Investigation of the Thermal Capacity of Railroad Wheels Using COBRA Brake Shoes

An objective evaluation of the thermal capacity of 36 in. CR wheels braked with COBRA brake shoes is presented and related to that of wheels braked with cast metal brake shoes. The wheel tread conditions, hardness and macrostructure of the rim, and residual stress patterns, which developed from high speed dynamometer braking-were investigated through three progressive test series. The results indicate that the thermal capacity of wheels braked with COBRA brake shoes far exceeds limits previously established for cast metal shoes.