The application for the study of the device, the work and also the malfunctions of the wheel pairs, the CA-3 automatic coupling and the axle box. Suitable for everyone who works on the railway. To machinists and their assistants, mechanics and repairmen of locomotive and wagon repair. The appendix describes the malfunction of the wheelsets and the actions of the locomotive brigade when they are detected along the line. Faults and CA-3 Coupling Dimensions. Device and faults axle knots of various types of locomotives and cars. As well as the driver’s actions when heating the books and the KTSM indicator for alarm indications (alarm 0, alarm 1, alarm 2) and much more. The application will help train drivers and assistants, as well as locksmiths to repair locomotives and wagons, to learn, to refresh or not to forget these nodes, which ensure traffic safety in railway transport.