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,

Glass - one of the most versatile

construction materials around...

but when it fails it's clearly a problem.

Smooth Operators...

Masterful machinery skills prevent future fails.

Machines gone wild!

Scary tools with a mind of their own!

Caracas disaster...

Two cranes...

Fifty tons of steel...

One giant hole.

What could go wrong?

In the world of construction,

glass is one of the most multifaceted tools of the trade.

But when glass fails we can all see it's a problem.

This wonder material isn't just for windows -

glass can be used for many things,

external cladding,

roofing,

even bridges.

As a go-to construction material

glass is expected to have a lifespan of at least 30 years.

But glass fails are a global problem,

as they discovered at this upscale Toronto Hotel,

where there have been numerous incidents of glass falling

since it opened in 2015.

Not even a break with a cup of coffee is safe.

Sometimes the glass isn't the problem,

it's humans who're at fault!

Worried glass might not be strong enough for the job?

The brains behind this bridge found the perfect method

to prove this glass walkway could handle anything!

And in China, designers came up with a "fun" gimmick

to attract more visitors -

LED screens in this 1180-metre-high walkway

appeared to be glass cracking whenever someone walks on them.

However, it was no joke when this sky path

shattered for real -

just fifteen days after opening.

The glass walkway clings to the side of a cliff

over 1800 metres up Mt. Yuntai, in the Henan province of China.

Terrified tourists feared the worst.

A similar incident also occurred at London's Tower Bridge

after they opened a new transparent walkway

over the River Thames.

Once again, just two weeks after opening,

one of the six half-tonne glass floor panes cracked.

So, what went wrong with these glass walkways?

The answer to all these fails could be embedded

in the glass itself,

Glass most often used in construction

is either tempered glass,

also known as "toughened" glass or laminated glass.

Made by cooling molten glass extremely fast,

tempered glass is up to four times stronger

than regular glass and more resilient

in fluctuating temperatures.

And if it fails, the glass shatters into small,

even pieces, rather than hazardous jagged shards.

But tempered glass may also contain dangerous contaminants -

invisible to the naked eye.

Nickel sulfide stones can form during the tempering process,

and if they do, these minuscule stones

can expand and grow when the glass heats up in the sun -

forcing the pane inside a frame to shatter.

It may seem spontaneous, but it's a rare and,

all too real, reason for tempered glass fails.

It's suspected that Nickel Sulfide was to blame

at the Toronto hotel, but was it also the cause

in China?

There the incident happened during the National Day Getaway,

one of the busiest tourist times of the year.

So, was overcrowding the problem?

It was busy, but the glass walkway was designed

to support 800 kilograms per square metre,

that's four full-grown male lions.

The see-through glass walkway is comprised

of three-layers of custom-made tempered glass panes.

Officials claimed only a single pane shattered

into coin-sized segments.

And that the cracks posed no threat to safety.

But worried visitors said the whole pane looked fractured.

At London's Tower Bridge, the cracked floor

was discovered to have been caused by a visitor

dropping a bottle of beer.

Then a stiletto heel further shattered it.

The top layer was designed to be easily replaceable,

so the attraction remained open -

despite the scary shattered glass.

After investigations in China, the official report revealed

the cracks were caused by a stainless steel mug

dropped on the walkway.

One small cup caused this terrifying incident -

and sparked the closure of dozens of glass bridges

across China.

And the Chinese Government is now scrutinizing

all glass structures for potential construction flaws.

Glass is simple, practical and beautiful -

and has transformed the world of construction,

but when it fails it's not all it's cracked up to be.

You know those sci-fi films where robots revolt,

terrorize the countryside and try to take out

their human masters?

This is the real life version.

Machines gone rogue.

This front end loader isn't so much a rogue,

as lonely.

All it craves is contact with another of its kind.

And it wants to play bumper cars.

Machines might not yet be running the world,

but they are running circles around us.

So, it might be time to get in training.

And you know what's a good workout?

Square Dancing!

Swing your partner do-si-do.

'Round in circles Here we go

Every Laddie Every Lass

Spin 'til I run out of gas!

