Before entering a main track at an electrically locked switch, what is required?

To safely enter a main track at an electrically locked switch, obtaining authority from the control operator is essential. This requirement ensures that the switch is properly aligned and locked for the intended movement. It also confirms that the main track is clear and that there are no conflicting movements that could lead to unsafe situations. By securing this authority, personnel are adhering to established protocols that prioritize safety and communication within the rail network.

The other options do not provide the necessary safeguards. Proceeding without restrictions would ignore the critical need for coordination and proper authorization. Notifying the nearest station may be part of operational procedures, but it doesn't replace the necessity of confirming that the entry into the main track is authorized. Checking train schedules could be useful for general operational awareness, but it does not ensure safe passage through the switch without proper authorization from the control operator.