A measurement campaign on audio frequency track circuits of Italian high speed railway systems

The new high speed railway lines, under construction in Italy, are electrified in 2times25 kHz - 50 Hz and adopt a signaling system with audio frequency track circuits (AF-TC), ranging from 2.1 kHz to 16.5 kHz. On this type of TC preliminary studies of the compatibility are required in order to test their correct operation. To this aim a measurement campaign on the AF-TC of the new high speed railway system Rome-Naples has been made. From the measurement results and their post-elaboration, based on accuracy and uncertainty analysis, the AF- TC voltage profile has been drawn with some interesting consideration about the operation of the AF-TC, that are reported in the present paper.