Railroad car truck side frame - bolster connection

A railroad car truck comprising a pair of spaced side frames formed with pedestal jaws to receive in a journaled relationship axle ends of a pair of wheelsets, each said side frame having formed therein a centrally located window for disposition of end portions of a bolster transversely positioned between said side frames, an upper compression member and a lower tension member, spaced side frame columns joining said compression and tension members to define said side frame window, two wear plates each fastened to an inner side of each said side frame column,

• spaced side frame inner and outer end walls joining outer sides of said side frame columns,
• an opening formed in each said end wall with each said opening defined in part by an inner edge portion positioned in proximate alignment with said side frame column, and
• a horizontal support rib formed on each of said column outer sides with said rib having ends joining said side frame inner and outer end walls so as to minimize torsion twisting,
• said horizontal support rib having an outer edge defined by a middle portion positioned in substantial alignment with said side frame column wear plate and radiused ends joined to said middle portion with an outer end point of each radiused portion joined to said side frame inner and outer end wall opening edges,
• wherein said side frame columns tend to remain substantially aligned during rotation of said bolster with respect to said side frames to cause contact therebetween with said wear plates remaining substantially flat to provide a substantial area of contact with friction shoes carried by said bolster.