How does rolling resistance of rail wheel depend on diameter?

[lemd]

Freight train is more efficient than truck due to lower rolling resistance. And I wonder which one has lower rolling resistance, small diameter or larger one or it doesn't not depend on diameter at all? Both are steel wheel on steel rail.

 

[Mordred]

a larger wheel has a larger torque mechanical advantage to overcome resistance

 

[lemd]

Thanks,

From some source, it seems larger wheel has lower rolling resistance, but explained by larger torque seems to be not really true because torque can be change by gear ratio. I think larger wheel will spread it pressure better and so deform ground less and so on, less rolling resistance.

 

[OCR]

From some source...

This source? → http://en.wikipedia.org/wiki/Rolling_resistance



OCR...

 

[tiny-tim]

This source? → http://en.wikipedia.org/wiki/Rolling_resistance

note #33 in that link does not confirm this

 

[Mordred]

note #33 in that link does not confirm this

lol good eye, I would have missed that notation,