I wasn't going to tell this story, but here goes.
40 years ago I was working at a Fertilizer Company. They received all their bulk fertilizer on train cars. Had a siding about 400 ft long in front of the storage building. I was unloading gravity cars onto a conveyor belt into the building. Had unloads hundreds similarly. When empty I'd use the center pivot loader to push the cars away from the building. Everything on flat ground. Lean up against the cars and give them a hefty, but short push with the loader and they would coast down toward the south end of the siding and stop.
I pushed one a bit too hard. It busted thru the switch and went onto the main line. I caught up to it with the loader, bouncing over the ties, hooked the bucket under the hitch and tried to stop the car which was going at an average walking speed. Immediately stood the loader on it's nose and lost contact with the car. A couple attempts and I gave up. Slight down grade away from the Fertilizer Company and town.
I went to the main office and told the Manager what had happened. He immediately called the rail company to report the runaway car. He said put the loader on the trailer and go South to the next town, 6 miles away and ask if anyone has saw a car go thru....
So I load up and go to the next town. Nobody saw a car. I went North to the first crossroad and looked up/down the track as far as I could see, no car. Went to the next crossroads, same thing. Went to the next crossroads, looked North. There it sat about a 1/4 mile away.
I unloaded the loader, straddled one rail and started bouncing my way toward the car. I pushed that car 3 miles bouncing over the ties on that loader at a very slow walking pace. Back at the Fertilizer company we cobbled up the switch and got the car back on the siding.
I never pushed a car like that again.
As Moss said, shocking how easy they'll roll......
