Here is a video of BNSF conductors job switching railroad cars
at a car crossing. So the bell you hear is the crossing arms
at the intersection. You can hear the radio conversation pretty
good on this video. This is most likely a “local” train because
there are 2 conductors and it’s at an intersection in town. Typically locals work days and are the best jobs but take a lot of seniority to hold.
You have to be very carefull when switching cars because this is
where the majority of accidents happen. You have to stay focused because it’s easy to get hit by another train switching cars or moving on another track.