Unitary bowl liner of substantially rigid synthetic resin for a bolster of a truck

摘要

A novel combination of a rail car supported on a within the center bowl of its truck bolster comprises a unitary wear liner closely fitted within the center bowl so as to require no exterior protection from grit and debris carried in the environment outside that of the center plate assembly held in the bowl. The unitary wear liner is required to be formed from specified reaction injection molded (RIM) polymers which when molded, are found to be free of microscopic voids >20 mu m and therefore, fully dense. This property of being fully dense unexpectedly allows the liner to have specified physical properties which permit a railroad car truck equipped with the liners to operate with exceptional reliability, safety and for a long period of time.