A rail pad, also called rail rubber plate, is designed between the rail tie plate and foot of the rail, made by an elastic polyurethane mat, which is interposed between steel rails and tie sleepers to protect the sleeper top from wearing and impacting. Its defined stiffness is used to increase the elasticity of the superstructure of the ballast and reduce shock and vibration in the rail system. With such upgraded load distribution, it will lead to greater passenger comfort and less wearing onto the superstructure. The strengthened elasticity effects positively onto the wear of the superstructure items and rolling stock. It’s always fastened within a fastening system by screw spikes or rail bolts into the sleeper ties. The reason why rail pad made up of rubber or plastic is to dampen the shocks or vibration of a passing train. Usually the starting stiffness is designed a little low in order that the relative deformation under the spring clip toe loads is substantial, which can guarantees the rail pad maintaining in close contact with the rail in spite of any vertical movements of the latter.