Compressor

Motorized rail vehicles carry onboard compressors that pressurize air for the air brake system, and sometimes other systems too. Compressors are typically powered by electricity, but on steam engines they are steam-powered.

Provided the needed powersource is available, the compressor activates whenever the main reservoir drops below a certain pressure (often at 75% of the full capacity), and deactivates once the reservoir is full (usually at 8 bar).

Compressors may sometimes produce a spitting sound when powering on or off. They do this to clear air lines of potential moisture.

On vehicles with a diesel generator, it is possible to increase the power of the compressor by applying throttle while in neutral reverser setting, for example.

Before setting the vehicle in motion, ensure that its compressor is enabled, either via breakers or valves.