What does the Automatic Block Signal System (ABS) consist of?

The Automatic Block Signal System (ABS) is designed to enhance the safety and efficiency of train operations by using signals that are automatic and responsive to the presence of trains on the track. It consists of a series of blocks, with each block governed by signals that activate depending on whether a train is present. This means that the signals change in accordance with the occupancy of the track blocks, which ensures that trains can only proceed when it is safe to do so.

In this system, as a train enters a block, the signals within that block communicate necessary information, such as whether the block ahead is clear or occupied, allowing for safe and regulated train movements. This automated process minimizes the risks of collisions and helps maintain efficient scheduling and routing of trains. By understanding this system, it becomes clear that it relies on signals that react to train presence rather than manual governance or simply controlling a singular main track or acting as a warning system for defects.