Abstract: An apparatus for detecting the presence of an approaching train, includes a warning indicator, a receiver for receiving a brake system status signal transmitted from an approaching train, and a relay for coupling a voltage potential to the warning indicator when the brake system status signal is received by the receiver, wherein the warning indicator, the receiver and the relay are positioned within a passenger vehicle. Also there is a method for detecting the presence of an approaching train by detecting a brake system status signal originating from the train.

Abstract: This invention relates to a device for determining lateral and/or vertical deviations in the path taken by a wheel at railway points or crossings. One of the aims of this invention is to provide data on the condition of such points or crossings, particularly as to the degree of their wear. Further, it is another aim of the invention to create a device which is easier to relate the signals from the sensors to the direction of the loads giving rise to these signals, and which at the same time is simpler and more economical to assembly while at the same time ensuring reproduceable results.

Abstract: A method and apparatus for detecting an impact sound, such as a sound caused by a railroad vehicle approaching a construction location. The apparatus comprises an arrangement for detecting impact sound or vibrations with a receiver mounted at the rail, for example, and, further, an evaluation circuit for processing the vibrations and triggering a warning signal when the intensity of the receiver-output signal continuously increases, for example, when the intensity in a predetermined frequency range passes through predetermined threshold values during predetermined times. Thus, an approaching railroad vehicle can be positively detected by monitoring a continuously increasing sound or vibration which is propagated in the rails.

Abstract: A process for localizing a mobile unit on a railway network, with a system that includes: a sensor (R) in the form of radar having an antenna (A) which is integral to the mobile unit and that cooperates with fixed markers (RP) placed alongside the railway track; a shaping circuit for a signal issued by the sensor; the radar being operative for measuring the distance traveled or the travel time; a database (BD) which contains the description of a graph of which knots or nodes represent the fixed markers and branches represent the railway tracks that connect them; and a circuit (OT) controlled by the shaped signal, connected to the radar and to the database, for determining the position of the mobile unit.