Causes of failures in the track circuit and automatic train control operation

In the rail system is widespread the numerical coded circuit blocking and continuous automatic train control system. The system uses the frequency channel, organized on the rail line. Depending on the type of traction, the carrier wave frequency is equal to 25 or 50 Hz. As the element base the electromagnetic relays are used. In consequence of the low liability and safety, this system does not meet the requirements for the modern train separation arrangements. The number of failures and malfunctions of the numerical automatic block signalling and automatic train control system is large enough. Most of them are caused by unstable operation in the process of ballast resistance changing and interference of the traction current.