The Effects of Tilting Trains on the Track Superstructure

The tilting technology, in comparison with the conventional trains, assures in the curved sections of the track alignment and for the same running speed, a smaller value of noncompensated centrifugal force on the car-body level. As a result, using this technology, the running speeds in curves can be increased while still keeping, on the car-body level, the same value of the non-compensated lateral acceleration. This increase of speeds, which comes up to 30%, whilst not affecting the passenger comfort it does have consequences on the track superstructure since it affects the geometrical positioning of the wheel-sets on the track (the curving ability of bogies) and through them the forces acting on the wheel rail interface. Within the frame of this theoretical paper, the effects of tilting trains on the track superstructure are investigated by means of mathematical models. The estimated quantitatively effects are related to the increase of guidance forces acting on the track, due to the raise of speed. The research covers: a) two different bogie technologies (bogies with conventional axles, bogies with auto-oriented (steering) axles) and; b) two cases of operation (running of tilting trains on new high-speed tracks, running of tilting trains on existing conventional-speed tracks)