The Engineering Book: From the Catapult to the Curiosity Rover: 250 Milestones in the History of Engineering

1893

Ferris Wheel

George Washington Gale Ferris, Jr. (1859–1896)

People will climb mountains and ride elevators to the top of skyscrapers like the Empire State Building to take in a good view.

So say that you wanted to engineer a ride that gives people a mountaintop view without the climbing—how might you do it? The Ferris wheel is one answer to the question. The first Ferris wheel opened in 1893 in Chicago, designed by George Washington Gale Ferris, Jr.

If you look at today’s tallest Ferris wheel—the High Roller in Las Vegas—you can see one reason why Ferris wheels are a favorite of engineers: they can be extremely efficient with materials. Like a bicycle wheel, which can be both strong and light because of its tensioned spokes, the High Roller looks remarkably sparse, with just a rim, the spokes, the hub, and the base. The cabins for riders attach to the rim and rotate with electric motors to stay level.

Because the wheel is so large at 560 feet (167 meters) in diameter, and so sparse in terms of materials, it is easy to lose track of how much weight it is carrying. Looks can be deceiving. First, there can be more than 1,000 people riding the wheel simultaneously. They ride in 28 cabins that hold up to 40 people each. Every cabin connects to a section of rim that is 53 feet (16 meters) long. Four steel cables (the spokes for this wheel) tie each rim section to the hub. A cabin weighs approximately 45,000 pounds (20,500 kg) empty, or up to 55,000 pounds (25,000 kg) fully loaded. So there is something like 1.5 million pounds (680,000 kg) hanging off the rim. It is an immense amount of weight for the structure to support and be able to rotate. In addition, there are a dozen tuned mass dampers in the base to even out any vibrations and create an extremely smooth ride.

The wheel turns at two revolutions per hour, meaning that a passenger stays on the wheel for about 30 minutes, allowing 2,000 or so people per hour to take in the view.

Ferris wheel at The World’s Columbian Exposition, 1893.