What is the standard brake pipe pressure for a freight train?

The standard brake pipe pressure for a freight train is 90 PSI. This pressure is established to ensure the effective operation of the air brake system, allowing for adequate stopping power while maintaining the safety and integrity of the train. The 90 PSI standard strikes a balance between providing enough force to engage the brakes effectively and ensuring that the system operates reliably without excessive stress or wear on the components. This pressure facilitates consistent braking performance across different types of freight cars, contributing to the overall efficiency and safety of freight train operations. Understanding this standard is crucial for anyone involved in railway operations, as it informs the maintenance and operational protocols necessary for safe train handling.