Somebody needs lots of cars to haul building supplies:

Railroad Centerbeams as far as the eye can see, Waupaca, WI

Centerbeam

Centerbeams are cars designed for carrying bundled building supplies including dimensional lumber, wallboard, and fence posts. They are essentially bulkhead flatcars that have been reinforced by a longitudinal I-beam truss down the center of the railcar. Along with adding strength to the railcar, the center truss helps protect cargo from damage caused by loads moving during transit. Due to their design, the railcars must be loaded symmetrically, with half of the payload on one side of the partition and half on the other.