June 10 – The Millennium Bridge Opens

Posted on June 10, 2015

It was the year 2000 – and people couldn't help being inspired by all those zeroes, and a whole new “millennium” (thousand years) beginning.

Many nations and major cities had projects that could be unveiled that year, and London in the United Kingdom was no different:

• It opened the Millennium Dome, with a major exhibition called the Millennium Experience on display for the entire year 2000.

• It opened the world's tallest Ferris world, the London Eye (aka the Millennium Wheel).

• It opened the Tate Modern, a modern art gallery.

• And it opened the Millennium Bridge!

The bridge was not designed for cars. Well, actually, it sort of WAS designed for cars, and that was a problem, because it should have been designed for people on foot. It was, after all a footbridge.

Let me explain:

The Millennium Bridge was the first new crossing of the River Thames in over 100 years. People could cross by foot from the Globe Theatre and the Tate Modern over to the City of London School and St. Paul's Cathedral, or vice versa.

However, the builders used computer software typical for a car bridge in designing this footbridge. People walking and cars driving are different sorts of movements, and the bridge developed an unexpected “wobble” that caused people to walk “in step” with one another (without meaning to), and the people walking in step with one another caused the wobble to increase!

This was not only unexpected, it was potentially dangerous. The bridge was closed, and structural damping was added. The bridge was re-opened in 2002.

So, even though the bridge had been designed to hold up to 5,000 people at one time, just 2,000 people actually walking on the bridge (which, after all, was the whole point) became very uncomfortable...more of a “white knuckle ride” than we want to experience in a bridge!

But don't worry. Next time you go to London, feel free to use the Millennium Bridge – it's all fixed now!

Also on this date:

Anniversary of the first University Boat Race  

Author/ illustrator Maurice Sendak's birthday 

Abolition of Slavery Day in French Guiana 

Portugal Day (a.k.a. Camoes Day)

Anniversary of the invention of the “outlook envelope”

Turtle Days 

Plan ahead:

Check out my Pinterest boards for:

• June holidays
• June birthdays
• Historical anniversaries in June

And here are my Pinterest boards for:

• July holidays
• July birthdays
• Historical anniversaries in July

March 19 – Sydney Harbor Bridge

Posted on March 19, 2015

Happy birthday to a bridge?

Sure! Why not?

This arched bridge is iconic and, along with the nearby Sydney Opera House, gains instant recognition among millions of people all over the world as being in Sydney, Australia.

Some people call it “The Coathanger,” because of the arched design, but Sydneysiders generally just call it “The Bridge.”

From the date the bridge was opened on this date in 1932 until 2012, it was the world's widest long-span bridge, and it remains the sixth longest spanning-arch bridge and the Number 1 tallest steel arch bridge in the world.

When you see an arched bridge, do you ever wonder how on earth engineers manage to make it? Here are two things that helped make the Sydney Harbor Bridge:

• Tunnels were dug on each shore. Steel cables passed through these tunnels and attached to the top portions of each half-arch to stop them from collapsing as they extended outwards towards one another.

• “Creeper cranes” were erected on each side of the bridge. These cranes were fitted with a “cradle” that could lift materials and men into position. Then the cranes would “creep” along the arches as they were built further and further out across the water, slowly closing the gap between.

The Sydney Harbor Bridge was begun in July of 1923. Finally, in August of 1930, the two halves of the arch finally touched each other. The bridge was completed in January of 1932.

You may wonder why the bridge builders waited two months before opening the bridge.

But of course the bridge had to be tested!

On January 19, 1932, the first test train safely crossed the bridge. In February, 96 steam locomotives were positioned end-to-end on the tracks for a load test. 

Eventually, after three weeks of testing, the bridge was declared safe for use, and the work sheds were demolished and the area cleaned up to get ready for the official opening.

You know how opening ceremonies are, right? They're....ceremonious!

Dignitaries were invited, people gave speeches, and there was a lovely ribbon ready for the Labor Premier of New South Wales, Jack Lang, to cut.

The "some guy in a military uniform"
turned out to be a man named Francis
de Groot.
Presumably he did NOT say, "I am Groot!"

Just before Lang cut the ribbon, though, some guy in a military uniform rode up on a horse and slashed the ribbon with his sword, apparently declaring the bridge open in the name of ordinary people.

The man was arrested, the ribbon was retied, and Premier Lang cut it again—and the bridge was officially open.

Also on this date:

Artist Betty Goodwin's birthday  

Saint Joseph's Day in Valencia, Spain

Battle of March 19 in the Dominican Republic 

Swallows Day at Mission San Juan Capistrano

Anniversary of the discovery of electric eels

Plan ahead:

Check out my Pinterest boards for:

•  March holidays 
•  March birthdays 
•  Historical anniversaries in March

And here are my Pinterest boards for:

• April holidays   
• April birthdays 
• Historical anniversaries in April

July 9 – Happy Birthday, Charles Bridge

Posted on July 9, 2013

Every once in a while, a bridge collapses. One just collapsed a couple of months ago in Washington state—luckily, only three people suffered minor injuries, and nobody died. The bridge was called “very, very old” in a newspaper report. I had to dig around a lot to find out how old you have to be to be called “very, very old”—and I finally discovered that the bridge was built in 1955.

