BINDLE STIFF
A hobo who carries a bedroll or a bundle of possessions

AIR MONKEY
A mechanic who repairs the air brakes of a railroad

HOBO
A migratory worker

DOLLY FLOPPER
A brakeman or switch-tender

PIN PULLER
A conductor

KNUCKLE
Part of a couple that locks

PADDLE
Slang for a semaphore-flag signaling system