A brief historical overview of the fatigue of railway axles

Abstract

The history of railway axle design against fatigue is reviewed through a discussion of several notable accidents caused by broken axles. The earliest accidents prompted research into fatigue which resulted in a phenomenological understanding. In the last 50 years, largely through research directed towards the aircraft industry, fatigue has been recognized to be a process involving crack initiation and propagation. Fracture mechanics is now used to assist in the timing of crack inspection intervals, but a small number of failures still occur. The paper concludes with a short discussion of modern design methods, which have their origin in the nineteenth century. Some current pressures, particularly the need to reduce unsprung mass at high speeds, continue to challenge axle designers.