All language subtitles for Inside.Mighty.Machines.Series.1.3of5.Hovercraft.1080p.HDTV.x264.AAC.MVGroup

♪

Chad zdenek:
A giant hovercraft--

Capable of transporting
400 passengers

And their cars,

All on just a cushion of air,

Over land or sea,

Designed by a madcap
british inventor

Experimenting
with a hairdryer,

Then supersized
by engineering genius

To become one
of the 20th century's

Most unusual machines.

Can you imagine

Something this big traveling
at over 70 miles an hour,

With hundreds of people on board
and their cars?

Now this extraordinary vessel

Has reached the end of its life.

Salvage teams are standing by,
ready to tear it apart.

This is gonna be awesome!

[crunching]

As they strip it back,

I'll get up close and hands on

To uncover the five
engineering innovations

That made it
a giant of its time...

And reveal
how the hovercraft revolution

Finally ground to a halt,

Leaving its technology
to the modern military.

Yeah!

Ha ha ha ha!

I'm chad zdenek.

I spent seven years building
rocket engines for nasa.

Now I'm taking things apart,

Breaking down
giants of engineering

Piece by piece

So I can discover what made them
legends of their time.

♪

Portsmouth, on the southern
coast of England.

The final resting place

Of what were once the world's
biggest hovercraft.

♪

I helped put shuttles
into space,

I've seen all kinds
of incredible engineering

Throughout my career.

But this is my first chance
to work on a hovercraft.

Its engineers had a vision

For a completely new
mode of transport--

Part boat, part plane,
part helicopter...

And all genius.

I've always wanted to know
how they did it.

And that's why I'm so excited

To finally get a chance to work
inside the biggest in the world.

There they are,
and they're giant!

Look at the size of them!

The princess anne
and the princess margaret

Are all that's left of a fleet
of six huge hovercraft.

They once each ferried
400 passengers and their cars

30 miles across
the english channel to France.

♪

Film narrator: Srn4--

A new transportation system
for a new world.

Chad: These craft
were launched in 1969

To do something incredible--

Glide from land onto the sea.

They were unlike
anything ever seen,

And right away, they captured
the public's imagination.

Film narrator: Bringing new
standards of speed and comfort,

The craft operate
day in, day out,

40-minute schedules
across the english channel,

And suddenly the channel
is half as wide.

♪

Chad: But in 2000, both vessels
were decommissioned.

That left only a handful
of passenger hovercraft

Working anywhere in the world.

And since then,

These two princesses
have been slowly rotting away.

Now they face
very different fates.

The anne will be preserved

And eventually
displayed in a museum.

But thanks to the soaring demand
for recycled metals,

The margaret's days
are truly over.

Now, the princess margaret
is going to be scrapped,

And her most valuable parts
are going to be reused

To preserve her sister,
the princess anne.

The rest is going to be
melted down and recycled.

♪

So here's my plan.

Over the next five days,

I'm going to help the team
tear her apart.

While they salvage what they can
to sell for recycling,

I'm gonna reveal the five
ingenious pieces of engineering

That made these craft

The mighty machines
they once were:

The incredible rubber skirt,

800 feet long;

The giant fans that
lifted over 300 tons;

The huge propellers
that broke the sound barrier;

Aviation's biggest drive shaft;

And the hull design that made
the margaret unsinkable.

Hey, I'm chad.

Lewis: Hello, I'm lewis.

Chad: Lewis, what are you
planning on doing?

Lewis: Now that the machine
is here on site,

We're going to be
lowering down the front door,

And then you'll be able
to get inside.

Chad: Ok.

Lewis: And then we're gonna
pull back some of this skirt

So we can see
what's underneath there.

We're looking to get a lot
of scrap metal from the job,

A lot of salvage from the job.

We'll start soft-stripping
inside the cabins as well,

Removing chairs...

Chad: Ok.

Lewis: ...Loose furnishings--

Anything basically
that's not metal,

We can get it out now--
chad: Ok.

Lewis: To make it easier
for the excavator

When doing the demolition.

Chad: Yeah.

First up,
the giant rubber skirt.

Turn the key on a hovercraft,

And fans drive air
underneath it,

Creating lift.

Early craft were open
around the sides.

So the air quickly escaped,
limiting its power.

To build a hovercraft
capable of heavy lifting,

Engineers needed
to contain that air.

Their answer
was a rubber skirt.

It was a simple idea

That they hoped would do
something extraordinary--

Trap air to lift a 300-ton craft
12 feet off the ground.

But getting this concept to work
was a serious challenge.

So before the demolition team
shred the skirt

To sell for recycling,

I want to get inside and see how
the engineering actually works.

Warwick jacobs has worked
with hovercraft all his life,

And he's agreed to tell me
all the trade secrets.

♪

Chad: All right, warwick,
you ready for this?

Warwick: No, 'cause as soon
as you chop that skirt off,

It ceases to be a hovercraft.

Chad: Yeah.

Warwick: Which is the beginning
of the end, isn't it?

Chad: I know
it's emotional for you,

But we've got to do it.

Warwick: Yep.

[buzzing]

There you go.

