How can trains move on rails? if the wheels are smooth and the rails are also smooth, how can it be enough friction for it to move?

Question

How can trains move on rails? if the wheels are smooth and the rails are also smooth, how can it be enough friction for it to move?

In: 2785

Answer 1

This is a challenge for trains, there’s only a little friction and a tiny surface area – this why trains have quite low gradient limits.

However, because there’s so little rolling resistance, once a train gets going on a flat track it takes far less energy than a truck or rubber wheeled vehicle would take to keep moving. So you save a huge amount of energy (and thus fuel).