||Railroad Brake, Signal, and Switch Operators and Locomotive Firers
- Signal locomotive engineers to start or stop trains when coupling or uncoupling cars, using hand signals, lanterns, or radio communication.
- Observe signals from other crew members so that work activities can be coordinated.
- Signal other workers to set brakes and to throw track switches when switching cars from trains to way stations.
- Set flares, flags, lanterns, or torpedoes in front and at rear of trains during emergency stops to warn oncoming trains.
||Loading and Moving Machine Operators, Underground Mining
- Signal workers to move loaded cars.
- Observe hand signals, grade stakes, or other markings when operating machines.
||Captains, Mates, and Pilots of Water Vessels
- Signal passing vessels, using whistles, flashing lights, flags, or radios.
- Tow and maneuver barges or signal tugboats to tow barges to destinations.
||Crane and Tower Operators
- Direct truck drivers backing vehicles into loading bays and cover, uncover, or secure loads for delivery.
- Signal transportation operators to stop or to proceed.
- Call out train signals to assistants to verify meanings.
||Excavating and Loading Machine and Dragline Operators, Surface Mining
- Observe hand signals, grade stakes, or other markings when operating machines so that work can be performed to specifications.
||Aircraft Service Attendants
- Guide aircraft to designated areas using hand signals, batons, or other methods.
||Rail Yard Engineers, Dinkey Operators, and Hostlers
- Signal crew members for movement of engines or trains, using lanterns, hand signals, radios, or telephones.
||Sailors and Marine Oilers
- Relay specified signals to other ships, using visual signaling devices, such as blinker lights or semaphores.