Everyone loves the sound of the whistle on a locomotive but how many know what the whistle signals mean? Here is a list of the most common the whistle signals the 611 uses: Note: "o" denotes a short sound; while a "-" is for a longer sound. - When stopped, air brakes applied. - - Release brakes, proceed. - - - When stopped, release brakes and reverse movement. - - 0 - Approaching a grade crossing (video demonstration provided below 🚂😀) | Norfolk & Western Class J No. 611