In the context of switching, what does "finally lined and locked" mean?

The phrase "finally lined and locked" refers to the procedure where a switch on a railway track has been properly adjusted to align with a specific track route and then secured in that position. This process ensures that the switch is stable and won’t accidentally move, maintaining the safety and integrity of the railway operations.

When a switch is "finally lined," it indicates that it has been set to allow trains to pass on the desired track. The term "locked" signifies that it has been made immobile, ensuring that the switch cannot be inadvertently changed or disturbed. This secure positioning is critical for preventing accidents or derailments, as switches can change the route of oncoming trains.

Thus, the correct understanding captures the importance of ensuring switches are set up safely for rail traffic, reflecting proper operational procedures in railway switching practices.