Original subtitles

They were once the most advanced buildings and structures on the planet.

The best achievements in design and construction .

Today they are abandoned, polluted and dead.

Spanning the widest rivers and deepest valleys,

bridges have always been the last word in technology.

In this series, we travel to the mountains of the Colorado desert

and we'll find out why a hidden technological wonder can disappear at any moment.

The Goat Canyon flyover is an amazing engineering feat.

It's straight out of the Wild West.

A classic piece of American history has been left in the wilderness.

We ask why a piece of concrete bridge in a Czech reservoir

is known as the Hitler Bridge?

The story becomes clear when all the water is removed from under the bridge.

Hitler's goal was to fuse together all the parts of the emerging empire,

but the army also had to be able to move quickly

to that part of the Reich that was currently in danger.

We learn how the world's tallest bridge collapsed in a minute.

The bridge took the wind and began to move.

Looking at the ruins of the bridge, it becomes clear,

how strong and ductile steel really is.

Plus we reveal the story behind Cape Town's 'Invisible Bridge'.

No vehicle has crossed this bridge .

The purpose of the bridge was to carry the wealthy laborers who worked in Cape Town to the end of the day

high above the "undesirables" into their suburban luxury homes.

Abandoned Buildings

Lost Bridges

High in the mountains of Southern California near the Mexican border

stands the Kitsekanjon flyover bridge.

The huge structure dominates the surrounding landscape.

This is no ordinary railway bridge

Kitsekanjon overpass is the largest curved wooden structure in the world.

Before dawn, the Southwest Railway Museum team sets up

ready to inspect this record-breaking structure.

They face a grueling 27-kilometer journey

along a railway line closed to traffic.

A structure awaits them, which took the last from the builders.

It is now abandoned and its time is running out.

At first glance, the Kitsekanjon overpass is a very impressive sight.

This huge structure looks so complicated.

It is one of the largest surviving arched wooden structures in the United States.

It's a brilliant idea and it's amazing that it's still standing.

In 1932, a small army of workers erected

camp in a remote Colorado desert canyon.

The conditions were brutal

there was no water for miles and nothing to protect from the sun.

Their task was to repair the railroad connecting San Diego with the United States.

The collapsed tunnel had to be replaced with a bridge, and it had to be done quickly.

Diana Hyatt, Director, South West Railway Museum,

is an expert on this railway line and the man who created it.

It all started with one man - John D. Spreckels,

who felt it was important for San Diego to have

rail connection to the eastern United States.

Southern California had a rail connection

and Spreckels believed that promoting San Diego and its natural harbor

will benefit business and the entire city.

John D. Spreckels was a San Diego millionaire businessman.

He was convinced that if you want people to live somewhere,

they must be provided with some form of transport,

which is convenient and most importantly - it must be cheap.

When Spreckels in 1907 Began work on the San Diego - Arizona Railroad,

the task was so difficult that it was called the "Impossible Railway".

The route crosses the most rugged terrain in North America .

The cheapest and seemingly craziest idea was this,

to descend into Mexico to avoid the altitude change.

The railway descends for 70 kilometers and rises again on the Mexican side at Linderos.

Next, the most difficult section of the railway was passed - the Carrizo gorge.

The Carrizo Ravine was a convenient gap between the mountains,

but building a railway there was extremely difficult and dangerous.

Only 22 kilometers of the line were built in 11 years .

Railway construction was accompanied by problems,

most of which was caused by instability in the region.

Some mountains are hard rock, some are composed of decomposed granite

and when the collapse begins, that it ends before everything is over.

Railroads had never been built in such hostile territory before.

In addition, there were problems with the construction of a railroad near the Mexican border.

Incident followed incident: there were kidnappings, there were killings.

The entire section of railroad between San Diego and Arizona was ready to collapse.

They did not build on hard rock, but on crumbled granite.

And to be there, knowing that the footing could disappear at any moment,

was not only absolutely terrible,

the fact that they completed the railway is absolutely incredible.

