The existing automatic gauge change systems in the national railway network allow trains to go from a line with Iberian gauge (1,668mm) to another with UIC standard gauge (1,435mm) or vice versa, without the need to change bogies or axles, varying the distance between wheels as the train passes through the facility designed for this.
These facilities are integrated with the communication, management and remote control systems of the connecting lines and in them the transition of the electrification voltage and the signaling systems is carried out.
Functionally, the weight supported by the wheels, coming from the vehicle body, is assumed, from a moment before entering the changer, by some support skates or rollers that move along rails in addition to the rolling rails. The wheels are unlocked and a convergent pair of rails jerks to move them sideways. They are then secured in the new position and leave the shifter again supporting the weight of the vehicle.
The speed of passage through the changer must be less than 30Km / h.
For the different movable rolling technologies of the trains that circulate in Spain, TALGO and CAF, conceptually similar, but with differences in terms of the train's support and the way of releasing and securing the mechanisms, different installations and platforms were initially used for width change.
The first advances towards the integration of technologies allowed the use of a single gauge change installation, although with two different platforms that were raised and lowered or exchanged in the horizontal plane. Subsequently, between 2006 and 2007, Adif developed a new type of Dual changer, with a single platform, in such a way that only the movement of some pieces allows the passage of Talgo and Caf trains, drastically reducing the necessary infrastructure, and with significant advantages:
- Improve operation with new guides and artificial vision.
- Reduces the width of the space required for installation.
- Reduces construction, operation and maintenance costs.
- Adaptable to other pairs of track gauges (1000/1435), (1435/1668), (1435/1520)
They are designed and built with modularity criteria, making it possible to modify the configuration if the needs change, and portability, allowing the transfer of the equipment as they are not fixed to the rail in a pit but to a removable platform.
With the need to advance in the versatility of the changers and in anticipation that international trains could integrate wagons or cars of various technologies, the Dual single-platform changer will allow the passage of vehicles with other European movable rolling systems such as the German “Rafia"and the Polish"SUW2000".