Hey everyone, Justin here. Today, we're going to be talking about something that was done
that people thought couldn't be done. But they were wrong! You know, like
taking pictures on the surface of Mars, that can't be done! It was done. Or flying in the sky like a
bird, that can't be done! It was done. Or even going to the top of the world, the North Pole,
it can't be done! But it was done. Or how about cleaning your room? That can't- Well,
actually I don't know if that was done. Maybe you should check that out after this video, huh?
But before we get into the video, before we learn about another impossible thing that was done,
let's do a little quiz, shall we? Can you tell me what all of these words have in common?
Draw, covered, beam, cantilever - I know there's a big word, cantilever - and suspension.
Here's a hint: here to there, there to here, up and over, and across.
Think you know it? These are all types of bridges! Here's a drawbridge,
there's a covered bridge, a beam bridge, a cantilever bridge, and a suspension bridge.
There are other kinds of bridges too, but today we're going to be talking about one
particular bridge. A very long, very well-known, very busy, suspension bridge. One that was called
the Impossible Bridge. Stay tuned as we learn some cool facts about the Golden Gate Bridge!
The Golden Gate Bridge is a national landmark in the United States. A national landmark can be a
statue, or a monument, a building. It could even be an area of land or even a bridge.
It becomes a national landmark when the United States government decides that it represents an
important part of America's history. Today you'll discover why people often refer to the bridge
as the Impossible Bridge. People just thought, "There's no way they're gonna build this bridge,
they're nuts!" So let's go back to the beginnings of the bridge, figure out why it was built,
and who wanted it in the first place. To do that, we go to the state of California.
This area here is where the San Francisco Bay meets the Pacific Ocean. This is a small
channel of water that's only about a mile wide. It was already known as the Golden Gate. But, at this
time the only way to get there was by ferry across the water. People would drive their cars onto the
ferry, and then ride the ferry to San Francisco. Cars are becoming pretty popular around this time,
but even back then, there was some congestion. The ferries were crowded and so were the roads since
people got in their cars to drive to their destination. Trying to solve these issues,
the head engineer of the city of San Francisco said "There's got to be a better way.
Let's see if we could try building a bridge across the water to make this whole thing easier."
So in 1921, he contacted an engineer in Chicago named Joseph Strauss. People were excited about
the possibilities of new jobs and easier travel. But, like with all new ideas, not everyone's going
to be all for it. Some people just didn't want a bridge altogether. They argued that it ruined the
natural beauty of the bay. They said it would get in the way of large ships trying to pass through.
What would happen if there was an earthquake, huh? And by the way, not really the best place
to build a bridge - there's fog so often here, you wouldn't be able to see half the time! Like
here's a picture of the Golden Gate Bridge with fog covering
all of it! I can see why that's a concern. And finally, the ferry companies
hated the idea. This bridge would basically ruin their businesses.
Regardless, Joseph Strauss got to work coming up with ideas and exploring possibilities to
see if he really could build a bridge here, or if it was all just a dream.
Tell me this, have you ever been like working on a homework assignment
and you're really not feeling it and after half an hour you're just like, "Man,
I'm done! It's good enough!" Well, Strauss kept searching and exploring possibilities for 3
years and then, it took him 10 years to convince people that his bridge could work.
Now, people had some very good reasons to be skeptical about this bridge.
Let's take a look at the area again. First off, the waters here are deep - 372 feet
deep. It's also located on a fault line. That means it's at high risk for earthquakes.
Like that! Up above the area has strong powerful winds, and below the tides are
treacherous - waves crash against lots of big huge rocks. And I mentioned this before fog.
Lots and lots of fog everywhere, so thick that you can't see two feet in front of your own nose.
But, Strauss had a plan. He got the go-ahead and construction finally began
in 1933. His first design was a combination, a kind of a hybrid between a cantilever bridge and
a suspension bridge. But he had to scrap that idea because people thought it was ugly and it wouldn't
work well. So, he instead decided to go for a pure suspension bridge. Another great example of having
to rework, rethink, and revise your ideas. Not everything is perfect the first time around. Now,
keep in mind we're in the 1930s now. These times were of great economic hardship,
thanks to the Great Depression. So it was hard to raise money to build the bridge. However, Strauss
personally went to the president of a large bank and got him to commit several million dollars. In
the end, building the Golden Gate Bridge cost 37 million dollars. Now that's a lot of money! But,
if it was built today, it would have cost about a billion dollars. Yeah, billion! With a b!
Remember, a lot of people were out of work during this time.
So, they jumped at this opportunity. The construction crew for the bridge was made up of
people who had never done this kind of work before - cab drivers, farmers, clerks, shop owners,
and many more people who were in need of work were now iron workers, cement mixer operators, and
other members of the construction crew. Because the waterway was so treacherous, these people
risked their lives to build this bridge. So, some important safety measures had to be created.
