Before detaching from a cut of cars, what brake pipe reduction is required, and what are the exceptions?

Before detaching from a cut of cars, what brake pipe reduction is required, and what are the exceptions?

• A. 20 psi with no exceptions
• B. 20 psi, except when Mechanical Department will perform an Inbound Inspection or when temperatures are below 25 degrees Fahrenheit
• C. 10 psi
• D. 25 psi

Answer: (B)

The main idea is to secure a cut of cars by using a controlled brake release before detaching. Reducing the brake pipe pressure by 20 psi causes the brakes on the cars in the cut to apply, so they stay from rolling away when you uncouple. The standard practice includes two exceptions: if the Mechanical Department will perform an inbound inspection, the 20 psi reduction isn’t applied because their procedures require different brake conditions; and if temperatures are below 25°F, the reduction is not used to avoid issues related to cold weather, such as unreliable brake action or icing. So the best answer is the 20 psi reduction with those two specific exceptions.

The main idea is to secure a cut of cars by using a controlled brake release before detaching. Reducing the brake pipe pressure by 20 psi causes the brakes on the cars in the cut to apply, so they stay from rolling away when you uncouple. The standard practice includes two exceptions: if the Mechanical Department will perform an inbound inspection, the 20 psi reduction isn’t applied because their procedures require different brake conditions; and if temperatures are below 25°F, the reduction is not used to avoid issues related to cold weather, such as unreliable brake action or icing. So the best answer is the 20 psi reduction with those two specific exceptions.