2. Q. How is this air compressed?

A. By an air compressor on the locomotive.

3. Q. Name the different parts of the air brake as applied to the
locomotive.

A. The air compressor, compressor governor, automatic and independent
brake valves, distributing valve, triple valve, auxiliary reservoir,
brake cylinders, main reservoir, air gauges, angle cocks, cut-out cocks
and the necessary piping.

4. Q. What is the purpose of the main reservoir?

A. It is used for storing a large volume of air for the purpose of
promptly charging and recharging the brakes. Where the engine is
equipped with either the E. T. or L. T. type of brakes, main reservoir
air is used to supply the air to the brake cylinders on the locomotive.

5. Q. What other appliances use main reservoir air?

A. It is used in the operation of the power reverse gear, sand blower,
bell ringer, water scoop, air signal, fire door, water sprinkler and
other devices.

6. Q. What does the red hand on each of the air gauges indicate?

A. The red hand on the large gauge indicates main reservoir pressure; on
the small gauge, brake cylinder pressure.