Interference-free track vacancy detection

Shortly after the opening of the first railway lines, at the beginning of the last century, it became clear that `rules of the line´ needed to be laid down if passengers were to be transported safely and operational procedures conducted smartly. As human error could never be ruled out, safely equipment had to be developed. Here, the author shows that the purpose of track vacancy detection equipment is to determine the occupancy of sections by rail vehicles. Thereby, the interlocking is supplied with vital information. He argues that automatic track vacancy detection equipment is a prerequisition for automatic train control