In electric traction systems in which power is supplied from an overhead contact wire via a pantograph, the mechanical design of the contact wire and its supporting equipment is clearly of importance in relation to the problem of current collection at high speed. Because of the great difficulty of making accurate measurements on the full-size system and the difficulty of making experimental modifications to it, a dynamically equivalent laboratory scale model has been designed and constructed. The limited information which was obtainable from the full-size system has been used to verify the performance of the model, which can now be used for a systematic study of the effects of design variables.