Fill a driverless tanker with energy drinks

and this baby's gonna go!

Whoops!

This truck's almost passed the test,

but even autopilots can fall asleep at the wheel.

Want to give it another shot?

I was sure I coulda made that jump.

I'm just going to rest my head here for a while,

and then I'll give it another try.

You know when your dog jumps on your bed to wake you up?

When it comes to winning the demolition derby,

this contender will do anything to crush the competition.

When machines go rogue, better stay out of their way.

Because if they turn on you, you're outweighed,

outclassed -

and out of luck.

London, England - famed for its neoclassical palaces,

Georgian Terraces and baroque cathedrals.

But on June 14th, 2017 one of its 70s tower blocks

hit the headlines.

Just before 1 AM,

Britain's worst residential fire since World War II,

broke out at Grenfell Tower.

Spreading rapidly up the building's exterior,

the fire and smoke penetrated all the floors.

A small fire in a fourth-floor apartment

grew into an unimaginable inferno in less than an hour.

More than 250 firefighters and dozens of fire trucks

were dispatched from stations across London.

The fire burned for nearly 60 hours

before finally being extinguished.

How did such a small fire spread so fast?

Tenants had repeatedly complained

about electrical power surges causing appliances to smoke.

Police confirmed a faulty fridge in a 4th floor apartment

started the fire.

A short circuit in the fridge, lead to a small electrical fire.

This spread through the kitchen and out the window,

igniting the exterior cladding.

A two year, 15 million dollar renovation

had just been completed with new windows,

heating system and new aluminum composite cladding.

The cladding wrapping the outside of the building

was meant to improve heating and energy efficiency -

and enhance the external appearance of the modern

Brutalist tower.

But cladding like this had already been implicated

in many high rise fires around the world,

like this building in Dubai.

When this 79-storey skyscraper opened,

The Torch was the world's tallest residential building.

And in February 2015 it lived up to its name.

The Torch Tower had flammable cladding

similar to that used at Grenfell Tower

and was blamed for fueling the spread of the flames.

The sprinklers and fast evacuation of the building

meant no-one was seriously injured

and firefighters had the flames out within a few hours.

It was a very different story at Grenfell.

The cladding used there

was never meant for high rise buildings.

In fact, it is not supposed to be used

on buildings taller than 18 metres.

It gets worse,

the insulation was not compatible with the cladding.

Worse still, the cladding was combustible

and when combined with the insulation

produced intense heat,

dense smoke and poisonous flammable gasses -

a devastating combination.

On the night of the fire, the gap between the cladding

and the insulation worked like a chimney,

vastly accelerating the spread of the fire.

External walls were not usually considered a fire hazard,

so the fire department was surprised

by how fast the blaze spread.

And were completely unprepared,

because they'd had no training

in the dangers of combustible cladding.

Unlike the Dubai building, there was no plan in place

for evacuating the tower.

Even entering and exiting the building was difficult -

it only had one entrance.

The stairwells and entire floors were filled with smoke

in less than an hour,

reducing visibility to near zero.

Inadequate fire doors, fire doors being propped open,

and problems with the ventilation system

all contributed to the smoke.

The building's lack of adequate sprinklers

had not been addressed in the recent renovation.

The electrical surges, combined with a faulty fridge,

the combustible cladding and insulation

all led to this devastating fire.

If they had spent 10,000 dollars more

on the fireproofing, the flames would have spread

at a much slower pace -

giving occupants more time to escape

and the fire department more time

to extinguish the blaze.

72 residents died.

The Grenfell Tower Inquiry

concluded that the cladding panels

with the polyethylene cores

had breached building regulation

and caused the fire to spread so rapidly.

There are still thousands of buildings

around the world covered with cladding.

But at least in Dubai at least they've amended

their building codes, requiring fire-resistant panels.

They've also found an innovative way to fight

any future blazes.

Dubai's Civil Defense unit's futuristic jet packs

mean firefighters will have an unlimited water source

and can avoid roads altogether.

On construction sites, mobile cranes

do all the heavy lifting.

