Original subtitles

[Narrator] Construction.

Heavy machinery. Tight schedules.

Millions at stake.

What could go wrong?

Everything.

Whether it's faulty equipment, poor design, human error

or just bad luck...

These are...

Construction Fails.

In this episode...

Power trip.

When this electrical generation station

reached the end of its road, it took all the power with it.

The crawler crane. A moving monster...

...with a terrible sense of balance.

Holding pattern.

Meet the German airport that just doesn't want to take off.

And talk about dropping in unannounced...

literally.

The lattice boom crawler crane is the multi-tasking champion

of the construction world.

Combining stability, mobility and brute strength,

the crawler crane can lift mammoth loads.

Wide tracks maneuver the cargo across tough terrain

while providing stability.

Its multi-function jib hoists the load

while a counterweight system balances the lift.

Like all cranes, the crawler works on the principle

of simple machines, like levers and pulleys.

But crawler cranes sacrifice some stability

for their mobility.

Those tracks are not as secure as they look.

It takes skills and smarts

to ensure the crane stays on its tracks

and the load goes where it's supposed to go.

Varese, Italy, May 2017

A 1000 ton lattice boom crawler

is lifting a section of railway bridge into place.

The 60-metre concrete beam was part of a viaduct

that would connect trains between northern cities.

Four hooks, suspended on heavy-gauge wire,

power-lifted the 400-ton beam

and ferried it up to the edge of the bridge.

But as the boom raises the beam into place,

it starts to swing unsteadily...

...and the giant machine flips.

In slow-motion, the crane caves under the weight.

Investigators initially blamed the incident

on faulty machinery.

But what was actually at fault?

Was weather a factor?

Wind is often to blame in crane collapses.

A powerful gust can actually topple a crane,

especially if the boom extends to 64 meters

like the Varese crawler.

If wind speed exceeds 32 kilometres per hour,

crane ops should stop work and clear the site.

But the weather in Varese was calm.

There was no wind.

Was the crane not strong enough?

Those heavy lifters are designed to hoist

up to 3500 tonnes.

So the Varese crawler crane should have been able

to lift that 400-tonne slab without difficulty.

The lattice boom crawler was purpose built

for a job like the Varese viaduct.

The counterweight system should have provided ample leverage

to hoist the load and the crawler tracks

should have distributed the weight evenly.

But they didn't.

So why did it overturn?

Because it wasn't the tools: It was the workmen.

Working from the ground up, a closer inspection of the tracks

revealed that matting under the tread

was installed incorrectly.

Unbalanced treads may have caused the crane to stumble

if it was pushed off balance.

And it was.

Critically, the counterweight suspended on the back

of the crane is the very thing

that should have stabilized the crane under the weight

of the concrete slab.

And it would have if it had been secured.

But it wasn't.

Instead of compensating for the load,

the counterweight swings forward,

towards the boom,

adding to the weight of the load.

And doing exactly the opposite of what it's supposed to do.

The sudden shift in the centre of gravity

catches the crane off balance.

The boom lurches forward and everything else goes down.

All the while, the crew watches in wonder

how this could have happened.

This is how.

If the crane operators had not failed in their job...

The mighty machine would not have failed to do its job.

Walk up to the Departure gate in Berlin's shiny new

Brandenburg Airport and you can check your flight time

on the glowing display screens,

which read, "Someday" "Not sure"

or "Possibly Never".

Because after 14 years of construction,

the Brandenburg airport currently has no flights,

no planes and not much confidence the building

will ever be completed.

With the fall of the Berlin wall the newly unified city

was ready to reclaim its role as the German capital.

And a new airport would become a major hub

for European travellers.

They broke ground in 2006,

but the 2011 completion date came and went

as incredulous inspectors

walked through a mockery of German precision.

Escalators that didn't go all the way up to the next floor.

Thousands of mislabelled wires.

Sixty kilometres of cooling pipes

installed without insulation-

which required tearing down brand new walls

in order to undo and redo the shoddy work.

Within the year the budget had ballooned

to 4.3 billion Euros,

twice the original estimate.

More delays led to more discoveries.

