What should be done if the handbrakes on a standing train are to be released on a grade?

Releasing the handbrakes on a standing train located on a grade requires that the air brake system be fully charged first. This is essential because a fully charged air brake system ensures that the brakes can function properly and maintain control of the train once the handbrakes are released. If the air brake system is not properly charged, there may not be enough air pressure to effectively operate the brakes when needed, which could lead to the train rolling uncontrolled down the grade.

The role of the air brake system is critical in train operations, particularly on grades where the risk of unintended movement is higher. Proper charging of the air brake system is thus a fundamental safety prerequisite that assures that all necessary controls are in place before any additional actions, such as releasing handbrakes, are taken. This procedure helps in mitigating the risks associated with potential rollaway incidents.