track

wheel rail

track irregularities

train bridge

The railway track and vehicle combination comprises heavy rigid wheels running on heavy rails. Imperfections in either will give rise to dynamic effects which increase with speed. These will supplement the contact forces which, on perfect track with perfect wheels, are basically the static wheel loads. The commercial necessity for higher speeds and greater axle loads has been established and this historical trend will probably continue. Forces and stresses will therefore become more severe unless technical progress is made in track and vehicle design. In this context, close co-operation between the Civil and the Mechanical Engineer is essential. Track must have a high standard of alignment and level and maintenance quality must be improved as far as practicable. The forces that the rails and track structure will withstand must also be specified. New vehicles, particularly those for high speed operation or with heavy axle loads, must not generate excessive track forces.

THE EFFECT OF TRACK AND VEHICLE PARAMETERS ON WHEEL/RAIL VERTICAL DYNAMIC FORCES