This paper presents the results of the International Benchmarking of Longitudinal Train Dynamics Simulators which involved participation of nine simulators (TABLDSS, UM, CRE-LTS, TDEAS, PoliTo, TsDyn, CARS, BODYSIM and VOCO) from six countries. Longitudinal train dynamics results and computing time of four simulation cases are presented and compared. The results show that all simulators had basic agreement in simulations of locomotive forces, resistance forces and track gradients. The major differences among different simulators lie in the draft gear models. TABLDSS, UM, CRE-LTS, TDEAS, TsDyn and CARS had general agreement in terms of the in-train forces; minor differences exist as reflections of draft gear model variations. In-train force oscillations were observed in VOCO due to the introduction of wheelâ\u80\u93rail contact. In-train force instabilities were sometimes observed in PoliTo and BODYSIM due to the velocity controlled transitional characteristics which could have generated unreasonable transitional stiffness. Regarding computing time per train operational second, the following list is in order of increasing computing speed: VOCO, TsDyn, PoliTO, CARS, BODYSIM, UM, TDEAS, CRE-LTS and TABLDSS (fastest); all simulators except VOCO, TsDyn and PoliTo achieved faster speeds than real-time simulations. Similarly, regarding computing time per integration step, the computing speeds in order are: CRE-LTS, VOCO, CARS, TsDyn, UM, TABLDSS and TDEAS (fastest)

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The plateau railway has especially tough condition compared to the normal railway, due to the effects from permafrost, high altitude, low temperature and some other extreme environmental condition. Thus, it is critical to assure the transportation capacity of the locomotive as well as the safety of train dynamics during transportation. To study the performance of locomotives on a plateau railway, this work investigates three sets of newly-developed diesel locomotive which are reconnected to pull 4000t of cargo on the Qinghai-Tibet Railway Gera section. The train operation is simulated considering the vehicle dynamics in lateral and longitudinal directions, with traction and braking conditions. The results from a simplified trainset model show that the traction capacity of the three locomotives can meet the requirements of freight transportation. The maximum hook force on the coupler can reach 1250kN at the starting condition, and the maximum pressure hook force on the coupler is 704kN in the long downhill cyclic braking condition, meeting the safety requirements. Using multi-body dynamics software, a detailed locomotive dynamics model is established, enabling the analyses for lateral dynamics of the locomotive. The simulation results show that the dynamic performance of the locomotive can meet the requirements under the maximum pressure state. The reduction of the free deflection angle of the coupler is beneficial to improve the dynamic performance of the reconnected vehicle. This paper provides a reference for the research on the adaptability of locomotive transportation in railways.