the evaluation device ae in the apparatus v signals as a precaution that the track section g is occupied and produces a fault signal which indicates the relevant disturbance state for this purpose the fault signal may for example be output in the form of a visual and or audible warning message in this case a reliable distinction can be advantageously drawn between a disturbance that is to say a cable fault and a regular free or occupied message furthermore determination of the phase shift and the comparison with the reference phase shift can advantageously be implemented with comparatively little complexity such that no or scarcely any additional circuit components are required thus achieving a cost saving in comparison to other feasible solutions it should be stressed that the illustration in fig1 is only a schematic illustration for example in practice further components may be provided or required which are not illustrated in fig1 for clarity reasons thus for example it is feasible for the apparatus v to additionally be designed to transmit data signals via the rails f of the track section g to a rail vehicle which is occupying the track section g in this case the transmitter s of the apparatus v advantageously has an external drive by means of which the data signals can be supplied to the transmitter s.