Lightweight fatigue resistant railcar truck, sideframe and bolster

摘要

The sideframe and bolster of a railway car truck are constructed such that basic overall sideframe and bolster appearance is maintained, but the actual material it is constructed of is changed. The material used is changed from cast steel to an austempered metal, such as, cast austempered ductile iron; whereas cast iron has a density, 0.26 lbs/in^3, which is approximately 8% less than steel, 0.283 lbs/in^3. This immediately allows for a reduction in weight. A second benefit is that iron is easier to pour than steel and actually increases in volume, slightly, as metal cools compared to steel which shrinks. Efficient use of materials is improved, meaning less metal is used to make the same final shape, as a way of reducing the sideframe and bolster weight. Both factures combined allow for a lighter weight railway car truck, sideframe and bolster, while utilizing standard designs.