In the early 1980's, when I lived in that corner of the world, the Southern's Murphy Branch had enough traffic to warrant a daily round trip from Waynesville to Andrews (and sometimes on to Murphy). Murphy was for interchange with the L&N, and there was a sawmill and a woodyard south of Andrews. Andrews supported a feed mill and a couple of woodyards. There was also limited interchange with the old Graham County Railroad at Topton. The problem with wood chips on the line was restricted clearances for the BIG chip hoppers. They wouldn't fit through the two tunnels. I don't recall a lot of other business in Byson City or Dillsboro. The problem was similar to that of the D&RGW narrow gauge -- steep grades. As I recall, the ruling grade on the line was 4% or maybe a bit more, with very sharp curves. The usual operating practice to to put three GP-30's on the train, even if only two were needed -- in case one failed somewhere inaccessible. And two units were needed if the train was more than about 10 cars!