It took high-tech inventions to give us our biggest buildings
By BILL WIIST
Special to The Courier-Journal
One of the best things about going to a large city is seeing the buildings.
Some are old and some are new. Some are plain and others are fancy. Some are
stubby, and some stand so tall they seem to scrape the sky.
Skyscrapers, as we call our tallest buildings, have been around for more than
a century. But those early models would hardly rate today.
The tallest buildings were only 10 floors high, but back in 1885 someone in
Chicago, dubbed them ‘‘skyscrapers.’’ People have been using the term
ever since.
TRUE TALL TALES
New technologies have helped people build taller and taller structures. Steel
is one such invention.
Before steel was invented, a building was supported by its outside walls. For
a building to be taller, the walls at its base had to be bigger to support the
extra weight. This is why the tallest structures in the world for a long time
were the Egyptian pyramids.
Architecture changed dramatically when steel was invented in the 1860s. Steel
is a strong, light metal made by adding carbon to iron. With the invention of
steel, people were able to make a strong framework that could support the
weight of a tall building. This steel ‘‘skeleton’’ is what makes
modern skyscrapers possible.
When people first began building skyscrapers, they covered the steel frame
with stone, but now you can find skyscrapers with stainless steel and glass
exteriors.
Why? Remember: a skyscraper is not like your house. Outside walls support your
house, but internal steel frameworks support a skyscraper. The outside walls
of a skyscraper are just its ‘‘skin.’’
A RIDE TO THE TOP
Another crucial invention? The elevator.
Think about it. Would you want to climb 10 to 100 stories of stairs every day
at work? Fortunately, Elisha Otis invented the first safe elevator in 1852.
In 1857, a very slow-moving steam-powered elevator of his design was installed
in a five-story New York City china shop. By 1903, the first modern electric
elevator was in New York’s Beaver Building.
Today, elevators such as the ones in Japan’s Yokohama Landmark Tower go up
and down as fast as 28 miles per hour.
New heating and plumbing techniques also played an important part in the
development of skyscrapers. Since it’s cooler the higher up you go, you need
heat to be pumped up to you to keep warm in the tallest skyscrapers. Also, you
need a way to pump water up many hundreds of feet above the ground — unless
you don’t mind having bathrooms only on the ground floor.
ARE SKYSCRAPERS SAFE?
Skyscrapers today are carefully designed so they will survive every kind of
disaster: earthquakes, fires, strong winds, even colliding airplanes!
Before a skyscraper is ever built, careful consideration is given to its
foundation. A skyscraper can be in a lot of trouble without a firm foundation.
Have you ever heard of the leaning Tower of Pisa? Ever wonder why it’s
leaning? It wasn’t originally that way. This old building has been slowly
tilting through the centuries because it wasn’t built on a firm foundation.
One reason New York has some of the world’s tallest skyscrapers is because
the island of Manhattan is made of solid rock — just the kind of foundation
you want for a skyscraper.
To make a foundation extra firm, steel rods called ‘‘piles’’ are
driven into the ground with a machine called a pile driver. Piles serve as big
nails that grip firmly into the ground. On top of these piles is laid a
concrete platform.
There’s no need to be afraid if you are in a skyscraper today during a
storm. They can take it! In 1945 a B-25 bomber flew straight into the 72nd
floor of the Empire State Building. It caused some damage, but the
building’s structure remained sound.
When you are up in a skyscraper you may feel it sway. Don’t let that scare
you! According to Robert Grubbs, a local skyscraper enthusiast, “Tall
buildings sway back and forth in high wind, some as much as 3 to 5 feet at the
top.” He goes on to say, “Skyscrapers have to have some amount of sway
built into them or they would eventually crumble and fall.” But what if you
don’t like to sway back and forth? Not to worry. Grubbs says some buildings
are built to counteract this problem. “Some buildings have mass dampers
installed at their top. When the building moves, a 400-ton block of concrete
riding on an oiled plate hesitates and then moves in the same direction.
Working on the principle of inertia, the damper reduces the buildings sway
almost 50 percent.”
WHY BUILD ’EM SO TALL?
One reason skyscrapers are built is because cities are crowded and land is
very expensive. To make more space, people are forced to build up rather than
out.
A second reason: one big building full of people can use less energy and
produce less pollution than many small buildings containing the same number of
people.
Finally, skyscrapers allow big companies to keep all their office staff under
one roof. Much more efficient, don’t you think?
TWO OF THE TALLEST
If you’re ever in Chicago, visit the Sears Tower. It is the tallest
skyscraper in America, standing 110 stories. The Sears Tower is so big it has
its own zip code.
The tower is like a small city. How many people work there every day? Nearly
17,000!
If you go, you can take a tour to the top and see all of Chicago. Along with
the view, you can also take in all sorts of interesting statistics about the
Tower and how it was built.
Of course, you don’t have to go all the way to Chicago to see a skyscraper.
If you live in Louisville, you can see many skyscrapers around you.
The Aegon Tower is the tallest in Louisville. It stands 34 stories high. You
can easily recognize it in the Louisville skyline — it is the building with
the dome
on top.
Sources: ‘‘Skyscrapers’’ by Andrew Dunn; ‘‘Skyscrapers and
Towers’’ by Chris Oxlade.