Abstract: The rail vehicle has two bogies each connected to the vehicle body by way of a single rod adapted to transmit traction and braking forces. The rods are disposed in the longitudinal center-plane of the body and are articulated to the body at one end and to the particular bogie at the opposite end. The rods are at an inclination such that the imaginary extension of the longitudinal axis of each rod intersects the transverse center-plane of the particular bogie concerned at a distance below the plane of the rail-top surfaces. To an extent corresponding to the distance, the axle loading of the leading wheel set of the leading bogie becomes greater than the axle loading of the second wheel set, thus compensating for the effect of reduced friction between the leading wheel set and the rails in bad weather conditions.

Abstract: In the railroad propulsion vehicle described, the traction forces are transmitted from the trucks to the vehicle body at a height h above the upper rail edges. The secondary support springs are each arranged at a distance x from the transverse center plane of the truck between the latter plane and the adjacent body end in order to balance out the tilting-up moment exerted on the leading truck. The distances h and x are adjusted to a desired distribution of the axle pressures A.sub.1 to A.sub.4 or the deviations Q.sub.1 to Q.sub.4 from a mean axle pressure value. On the basis of the chosen distribution, the values x and h can be calculated in a simple manner.The distribution of the deviations Q is, for instance, chosen so that all three leading axles are equally load-relieved and the fourth axle is loaded accordingly. According to another embodiment, the first axle is less load-relieved by .DELTA.Q than the second axle, and the latter is load-relieved the same as the third axle.