You may not know the Willis Tower. It was the tallest building in the world and the Western hemisphere for a time. Its name changed in 2009 but prior to that, it was known as the Sears Tower. It sits in the windy city of Chicago, Illinois. It gets about a million visitors every year keen to see the sight from what was, until recently, the highest building in the United States of America.
The tower was the headquarters’ of the Sears company. At one point Sears was the largest retailer in the world. Think Amazon, but instead of the internet, you order via a catalogue. The company had some 350,000 employees to house. They purchased two blocks of the city for the building.
The construction was quite novel. Given its height, it needed immense amounts of concrete. It would certainly have kept https://www.monstermixconcrete.co.uk/concrete-tewkesbury/, a Concrete Tewkesbury based company, plenty of work. Rather than build straight up in one long section, supporting “tubes” were constructed, giving better support and safety to the whole structure.
Each tube could be a part of the main building, or the section could be rented out to other companies if needed. In this way, it only took 3 years to finish the 108 floors. There is an observation deck and restaurant with a view. The toilets on the 103rd floor are the highest place in the western hemisphere where you can do your business.