INTRODUCTION
The railway train running along a track is one of the most complicated dynamical systems in
engineering. Many bodies comprise the system and so it has many degrees of freedom. The bodies
that make up the vehicle can be connected in various ways and a moving interface connects the
vehicle with the track. This interface involves the complex geometry of the wheel tread and the rail
head and nonconservative frictional forces generated by relative motion in the contact area.
The technology of this complex system rests on a long history. In the late 18th and early 19th
century, development concentrated on the prime mover and the possibility of traction using
adhesion. Strength of materials presented a major problem. Even though speeds were low, dynamic
loads applied to the track were of concern and so the earliest vehicles used elements of suspension
adopted from horse carriage practice. Above all, the problem of guidance was resolved by the
almost universal adoption of the flanged wheel in the early 19th century, the result of empirical
development, and dependent on engineering intuition.
5