You need to be extremely careful, because the train is a wily predator! First, make sure you NEVER take the same path twice. It will learn your habits VERY quickly, so the more random you are the better you'll be. Second, always carry some coal on you in case one spots you. This way, you can toss it in the opposite direction in the hopes the coal distracts your foe. (If it's not a coal-burning train, though, this will do nothing.) Finally, whatever you do, DON'T stare directly at it! It will view this as a challenge to its position within the train hierarchy, and you might as well lie down and wait for your inevitable death at that point.