A method and apparatus to detect breaks in tracks and/or detect the presence of a vehicle, which can include for example a train, in a monitored section of the track or rail. Embodiments of the present invention measure the change in amplitude and/or phase angles. Electrical shunts are connected between the rails at spaced-apart intervals. At least two different frequencies of alternating current are generated and fed into the segments of rail (for example at or near a mid-point between the shunts). If a rail break occurs, the total inductance of the rail at that segment will change. Using two or more frequencies allows a rail break to be differentiated from environmental rail-to-rail and rail-to-earth leakage.

A method and apparatus to detect breaks in tracks and/or detect the presence of a vehicle, which can include for example a train, in a monitored section of the track or rail. Embodiments of the present invention measure the change in amplitude and/or phase angles. Electrical shunts are connected between the rails at spaced-apart intervals. At least two different frequencies of alternating current are generated and fed into the segments of rail (for example at or near a mid-point between the shunts). If a rail break occurs, the total inductance of the rail at that segment will change. Using two or more frequencies allows a rail break to be differentiated from environmental rail-to-rail and rail-to-earth leakage.

A system and method for virtual block operational status control with long block time delay is presented. The present disclosure can advantageously increase the capacity and safety of the existing railroad track infrastructure used by the railroads by determining whether a virtual block is healthy or unhealthy. The long block mode can provide a coarse granularity on the presence of a train. In virtual block mode, the system can implement a finer granularity so the virtual aspects of the sub blocks can be realized. The present disclosure provides a long block mode that can provide the system an opportunity to analyze the potential tradeoffs between granularity and reliability by determining which mode (virtual block or long block) is best utilized in a given situation. The system can operate by default in long block mode and ignore the virtual block capabilities until absolutely needed.

A maintenance apparatus (10) transmits a pulse signal from a predetermined observation point (P) of rails (R), observes an observation signal that appears at the observation point (P) after transmission of the pulse signal, compares an observation history of the observation signals and the observation signal received this time, and detects occurrence of abnormality in any one of the rails (R) and at least one electric apparatus (20) connected to the rails (R).

A system and method for virtual block operational status control with long block time delay is presented. The present disclosure can advantageously increase the capacity and safety of the existing railroad track infrastructure used by the railroads by determining whether a virtual block is healthy or unhealthy. The long block mode can provide a coarse granularity on the presence of a train. In virtual block mode, the system can implement a finer granularity so the virtual aspects of the sub blocks can be realized. The present disclosure provides a long block mode that can provide the system an opportunity to analyze the potential tradeoffs between granularity and reliability by determining which mode (virtual block or long block) is best utilized in a given situation. The system can operate by default in long block mode and ignore the virtual block capabilities until absolutely needed.