Study On The Number Of Ordinary Freight Trains

In the context of the urgent need for reform and breakthroughs in the development of railway freight transport,this paper studies the number of cars in a freight train and the marshalling mechanism of fluctuating number,which is conducive to shortening the stopover time of transfer trains at marshalling stations,improving the timeliness of freight transport and speeding up the turnover speed of freight trains,in order to promote the reform of railway freight transport organization and expand the railway freight transport market.The main contents of this paper are as follows:(1)by analyzing the characteristics of full-axis marshalling mode and fixed-point marshalling mode,the method of determining the number of cars in a freight train and its adaptability to the transportation market environment,it is clear that the fluctuating vehicle marshalling mode has significant advantages in shortening the transit time of freight cars,reducing the loss of locomotive line capacity,and reducing the generation of residual train units.(2)through quantitative and qualitative analysis,this paper defines the maximum number of cars in a freight train,which is constrained by factors such as locomotive traction weight,interval restricted gradient,effective length of station arrival and departure lines,and the minimum number of cars in a freight train,which is constrained by factors such as locomotive number,locomotive turnaround time,interval passing capacity and technical station disassembly operation capacity.At the same time,through the simulation and statistics of the distribution law of residual train units and accumulation time,it is clear that there are two key inflection points in the change relationship between ξ,m and u,and the P(u<m)of inflection points are close to 0.79 and 0.92,respectively.It is clear that there is a key inflection point in the change relationship between T集,m,u and ξ,and the value of m of the key inflection points is close to the value of u.It is clear that when the number of freight trains of fixed marshalling mode is the same as the average of number of freight trains of the fluctuating vehicle marshalling mode,the accumulation time in the fixed marshalling mode is greater than that in the fluctuating vehicle marshalling mode.(3)this paper constructs a interpretative structure model for the number of freight trains and other relevant factors,with the number of freight trains as the core.According to the interpretative structure model,constraints of the number of cars in a freight train under fluctuating vehicle marshalling mode based on transport capacity and transport efficiency are constructed sequentially,and the reasonable value space of the number of vehicles of fluctuating vehicle marshalling mode is determined.(4)this paper establishes a mechanism for fluctuating vehicle marshalling mode.The criteria for judging the end of the assembly process are that the number of trucks reaches the prescribed number range at the end of the assembly and that the condition of extra-line departure is satisfied at the time of full-axis assembly.Taking Guangyuan South and Baoji East-bound traffic flow of Chengdu North Station as examples,the feasibility and superiority of the undulatory vehicle marshalling mechanism over the fixed vehicle marshalling mechanism in railway freight transport organization are verified by simulation statistics.