 A further problem lay in the power bogies; there was a good reason for unpowered wheels on a steam locomotive, in that they served a function of stabilising the locomotive, reducing its tendency to wander or 'hunt' when rolling on straight track, and leading the locomotive into curves and thereby reducing derailments.Early Fairlies had a tendency to be rough-riding, rough on the track they rode, and more prone to derailment than they should have been.This was certainly in part true of "Little Wonder", which was worn out and replaced by the FR after less than twenty years' intensive use.