This program is intended for Russian Railways OJSC personnel servicing locomotive safety devices, as well as for locomotive crews who may encounter emergency situations in the operation of safety devices along the route. When a locomotive enters the depot due to a malfunction of safety devices, repair personnel waste time searching for technical documentation necessary to promptly eliminate the malfunction; the information found may turn out to be irrelevant, which can only complicate the elimination of the malfunction on the locomotive. A mobile reference book on safety devices will reduce the time spent searching for necessary and up-to-date diagnostic information, since all the necessary information is systematized in the application, taking into account the need for troubleshooting locomotives. As a result of using the program, the downtime of traction rolling stock during unscheduled types of repairs is reduced, the number of unscheduled types of repairs is reduced, since maintenance personnel receive promptly necessary methodological information, which allows them to eliminate malfunctions of safety devices before setting them up for unscheduled repairs. When using the application by locomotive crews, the effectiveness of actions in the event of emergency situations increases, since the locomotive crew quickly receives information about eliminating breakdowns of safety devices along the route.