It was only in 1919 that Spreckels was able to drive a golden rail nail,

which showed that his 240 kilometer railway was complete.

However, success came at a price that was too high.

By 1919, he had completed the railroad at a cost of $18 million

and it nearly bankrupted him.

San Diego transpordiinsener Dan Davis

has studied the construction of the Impossible Railway.

They wanted to get by as cheaply as possible

and one possibility for this was the construction of a wooden overpass.

To my left is the collapsed 15th tunnel.

There is a large collapse area on this hillside .

The old railway line was about the top of the portal.

It was dug 5-6 meters lower.

The result is the admirable Kitsekuru flyover.

180 meters long and 60 meters high

it is the largest curved wooden structure in the world.

The Goat Canyon flyover is an amazing engineering feat.

The question is: was it really necessary? Or was it a product of its time?

The story was, "We can't make it from here , but we can do it."

Building in Goat Canyon must have been an absolute nightmare.

Look where it is - it is in the middle of the desert.

There is no water here, the temperatures are high here,

you build it with wood, which gets extremely dry here.

A little spark or a cigarette can set it all on fire.

These are extremely dangerous working conditions.

However, they got it done.

Building a trestle out of wood was the fastest way

to replace the railway line that was broken due to the collapse of the tunnel.

But this also meant that the flyover was in constant danger of fire.

It was threatened by wildfires , and the fire was also caused by the railway itself.

But the engineers had a solution.

Steam locomotives were more of a problem for tunnels because of the gases

the smoke rises and is absorbed into the wood of the tunnel.

Due to the road's 1.6 percent drop, the brakes caused problems.

Since it was necessary to brake for a long time,

the brakes heated up and hot pieces of metal came out of them,

which fell into the overpass structure.

There is a water tank connected to pipes above the overpass , which was supposed to

put out every fire threatening the bridge that cost $300,000 .

There was always a person waiting for trains crossing the bridge,

then turned on the faucet and started the sprinklers,

so that the hot brake pads don't set the bridge on fire,

without it the bridge would have been in great danger.

But out of ignorance, they added features that reduced the strength of the bridge.

Due to the 14-degree curve, the speed on the bridge is about 15 kilometers per hour.

In fact, it is a very sharp curve.

It is very difficult to maintain and very destructive to the structure.

Structures similar to Kitsekanjon's wooden trestle are flexible.

As you stand there and watch the big train rumble across the bridge,

then you can see the movement of the bridge parts, the movement of trestles and bars,

everything is meant to move. All this makes the bridge beautiful.

During movement, the stresses are dispersed and do not affect one point.

In fact, wood expands in heat and contracts in cold,

some types of wood dry faster than others,

thus, flexibility may be the cause of bridge disintegration.

The wood itself is still in good condition,

but all this movement has loosened the bolts

and they are no longer tightened, so the structure is no longer solid.

Despite the success of the engineers in Kitsekanjon,

the rail line between San Diego and Arizona was short-lived.

San Diego and Arizona Railroad hours in a bad way

as "slow, dirty and boring".

There were no air conditioners in the carriages, only steam locomotives were used there,

which suffocated with steam and gases when passing through the tunnels

and when the windows were closed the temperature rose to 40 degrees,

so it was not a pleasant ride in my opinion.

In some years there was a profit, in bad years money was lost.

When Hurricane Kathleen passed through the area in 1974

and swept away some trestles,

The Southern Railway Line finally decided to throw the spoon in the corner.

Abandoned Buildings

Lost Bridges

Abandoned Buildings

Lost Bridges

The Goat Canyon flyover is surrounded by barren mountains

hiding it from all travelers who are extremely indecisive.

In the heart of Europe is another hard-to- see bridge from the 1930s.

It is almost drowned in the reservoir of the Czech Republic.

And it is one of the most complex bridges of that time.

The Borovsko Bridge is called "Hitler's Bridge" by the local people.

Of course it's known as Hitler's Bridge.

