First - What are we looking at?
Second - Ok, now we get what's going on.
Third - Still scary.

is actually still on the rails. The mechanism which rolls the car over clamps the car and the tracks together, and as soon as the car is empty, it rolls on over so that the car can be rolled out of that area. This is same way that coal cars are emptied at electric power plants. In most cases the cars have couplers which can swivel so that a car still in a train can also be emptied, one car at a time.

That is one nasty pinch-point.

I've never seen such sight. What happened to the cart that rolled into that chamber on those tracks? Did it just roll off the tracks down into oblivion along with its load of copper? And look at the flimsy housing they built around such a powerful impressive machine. Strange.

[That "cart" is a fifty-ton railcar. It goes back on the train tracks after being emptied. - Dave]

NOW I see the railcar still in there. I didn't realize I was looking at the back of the railcar. I thought it was just the back of the chamber. ¯\_(ツ)_/¯