The first skyscraper ever built was the Home Insurance Building, Chicago. Built between 1884 - 1885, it stood at 10 stories and 138 ft tall.
Impressive at its conception, 120 years later we live under the shadow of the Burj Khalifa, the tallest man made structure in the world. 160 stories and a whopping 2,717ft tall, how did we get here?
Well, we’re going to break it down for you.
"120 years later we live under the shadow of the Burj Khalifa. So, what innovations got us to this point?"
First up, previous to the Home Insurance Building in 1885, we had the Equitable Life Building in New York. Built in 1870, although it does not meet the criteria of a minimum of 10 stories, it is the first sign of skyscraper technology in construction history.
Equitable Life was a 7 storey office building with one extra special detail. It was the first office building with an elevator.
Why was this so important to the development of the record breaking structures we live beneath now?
Well according to the architectural historian, Professor Andrew Dolkart, back in the 1800s if you were a business on any floor above the 3rd or 4th you would lose out on custom because of the amount of stairs customers would have to climb to get to you.
Makes perfect sense to us!
So, when Equitable Life was designed they knew they would need an elevator. At this time, elevators had the potential to be incredibly dangerous. If the rope broke there was nothing stopping passengers plummeting to their deaths. That is until the incredible Elisha Graves Otis invented the world’s first automated safety elevator.
How did it work?
Using a powerful wagon spring mounted on top of the cab connected to a set of prongs on either side of the elevator. These ran along guide rails fit with a row of teeth. If the rope breaks, the spring relaxes and forces the metal prongs in to the teeth, locking the cab in place.
"If the rope breaks, the spring relaxes and forces the metal prongs in to the teeth, locking the cab in place."
This completely revolutionised architecture in cities across the US and the rest of the world. Suddenly higher floors could be rented at higher rates, more space was being used and our buildings could reach higher and higher.
Previously, buildings had been made almost exclusively out of stone. This made taller structures incredibly complex as the stone was so heavy it meant lower floors needed walls up to 2 meters thick. Not only this, in some cases it meant that buildings would sink in to the ground!
"In some cases buildings were so heavy it meant that buildings would sink in to the ground!"
What could be done about it?
An architect who had dealt with this problem previously, Daniel Burnham, was commissioned to design a building in a small plot in New York City. The famous Flatiron Building.
To build in this small space with stone would have been impossible without making the ground floor increasingly smaller. He came up with the idea of a steel skeletonfor his 22 story project.
You’re probably thinking:
“But, wait, the Flat Iron looks like it’s made of stone, not steel.”
The steel columns and beams making up the skeleton of the building had a thin layer of masonry hung over it’s sides like a curtain.
This meant we could make taller and taller buildings without compromising the foundations they are built on or space for residents on the lower floors.
Construction is a complicated process at the best of times, so, at 160 stories, there is potential for incredible difficulty.
"This meant we could make taller and taller buildings without compromising the foundations."
This takes us to the next set of construction innovations.
"The 110 floor Twin Towers at the World Trade Centre in New York, at completion were the tallest of their kind in the world."
The 110 floor Twin Towers at the World Trade Centre in New York, at completion were the tallest of their kind in the world. This meant that engineers had to get creative with how they planned to make it happen.
By having sections of the building’s facade prefabricated elsewhere, this would massively speed up construction and save workers dealing with complicated and potentially dangerous work.
But now we need a way of getting those pieces so high up.
Time for the Kangaroo Crane to jump on to the scene
Invented in Australia, these cranes could lift up to 50 tonnes and fit comfortably at all four corners of the building and thus reach every part of the project. Once each of the cranes had completed around 3 floors worth, the bottom of the crane would unlock and slide upwards before locking again. Then, the rest of the crane would slide up to meet itself. Essentially jumping up another level.
"The combination of engineering and creativity, along with blue sky thinking has taken construction and skyscrapers to incredible new heights."
The future of the skyscraper is a bright one. Already in the pipeline we have an incredibly ambitious project from the designer of the Burj Khalifa, Adrian Smith.