Now, that's not been seen
for 20 years.

Chad: There's another skirt!

This next layer of rubber
is a giant inner skirt.

Together, they form a tube that
channels air around the craft

And into a huge central space
known as the plenum chamber.

So this is like a giant balloon,
if you will, on this side...

Warwick: It is, yeah.

Chad: ...And then the air
flows in that way.

Warwick: Yeah, and it builds up,
changes pressure

As it pushes down
through those holes.

So the same again for you, chad.

Cut the next bit,
and then we're in.

[buzzing]

Chad: There we go.

There's a doormat for you.

Warwick:
And you're in now, yeah.

Chad: Oh, wow!

Look at this.

Geez.

It's getting
a little tight in here,

Real tight and real dirty.

It's small for me under here,

But there's a lot of space
on the underside.

This whole thing looks like
it's layered with the skirt

So that when it lifts up,

That's how we get
12 feet higher.

I've cut through
both walls of the tube,

And right now
I'm in the plenum chamber.

This is the empty space
at the heart of any hovercraft.

Lift fans
forced air into the skirt,

Which inflated.

Holes in its inner wall

Channeled air
into the plenum chamber,

Where it was trapped
by the layers of rubber.

A cushion of
high-pressure air built up,

Lifting the 300-ton
princess margaret off the ground

Or the water.

It was an incredible
breakthrough,

But it came
with an unexpected price.

The hovercraft was so fast

That the impact of the waves
on the rubber

Actually tore the skirt,

And that meant a lot
of expensive maintenance.

Warwick: Every night
the craft would go on jacks

That would lift
the whole craft up.

One craft a night.

Chad: The jacks lifted the craft
clear off the ground...

Leaving the skirt hanging free

And ready for repair.

Warwick: All night long,

15 guys would be there
with their spanners and saws,

Repairing the skirts

And fixing it,
ready for the next day,

Because with a dodgy skirt,

Performance goes down
pretty quick.

Chad: The skirt
was hundreds of feet long,

And it all had to be kept
in perfect condition.

So, how many feet of skirt
do we have?

Warwick:
It's 185 foot long each side,

Inside and outside,

So you've probably got
800 feet of skirt,

End to end there.

Chad: Maintaining the skirt cost
millions of dollars every year.

But today, the salvage team
is hoping to make money

By recycling it.

♪

♪

This skirt is about
three-eighths-of-an-inch-thick

Neoprene rubber.

And this excavator
is tearing it apart

Like it's paper.

I gotta give it a shot.

♪

All right, enough of
the reciprocating saw.

Now I'm ready to do some work.

This is gonna be awesome.

♪

This excavator can really shred.

But for this job,

It's as much about precision
as power.

That's because
when it comes to recycling,

It's important
to separate your materials.

Otherwise
you get paid less for them.

So you can see,

We've actually ripped off
all of the hinges along the way,

And the reason why

Is because if there's any rubber
that's mixed in with the metal,

Our recycling rates
are going to be a lot lower.

So it's a meticulous job,

And it's taking
quite a long time,

But it's going to pay off
big time for us in the end.

♪

Finally! We've made
a 30-ton pile of rubber.

The plan now is
to shred it and sell it

So it can be used for
the springy floor covering

Parents will recognize
from kids' playgrounds.

But the skirt
just held the air in.

The next piece of engineering

Is what really got this thing
off the ground.

I bet I could crawl in
through those blades.

We've just ripped
the 800-foot rubber skirt

Off the princess margaret
hovercraft.

But that was
only part of the system

That allowed
this thing to hover.

It's day two.
Time to take a look at the fans.

Just how big did they need to be

To lift this beast
into the air?

There are four fans.

But getting to them is tricky.

We have to cut through
the side of the hovercraft

And don't want to damage
the interior

Before we've had a chance
to salvage the seats.

Hovercraft have kind of
a cult following around here,

And these seats could actually
sell to collectors at auction.

If you could give me a cut
right down this section...

Roy: No problem at all.

Chad: If we can take
all this out along here,

All the way to this section.

Roy: Yeah.

Chad: What I'm worried about
is the cabin.

We still gotta take
those seats out inside.

So if you're able to do this

Without affecting
the floor of the cabin

So we can keep working there...

Roy: It shouldn't
affect the structure

Of the hovercraft at all.

Chad: Ok.

♪

Roy has a special machine
for this job.

It's a set of hydraulic jaws...

With a surprisingly
delicate bite.

It's amazing
how accurate he can be

With such a huge machine.

Man: Good job, roy.

Chad: Yeah, it's great.

It's amazing to have
this kind of a view

On a giant machine like this.

Now I can climb
right into the guts

Of this huge hovercraft.

I bet I could crawl in
through those blades

And get a closer look.

♪

This is not
where you'd want to be

When the engines start.

I'd be sliced and diced.

Oh. Wow!

This is a big inlet.

I'm in a giant fan.

It's mounted not vertically,
but horizontally.

It sucks in
thousands of tons of air

Through this giant inlet

And forces it down
through the skirt

And into
the plenum chamber below.

This is what made
the hovercraft hover.

