Objective: To study the nature of fatigue damage in modern tank cars using the results of multiple collision life tests. To show the need for life tests by making appropriate changes to design documentation and increasing the competitiveness of products due to the increase in service life. To confirm the possibility of a longer service life of the wagons. To identify potentially hazardous areas in car’s structure, most susceptible to damage during operation. Methods: An experimental method was applied to assess the indicators of the cyclic durability on elements of the car’s structure by testing the resource in multiple collisions. Mathematical statistics were used to assess the test results and identify fatigue damage. Results: A comparative analysis was conducted on the design features of tested cars. The procedure for testing in impacts is also described. A statistical assessment of loading modes and accumulated fatigue damage is presented. Failures were experienced that impeded further testing. The results of the tests confirmed an increase in the service life of the cars of up to 32 years. On the basis of the detected damage, the car structure zones most susceptible to damage in operation were statistically determined. Practical importance: The need to increase the service life of cars up to 32 years was confirmed. The results of the tests carried out made it possible to make appropriate changes in the design documentation and to increase the competitiveness of cars produced by JSC Ruzkhimmash in the modern market. The accumulated experimental data can be used in the future design of tank cars giving improved operational characteristics compared to the existing rolling stock, including structural units subject to fatigue damage during operation.