Abstract: In a railway car truck a lower transom extends between transversely spaced side frames. The side frames include depressed portions having transversely aligned vertical openings or slots which receive spring groups. A bolster including a center connection extends between the side frames above the transom and rests on the spring groups. The side frames each include a hollow post extending upwardly between the spring groups. The bolster includes a depending post which surrounds the side frame post. A friction damping assembly including upper and lower wedges is located within the side frame post and the bolster post. The upper and lower wedges include rear wear plates which engage the side frame post. The upper and lower wedges include an opening to receive a spring extending upwardly from the side frame depressed portion. The lower wedge has at least one inclined surface which slidingly engages at least one inclined surface on the upper wedge.

Abstract: In a railway car truck a transom is provided comprising a pair of tubes rigidly connected respectively to a pair of longitudinally extending side frames. The tubes are longitudinally and vertically aligned and are located below a bolster which extends between the side frames above the transom. A bearing rigidly attached to one of the tubes extends within the other of the tubes. The external surface of the bearing is provided with low friction material to allow the side frames to rock in respective vertical planes about a transverse axis as ups and downs in the track are transversed. However, the transom resists the tendency for the side frames to move longitudinally with respect to each other, and thus maintains the truck in tram.