It was to form an important part of the future Central European highway

and this was his vision,

how to fuse the different parts of the empire to be created,

but the army also had to be able to move quickly

to that part of the Reich that was currently in danger.

If millions of liters of water could be taken from under it,

the whole structure would begin to appear.

But as you can see, it is not visible. This is a hidden gem.

Engineer Petr Bily is committed to publishing this story.

At the time the bridge was built, Czechoslovakia was one of the few countries

where it was planned to build such wide roads.

The width of the bridge is 22 meters.

It is divided into two bridges.

Both bridges were to have two lanes.

Czechoslovakia's road-building program came to an abrupt halt in 1938.

That year, Hitler took advantage of the weakness of England and France

and sent troops to occupy the country.

Hitler targeted Czechoslovakia because

that there were very many ethnic Germans.

This was part of his attempt to bring the Germans back into the Great Reich.

But there were other factors,

such as Czech industry and especially its efficient arms industry

and Hitler knew that if he got hold of such equipment,

then it will be of great use to him in the coming war.

Hitler's engineers were already working on a huge new road network,

Autobahns were supposed to connect all corners of the Reich.

The highways are arranged in such a way that

which avoids intersections and other obstacles to traffic

and foreign experts consider them to be the safest roads in the world.

Bridges and flyovers span rivers and valleys

and the new national highway network connects all populated points in Germany.

Only seven months after the conquest of Czechoslovakia

they started building a bridge that had to carry

the bridge connecting the central part of the country with Prague and Berlin.

Czech engineers had to surrender their experience to the new masters.

The construction of the bridge began in 1939.

By 1942, most of the load-bearing structures were ready.

At the beginning, 800 construction workers were considered,

but in the end only 150 men were received.

There were some delays in construction,

however, it was still possible to finish all the load-bearing structures in two years.

A bridge over the Svihov valley near the village of Boroskovo

was 100 m high, one bridge arch stretched across the stream.

It was designed to carry the flow of traffic into the heart of Germany.

The bridge was straight, but there should be a bend behind the bridge,

so the bridge leans to the right side.

The bridge was designed for vehicles moving at a speed of 160 km/h.

To reduce the forces acting on cars ,

the bridge must be constructed slightly slanted.

This is not caused by foundation subsidence, that's how it should be.

Hitler's Autobahns weren't just for getting from point A to point B.

They were a matter of national pride,

they were supposed to say, "Oh, look at that crazy Autobahn,

it is used by vehicles that communicate with the Reich

and make us world leaders."

It was about dominance. That's what Hitler needed Autobahns for.

Germany demanded that roads and bridges be completed by 1943.

Despite shortages of labor, equipment , and even cement,

Borovsko's engineers used the latest technology at the bridge.

If you could remove everything around you and see the structure of the bridge,

then it is a reinforced concrete arch, which is a very common type of bridge,

but it was completed in the 1930s.

At that time, reinforced concrete was not used in such structures.

This shows how progressive Czechoslovakia was

in terms of its infrastructure technology.

Hitler began his invasion of the Soviet Union in June 1941

and in Czechoslovakia all work was suspended except that of the Borovsko Bridge.

Tons of concrete needed to build roads and bridges

was directed to the construction of huge defense systems.

Half-starved workers could have built Hitler's bunkers,

but the Borovsko bridge needed engineers, so the work continued.

There were no computers back then,

so everything was calculated with just paper and pencil.

Here we use a new material that gives integrity to the structure.

This is an arch bridge. Making complex shapes and forms.

It was a new technology, which at that time spanned the limits.

However, in May 1942, he was murdered by Czech agents.

Reinhard Heydrich , the hated leader of Czechoslovakia .

The assassination of Reinhard Heydrich, a member of Hitler's inner circle

sent a shockwave through the Reich that they were not invincible.

In fact, they were vulnerable.

As a result of Heydrich's murder, 13 Czechs lost their lives.

After the war, it seemed that Czechoslovakia was finally free.

The spring of 1945 meant the end of the war in Europe.

A return to peace for the independent republic of Czechoslovakia

and freedom they had not had since 1938.

