What is the normal main reservoir pressure range in pounds?

The main reservoir pressure in a train's air brake system is crucial for optimal performance and safety. The correct range for a normal main reservoir pressure is between 125 to 150 pounds per square inch (psi). This pressure range is necessary to ensure that the brakes can apply sufficient force efficiently and effectively when needed.

Operating within this range allows the train's air brake system to function properly, ensuring that the brakes engage smoothly and can lock when required. This is particularly important for maintaining control over the train during various operations, such as acceleration, deceleration, and stopping.

The other ranges presented do not align with standard practices in train operations. For instance, a lower pressure range might result in insufficient braking power, hampering safety and efficiency. Conversely, a higher range could lead to stress on the components of the air brake system, increasing the risk of failure or malfunction. Therefore, maintaining the correct pressure range is vital for safe and efficient train operation.