I was on a train traveling from West Berlin to West Germany, before the fall of the Berlin wall. The train was stopped at the border of West Berlin and East Germany, and East German engines were attached to the cars. Three East German soldiers, with guns drawn, boarded each car. Two of the soldiers stood at each end of the car with their rifles upright across their chests. Another soldier went through the car, asking each rider for their papers. While this was going on inside, outside, other East German soldiers, with guns were standing alongside the train while other soldiers went up and down the train with German Shepherd dogs, and still other soldiers with dinner-plate sized mirrors on long poles passed the mirrors under each car, looking for stowaways. All of this was accomplished in silence. It was pretty damn frightening.
ailie's story reminds me of another train story:

I was traveling in Europe, going north from Germany, through Denmark and on to Norway. I was awakened in the middle of the night because my train seemed to be going forward a short distance, bumping into something and clanking, and then backing up, repeatedly. We were in Gotland or some such place and the train was being boarded upon a ship, in its belly. The train would go forward, deposit 3 cars, then back up, and repeat. When my car was still, I got up to check things out. Automobiles were on the floor above us, and then people on the floors above that. Being a south Texas denizen, I found this mode of transportation completely weird.