19世纪60年代北美许多铁路已达到了线路最大通过能力,载重货物列车在陡峭的上坡铁路上运行特别困难,因为车钩强度限制了增加列车长度和在列车头部增加多台机车。在列车尾部或列车中部插进补机,虽解决了短距离线路上的一些困难,但因人力和设备的使用效率低,提高了运输成本。在列车中编组无线电控制的机车组,可在不增加人力费用的情况下,使列车编组长 Many railroads in North America in the 1860s have reached the maximum capacity of the line and carrying freight trains is particularly difficult on steep uphill railways as the strength of the coupler limits the length of the train and adds more locomotives to the head of the train. Inserting a machine at the tail of a train or in the middle of a train solves some of the difficulties on short-distance lines, but lowers the manpower and equipment efficiency and increases the transportation cost. In the train group radio controlled locomotive group, without increasing the cost of manpower, make the train group leader