How far away can a train be heard?

I'm writing a short story and theres a part where the characters are playing on the train tracks, but its on a curve, so they cannot tell which direction a train is coming in. How far away can a train be heard (NOT the train horn but the train engine and its cars approaching) because I want the train to come... show more I'm writing a short story and theres a part where the characters are playing on the train tracks, but its on a curve, so they cannot tell which direction a train is coming in. How far away can a train be heard (NOT the train horn but the train engine and its cars approaching) because I want the train to come around the corner surprisingly, making the characters run and jump off the tracks just as its about to come
Update: I know its dangerous and illegal lol, thats the point of my story. They are being stupid teenagers and never follow the warnings until a near death experience occurs.
10 answers 10