Which led to more delays.

The jewel in the dunce cap

was the airport's Fire Protection System.

It was designed by an ambitious fraud whose sole credential

was a business card that read: "engineer".

The sprinklers didn't sprinkle.

The fire doors wouldn't close.

And instead of the smoke rising naturally through vents

in the roof, the design called for an elaborate pump system

to funnel the smoke down into the vents in the basement.

On top of that,

three thousand actual smoke detectors had gone missing.

By 2016 the new airport was operational.

But there were still no passengers or planes.

Because Brandenburg's transformer station exploded.

And the exterior vents were leaking rain water.

And the automatic windows wouldn't work

on a warm summer day.

And 600 fire protection walls had to be replaced -

because they were flammable.

And it looked like the roof might cave in.

Also, there weren't enough check-in desks.

Not that there have been any passengers to check in.

After years of throwing good money after bad,

the uber-budget was sitting at 10 billion and counting.

300,000 euros a day to pay for the army of cleaners

and technicians that work at the ghost airport

to make sure everything is in smooth running order.

And every day, it still isn't.

The Brandenberg Airport is slated to finally open

in the fall of 2020.

Just one small detail, after all those years

of displaying the same thing, the flight information screens

were burned in and had to be replaced.

When it comes to air travel,

blind optimism is never a good idea.

But if you do decide to fly out of Berlin's Brandenburg Airport,

hopefully your flight will

be upgraded from "Never" to "Strong Maybe".

Power stations.

They generate the majority of the world's electricity needs.

And power stations are defined by the elegant curved profile

of their cooling towers.

Whether powered by coal or natural gas,

these massive installations

burn vast quantities of fuel.

And all that fuel creates a tremendous quantity

of superheated steam...

...with temperatures as high as 570 degrees Celsius.

To dissipate that heat, power stations rely

on those massive cooling towers.

Their curved shape isn't just an elegant detail...

It makes the evaporation process more efficient.

As hot water turns to steam, it is less dense than cool air

so it rises in the tower.

The narrowing middle makes the rising steam less turbulent,

allowing the tower to release the heat faster.

The Didcot Power Station in Oxfordshire, England

was a typical example.

Each of its 500 megawatt generating units

burned through 3.7 metric tonnes of coal a year.

But, in August of 2019,

after more than 40 years of constant use,

Didcot was going to be laid to rest.

A large crowd gathers to watch the controlled demolition.

The three towers represent 40,000 tonnes of structure.

The demolition requires 180 kg of high explosives.

No one is disappointed.

Or so it seems.

Without warning, electrical fires erupt

on power lines far from the explosion.

People are injured.

Cars are damaged by debris from the fires.

49,000 homes are left without power.

So, what went wrong?

After all, power stations are being blown up

all over the world without incident.

As electrical generation infrastructure ages,

cooling towers are dropping like so many stones...

...especially at Didcot.

The 2019 demolitions were not the first

at the power generating facility.

In July of 2014, Didcot successfully demolished

another set of cooling towers without incident.

The three towers were slated for an early morning demolition.

As with the 2019 demolition, a large crowd turned out.

No one was disappointed.

And the power stayed on.

The two demolitions were remarkably similar.

Three towers.

40,000 tonnes of structure.

180 kilograms of high explosives.

So what was the difference between these two demolitions?

As investigators discovered, although the two explosions

were similar, the protective material

used to contain the explosive spray of debris

from the demolition was not.

In the 2019 demolition, debris protection material

detached from the top of one of the cooling towers

and made contact with a 33 kilovolt overhead line.

The shockwave from the explosion was so powerful

it set overhead wires swaying a kilometre from the site.

The flying debris caused cascading failures

across the local grid.

The material meant to contain the explosion

actually ended up creating a bigger problem.

The day started innocently enough,

as passengers at China's Nanchang Airport's Terminal 2

got ready to board.

Suddenly the calm was shattered

by a series of staccato cracks.

Too stunned to run, travelers watched

through the building's glass wall as chunks of the roof

ripped away, clattering onto the roadway below.

For a moment it seemed like the airport was under attack.

