[troy McClure]

http://www.hornblasters.com/products/details.php?i=nathan-airchime-p3-540-train-horn-kit

[PapaNew]

Exactly. Back in the late 50’s, my brother mounted a one-piston diesel horn on his VW bug. He and his girlfriend would drive into the bushes next to a RR crossing and blast it whenever a car was in the middle crossing the tracks.