When rails become rusty, the short-circuit impedance becomes higher to make it difficult for the track circuit to detect a train exactly. This is a problem of the rail-wheel contact system. We measured the state of track short-circuit for 18 months. This paper describes the analysis of the data obtained from a long-term test and proposes a new train detect method to determine train detection by analyzing the waveform of track-circuit signal.

Copyright (c) 2002 Railway Technical Research Institute