> Is it structural? Yes, the cars' weight rests on the end of each axle via a "bogie" that holds the suspension and brakes and such, and then the multi-axle bo

> Is it structural? Yes, the cars' weight rests on the end of each axle via a "bogie" that holds the suspension and brakes and such, and then the multi-axle bogie itself rotates on a center pin: https://en.wikipedia.org/wiki/Bogie#Components https://en.wikipedia.org/wiki/Bogie#Components https://en.wikipedia.org/wiki/List_of_railroad_truck_parts#Axlebox https://en.wikipedia.org/wiki/List_of_railroad_truck_parts#A...