Really? Hmm if I had to guess. It looks like it might have stored something before. The top looks kinds like a silo for holding grain or something like that. And mid ways you can clearly see a rusty chute of some sort. So It was probably used to store and load up trucks or rail cars for it to be shipped out. The container just rolles up under the chute and they fill it up. Which to me sounds like it makes sense since you said there is a nearby rail yard. But that is my best guess at it.