What automatic brake valve position is used for trailing locomotive(s)?

What automatic brake valve position is used for trailing locomotive(s)?

• A. Run
• B. Handle off
• C. Emergency
• D. Suppression

Answer: (B)

The main idea is isolating a trailing locomotive from the train’s automatic braking commands. When a locomotive is simply following the lead engine, you don’t want it to independently respond to brake commands. Setting the automatic brake valve to the handle off position disables that unit’s automatic braking response, so changes in brake pipe pressure from the lead locomotive don’t cause the trailing locomotive to apply or release its brakes. This keeps the trailing unit from altering the train’s braking unintentionally and allows the lead locomotive to control the train’s braking as a whole. Using other positions would cause the trailing locomotive to participate in braking—either applying or reacting to commands—whereas handle off keeps it effectively passive in the train’s braking system.

The main idea is isolating a trailing locomotive from the train’s automatic braking commands. When a locomotive is simply following the lead engine, you don’t want it to independently respond to brake commands. Setting the automatic brake valve to the handle off position disables that unit’s automatic braking response, so changes in brake pipe pressure from the lead locomotive don’t cause the trailing locomotive to apply or release its brakes. This keeps the trailing unit from altering the train’s braking unintentionally and allows the lead locomotive to control the train’s braking as a whole. Using other positions would cause the trailing locomotive to participate in braking—either applying or reacting to commands—whereas handle off keeps it effectively passive in the train’s braking system.