Abstract. This paper deals with the problem of internal rail stress estimation. It is based on a detailed research of contemporary situation in the field, presents basic outlines of the problem and sums up the major research areas and their possible applications in the current state of railway infrastructure management.The directions are divided into four categories in the paper: Displacement Methods, Rail Shifting Methods, Methods Based on Acoustoelastic Effect and Methods Based on Magnetoelastic Effect. Particular methods, both scientific and industrial, are presented in their section respectively.Every method that is presented within the scope of this paper is briefly described and its advantages and disadvantages are mentioned. In the end, potential of application of some of the presented methods in the practical use is discussed.

Continuously welded rails are a part of the track structure since the 1950s. Total stresses in continuously welded rails include residual stresses generated during the manufacturing process as well as the service life of rails. The control of rail stresses is very important for traffic safety. Measurement methods for residual stress in rails are presented in this paper. Since destructive measurement methods are unsuitable for use in the railway track, the modern non-destructive methods were particularly presented and discussed. The advantages and disadvantages of X-ray diffraction, ultrasonic, magnetic and electromagnetic methods are particularly explained and considered.

<p>The reliability of the railway superstructure depends, among other things, on the actual fastening of the rail to the sleepers. This structure is extremely dynamically loaded. In the paper, the attention is paid to the flexible Vossloh W14 fastening system with the use of SKL14 tension clamps. These clamps are often damaged by fatigue failures, especially in curves of small radii (R &lt; 400 m). Within the research, fracture areas were identified and a fractographic analysis was performed. The analysis proved fatigue failure and, therefore, an estimation of the service life of the clamps was made. The evaluation was focused on a selected area of railway track where the fatigue-damaged clamps were found. The strain gauges were placed directly on the clamps at critical points and the obtained values were confronted with the experimentally obtained fatigue curve. Based on the presented findings, the service life of the clamps in the selected track was identified.</p>