Even if they did use pure-copper discs, the quarters you use to pay for the pressing are probably worth more. Assuming that you refill the slugs at the same time you empty the money, and that the respective reservoirs are sized appropriately, on average, at any randomly-selected time, the machine will contain 50 cents of coins per blank slug.
Whoosh
I used to get those all the time as a kid, if you looked at the backside you could clearly see the stretched and flattened image of the penny. I remember getting one at the Statue of Liberty in the late-80s.
Always assumed it was squishing the penny you inserted since we always went out of our way to find the shiniest penny we could so the final souvenir was just as shiny. Using dull discolored pennies gave a crappy result.
Every one I have ever seen used a real penny and you got to observe the smooshing but it’s been years since I paid attention to one.
That’s why I would bring some tape with me to hold the coins down to the rail. A fast commuter train would otherwise send them flying to who knows where.
Quarters? We just put 'em on the train tracks when a train was coming…
There was an episode of The Adventures of Pete and Pete where Pete the younger’s lucky penny had to be recharged by getting it run over by a train.
No derailment, though this was mentioned.
My experience is the exact opposite. I have seen several machines over the years and I’ve never seen one that have the squishing penny in plain view somehow (either a window or a complete plexiglass cover).
Every time I tried that, I could never find the coin afterwards. I suspect that instead of getting squished that the coin just ended up being shot out into the weeds and lost forever.
As kids we always talked about coins derailing trains, but if you’ve ever lived in an area with old crappy railroad tracks it should be obvious to you that a train can handle a bigger bump than a quarter. But as kids we never made that connection, even though we lived in an area with old tracks.