Monster machines lumbering across the skyline.

Giant hydraulic arms towering overhead

as they move massive steel structures into place.

The technology is actually quite simple.

As long as you obey the laws of physics.

But if you break those laws or ignore a pesky detail -

like gravity -

a construction site can turn into a disaster area.

And that's exactly what happened in Caracas, Venezuela.

At the La Mercedes construction site,

twin 100 ton cranes were planted on either side

of an access shaft.

The job?

Lift a 60 ton metal truss - structural support

for the roof of a brand new subway station.

As the crane operators jockeyed the truss into position,

one crane suddenly keels over

like it's had one too many.

The truss lurches forward, takes a dive

and takes the second crane down with it.

So, what went wrong?

The two cranes were positioned so each would shoulder

half the 100-ton payload.

But when one crane lost its footing,

the delicate balance of distance and force was upset -

and it all came crashing down.

A tug of war where everybody loses.

Could it have been the wind?

Wind speeds as low as 30 kilometres per hour

can affect the stability of a crane.

A freak gust of wind could have turned the truss beam

into a heavy metal sail - and pushed them over the edge.

But the truss beam actually dips forward and straight down -

not swept forward by a gust of wind.

Was it a weight problem?

Each crane should only handle 75 per cent of its maximum load.

Even the slightest weight could send them over the edge.

But these twins can take 150 tons between them.

More than enough to handle the 60-ton truss.

If it wasn't the wind and it wasn't the weight,

then what took them down?

Mobile cranes are equipped with outriggers.

Mechanical feet planted on either side of the machine

that makes a solid, stable base to support the lift.

When a crane does a heavy lift,

the outriggers help to distribute

the weight of the crane and its load.

However, the crane and load can shift to just one outrigger.

Exerting thousands of kilograms of force on that one footing.

So, you'd better be sure the ground is solid and stable.

Or you're going down.

And that's exactly what happened in Caracas.

The outrigger sank into the dirt,

the crane literally lost its footing and overturned.

It lets go of the 60-ton truss,

which drags the second crane down.

An epic construction fail.

This could have all been avoided

if they'd better distributed the weight.

The outriggers need to sit on top of adequate cribbing.

Cribbing is the padding sandwiched between the ground

and the outrigger.

These pads distribute the weight of the crane

and the pressure of the load over a wider area.

To keep the outrigger's feet on the ground -

instead of under it.

Half of all crane incidents occur

because the mobile crane or outriggers

are not set-up properly.

A successful lift requires many steps and detailed calculations.

One wrong step and the ground can shift right under your feet

or outrigger.

20 bucks worth of plywood

could have prevented a million dollar disaster.

To prevent future construction fails

it helps to master the machinery.

When we think about "smart machines"

we imagine the phone in our pocket

or the computer on our desk.

Heavy weight construction equipment is usually cast

as the big dumb friend - or the renegade robot.

But when a monster machine partners with a master operator

you'd be amazed - or at least amused -

at what they can do.

This excavator, like all great athletes,

knows before you get down to business,

you need to do your warm-up exercises.

Of course, you can't make an omelette

without breaking an egg.

No omelette tonight then.

How many 40-ton excavators does it take to screw in a lightbulb?

Just one apparently.

This excavator is having a play date

with his little friend Mr. Builder.

Le-go my head please.

Hello, that's my head.

After working hard all day these guys are treating themselves

to a stroll on the beach and a refreshing cocktail.

If those are the straws, imagine the size of the Daiquiris.

Digger, heal thyself.

When the chain fell off the wheels,

this operator opted to DIY it,

using his machine to fix his machine.

The arm reaches out, scoops up the chain

and slips it on like a comfy old shoe.

And in just a few minutes they're back on track.

A smooth operator can wield a super-heavy attachment

with surgical precision.

Although you may not want an excavator

removing your appendix.

Or making a salad.

Now that these talented machines have had a taste of show biz

it might be hard to get them back to their day jobs.

What would you rather do?

Dig ditches - or do tricks for a living?

Bravo. Take a bow.

♪ ♪