Patent attributes
A rail road car truck has side frames mounted to rock on the wheelsets. A bolster is mounted cross-wise on the sideframes, each end of the bolster being seated on a spring group, each spring group being seated in one of the sideframe windows. The bolster has damper groups mounted at each end to work between the end of the bolster and the columns of the sideframe windows. The truck has a dynamic response to lateral perturbations that includes a first component due to the swinging of the sideframes on the sideframe pedestal rockers, and a second component that is due to lateral shear in the main spring groups. The pendulum action may tend to be softer than the lateral shear in the springs, and so therefore may tend to dominate the lateral response. This swing-dominant lateral response may be combined with a multiple damper arrangement.