What should be the position of the MU-2A valve and the independent brake valve handle after MU-ing the BN 7042?

The position of the MU-2A valve and the independent brake valve handle is crucial for efficient and safe train operation, especially after multiple units (MU) are combined. When the question specifies the positions after MU-ing the BN 7042, the correct answer indicates that the MU-2A valve should be released, and the independent brake valve handle should be in the trail position.

In this configuration, the MU-2A valve being released ensures that the brakes are not applied to the units that are now in trail, allowing for proper functionality of the leading unit’s brakes while still allowing the air brake system to control all trailing units as required. The independent brake valve handle in the trail position disables the independent brakes of the trailing unit. This is essential because it prevents any unintended braking effect from the trailing unit, allowing for smoother handling and control of the entire train when moving.

This operational setup is essential for a seamless integration of the MU'd units, as it allows the crew to concentrate on managing the leading unit without interference from the independent brakes of the trailing units. Proper understanding of these configurations ensures operational safety and efficiency.