Which means that I am older than the bridge!

Today's “birthday bridge” is a fair bit older than that bridge in Washington. As a matter of fact, the construction of it began on this date in 1357!

Which means that the bridge is even older than me! 

Actually, it means that the bridge is more than 650 years old!

Now that's an old bridge!

The Charles Bridge crosses the Vltava River in Prague, in the Czech Republic. It is 621 meters long and nearly 10 meters wide (more than 2,000 feet long, and almost 33 feet wide). The bridge rests on 16 arches and is protected by three bridge towers. 

There are 30 statues decorating the bridge at spaced intervals.

I don't want you to think that the bridge has lasted all these centuries without any need for repairs! Quite a lot of the problems the bridge has encountered damaged or toppled the statues—this happened, for example, when Swedes battled the locals on the bridge, during the Thirty Years' War. Other problems occurred during huge floods, when trees and rafts were swept from upstream into the bridge's pillars. The bridge withstood many floods, but part of it collapsed in 1432 and again in 1890 during particularly disastrous floods. Most of the bridge has been reworked and stabilized, and missing statues have been replaced with replicas.

This primer on Prague lists Charles Bridge as one of the top ten things to do and see in the city. 

By the way...

Today isn't just the anniversary of the day that construction on the bridge started—it's the anniversary of King Charles IV himself laying the first stone of the bridge at exactly 5:31 a.m. Why at that very early hour, you might ask? Well, Charles IV was superstitious and believed that numerology could help keep “his” bridge safe. He said that the date and time 1357 9, 7 5:31 built a bridge of numbers to support the actual bridge. Obviously, Charles IV's “number bridge” starts with the year, the the day, month, and time. This creates a sort of palindrome of odd numbers. (A palindrome is something that reads the same backwards and forwards, such as “A Toyota's a Toyota,” “A man, a plan, a canal, Panama!” and “Step on no pets.” In this case, it is an arrangement of numbers that reads the same either direction, like 3941493.)

Also on this date:

Inventor Elias Howe's birthday 

Independence Day in Argentina

Anniversary of the settling of Romanov rumors through DNA testing

Plan ahead:

Check out my Pinterest pages on July holidays, historical anniversaries in July, and July birthdays.

And here are my Pinterest pages on August holidays, historical anniversaries in August, and August birthdays.

January 5, 2013 - Golden Gate Bridge Begun

– 1933

It couldn't be built, some experts said. And if it were built, it wouldn't last. A bridge across what was termed the “golden gate” to San Francisco Bay certainly couldn't stand up against the vigorous tides, swirling currents, and strong winds common in that area.

But it was a terrible hassle for people living in San Francisco to drive all around the bay to reach the land just 6,700 feet (some 2,000 meters) away to the north, which is now Marin County. Instead of driving all that long way, people had to take a ferry boat—carefully driving their cars onto the ferry, traveling for about half an hour across the water, and then driving off again as they reached their destination.

People wished that it was practical and affordable to build a bridge!

Well, some people wished for a bridge. The owners of the Southern Pacific Railroad were dead-set against building a bridge, because they also owned the ferry service, and it was very profitable. Very, very profitable—after all, they had a monopoly...people who wanted to go from San Francisco to Marin County, or vice versa, didn't have too many choices!

When a dreamy, ambitious engineer named Joseph Strauss promised the city of San Francisco that he could build an affordable bridge across the strait, the railroad company opposed the project and even brought a lawsuit against it.

So people boycotted the ferry service. That means that, even though they would normally use the Southern Pacific's ferries—even though they wanted to and needed to use the ferries—they didn't use them, in order to make a point. The point was this: We want a bridge. And if you prevent us from getting our bridge, we won't use your ferry service.

The massive boycott worked. A few pro-bridge court rulings plus a state law later, planning went forward, and construction began on the Golden Gate Bridge on this date in 1933.

Hooray for poets and dreamers!

Joseph Strauss, head engineer of the Golden Gate Bridge, was also a poet and was even class poet at his university. He is credited with building more than 400 bridges around the world; after the Golden Gate Bridge was complete, he wrote his most famous poem, “The Mighty Task Is Done.”

At last the mighty task is done;
Resplendent in the western sun
The bridge looms mountain high;
Its Titan piers grip ocean floor,
Its great steel arms link shore with shore,
Its towers pierce the sky.

On its broad decks in rightful pride,
The world in swift parade shall ride,
Throughout all time to be;
Beneath, fleet ships from every port,
Vast land-locked Bay, historic fort,
And dwarfing all--the sea.

Launched 'midst a thousand hopes and fears
Damned by a thousand hostile seers
Yet ne'er its course was stayed
But ask of those who met the foe,
Who stood alone when faith was low
Ask them the price they paid.

