Railway turnouts are important components of a railroad network. Compared to a normal track, they are more expensive and have many areas with complex dynamics. One of these areas is the transition from long sleepers to short sleepers at the end of a turnout. The dynamics that arise there affect both the vehicles and the infrastructure. As such, understanding and addressing these dynamics is crucial, as they can lead to increased maintenance needs, a reduced availability and, consequently, higher costs.
To better understand the occurring dynamics at this jump in stiffness, the actual reaction of the transition must be recorded. As part of the FFG-Comet project Rail4Future, measurements were performed on a turnout in an Austrian main line to this end. These measurements included recording the vertical sleeper displacements at multiple positions in the transition zone as well as the dynamic axle loads outside of the influenced area. The data was used to study the behaviour of this transition zone, especially looking at influencing factors on track panel twist, such as vehicle type, axle load and travelling speed. These new insights into the transition in sleeper length can be used, among others, in the evaluation of vehicle-based measurements, as the measurement itself is influenced by the vehicle.

sleeper length transition; turnout; stiffness jump; track panel twist