This was the very first construction project to install a safety net, something that's common
now at construction sites. And thank goodness it was, because at one point during construction,
the net saved 19 workers from plunging down into the rocky dangerous water below.
It was also the first project to have workers wear hard hats. And it's also the first time
a construction project used cement mixer trucks like the ones you see today. That's not really
a safety issue, but it's pretty interesting! Another first, this was the first bridge support
built out in the open ocean. How do you do that? Like where do you even begin with something like
this? Well, the Bethlehem Steel Company provided a lot of the steel that was used in the construction
of the bridge. They would start with assembling the pieces, just to make sure that they fit,
and then take them apart and load them onto trains. There was so much steel - nearly 70,000
tons of it - that it took miles of railway cars just to move it all to the docks
where it was then loaded onto ships. Then, those ships would sail down the east coast
through the Panama Canal and back up the west coast into California.
One of the first stages of construction of the bridge involved experienced divers. They would
dive deep, 90 feet deep, into raging ocean currents just to get to the bottom where they
would blast away at the rocks there. Then, they built sturdy foundations into the sea floor. Then,
they built huge towers used to hold up the bridge on top of those foundations. The construction of
the towers themselves took two years to complete. How does a suspension bridge work, you may ask?
Well, the cables, towers, and suspenders basically all work together to help keep
the road that's in the middle of the bridge up and supported. The roadway is connected to the cables,
and the cables are connected to the towers on either end of the bridge. We could do a
whole video about bridges and how they work, but let's stay on topic here. The Golden Gate Bridge.
Each of these bridge's cables is made up of 27,000 small steel wires,
each about as thin as a pencil, and they're all spun together to make one big, back supporting
cable. Taking into account all these little wires, this bridge consists of over
80,000 miles of wire. These are the biggest cables ever built. In fact, if you took all the wires and
stuck them end to end, you can wrap it around the Earth three times! Construction crews also added
shock absorbers to both sides of the bridge in order to help it survive the force of an
earthquake, or of huge winds. Then, the roadway had to be built. Don't forget, this is a bridge
that people are going to drive across, right? In order to keep the weight of the bridge balanced,
construction started on both ends of the bridge, moving forward and forward until finally meeting
up in the middle. Then, concrete was poured into that framework to make the actual road.
When the bridge was finished, it was painted with a reddish-orange sealant to protect it from water
damage and the public was in love with that color. It looked great and helped the bridge stand out in
the heavy fog. So, when it came time to pick out a paint color for the finished bridge, designers
went with that orange you can see today, called International Orange. The completion of the bridge
took just under four and a half years to do. Let's jump forward to the year 1937 now. The roadway
for the bridge has just been completed, and the bridge itself is finally opened to the public.
Just for pedestrians on that first day, though. That means it's only for people to walk across.
And over 200,000 people who came out that day did just that - they got to walk across
this beautiful, majestic bridge. It was quite the celebration! The very next day
President Franklin Roosevelt opened the bridge to cars and the rest of the world.
The impossible had been achieved - the bridge that could never be built was built! The Golden
Gate Bridge was the longest suspension at the time of its building, and it held that title for almost
30 years. The Golden Gate Bridge is 2 miles long and about 90 feet wide. The towers themselves
are 750 feet tall. The Golden Gate Bridge was actually the tallest bridge of any kind until
1993. The Golden Gate Bridge survived an earthquake in 1989, and in 75 years of operation,
it's only been closed 3 days due to weather conditions. It's currently the most photographed
bridge in the world. It's been noted as one of the Seven Wonders of the Modern World, and it comes in
second on the list of the top 10 most impressive construction achievements of the 20th century.
It is truly a testament to American ingenuity, progress, and modern engineering. That bridge
is out there every day being bombarded with the hot sun, the rain, the humidity, the salt from
the ocean, and of course, the moisture from the fog. Did I mention how foggy it gets over there?
The roadway sees about a hundred thousand cars each day, and there are over a hundred
people whose work revolves around the Golden Gate Bridge. They help keep the bridge safe.
They look for rust, they paint over the bridge, and they also repair the cables and roads!
Oh my gosh, can you see the workers that are just on that cable? Visitors to the bridge
can also visit their visitor center to learn more about this amazing national landmark.
This bridge that couldn't be built, despite the tides, the winds, the rocks, the fog,
the earthquakes, is now an iconic landmark that's famous across the world.
There's so much more about the Golden Gate Bridge that I didn't get to cover in today's video.
It's probably a good idea for you to do your own research and see what kind of cool things
you can discover about this amazing structure!
That's it for today, friends! See you soon, and in the meantime, remember to always be clever!