A switch or switch is a track device that allows trains to change from one track to another.

It can be right or left, depending on its location in relation to an observer located between the gear needles and looking towards the intersection. They are made up of needles (moving rails) that rest on their respective counter-needle (fixed rail) and that are joined to the rail by welding or screwed joints, depending on the type of deflection, leaving a part of the skate removed to allow the necessary flexibility to move and couple or decouple the tip of the needle on the counter-needle. In turn, the head of the needle is machined to allow proper coupling.

Contenido

Los componentes principales del desvío son las agujas (en marrón), las contraagujas (en negro), los contracarriles (en azul) y el corazón (en verde):[1]​.

Y los tramos de los que se compone son: Cambio de agujas (1), Carriles de unión (2) y Cruzamiento (3).

Las agujas tienen la cabeza limada para permitir que encajen con su respectiva contraaguja, guiar y soportar las ruedas del tren. Estas agujas se pueden fabricar a partir de raíles normales o raíles especiales para agujas. Existen perfiles especiales de eclisa más gruesa y se usan especialmente para hacer agujas más largas y robustas que permiten mayor velocidad de circulación. Según el ángulo que formen en el cambio, las agujas serán:.

Esta última es la que proporciona un menor ángulo de desviación y está siendo normalizada en los ferrocarriles europeos. A agujas y contraagujas se unen los tirantes, que unen las agujas con el fin de solidarizar sus movimientos.

Parameters

The parameters with which a change is defined (for example, in plans or reports that need to indicate the characteristics of a change) are:

Of the roads into which a detour forks, two types are distinguished:

The biggest problem posed by the detour is the maximum allowable track speed of the diverted track, since it does not have a bank and the radius of the curve described is usually small. Therefore, the normal acceleration is very strong if long detours are not made. Recent technologies have developed new ways to solve these problems and collisions with the rail, creating mobile hearts and hare legs that join perfectly to the rail, giving the whole more stability.