Unfortunately, this freedom did not last long.

The Communists took over and like the rest of Eastern Europe,

this country also fell under the influence of the Soviet Union.

The Borovsko bridge could have been finished at last,

but the new regime in Czechoslovakia was not interested in the roads leading to the West

and once again the bridge was abandoned.

In the 1960s , the valley below the bridge was flooded,

to create a new reservoir for the city of Prague .

The bridge that was to become the link connecting Czechoslovakia to the Reich,

disappeared under the rising water.

Abandoned Buildings

Lost Bridges

Abandoned Buildings

Lost Bridges

Hitler believed that Autobahns would unite Europe,

but in the USA, the entire continent was connected by railroads.

Located in Pennsylvania's Kinzua Gorge, one of the world's largest railroad bridges

seemed like a triumph of American engineering.

At the time of its commissioning, the Kinzua Viaduct was the highest bridge in the world,

however, a hundred years later, a tornado exposed flaws in its design.

Looking at the ruins of the bridge, it becomes clear,

how strong and ductile steel really is.

When steel became abundant and cheap to produce,

it became the shiny new material that everyone wanted to build from

and in the case of the Kinzua Bridge, I even went so far,

that even wrought iron was replaced by steel.

The Kinzua Bridge became known as the eighth wonder of the world.

It was, in a way, the American Industrial Revolution

and this thing was so crazy.

For a few years it was the tallest bridge in the world

and one of the most admirable engineering achievements.

Northern Pennsylvania was an unlikely place for the eighth wonder of the world,

but that's what the Kinzua Viaduct was called when it was opened in 1882.

The bridge was supposed to carry coal trains bound for the Great Lakes

and was the tallest bridge in the world for two years .

But was the 90 m high and 610 m long structure suitable for the job?

At the time when the Kinzua Bridge was built - in the 1880s

wrought iron was used for such structures .

It was stronger and much lighter than stone or brick bridges

and it was much more flexible.

Wrought iron was typically used in that era

and looking at photos taken of the bridge at that time,

it looks fragile and narrow and thin. But it worked.

The speed of trains depends only on the power of the locomotive.

Even more, it depends on the weight of the train, the curves and the slope of the road.

We always try to make the railway line straight or flat,

where the rise is too steep, we cut a tunnel there.

Where the descent is too steep, we build a viaduct there,

which carries our train on stilts.

The wrought iron posts supporting the viaduct had a radical hollow design,

which provided sufficient strength without being heavy.

The pole maker, the Phoenix Bridge Company, claimed,

that, if necessary, the posts can also support a 300-meter-high bridge.

Kinzua Bridge construction of railway bearing towers

can be quite deceiving with its seemingly fragile legs .

The trick was that all the details, all the components of these towers

were put under pressure and wrought iron can handle it very well.

You will soon find out that trains will cross the viaduct

cause such a vibration through fine pillars ,

that their speed was limited to 8 kilometers per hour.

But was it possible to make the whole structure stronger?

Mainly coal was transported over the bridge

and when the Industrial Revolution took place in the United States,

business and trade demanded that it was necessary to transport coal

and the loads to be carried over the bridge became larger and heavier,

for the wrought iron forming the bridge to become more and more stressful.

So at some point it was decided to replace wrought iron with steel.

Iron containing carbon can have different proportions.

Cast iron, for example, is extremely brittle.

It could be compared to fluffy cookies,

wrought iron is again like a very soft chocolate chip cookie,

which are tender and soft when tugging

and steel is somewhere in between the two.

Both wrought iron and steel are made from iron ore.

They are made differently. Wrought iron is much more primitive.

When wrought iron is viewed under a microscope,

then it is quite grainy, it has defects,

it breaks when bent.

The steel structure is much more ordered.

If you try to bend it, it will bend

and bends quite a bit before breaking.

In 1900, the old iron pillars were taken down

and new steel structures were put in place .

When Canada fell in 1907. the second bridge built by the Phoenix company

and killed 75 workers, the decision seemed to be the right one.

