Among all the technical factors that govern the complex dynamics of pantograph-catenary interaction, the one that has the greatest effect on the maximum travel speed of the train is the tensioning of the contact wire.

The most direct solution to increase the speed, i.e. the greater stringing of the conductors, involves considerable problems related to the adaptation of the infrastructure (greater resistance of the poles, modification of the contact line so that the material is able to withstand the greater loads) and consequently the high costs and disruptions of rail traffic necessary to implement the changes.

The alternative solutions to the stringing of conductors so far devised, all present problems that make them unsuitable for their application either for economic reasons or for the limited technical benefits obtained from their implementation.

The damping device of Officina Fratelli Bertolotti solves the typical problems of the existing solutions thanks to a totally innovative model than previous formulations. Our damping system exploits the nonlinear kineto-dynamics, obtained by the specific construction, is mechanically simple, it is not tuned to a specific frequency, and works for small and large oscillations, does not use fluids that may be dispersed in the environment, and can be inspected visually to verify its functionality.

The damping device is compact and dimensionally compatible with the demands of the sector. Furthermore, our solution allows to reduce at least by a factor 10 the costs that the railway infrastructures would have to incur in the case of an increase in the stringing of conductors.
Our innovative solution considerably improves the collection efficiency since it solves the problem of loss of contact between the wire of the overhead line and the contact strip, both on trains with one or two pantographs.

We studied the effect of the damping device on the pantograph-catenary contact for a double pantograph train in accordance with the most recent sector regulations.

The analysis showed the enormous effectiveness of our device in cushioning the vibrations induced by the first pantograph on the second, which completely eliminates the problem of loss of contact. Our damping device introduces a very significant technical improvement, such as to allow for an increase in the speed of transport on the railway lines. The Officina Fratelli Bertolotti device have been considered interesting not only for high-speed railway lines, but also for rail freight transport.

Officina Fratelli Bertolotti has patented the device developed in collaboration with the Department of Mechanical and Aerospace Engineering (DIMEAS) of Politecnico di Torino (Polito).