In railroading, derailment occurs when a rail vehicle such as a train comes off its rails. Although many derailments are minor, all result in temporary disruption of the proper operation of the railway system and they are a potentially serious hazard.

What are Derailers used for?

A derail or derailer is a device used to prevent fouling (blocking or compromising) of a rail track (or collision with anything present on the track, such as a person, or a train) by unauthorized movements of trains or unattended rolling stock.

How does train derailment happen?

A derailment is when a train runs off its rail, either because of a collision with another object, a conductor error, mechanical track failure, broken rails, or defective wheels.