Millwrights install, replace, dismantle, and repair machinery and heavy equipment used in power generation, including wind power, hydroelectric damns, and natural gas turbines, and in manufacturing plants, construction sites, and mining operations. The development of new technologies requires millwrights to work with new industry-specific and highly complex precision machines. Some of these machines have tolerances smaller than the width of a human hair.
The millwright’s responsibilities begin before a new piece of machinery arrives at the jobsite. Millwrights consult with production managers, industrial engineers, and others to determine the optimal placement of the machine in the plant. Some equipment, such as a metal forging press, is so heavy that it must be placed on a new foundation. Millwrights either prepare the foundation themselves or supervise its construction. As a result, they must know how to read blueprints and to work with a variety of building materials.
When the new machine arrives, millwrights unload, inspect, and move the equipment into position. To lift and move light machinery, millwrights use rigging and hoisting devices, such as pulleys and cables. With heavier equipment, they may use hydraulic-lift trucks or cranes. Lifting such heavy equipment requires millwrights to understand the load properties of cables, ropes, hoists, and cranes. Parts of power plant turbines and other machinery can weigh more than 100 tons and must be precisely positioned; even nuts and bolts can weigh a few hundred pounds each and require a crane to move.
Next, millwrights assemble the machinery. They fit bearings, align gears and wheels, attach motors, and connect belts, according to the manufacturer’s blueprints and drawings. Precision leveling and alignment are important in the assembly process, so millwrights measure angles, material thickness, and small distances with calipers, squares, micrometers, and other tools. When a high level of precision is required, they use devices such as lasers and ultrasonic measuring and alignment tools. Millwrights also work with hand and power tools, such as cutting torches, welding machines, hydraulic torque wrenches, hydraulic stud tensioners, soldering guns, and with metalworking equipment, including lathes and grinding machines.
In addition to installing and dismantling machinery, many millwrights work with industrial mechanics and maintenance workers to repair and maintain equipment. This includes preventive maintenance, such as lubrication and fixing or replacing worn parts. If a spare part is unavailable, a millwright may use a lathe or other machine tool to cut a new part.
Increasingly sophisticated automation means more complicated machines for millwrights to install and maintain, requiring millwrights to specialize in certain machines or machine brands. For example, some millwrights specialize in installing and maintaining turbines in power plants that can weigh hundreds of tons and contain thousands of parts. This machinery requires special care and knowledge, so millwrights receive additional training and are required to be certified by the turbine manufacturer.
Millwrights in manufacturing often work in a machine shop and use protective equipment, such as safety belts, protective glasses, and hardhats, to avoid injuries from falling objects or machinery. Those employed in construction may work outdoors in difficult weather conditions.
Millwrights at construction sites may travel long distances to worksites. For example, millwrights who specialize in turbine installation travel to wherever new power plants are being built.
Advanced equipment, such as hydraulic wrenches and hydraulic stud tensioners, have made the work safer and eliminated the need for millwrights to use sledge hammers to pound bolts into position. Other equipment has reduced the strenuous tasks that caused injuries in the past.
Millwrights work independently or as part of a team. Because disabled machinery costs time and money, many millwrights work overtime and some work in shifts; about 39 percent of millwrights report working more than 40 hours during a typical week. During power outages or other emergencies, millwrights often work overtime.
Median hourly wage-and-salary earnings of millwrights were $21.94 in May 2006. The middle 50 percent earned between $17.13 and $29.42. The lowest 10 percent earned less than $13.84, and the highest 10 percent earned more than $34.39. Earnings vary by industry and geographic location. Median hourly wage-and-salary earnings in the industries employing the largest numbers of millwrights were:
Pulp, paper, and paperboard mills $25.43
Iron and steel mills and ferroalloy manufacturing 20.91
Nonresidential building construction 20.34
Building equipment contractors 19.67
Sawmills and wood preservation 17.55
About 50 percent of millwrights belong to labor unions, one of the highest rates of membership in the economy.
Nuclear power plants trust the millwright for all their precision work.