Under what circumstance can switches or derails be operated?

The operation of switches or derails is allowed with permission from the train dispatcher because this ensures that operational control and safety protocols are maintained. The dispatcher has a comprehensive understanding of the overall train movements and conditions on the tracks, allowing them to authorize switch operations safely. This permission is critical to prevent accidents or miscommunications that could arise from unauthorized operations, ensuring that all train movements are coordinated and that safety is prioritized.

In contrast, while it might seem reasonable to consider watching from a colleague or during maintenance periods, neither of those scenarios provides the necessary oversight and coordination that comes from dispatcher authorization. Additionally, a safety briefing is essential but does not replace the need for official clearance from operational control. Thus, the need for dispatcher permission reflects protocol adherence and the importance of centralized operational control in maintaining safety in rail operations.