Supervise and coordinate activities of crew engaged in operating and maintaining engines, boilers, deck machinery, and electrical, sanitary, and refrigeration equipment aboard ship.

Operate or maintain stationary engines, boilers, or other mechanical equipment to provide utilities for buildings or industrial processes. They operate equipment, such as steam engines, generators, motors, turbines, and steam boilers.

Perform precision assembling, adjusting, or calibrating, within narrow tolerances, of timing devices such as digital clocks or timing devices with electrical or electronic components.

Assemble or modify electromechanical equipment or devices, such as servomechanisms, gyros, dynamometers, magnetic drums, tape drives, brakes, control linkage, actuators, and appliances.

Perform technical activities at power plants or individual installations necessary for the generation of power from geothermal energy sources. They monitor and control operating activities at geothermal power generation facilities and perform maintenance and repairs as necessary. They install, test, and maintain residential and commercial geothermal heat pumps.

Install, inspect, test, maintain, or repair electric gate crossings, signals, signal equipment, track switches, section lines, or intercommunications systems within a railroad system.

Install, service, adjust, or repair coin, vending, or amusement machines including video games, juke boxes, pinball machines, or slot machines.

Inspect, diagnose, adjust, or repair wind turbines. They perform maintenance on wind turbine equipment including resolving electrical, mechanical, and hydraulic malfunctions.

Perform work involving the skills of two or more maintenance or craft occupations to keep machines, mechanical equipment, or the structure of an establishment in repair. Their duties iclude pipe fitting; boiler making; insulating; welding; machining; carpentry; repairing electrical or mechanical equipment; installing new equipment; and repairing buildings, floors, or stairs.

Repair percussion, stringed, reed, or wind instruments. They specialize in one area, such as piano tuning.