The locomotive provides all train air by diverting steam from the boiler to operate two (or more) air compressors or pumps. On D&SNG K-28s, the air pumps are mounted on the front of the smokebox, prompting crews to dub them "sports models" from their racy appearance. Usually, the pumps are located in front of the fireman under the running board on the left side of the locomotive.
Quick facts
How brakes work
Brake reductions