Operating engineers operate various types of power-driven construction machines such as shovels, cranes, tractors, bulldozers, pile drivers, concrete mixers, and pumps. There are approximately 353,000 operating engineers employed in the United States. Although it is not understood precisely how it was accomplished, the ancient Egyptians used some type of hoisting system to move the giant
Plastics engineers engage in the manufacture, fabrication, and end use of existing materials, as well as in the development of new materials, processes, and equipment. The term, plastics engineering, encompasses a wide variety of applications and manufacturing processes. Depending on the processes involved, plastics engineers develop everything from the initial part design to the processes
Stationary engineers operate and maintain boilers, engines, air compressors, generators, and other equipment used in providing utilities such as heat, ventilation, light, and power for large buildings, industrial plants, and other facilities. They are called stationary engineers because the equipment they work with is similar to equipment on ships or locomotives, except that it is