The Dixie Flyer (1926)

The railroad is building a new line, but the workers are unhappy because one of the board members, hoping to oust the man in charge of the project (Rapley), has a saboteur on site. Rapley's daughter Rose sneaks out to the project to become their telegraph operator, and with help from the supervisor "Sunrise" Smith, eventually discovers the plot and helps catch the bad guys amid several thrilling train chases.