Ask of the steel, each strut and wire,
Ask of the searching, purging fire
That marked their natal hour;
Ask of the mind, the hand, the heart,
Ask of each single stalwart part
What gave it force and power.

An honored cause and nobly fought,
And that which they so bravely wrought
Now glorifies their deed;
No selfish urge shall stain its life,
Nor envy, greed, intrigue, nor strife,
Nor false, ignoble creed.

High overhead its lights shall gleam,
Far, far below life's restless stream
Unceasingly shall flow;
For this was spun its lithe fine form
To fear not war, not time, not storm,
For Fate had meant it so.

One of the best things I read about Strauss was that he came up with a way to use movable safety netting beneath the construction site. This innovation was credited with saving 19 workers' lives. (Unfortunately, 10 workers died when the netting failed under the stress of a fallen scaffold, and one more died in another way.) But the death toll from falls would have been 30 rather than 11!)

Also on this date:

Bird Day 

Anniversary of first woman governor in the U.S.

Birthday of Aaron Lapin, the “King of Whipped Cream”

October 20, 2012 - Bridge Day

Have you ever wondered how people build bridges? How do you start? Do you build from the bottom up, or from the top down? How do you start to reach from side to side over treacherous waters or a deep chasm?

The Niagara Falls Suspension Bridge is an early example of a bridge that allowed pedestrians, carriages, and trains to cross a wide river—as a matter of fact, it is the world's first working railway suspension bridge. And that first step—the laying of the first line across the wide and turbulent Niagara River—was accomplished by flying a kite!

The builders were stumped because the water was so turbulent that the rapids were called Whirlpool Gorge. They didn't think a boat could take the first wire across the river to start the bridge. Someone suggested shooting a rocket attached to a wire, or some sort of bombshell with a wire, shot out of a cannon. But one many suggested offering a cash prize to the first child who could fly a kite over the gorge.

A 15-year-old boy named Homan Walsh won the prize (either $5 or $10—accounts vary) by flying a kite from the Canadian side of the gorge. Eventually, when the winds subsided, his kite descended and got caught in a tree on the American side. The day after this contest-winning flight, a stronger line was attached to the kite string; a rope followed, and then a cable made of wire.

Next, the builders created a temporary suspension bridge across the Niagara River. They used that temporary bridge to build a better, stronger, permanent bridge.

I've always wondered how bridge builders create those supportive towers in water. I found out that, in the olden days (such as the days of the Roman Empire), huge boulders were piled up in the water, and the bridge was built on and secured to the boulder piles. Later, builders would lower a caisson, which is a huge cylinder made of steel and concrete, into the water and onto the river-, lake-, or seabed. The water was then pumped out of the caisson. At this point, the caisson became a sort of circular dam that kept water away from workers and equipment. Since the 1930s, bridge builders generally float enormous metal caissons to the designated spot and then sink the caissons by gradually filling them with concrete and water. Divers are on hand to make sure that the sinking caissons settle on the right bit of ground.

To learn more about building bridges, check out the Worsley School Building Bridges page. Also, check out the Official Bridge Day website.

• Also, this earlier post deals with a bridge disaster, 
• this earlier post discusses cantilever bridges, and 
• this earlier post links to some fun bridge experiments. 

Also on this date:

Architect Christopher Wren's birthday 

Baseball great Mickey Mantle's birthday 

November 7, 2011 - Suspension Bridge Collapses

One morning (November 7, 1940, to be exact) the Tacoma (Washington) Narrows Suspension Bridge began to sway in a 40 mph (65 kph) wind.

This slender, graceful bridge, one of the longest suspension bridges in the world at the time, had only been open to traffic for four months.

A newspaper editor named Leonard Coatsworth was driving over the bridge when the swaying became so violent that he lost control of the car. He jammed on his brakes and tried to get out. He was flung to the ground, and his face hit a curb. Hearing concrete cracking all around him, Coatsworth couldn't get onto his feet—so he crawled desperately back toward the toll plaza.

He thought he was a goner.

Fortunately, Coatsworth was able to crawl about 500 yards to the towers. He was gasping for breath, and his knees and hands were raw and bleeding. He finally was able to get to his feet and run—although he had to start-and-stop with the swaying—and he finally made it to safety.

Unfortunately, Coatsworth had been taking his daughter's black cocker spaniel back to her house when this happened, and the terrified dog didn't follow him to safety. There was a lull in the wind, and two other men—an engineering professor and a news photographer—risked their lives trying to rescue the dog. However, the dog still refused to leave the car, and in its terror, it even bit one of his would-be rescuers. The bridge began to sway violently again, and the two men lurched back to safety without the dog.

Several people filmed the disaster with motion picture cameras, and as Coatsworth and others watched, the bridge broke apart, and bridge and car fell into the water. The dog's body was never recovered. No human life was lost.

Because it happened more than 50 years ago, it seems crazy that we have great film on the collapse of the bridge, but we do—in color!—and here it is.

Engineers learned from the bridge's collapse and were able to make later bridges safer. Try your hand at bridge engineering on this Nova website—where you will find info and a bridge-building game!