Function of a tram switch

A classic tram switch which can be set remotely is called a “single switch”. The necessary impulse for control comes from the vehicle. It is therefore not set via interlockings, as is the case with railroads. However, the technical effort and the safeguarding before, during and after the operation of such a switch is similar to the processes of a route. In this chapter, the processes of this switch system in tram operation are described chronologically.

A variant of the train-operated setting process is the methodical request by radio. With this method, the vehicle receives an order via a trackside beacon to send a radio telegram to the switch after a certain distance of track has been covered. The switch controller then gives the setting command to the switch, whereupon it sets and locks. It is then driven over and cleared, similar to a route in railroad engineering.

Flank protection switch

Flank protection is one of the most important safety conditions which is realized by train routes controlled by signal boxes. As the name implies, a flank protection switch avoid collisions of trains to each other from the side. This dismissive position of the switch is normally for safe routes. For all neighbouring switches the dismissive position is a basic requirement of a route.

But not always this requirement can be implemented in logical route requirement. There are some exceptions. If there are two routes for example. When both of them need the dismissive but different position of the same flank protection switch. If switches can´t ensure flank protection, then the function has to ensured by a signal or a trackside derailer. Both the rule and the exception are explained in this clip.