In particular, how does a train stay on a track—especially when it's a track with a curve in it? It's easy right? You might think that these train wheels have a flange inside the track that ...

It can be hard to fathom how they manage to stay on track ... sending a train off-track can and occasionally does happen. The train wheels we know today have been around for decades upon decades.

It can be hard to fathom how they manage to stay on track ... can and occasionally does happen. Read more: 11 Of The Oldest ...

How do they look similar or different ... This same principle you observed on the incline also helps the wheels stay on track when a train is turning. As the wheel sizes change when the train ...

But that's impossible to do in a train, so how do locomotives stay on a bending rail ... train shifts left or right on the track, the diameter of the wheels can change. But because the wheels ...

The next time a subway car or commuter train rolls into the station, try to sneak a quick peek at its large metal wheels ... do with how perfectly the cups are centered at the top of the track ...