Gauge indicators on Engineer's Control Stand—what does the first gauge indicate?

Gauge indicators on Engineer's Control Stand—what does the first gauge indicate?

• A. Main Reservoir (Red Hand) and Equalizing Reservoir (White Hand)
• B. Brake Pipe (White Hand) and Brake Cylinder (Red Hand)
• C. Both gauge indicate Main Reservoir only
• D. Only Equalizing Reservoir

Answer: (A)

The first gauge is a dual-reading instrument. It shows the pressures in two important storage reservoirs: the Main Reservoir and the Equalizing Reservoir. The red hand indicates the Main Reservoir pressure, and the white hand shows the Equalizing Reservoir pressure. Having both pressures displayed on one gauge lets the engineer quickly verify that there’s enough stored air and that the system can balance braking forces across the train. This is distinct from gauges that would monitor brake pipe or brake cylinder pressures, which are shown on other indicators.

The first gauge is a dual-reading instrument. It shows the pressures in two important storage reservoirs: the Main Reservoir and the Equalizing Reservoir. The red hand indicates the Main Reservoir pressure, and the white hand shows the Equalizing Reservoir pressure. Having both pressures displayed on one gauge lets the engineer quickly verify that there’s enough stored air and that the system can balance braking forces across the train. This is distinct from gauges that would monitor brake pipe or brake cylinder pressures, which are shown on other indicators.