The object of research is the processes of emergence, perception, and redistribution of loads in the supporting structure of a flatcar with a floor made of sandwich panels. To reduce the impact of dynamic loads on the supporting structure of a flatcar, as well as the safety of goods transported in it, it is proposed to manufacture floors from sandwich panels. Within the framework of the study, mathematical modeling of the dynamic load on a flatcar when it runs in a loaded state was carried out. It was found that, taking into account the proposed solution, the accelerations acting on the supporting structure of a flatcar are reduced by 8.4 % compared to the typical one. At the same time, accelerations acting on cargo placed on a flatbed car are reduced by 11.7 %. The results of calculating the strength of sandwich panels, when arranged on a flatcar, proved the feasibility of the proposed improvement. The main indicators of dynamics of the improved flatcar structure operated in an empty state were determined. It was established that the flatcar movement is assessed as "good". A feature of the results reported here is that the improved supporting structure of a flatcar contributes not only to reducing its dynamic load but also to improving the safety of transported cargoes. The scope of practical application of the results is the engineering industry, in particular, railroad transport. The condition for the practical application of the research results is the use of energy-absorbing material in the structure of sandwich panels. The study could contribute to devising recommendations regarding the design of modern structures of railroad vehicles and increasing the efficiency of the functioning of the transportation industry