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Introduction. The article considers the determination of the impact velocities of empty and loaded Class 2 dangerous freight cistern cars on a gravity hump, the forces acting on the car through the automatic coupler, as well as the accelerations acting on the loading and unloading, safety valves and elements of the tank shell interior. Currently Class 2 dangerous freight cars with Classification Code 2112 and UN numbers 1011, 1965, 1969, 1978 could be shunted over the gravity hump only with a shunting locomotive, backing off with extreme caution, without jerks or sudden stops. This limitation prevents shunting gas cistern cars on automated gravity humps, which complicates shunting operations during train formation.Materials and methods. Impact test of a cistern car alternately equipped with cushions of Classes T1, T2 and T3 with measurement of speeds, forces and accelerations.Results. The maximum permissible impact velocities of the cistern car are determined.Discussion and conclusion. According to the test results, as well as the GOST 32913–2014 requirements, the authors state that the implementation of the previously developed technology for shunting Class 2 dangerous freight cistern cars equipped with Class T3 draft gears on gravity humps, with a maximum approach speed of 3 km/h complies with shunting safety requirements.

Introduction. Until now, the requirements for manual and automatic couplers for locomotive-hauled passenger carriages and electric trains have been completely identical, despite the significantly lower level of longitudinal forces during the movement of multi-unit rolling stock with distributed traction. The introduction of specialised designs of coupling devices for electric trains led to the development of strength requirements that enable the creation of new models with smaller dimensions and weight. Operating experience has shown that parts of couplings may be destroyed, leading to the uncoupling of trains. Fatigue damage may cause accidents. However, there were studies of the draft loads of electric trains couplers in operation, on the basis of which it was possible to develop regulatory requirements for specialised coupling devices.Materials and methods. The authors measured the forces acting in the couplings of electric trains of various categories and types during normal operation, as well as the frequencies of the occurrence of forces of various levels. The article includes histograms based on the results of processing the received data showing the distribution of longitudinal forces acting on the inter-car couplers and the parameter characterising the accumulation of fatigue damage per 100,000 km. Results. According to the results of processing of the experimental data, the calculation of the accumulation of fatigue damage to the couplers was carried out and the requirements for their expected service life were established. Test procedures have also been developed to evaluate strength and fatigue resistance under high-cycle and low-cycle loading conditions. The article provides ground for introducing a correction factor into the procedure for processing test results, which makes it possible to perform life tests on equipment with different values of the load cycle asymmetry factor.Discussion and conclusion. The authors have evaluated the draft loads in coupling devices during the operation of electric trains, on the basis of which technical requirements and test methods were developed and approved by JSC Russian Railways. Development and acceptance of all new models of coupling devices for electric trains will be carried out in accordance with these regulatory documents.

The paper tackles the protection problem of freight cars carrying hazardous materials while being solved through use of coupler center draft gears with increased energy absorption capacity. It is demonstrated that the adopted commodity-based classification of draft gears, eligible under different energy absorption capacity requirements, ensures more reliable protection and prevention of hazards in possible emergency situations involving such cars. The method is put forward allowing for quantitative evaluation of the draft gear energy absorption capacity influence on the reduction in forces acting upon a freight car as well as on the car damageability degree in operation under emergency conditions and increase in the bearing members remaining life expectancy of the car body structure. There are presented results of the impact tests of freight cars equipped with draft gears having various energy absorption capacity added with the outcomes of these results based car loading calculations. The tests confirmed that freight car equipping with draft gears having extended energy absorption capacity contributes to considerable increase in the life time expectancy of freight car structure and increase in the safe impact speeds at which the level of forces does not exceed the car strength level (thus reducing the probability of contingencies and accident severity as well).

The influence of increasing energy consumption of center coupler draft gear on changing longitudinal forces during the motion of the train was studied. It was shown that the level of force is greatly reduced when equipping tank cars with draft gears of increased energy consumption (class T2 and T3). Article provides technique and results of train tests obtained during the run of the tank car train equipped with draft gears of T2 and T3 classes, and the same train in the same modes with draft gears of the T0 and T1 classes. On the basis of results of comparison tests not only qualitative, but also quantitative impact assessment of high class draft gears was performed on longitudinal dynamics of the train. The analysis of standards of American, European and Russian Railways in this field is provided, also confirming validity of the existing requirements to the draft gears of automatic couplers for cars of the 1520 mm gauge tracks. On the basis of performed complex of tests, including train and impact tests [1], a conclusion about a big positive effect of use of draft gears of high classes is confirmed.