Gauging of rail sidewear on Docklands light railway (PP) (TR-VDY-019)

Sidewear of the high rail on a curve (and associated flangewear) has been a problem since the early days of railways. From time to time remedies (e.g. lubrication, special rail steels, steering bogies) have been advocated with varying degrees of success, but ultimately the question still remains - how much...