However, in the rush to replace Kinzua 's iron beams , a fatal mistake was made.

Amazingly, 40 men were able to rebuild the bridge

in just 90 days. Imagine that for yourself.

But they got away with it by not replacing the anchor bolts.

The towers were redone from top to bottom,

giving the bridge the ability to carry larger loads.

But they left one component unchanged,

which is probably one of the smallest components of the bridge

anchor bolts that hold the towers to the ground.

Wrought iron anchors remained at the foot of the bridge ,

which was not enough to hold the steel bridge to its foundation

and the wrought iron was connected to the steel with a spacer.

Engineers not only replaced wrought iron with steel,

1902 the entire bridge was renovated, some improvements were made,

among other things, was installed at the foot of the eastern towers,

where the winds mainly blew, small camps,

which were supposed to add more flexibility.

With them, winds hitting the bridge affect the towers less,

bridge details and anchors that hold the bridge to the ground.

The Kinzua Bridge operated for the next 50 years,

until local coal supplies ran out.

The bridge was sold for scrap in 1959 and salvaged,

when the Pennsylvania Union turned it into a tourist attraction.

In the 1960s it was very unusual to take a rickety old railway

and turn it into a tourist attraction. No one did such a thing.

In 2003, the viaduct was closed for reconstruction.

On July 21, work was suspended due to the approach of a storm.

But this was no ordinary storm.

At 3:15 p.m., a full-scale tornado hit .

East side of Kinzua Bridge.

Winds of 150 km/h tore steel columns from stone foundations.

The wrought iron anchors were not strong enough,

to hold the steel structure.

When the wind came and dragged the bridge up,

spacers cracked because they weren't strong enough.

Under great pressure, the anchor bolts bent, broke

and the bridge was no longer attached to the ground.

The bridge lifted up and the wind tossed it around,

imagine this man-made structure,

which is almost like life in the wind .

In less than a minute , half of the Kinzua Viaduct was covered

turned into a twisted wreck.

Incredibly, no one died.

however, the historical building that had stood for so long turned into ruins.

Instead of crushing what's left,

The state of Pennsylvania decided to leave the towers and rails in place.

A public viewing platform was built on the preserved section ,

for visitors to view evidence of the brute force of hope.

Abandoned Buildings

Lost Bridges

Abandoned Buildings

Lost Bridges

It took a tornado to tear down the Kinzua viaduct ,

however , one bridge section is missing in Cape Town, South Africa

due to a completely different storm.

For more than 30 years, the rival engineers battled

because of the so-called Invisible Bridge - the Foreshore Viaduct.

Cape Town was one of the most important ports in South Africa at the beginning of the 20th century ,

but this led to the decades -long Foreshore Bridge conflict.

Demonstrations against the apartheid policies of the South African government

became shockingly violent.

Dr Lisa Kane is a road construction sociologist,

who has explored the complex history of the bridge that never was.

We are on an unfinished stretch of road

and as you can see it is right in the middle of Cape Town.

In front of us is the harbor and there ahead

there is another part of the road which is also unfinished.

This whole area from the harbor to these high rise buildings

is part of the bog spring beach, and that's where our story begins.

Cape Town's baguette quarter area is 194 hectares of land reclaimed from the sea.

New roads had to be created to join this city

and that's when the problems started.

Two parties were interested in this land, one of them was the city itself

and the other was the Port Authority.

Cape Town had an idea that Europeans would come to town by ship

through a monumental entrance that is like a gateway to Africa.

The port authorities wanted a functional road network for traffic,

but the city had something more detailed in mind .

Cape Town authorities brought over from France

the architect Bauduini, who had been involved in the planning of Paris

and development and was quite famous at the time.

He devised a scheme based on the plan of Paris,

where the boulevards ran from east to west and from north to south.

A fairly straight grid -based plan.

The port wanted a workable solution and rejected the French plan.

During World War II, both plans were shelved.

After the end of the war, both sides waited for the problem to be solved.

But now a third vision of Cape Town's future has joined the game.

