The main hall of the GE Power plant in Greenville, South Carolina, has 65-foot-tall ceilings and is the length of several football fields. Here workers assemble heavy-duty gas turbines that are over 10 feet wide and 30 feet long, and which weigh up to 560,000 pounds. The largest of these turbines installed in a typical power plant can generate enough electricity for 500,000 U.S. homes. The complex job of assembling one turbine can take six weeks.