据列车纵向动力学理论建立拨车机动态仿真模型，考虑缓冲器强非线性特性、车钩间隙效应、车辆启动及运行阻力等因素开发出拨车机动态载荷仿真系统。通过列车拨车试验数据验证模型的有效性，据出口拨车机系统初始设计速度曲线预测4万吨列车拨车载荷。结果表明，初始设计速度下拨车机最大载荷为1414.9 kN。通过对4万吨列车速度曲线的优选保证拨车效率及每次拨车距离，拨车机载荷较原方案下降30%，时间缩短5 s。该动态仿真系统可为重载列车拨车机设计提供新手段。

As an important part of car dumper system, the indexer is a device to pull and park the train to the specified position accurately, it has a strong affects on the dumping efficiency and manufacturing cost of the car dumper directly. If the indexer design load is too large, it will greatly increase the production cost; otherwise the design small load, it will not meet the car dumper efficiency. With the increase of train traction tonnage, index power increases obviously, in the process of moving vehicle draft gear deformation is very significant, this will produce the vibration in longitudinal direction, plus the draft gear strong nonlinear, the dynamic load design of the indexer becomes very complicated. So far, the biggest domestic indexer only used for 10000 tons train, 40000 tons train indexer exported to Australia challenge dynamic load design. The simulation model for indexer dynamic load is established based on the train longitudinal dynamics theory. In the model the important factors of the strong nonlinear characteristics of draft gear, coupler slack effect, the vehicle starting and running resistance are considered, and indexer dynamic load simulation system is developed. The indexer test data is used to verify the validity of the model. According to the 40000 tons train indexer initial design speed curve, dynamic load is predicted for the 40000 tons trains. Under the initial design speed condition, the indexer maximum load is 1414.9kN. After optimization of the velocity curve, the optimization scheme to ensure dumping efficiency, and train moving distance, the maximum load decreased by 30% than the original design, shorten the time of 5s. This dynamic simulation system provides a new tools for heavy haul indexer load design.