Why would an engineer need to make a 70 psi brake pipe reduction?

Why would an engineer need to make a 70 psi brake pipe reduction?

• A. (1) At terminals where Mech Dept will perform immediate inspections after locomotives are detached
• B. Only when separating a train in temperatures below 25 degrees F
• C. (1) At terminals where Mech Dept will perform immediate inspections after locomotives are detached and (2) When separating a train in temperatures below 25 degrees F
• D. Never

Answer: (C)

The main idea is using a controlled brake system state when you’re about to split a train or detach locomotives. Reducing the brake pipe pressure to a specific level (70 psi) creates a predictable condition that helps ensure safety during separation and makes it easier for maintenance to inspect equipment right after detachment. In terminals where the mechanical department will inspect immediately, having this known pressure helps avoid surprises as the locomotives come off and as brakes on the remaining portion respond. In cold weather, components can be sluggish or more prone to sticking, so a deliberate 70 psi reduction gives a conservative, predictable brake response that reduces the risk of unintended brake applications or releases during the split and reassembly. Because both situations benefit from a controlled, known state, the best choice is the one that covers both conditions.

The main idea is using a controlled brake system state when you’re about to split a train or detach locomotives. Reducing the brake pipe pressure to a specific level (70 psi) creates a predictable condition that helps ensure safety during separation and makes it easier for maintenance to inspect equipment right after detachment. In terminals where the mechanical department will inspect immediately, having this known pressure helps avoid surprises as the locomotives come off and as brakes on the remaining portion respond. In cold weather, components can be sluggish or more prone to sticking, so a deliberate 70 psi reduction gives a conservative, predictable brake response that reduces the risk of unintended brake applications or releases during the split and reassembly. Because both situations benefit from a controlled, known state, the best choice is the one that covers both conditions.