Characterisation of Pantograph Dynamic Behaviour at Different Operating Heights

The dynamic interaction between railway pantographs and overhead contact lines (OCL) is a key factor governing current collection quality, component wear and system reliability. Existing pantograph characterisation methodologies and numerical models are typically identified and validated at a single nominal operating height, despite pantographs routinely operating across a wide range of extensions imposed by infrastructure constraints. This paper experimentally investigates the influence of operating height on the dynamic behaviour of a Wabtec-Brecknell Willis High Speed Pantograph (HSP). A comprehensive test programme is conducted using a full-scale pantograph test bench, including quasi-static stiffness measurements, force hysteresis tests and harmonic frequency sweep excitations. The pantograph is assessed at five representative operating heights spanning its working range. The results show that the pantograph exhibits dynamic response variation with operating height due to its nonlinear behaviour associated with friction and hysteresis. In particular, differences in frequency response characteristics are observed, including changes in resonant behaviour and response magnitude at higher frequencies. The findings demonstrate that pantograph extension has influence on dynamic performance and indicate that height-dependent pantograph models may provide a more representative basis for pantograph-OCL simulations involving contact wire height variations.