When using the independent brake, which of the following must be true?

The statement regarding the independent brake valve handle not being blocked in the ACTUATE position is essential for proper functionality. When the handle is allowed to remain in the ACTUATE position, it ensures that the independent brake can engage and disengage as needed without any obstructions. This is crucial for safe train operations, as the independent brake is used for controlling train movement independently from the system brakes applied by the engineer. A blocked valve handle could prevent the brake from functioning correctly, potentially leading to safety hazards.

Other statements might imply misunderstandings about the usage and function of the independent brake. For instance, while the independent brake can generally be used at any time, saying it can be used without regard to conditions oversimplifies the guidelines concerning safe operation. It’s necessary to consider the situation, including train dynamics and track conditions, before deciding when to engage the independent brake. Similarly, there isn’t a requirement to always use the independent brake first; it is typically deployed based on the context of the situation. Lastly, adjusting the independent brake every five minutes is not a standard practice in train operations and may distract from the focus on safe braking.