only are there still many machines for squashing pennies (there’s one at every rest stop on the Pennsylvania Turnpike, for example), but there’s also a sub-set of numismatists that collected. The group is called TEC (The Elongated Coins), and they have about 2,500 members worldwide. They even had a booth at last year’s Coin Show in Philly.

Tips on railroad track squashing–tape it down with electric tape. The unfortunate side-effect is that some of the black tape will be imbedded in the coin. I have one from my pre-teen days still bearing marks of the tape.

Sometime it works, but sticks to the wheel instead of the track.

Here’s the way to do it:
Get several pennies (preferably older, real copper ones) and lay them in a line with the edges overlapping just a little. You’ll probably want to tape/glue them down, as it’s really easy to shake them loose. Anyway, if it works (and you have enough pennies and a heavy train), it’s possible to get a strip of copper 4 feet long that you can see through :smiley:

I did the penny-on-the-track exercise years ago: ended up with a flat pear-shaped disk with just enough of a hole at the top to thread a string through. Still have it.

Someone mentioning ketchup packets reminded me of an old school bus stop trick. Save your lunchtime banana, be first off the bus and stick the banana under the front sidewalk side wheel, lure someone into the spot on the sidewalk when the bus drives off. A rooster-tail of banana guts sprays out for about ten feet. The greener the banana the farther the spray.

Heard about a train derailing because someone put a refrigerator on the tracks.