By the way, it seems to me that the part of the track that comes into contact with the ground would be more likely to be bare and shiny metal than to be rusted metal, don't ya think?
Due to the cheap grade of ore supplied to the builders ( government doing it on the cheap again) the tanks have only to stop to let the cake and tea trolley go past and the darned rust has made an appearance. When they do a Pimp My Tank we will get the upgraded ones fitted
Hope that helps
Cheers
Fritzy