The opening on the upper end is different from the relatively square lumber doors on cars I have worked on. I wonder if it was used for loading grain.
Does anybody know how a lumber door was used? Loading the lumber into the car through the door seems difficult. We have wondered if when one had lumber that was longer than the distance from the front edge of the regular door to the back of the car (ca 23') one walked in the door with the long lumber, stuck the lumber through the lumber door from the inside and then, having gotten around the front edge of the door opening, pulled the lumber back inside the car and onto its stack.