Before granting 241 permission, what must the dispatcher ensure?

The correct answer is that the dispatcher must ensure the affected appliances are secured with blocking devices before granting 241 permission. This is crucial for safety, as blocking devices prevent accidental movement of trains or equipment during operations that could pose a risk to personnel or the equipment itself. Ensuring that blocking devices are properly secured provides a safeguard against potential hazards, allowing for a controlled environment within which the 241 permission can be safely granted.

In the context of railroad operations, the priority is always on ensuring the safety and security of both the personnel and the infrastructure. This measure not only follows protocol but also minimizes the risk of incidents during activities such as train movements that require specific permissions like 241.