GCOR 5th Ed., Rule 5.8.1 - Ringing Engine Bell
Ring the engine bell under the following conditions:
Before moving, except when making momentary stop and start switching movements.
As a warning signal anytime it is necessary.
When approaching men or equipment on or near the track.
When whistle signal (7 [5.8.2 - L,L,S,L for crossings]) is required.
Approaching public crossings at grade with the engine in front and sounding of the whistle is prohibited, start signal at the crossing sign. If no sign, or if movement begins between sign and crossing, start signal soon enough before crossing to provide warning. continue ringing bell until the crossing is occupied.
That makes sense for the most part but I still wonder about crossings.
I live by several UP, KCS, and BNSF crossings and I never notice the bell at the crossing itself. Maybe at a siding when the loco starts to move but that's it.
BNSF, KCS, and UP all use GCOR, perhaps you're in a quiet zone, some other means of protecting the crossing is instituted (i.e. flagging), or they just don't care.
None of the crossings here in my town are "quiet" and I almost never hear the bells. I go down to the local joint BNSF/UP yard here a lot, but rarely do I hear them using their bells. Sometimes the UP switcher will use it, but I don't recall hearing the BNSF switcher using its bell.
Like dricketts said, I don't think it's enforced much.
