What is required if a train is to meet an opposing train on the main track?

When a train is to meet an opposing train on the main track, it is essential to leave the switch lined for the opposing train to pass. This action ensures that the train will be able to proceed safely and that the switch position is set appropriately for the intended movement. Aligning the switch correctly is vital for preventing accidents and ensuring smooth operations when two trains are interacting on the same track.

The requirement to line the switch is a standard safety protocol that mitigates risks associated with train meetings. It allows each train to navigate the junction or switch without confusion or conflict. Properly aligned switches help maintain the flow of operations and contribute to the overall safety of railway operations.

While it may seem important to delay until the opposing train has left the block or switch to the nearest siding, these actions are secondary to ensuring the switches are appropriately set. Notifying other trains can be relevant in some circumstances, but it is less critical than ensuring that the switch is correctly lined for safe passage. Thus, ensuring the switch is lined for the passing train is the most crucial step in this scenario.