Track occupancy using balls?
Posted: Sun Jun 22, 2014 7:17 pm
I just read "signalmans morning" and "signalmans twilight". There was a short description of track occupancy display using metal balls that would be either in sight or out of sight in the track diagram to show if the track is occupied or not.
Can anyone give me an idea on how this worked?
Can anyone give me an idea on how this worked?