Does anyone know what cars were used to ship lumber before the advent of
the “lumber car” we see today? Just boxcars?
Bulkhead flats or even regular flats were also used in addition to box cars.
Flatcar, bulkhead flatcar, boxcar with a lumber door (a small door high on one end of the car through which lumber could be passed a piece or two at a time. The Bachmann On30 boxcar has a lumber door)
Kiln dried lumber, plywood and milled lumber (fancy shapes) were usually hauled in boxcars. If the lumber was plain old stick wood, it was usually hauled stacked on flatcars or in gondolas. Occasionally, on the off-seasons, lumber was also hauled in stockcars.
Lots of box cars built before WWII (and a very few after) featured a lumber door, as did many stock cars.
Lumber is still commonly shipped in boxcars and bulkhead flatcars. I have seen lumber on regular flatcars a few times also.