How can trains turn corners?

The wheel bevels are specifically designed so that when the train goes around a corner it stays on the tracks. The wheels that have to travel a greater distance have a greater diameter, and everything stays aligned. The end result is a train that stays on the tracks.

Why do trains tilt when turning?

As a train (or other vehicle) rounds a curve at speed, objects inside the train experience centrifugal force. Tilting trains are designed to counteract this by tilting the carriages towards the inside of the curve, thus compensating for the g-force.

How does the train turn?

The wheels on each side of a train car are connected with a metal rod called an axle. This axle keeps the two train wheels moving together, both turning at the same speed when the train is moving. This is where the wheels’ geometry comes in. To help the wheels stay on the track their shape is usually slightly conical.

Why do train wheels spin at the same rate?

This means that when the train shifts left or right on the track, the diameter of the wheels can change. But because the wheels are connected by an axle, they still spin at the same rate. Effectively, this means that the wheels will travel different distances per revolution.

How do trains stay on the tracks when they turn?

As a result when a train is turning it is momentarily running on wheels that are effectively two different sizes. As the outside wheel’s circumference becomes larger it is able to travel a greater distance even though it rotates at the same rate as the smaller inside wheel. The train successfully stays on the tracks!

What happens when a train goes around a bend?

But when a train needs to go around a bend the fact that both wheels are always rotating at the same rate can become a problem. The outside of a curve is slightly longer than the inside, so the wheel on the outside rail actually needs to cover more distance than the wheel on the inside rail.

Why do trains have conical wheels instead of cylindrical?

The most critical advantage that slightly conical wheels (in trains) have is that they can rotate at slightly different speeds, while cylindrical ones can’t (at least not as smoothly as conical ones). You see, when a conical wheel turns, it slides to the larger part of the cone on the outside wheel and the smaller part on the inside wheel.