In the end, it seemed that there was no way to reach a decision after all

and construction of the Foreshore Viaduct can finally begin.

The reason why the bridge is the way it is is not clear to many.

It was constructed as an expressway to Cape Town,

because that's what the pressure groups - US car manufacturers - wanted.

Not just in Cape Town, but all over the world.

Wide highways filled with big American cars.

After 20 years of division

was worked in 1963. out the plan as we see it today.

Construction finally began in the late 1960s .

After 20 years of waiting, Cape Town was finally to get a modern traffic system.

But everyone had forgotten one thing - public opinion.

From a commercial perspective, we can understand the Port of Cape Town,

who needed a large infrastructure to transport goods in and out,

which would be as efficient and fast as possible.

One can also understand why the residents were against it.

If you live constantly in the shadow of such a great highway,

it has an impact on the local community

and I understand why they were adamantly against it. Anyone would.

The Forshore Highway began to be affected by South African politics.

Apartheid laws enforce racial segregation

led to Cape Town's ethnically diverse 6th District being allowed.

Anti- apartheid protests broke out in South Africa .

Hundreds were killed when police opened fire on demonstrators.

The apartheid government of South Africa decided not to build the bridge

and not spend money on the road ,

but to take the multi-ethnic commune in the heart of Cape Town

to some minor place.

The question was where to spend the money.

Work progressed slowly until a few more sections of road were missing.

However, in the early 1970s, when the end was already in sight, the work stopped.

There are several theories as to why the highway was not completed

and it remained suspended in the air as you see it today.

One theory is that there was a shop owner,

whose property was right in the way of the bridge and who did not sell it.

Another theory is that the engineer who designed the bridge realized

that the ends of the bridge cannot meet.

The idea that the Invisible Bridge exists because an engineer miscalculated

and the two sides of the bridge don't fit together, I don't think they match at all.

There is no way this is possible for such a large project .

There are so many things that need to be done in this kind of construction ,

so many brains are involved in it that such a thing never happens.

Since then, the two ends of the Foreshore Highway have been waiting,

for the last bridge section to be installed .

Resourceful townspeople have found several uses for the monster.

Since its abandonment, the highway has been used for artistic applications,

such as for film shoots and shooting supermodels.

But probably the most innovative was the

when it was used for the 2010 FIFA World Cup.

Never before has morning rush hour resembled a Mexican fiesta.

And the trumpets you hear in the stadium? A huge trumpet was installed here,

which caused heart attacks and traffic accidents,

so all that had to be given up.

The city authorities tried again and again

find a solution to the Foreshore Highway problem.

Although this is supposed to be striking, I have studied the history

and it is about the struggle of a child from Cape Town and South Africa.

The bridge could be torn down, but it is expensive and dangerous

or do something like New York did with their road.

There could be gardens and cafes and tourists could go there,

so that's probably the best idea.

Engineers who created Goat Canyon, Borovsko,

Kinzua and Foreshore Bridges, coped with formidable obstacles.

The fact that the bridges are still standing is a testament to their skill .

The Borovsko bridge could not and probably will not be completed,

but historians and engineers like Petr Bily

have begun to understand the importance of the bridge in the history of technology.

It is a living example of Nazi architecture and ambition.

It must remain as a reminder and example

of what misguided people are capable of.

Although destroyed by the tornado, the Kinzua Viaduct has not been forgotten.

Thousands of tourists visit it every year ,

who walk to a platform with a glass floor at a height of 90 m .

But Kinzua offers more than just a beautiful view.

It tells a great story

and there is something special when you can go and see and be part of it.

More than that, it's something for engineers to explore

and something to learn from for future projects.

If you replace wrought iron with steel, replace it completely.

Unlike Kinzua, the Kitsekanjon overpass is not accessible to tourists

and this aging wood may at any moment be destroyed by an earthquake,

that regularly hit Southern California .

Traffic no longer crosses these abandoned bridges,

but these incredible structures drive our imaginations

to other times and other worlds.