But what was the threat?

Nanchang was too far inland for a tropical storm.

And the last reported earthquake was over 2000 kilometres away.

The assailant was invisible - yet invincible.

You couldn't see it.

But you could witness its awesome power.

It was the wind.

Wind is air under pressure.

When the air is warmed by the sun it rises,

creating an area of Low Pressure.

Cold air from the poles rushes in to fill the gap

with High Pressure - causing the air to move.

And make the wind blow.

The rotation of the earth causes the wind to curl and swirl.

This motion results in everything

from a gentle summer breeze to a violent superstorm.

But it doesn't take a hurricane or a tornado to raise havoc...

or the top off of a building.

Given the right conditions and substandard construction,

a strong wind can peel off a roof

like the top of a sardine can.

The wind that whipped the Nanchang airport

was strong but it should have been no match

for a properly-designed overhang.

But that's the wicked nature of wind.

It gets into cracks and crevices to find the weakest link,

tearing at those loose tiles and shingles.

We measure the weather with our eyes.

But we can't see the wind.

So the best way to quantify wind force

is to gauge the impact it has on buildings,

and people in its path.

Wind speed is wind power.

You can certainly feel a 70 kilometre per hour gust

but it's not going to do much damage

except maybe to your hairdo.

Ramp that up to 90 clicks and the wind starts

to re-landscape your backyard.

Lighter objects get rattled or go flying.

And you might get pushed along the street...

Or knocked right over.

At 100 kilometres per hour the wind can wield

a real threat to solid structures.

Loose fence posts and shingles launch into the air -

deadly projectiles that can pierce brick and shatter glass.

The wind can flip over an untethered trailer

and send small structures flying.

Once you hit 120 kilometres per hour

you're in hurricane territory.

The wind will tear the roofs off taller buildings,

and pummel their facades.

It starts tipping over trucks and sending them sliding along

the asphalt like tumbleweeds.

Anything over 150 kilometres per hour

means full on Armageddon.

Uprooting trees, upending buildings,

the wind carves out a path of destruction,

flattening anything in its way

and leaving a trail of devastation in its wake.

On the day of the disaster the Nanchang airport

clocked wind speeds at 30 metres per second

or 108 kilometres per hour.

Powerful enough to shred big chunks of the roof

off the building.

The only things taking off that day

were pieces of Terminal 2.

And a tarmac full of flying debris.

There are measures you can take to protect yourself

and your property against the wind -

but you won't see it coming until it starts

to shake the trees -

or yank them out of the ground.

Then the best thing to do is take cover.

Or you might get blown away.

It's comforting to know when you walk into a room

that you're safely enclosed.

A solid floor underfoot

and a protective ceiling overhead.

Not so fast.

There are all sorts of reasons that floors give way

and ceilings collapse.

Most of them are invisible - or at least unnoticeable -

until it's too late.

Floors and ceilings sit on platforms of wooden joists.

Cross beams that make up the skeleton of the house.

They're built strong.

But they're not indestructible.

The right combination of things going wrong,

and every movie playing at the mall

becomes a disaster film.

Water can do serious damage.

A major downpour can burst through the ceiling

and wash away whatever...

...or whoever - is unlucky enough to be under it.

A steady trickle of water

will eventually eat away at the wood

and rupture the drywall.

Once the structure is compromised,

it won't do the job it's designed for.

These young students are getting their first

practical lesson in gravity.

Even excessive noise vibration can rattle the joists.

Ceilings can be deceptive.

The frames can be pretty flimsy.

Toss the bouquet in the wrong direction

and the honeymoon's over.

And a badly thrown bowling ball becomes a wrecking ball.

Dropped ceilings conceal plumbing,

ductwork and wiring.

They can also hide uninvited guests.

Sometimes you can see the early warning signs

of an imminent downfall.

The walls start to bow and crack.

Warped doors and windows don't shut properly.

But if you don't get to the problem in time.

A pail isn't going to do it.

Like the song says, "one man's ceiling

is another man's floor."

So tread lightly.

Because if the floor gives way,

you'll be dropping in unannounced.

♪ ♪