early in the 1800s. One has only to look at illustrations of early
passenger coaches to see how closely they resemble
the road vehicles of the previous century.
As railway experience was gained, the design of rolling stock also
evolved. Springing, body structure, wheels and axles all are subject to
varying loads and stresses, when comparing slower speeds on rough
roads to much faster speeds on railways, with a comparatively
Railway rolling stock generally runs on hard wheels on hard rails. The
wheels are not only supported by the rails but are guided by them. The
only exception to this is for a small number of metros where rubber
tyres have been introduced. In this case the supporting function of the
rail may be separated from the guiding function.
In all cases railway rolling stock will transmit vertical, horizontal and
longitudinal forces to the track and its supports. Most railways have
adopted twin rails and flanged wheels. Forces are transmitted to the
structure either by direct bearing on the rail top from the wheel tyre,
or by bearing laterally through the flange, or by longitudinal friction.
Potential ‗overturning‘ forces, caused by centrifugal force on curves,
coupled with wind forces on exposed locations are resisted by vertical
dead weight and
super-elevation or ‗cant‘ on curves.
The Range of Railway Rolling Stock
Today there is a very wide range of rolling stock used throughout the
on different railways. This range includes the following basic types:
• Freight wagons
• Passenger coaches
• Multiple units (with motive power in-built)
• Metro cars (usually multiple units)
• Light rail/Trams (usually articulated units)
• Rail mounted machines (cranes, tampers etc.)