When I was still a conductor, I would do it all the time at each station - for a few reasons.......
1) to get the people on or off the train and away from the doors
2) to wake up my crew members (head brakemen) who probably aren't paying attention or looking at me
3) to make sure the doors wouldn't close before I told the crew too (meaning that I wouldn't get left) - my brakeman knew that If he didn't hear me, to NOT shut the doors!!!!
On the RR, "believe nothing you hear and only half of what you see"
John, aka "JTGSHU" passed away on August 26, 2013. We honor his memory and his devotion to railroading at railroad.net.