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THE STORY OF GIANT WHEELS PART 1: THE CHICAGO FERRIS WHEEL
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20943 dated 30.01.2018
Published by
Alberto Fabbri
Source
NATIONAL GEOGRAPHIC
The story of Observation Wheels from Chicago Ferris Wheel to Singapore Flyer.

This very nice and interesting documentary of National Geographic tells the story of giant Ferris Wheels and all the technological advances made to build bigger and bigger up to the biggest wheel, including all failures and the risks faced by engineers during that incredible advances.

Giant Ferris wheel started from Chicago wheel 80 meters, through Earl’s Court London Giant Wheel, London Eye, Star of Nanchang to Singapore Flyer; more than 100 years of engineering breakthroughs, outstanding technical innovations that allowed engineers to go further and further. This is the incredible story that tells the inventions that allowed to build bigger and bigger up to the world’s biggest.

We propose you here above the video of the part 1 in English, Spanish and Portuguese.

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PART 1: 1893, THE CHICAGO FERRIS WHEEL, 80 m.

Nowadays Singapore Flyer stands with its 42 stories height, carrying more than 20.000 a day, with its spectacular view of 3 nations, Indonesia, Singapore and Malaysia. It is one of the marvels of technology; is no fairground ride, is a totally different way to see the world.

To understand how Singapore Flyer can be this tall and how engineers could build such a marvel of technology, we must fly back in time.

Chicago, 1893. At the closing of nineteenth century, Chicago is a metropolis in the American Midwest. In occasion of the international fair, occurring right in Chicago, the town wanted to build something that is a celebration of american engineering, a marvel that showed the economical power of USA.
Many projects, pale imitations of Paris Eiffel Tower, were rejected. They wanted something completely new. They wanted something the world has never seen before

George Ferris, a successful engineer in railway industry well known for his skills to build record breaking bridges, had a vision:. He had the idea to build a 80 meters tall giant wheel in steel, that would bring passengers high in the air. The idea was accepted with enthusiasm and was accepted. Now Ferris had to build his wheel.


To do this he would have to completely reinvent the wheel. People thought Ferris was mad.

Normal railroads wheels were very heavy; Ferris could not build a giant wheel in that way.
Must build a lighter wheel. He took the model from the bicycle wheels, built with light spokes, something called a “tension wheel”. So Ferris decided to build a giant bicycle wheel.

A lattice steel frame formed the rim, and steel spokes, just 6 cm thick, tied the rim to the hub. By using such thin spokes, Ferris could made the wheel much lighter. On paper everything sounded good, but now Ferris must find a way to build it.

As Ferris build the pillars, put the giant hub and the bottom half of the wheel, the weight of the wheel was hanging on the spokes. But as he reaches the top half, the weight would buckle the thin spokes and the rim would eventually collapse. So before the wheel is a completed circle, it is in danger of collapsing.

To support the upper half of the wheel during the erection, Ferris built a giant scaffolding frame to support tit. He also inserted support temporary trusses between the axle and the rim, who temporarily take the load while the rim was completed. Once the rim was completed, Ferris removed the struts and the scaffolding, and the wheel support itself

When it opened in 1893 was the star of the Chicago world fair; People came from far and wide to ride the new incredible wheel. In 1893, an age before airplanes and before the age of welding machines , this is the first time the general public has the chance to see the world from above. In 10 months over one 1,5 million people spent 50 cents to ride the wheel, making the investors earn a fortune for those days.

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Also the Singapore Flyer is made the same way of Ferris wheel. All the structure is hanging on spoke made of only 8 cm steel cable. It’s a tension wheel, just like the one of Ferris. And as the original Ferris Wheel, this wheel support itself only once the rim has been completed with all the spokes. Steel cables work only when you try to stretch them, but if you try to compress them, they collapse

So, in building the Singapore Flyer , they had to invent a way to hold the rim in place while all steel cable were put in tension. Just as Ferris did, they had to put a temporary scaffolding and temporary struts to support the rim. These temporary struts started to hold the weight from the very beginning. Using this method, section by section, the entire wheel is built slice by slice, without the need of an outer scaffolding. Once the wheel is completed, the engineers remove the temporary struts and the wheel supports itself.

Today the Singapore Wheel is a symbol of economic power and success, just as it was when Ferris built his wheel more than 100 years ago.