A railroad freight car that may include multiple units, the body of at least one unit including a container well for carrying intermodal freight containers, the body including a pair of side sills generally of closed box beam configuration with holes and reinforcing rings and with longitudinally extending reinforcing members in the top or bottom, or both, of the beams. The ends of the longitudinally extending reinforcing members are tapered and have their extremities attached to a portion of a side sill web spaced apart from the extreme top or bottom members of the beam.