In connection with the forthcoming development of deep quarries to the rolling stock will be even more insistent two basic requirements: reducing the dead weight of the train and the ability to overcome large gradients. Reducing the tare coefficient of the train about two times and overcoming gradients of about 80-100% in railroad transport can be realized by the usual replacement of locomotive traction by motor cars. However, at these gradients the required number of motor cars is large. This complicates the operation of rolling stock and increases capital and operating costs. For example, according to V. E. Rosenfeld, E. V. Chebotarev and B. G. Kamenetsky, the economic cost of the railroad cars is higher. G. Kamenetsky, the economic feasibility of using motor cars is limited by the slope of only 63%.