Early mechanical engineers quickly discovered that rough track required a suspension system. The weight of the locomotive is supported on the axles where they protrude through the journal boxes. Springs are attached to a special fitting called a pedestal, in which a journal bearing (or "brass") slides up and down to compensate for differences in track height and undulation. Every driving wheel on a locomotive is mounted in its own pedestal. The springs are cantilevered between the pedestals, and the weight of the locomotive rides on fittings at the center (highest part) of each set of springs.
Quick facts
Equalization
First use in England