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.
Work environment. 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.
| 1. | Replace defective parts of machine or adjust clearances and alignment of moving parts. |
| 2. | Align machines and equipment, using hoists, jacks, hand tools, squares, rules, micrometers, and plumb bobs. |
| 3. | Connect power unit to machines or steam piping to equipment, and test unit to evaluate its mechanical operation. |
| 4. | Repair and lubricate machines and equipment. |
| 5. | Assemble and install equipment, using hand tools and power tools. |
| 6. | Position steel beams to support bedplates of machines and equipment, using blueprints and schematic drawings, to determine work procedures. |
| 7. | Signal crane operator to lower basic assembly units to bedplate, and align unit to centerline. |
| 8. | Insert shims, adjust tension on nuts and bolts, or position parts, using hand tools and measuring instruments, to set specified clearances between moving and stationary parts. |
| 9. | Move machinery and equipment, using hoists, dollies, rollers, and trucks. |
| 10. | Attach moving parts and subassemblies to basic assembly unit, using hand tools and power tools. |
| 11. | Assemble machines, and bolt, weld, rivet, or otherwise fasten them to foundation or other structures, using hand tools and power tools. |
| 12. | Lay out mounting holes, using measuring instruments, and drill holes with power drill. |
| 13. | Bolt parts, such as side and deck plates, jaw plates, and journals, to basic assembly unit. |
| 14. | Level bedplate and establish centerline, using straightedge, levels, and transit. |
| 15. | Dismantle machines, using hammers, wrenches, crowbars, and other hand tools. |
| 16. | Shrink-fit bushings, sleeves, rings, liners, gears, and wheels to specified items, using portable gas heating equipment. |
| 17. | Dismantle machinery and equipment for shipment to installation site, usually performing installation and maintenance work as part of team. |
| 18. | Construct foundation for machines, using hand tools and building materials such as wood, cement, and steel. |
| 19. | Install robot and modify its program, using teach pendant. |
| 20. | Operate engine lathe to grind, file, and turn machine parts to dimensional specifications. |
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