What is the standard brake pipe pressure for yard service?

The standard brake pipe pressure for yard service is 90 psi. This pressure is established to ensure adequate braking capacity while providing safety and efficiency in yard operations. In yard service, the lower pressure helps to accommodate frequent starts and stops, as well as short movements, which are typical in this environment. It also allows for more controlled braking, reducing the risk of damage to equipment and cargo.

The choice of 90 psi balances the need for effective braking with considerations of wear and tear on the train's braking system. In contrast, higher pressures may be more appropriate for through freight operations where longer distances and higher speeds are involved, but they can be excessive in a yard setting where trains are often working in close proximity.