What is the purpose of a block signal?

The primary purpose of a block signal is to govern trains entering and using a block. A block is a section of track that is designated for the use of a single train to ensure safety and prevent collisions. The block signal provides vital information to train crews about the occupancy of that block, indicating whether it is clear for the train to enter, occupied by another train, or if there are any restrictions. By controlling the movement of trains into and through different blocks, block signals contribute significantly to safe and efficient train operations. This function is crucial for maintaining a structured flow of traffic on the railway network, ultimately enhancing both safety and operational efficiency.