Final answer:
An 'absolute block' on a railway track means that a defined segment is reserved for a single train at a time, ensuring that no other train can enter until it is clear, as a safety precaution.
Step-by-step explanation:
When train operators encounter a bulletin order stating that a section of track is to be treated as an "absolute block," they should understand that this means no other train is permitted on that particular section of track while it is being occupied by another train. The absolute block system is a safety mechanism within railway signalling designed to prevent collisions by guaranteeing that only one train can be on a given stretch of track at any time. It is a crucial aspect of train operations that ensures the safety of both passengers and train personnel.
The term absolute block is not referring to a physical block, but rather a block in the sense of a segment of track. This segment must be guaranteed to be free of other trains, which is typically enforced by signals and track circuits that communicate the occupancy status of the block to dispatchers and train engineers. Compliance with absolute block rules is vital for the efficient and secure movement of trains within a rail network.