An important issue during the operation of rail vehicles is the dynamics of forced loads. The identification of these workloads and the evaluation of their impact on the reliability and durability of the structure is essential for maintaining the safety of operation. For this reason, an important issue in the assessment of durability is to identify potential hazards that cause object failure. This paper presents the results of fatigue tests for the selected structure of a rail bogie. The results were then used to conduct the Degradation Analysis of the object. The purpose of this analysis was to estimate the real values of the durability and reliability indicators of the bogie frame from the point of view of the safety of its operation.