From what I can recall from reading a number of articles and books dealing with short line railroads in years gone by, the timetables for mixed trains were little more than a suggestion of when the train would actually arrive and depart from a particular station. It all depended upon the amount of work to be done along the way.
Also, one of the railroads I worked on about 30 years ago had all the switches located so that all the work was done on the outbound trip, except for the last station on the line. That meant that once all the work was done there, returning home was a non-stop run that took about an hour and 20 minutes, while the outbound trip sometimes took 3-4 hours.
