This invention relates to an oscillation dampening system for railway tracks.
More particularly, the invention relates to a track for rail vehicles in which each rail is secured onto a foundation by means of spaced rail sleepers or ties. Each rail is incited to oscillate by the wheel of the railway vehicles running thereover, and additional masses are provided which are attached to the rail to dampen these oscillations.
In the normal usage of railway tracks, ripples are produced in the tracks. These ripples are produced as a result of a vertical oscillation or alternating upward and downward slopes which arise on the running or travelling surface of the rail in a longitudinal direction of the rail. A wheel which travels or moves over a rail with ripples produces a noise. This noise increases with the speed of the wheel and the noise which is produced is greatly increased when compared with the noise made by a wheel running over a rail which is free from ripples. Not only is the noise a problem today because of environmental conditions and the desire to reduce the noise for reasons of environmental protection, but the noise problem has existed for many decades, and scientists have been occupied with the problem of the appearance and removal of ripples for a long time. In addition to the noise factor, the rail sub-structure and the rail securing elements are greatly stressed and may even be damaged as a result of the shaking caused by running wheels on rails with ripples. Corresponding dangers exist for the vehicle running over such a rail with ripples. Without being able to explain in detail the mechanism which causes the appearance of ripples, specialists have previously generally assumed that the formation of ripples is connected with the oscillations of the wheel of a railway vehicle or the rail/wheel system.
A number of proposals have been made to remove the ripples as well as to reduce the ripples. Some of these proposals have been carried out and others have not. Thus, it was proposed (Eisenbahningenieur 27 (1976), 5, pages 200-207) either to use a particular alloy for the rail material or to arrange the rail on a less elastic superstructure, or to follow both proposals. It was further proposed to take special steps in connection with the wheel or with the wheelset, e.g. to provide for the reduction of the unsprung wheelset mass. A further proposal (German Pat. No. 966,656, Swiss Pat. No. 321,783) was to provide cross-sectional alterations distributed at unequal distances over the length of the rail, e.g. in the form of thickening (such as, additional masses), to dampen the characteristic oscillations of the rail. None of these proposals have up to the present time led to a satisfactory result. It is still necessary to grind off the ripples on the surface of the rail from time to time.