Railways

ELASTIC RAIL FASTENINGS

When trains travel past, they cause tremors and structure-borne sound caused by the load moved, rough surfaces on wheels and rails, and local oscillations in track section stability. In such cases, a distinction is made between high-frequency impacts caused by interactions between the vehicle and the track system (wheel imperfections, grooves, incorrect track positions, rail corrugations and similar) and low-frequency impacts caused by wheelset loads, travel speed, and distances between axles, bogies and carriages. The track system is subjected to high stress loads due to these effects. Using highly elastic materials such as special EPDM in vibration-optimised track bed structure shapes can permanently limit tremors entering the sub-structure effectively.
 
Using elastic rail pads and base plate pads in special rail fastening systems exploits the load-transferring effect of rails. The forces induced by the wheel load are distributed across several points of support so that the stress load is greatly reduced on the rail support point subject to direct load.
 
Noise is also generated by factors such as friction resistance, uneven surfaces, grooves and rail corrugations and the vibrations generated by trains passing over. Noise is reduced to a minimum if railway vehicles and railway tracks are in good working order. High-frequency vibrations that are transmitted into the ballast bed via the rail and sleeper are reduced by the use of elastic rail pads, which also counteracts the destruction of ballast.
 
It is highly elastic foamed EPDM base plate pads which mainly provide the elasticity required in ballastless track systems, thus ensuring smooth operation over long periods of time.