Zig zag (railway)

A railway zig zag or switchback, is a method of climbing steep gradients with minimal need for tunnels and heavy earthworks. For a short distance (corresponding to the middle leg of the letter "Z"), the direction of travel is reversed, before the original direction is resumed. Not all switchbacks come in pairs, in which case the train may need to travel backwards for a considerable distance. A location on railways constructed by using a zig-zag alignment at which trains have to reverse direction in order to continue is a reversing station.

Zig zag (railway)

A railway zig zag or switchback, is a method of climbing steep gradients with minimal need for tunnels and heavy earthworks. For a short distance (corresponding to the middle leg of the letter "Z"), the direction of travel is reversed, before the original direction is resumed. Not all switchbacks come in pairs, in which case the train may need to travel backwards for a considerable distance. A location on railways constructed by using a zig-zag alignment at which trains have to reverse direction in order to continue is a reversing station.