A modern City is hard to be imagined without skyscrapers. However if you would have walked a city 100 years ago this would have been wastely different. For something that changed the face of our cities so drastically in the last century there is awfully little to find about how Skyscrapers came to be. This Article will try to give a brief inside into the technologies and personalities that allowed the Skyscraper to enter our cities.
The Chicago Home Insurance Building (1885 – 1931) is wildly accepted as the first “skyscraper” even though with only 10 stories and a height of only 42 m you would probably hardly notice it today. This however was very different in the days it was being built. City officials grew so concerned when they saw that building that they halted construction to investigate its safety. What made the “Chicago Home Insurance Building” so revolutionary was its metal-frame-structure.
It is not that it is impossible to reach some height with normal mansory buildings, however it gets uneconomical very soon. As mansory walls are very ineffective at taking latheral loads they have to be rather thick, that however increases the weight of the structure to such an extent that the lower walls have to be even thicker, in order to support the weight of the upper walls. A good example of that principle is the Monadnock Building, the tallest load-bearing brick building. With its height of 46m (150 feet) it is comparable in height to the Chicago Home Insurance Building, however its walls are 1.8 m (6 feet) thick at the bottom and 46 cm (18 inches) thick at the top. If the building would have been any higher the walls would take up so much of the rentable space that the building would have been uneconomic.
The floor plan shows the thick walls of the building. (Source: Keohan, Thomas G. (July 1989). “Historic Interior Spaces No. 2: Preserving Historic Office Building Corridors”. Preservation Tech Notes. (Washington, D.C.: National Park Service). p. 2.)
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ThyssenKrupp recently unveiled a world first: “The world’s first rope-less horizontal-vertical elevator system” at first this name sounds a bit far-fetched. It reminded me of euphemisms like “The tallest building in the western hemisphere” which is an award given to the One World Trade Center.
However, the elevator called Multi, is indeed quite game changing and could have a chance to have the same impact on the real-estate industry as Elisha Otis safety locking mechanism had in 1854. Prior People did have no trust in using elevators, due to certain death if a cable broke. But his dramatic demonstration, in which he ordered an axeman to cut the only rope holding the platform he was standing on, convinced the public of his inventions safety. This safety locking mechanism was what allowed skyscrapers to boom in the late nineteenth century.
Why is the Multi as important as the invention of the save elevator?
- It can go sideways; this will allow all sorts of new shapes for skyscrapers.
- It will reduce waiting times for elevators drastically.
- It will make the construction of Mega-tall-buildings possible
Before I explain each of these promises, let’s briefly dissect how the Multi works.
In contrast to the elevators present everywhere today, the Multi does not use ropes. Instead it uses the linear motor technology originally developed for the Transrapid magnetic levitation train. Without going into to much detail, each cabin moves independently on a set of rails in the same fashion as a locomotive. This allows multiple cabins being in the same shaft at the same time. Thus more people can be transported simultaneously.
The rails are also what allows the elevator cabins to change from vertical to horizontal travel. This is achieved by turning rails 90°. If you want to see it in action, I recommend the following video:
Why will the Multi make the construction of Mega-tall-buildings possible?
First of all, the length of the rope used by conventional elevators is physically limited. The Multi however does not have this physical limitation. This would of course be possible to solve by making the passengers change into a second elevator when the limit of the first one is reached. However, there is a much bigger problem with conventional elevators, that drastically influences the height we can build at the moment. Because each elevator shaft can only be used by one cabin, the higher the building the higher the number of elevators needed. This leads to a point of height where most of the tower consists of elevators, and that surely can’t be economical. ThyssenKrupp claims that the Multi cuts the Space needed for elevators in half. That would make the dream of Mega-tall-buildings possible.