The article analyzes the main factors affecting the destruction of the side frames of freight wagonsʼ trucks.
It is noted in the paper that the side frame of the freight car carriage is a complex and important cast piece, the safety of movement depends on reliable operation of it.
In the opinion of the author, in examining the technical condition of the side frames of the wagonsʼ trucks, one should take into account the influence of the operation, maintenance and repair system, namely: overloads, wagons outside the main roads on factory roads, which are not officially reported, violation of rules for the formation and disbanding of freight compositions with the use of slides (exceeding the speed of the collision), emergency braking, unreasonable replacement of the units and parts of the trucks with old ones, with less final resource, counterfeit, violation of rules of inspection and certification etc. The use of spares and parts in the wagonʼs truck construction with deviation (spring set, friction wedge) contributes to strengthening the complex effect of negative factors on the propagation speed of the crack in the side frame of the freight wagon.
It also is necessary to take into account the development of cracks in the side frame of the wagonʼs truck the speed of its movement, congestion, as well as the technical condition of the railway track. This is due to the fact that with greater loading and high speed of movement, greater dynamic forces can act than on the side frame with faulty friction vibration dampers at low speeds and incomplete loading of the wagon.
Due to the lack of appropriate techniques it is difficult to assess the degree of influence of these faults on the rate of crack development.
For more precise determination of the causes of the fracture of the sidewall during the conduct of judicial railway and transport expertise it is suggested to perform its strength calculations, build a mathematical model of the car in order to more accurately assess the influence of deviations in the design of the wagon and the railway track.