A professional who assists treating engineer in impregnating wood products with preserving or fireproofing chemicals, performing any combination of following duties. Respnsibilities include:

• Opens and closes retort door, using pneumatic wrench.
• Turns steam, vacuum- or hydraulic-pressure, or solution valves in response to signals.
• Tends pumps to transfer chemicals from railroad cars, trucks, or boat tankers into storage tanks.
• Drills test-bores in treated or untreated wood, using hand drill.
• Moves trams loaded with products in and out of retort.
• Performs other duties as described under helper master title.