Advantages of Automatic Block Systems:
Due to automatic signaling, human error is eliminated which leads to greater safety and efficiency.
Less number of personnel for operating signals is required which reduces the operating cost
3. The system is a “fail safe system” i.e. in case of any failure of signals due to current, are made to bring the signals the signals at Danger position.
Track Circuit - Block Unoccupied
This diagram shows how the track circuit is applied to a section or block of track. A low voltage from a battery is applied to one of the running rails in the block and returned via the other. A relay at the entrance to the section detects the voltage and energizes to connect a separate supply to the green lamp of the signal.