♪

Aviation had
the wright brothers;

Hovercraft had
sir christopher cockerell.

He was the british inventor

Behind this inspired piece
of engineering.

Cockerell noticed
how water creates friction

Against the hull of a boat,

Slowing the vessel down,

And he came up
with an extraordinary solution.

Christopher cockerell:
You begin to ask yourself,

Well, now is there a way
around this?

One day, one thought,

Well, let's see
how it would work out

If one used air
instead of water.

Chad: Cockerell experimented
with hair dryers and tin cans...

Before designing a prototype,

Building a scale model,

And then, in 1959,

Unveiling
his revolutionary craft

To a stunned public.

Cockerell's
flying saucer prototype

Had just one fan.

But the princess margaret
has four,

And they're enormous.

Roy is tearing one out
so I can take a closer look.

It's a really simple
piece of engineering--

Just wood
covered in sheet metal.

So, how do four of these
very basic-looking fans

Lift a vessel
like the princess margaret?

♪

Each of the four fans
is 12 feet wide

And could spin
at over 400 miles an hour.

That was fast enough
to fill the enormous skirt

In just six seconds...

And create the air cushion

That made the 300-ton
princess margaret hover.

It solved the very problem

That had driven cockerell
to invent the hovercraft.

The margaret didn't have to drag
its bulk through the water.

Instead,
it could fly over the top,

Creating almost
no surface friction.

Film narrator: The srn4 rises up
on its 8-foot-high skirt

And glides down the ramp,
across the sand,

And begins
its 40-minute hover to France.

Chad: Like the seats,
these fans could be popular

With the hovercraft fanatics
around here.

So they'll be put up for sale
at a collectors' auction.

But if they don't sell,

They'll have to be
scrapped instead.

Two days in, and we've removed

The hovercraft's
huge rubber skirt

And its four giant lift fans.

On their own,

These are two really simple
pieces of technology.

But they show that
sometimes in engineering

The most complicated problem
needs the simplest solution.

What amazes me

Is cockerell's ingenuity
in combining them both.

He did what nobody
thought was possible--

Keeping 300 tons of hovercraft
floating on air.

And to me, that's genius.

♪

Cockerell had unveiled
his invention to the world.

Now he had to prove it could be
put to commercial use.

So he set himself
a bold challenge--

To make the 30-mile journey

From calais in France

Across the english channel
to dover,

Using his prototype srn1,
the world's first hovercraft.

On July 25, 1959, cockerell
set out to make history.

The crossing took two hours.

But the moment the vessel
slid onto the beach in England,

A legend of transportation
was born.

Film narrator:
Although it was only 6:50 a.M.,

People had gathered
in large numbers to welcome her.

The principle of hovercraft
had been abundantly proved.

The small prototype
had turned the page

To a new chapter
in modern transport.

Chad: Cockerell's success
inspired a new vision.

If he could
supersize his design

To offer greater power
and more lift,

Then he could build
a giant hovercraft.

It could carry more cargo,

Have enough seats
to serve the masses,

And connect britain
to mainland europe

In just minutes.

♪

Ten years later, in 1969,

Cockerell launched
the princess margaret.

For the next three decades,

This would be the world's
biggest hovercraft.

♪

Almost everything about it
was a record-breaker,

Like the four giant propellers
that provided thrust.

It's day three,

And these are
the next innovation

I want to explore up close.

At 21 feet in diameter,

These props
still hold the record

For being the world's largest
propeller blades.

And they had to be

To propel 300 tons of hovercraft
across the channel

At speeds of up to
60 miles an hour.

♪

Wow!

These are huge!

That's a lot of propeller blade.

These props may be wide,

But their lifespan was short.

They were vulnerable
to damage from debris

And were designed to be replaced

After just
5,000 hours of service.

That meant the princess margaret
needed a new set

Every two years.

And they didn't come cheap.

These blades
were last made in 1999.

A set of four propellers
took over a year to make

And cost a million dollars.

Unbelievable!

The props were made of aluminum,
so they were light and strong.

Today, aluminum is valuable
as a recycled material,

But this propeller
won't be recycled.

♪

Can you, uh...

Yeah, there you go,
right there.

Instead, the demolition team
will donate it

To the local hovercraft museum.

So we're taking it apart
to put into storage.

Set her down.

There you go.
Yeah, right there.

Man, these are heavy!

♪

Lift it up. You guys lift up...
There you go.

♪

Each prop was mounted
on top of a tall pylon,

A structure
that allowed the propellers

To pivot left and right.

The pilot could control
the angle and speed

Of each propeller separately,

And, that way,
steer the hovercraft.

So are these really the biggest
propellers in the world?

Warwick: They're the biggest
propulsor propeller

In the world.

You have bigger blades
on windmills and wind turbines,

But as a propeller
for pushing you along,

They're the biggest
propulsors in the world.

Chad: The propellers rotated
at up to 1,000 rpm.

That may not sound like much
compared to the engine of a car,

But the size of the propellers
had a really dramatic effect.

I just want to get an idea

Of how fast
those props were moving.

So, they're 21 feet
in diameter...

Circumference of a circle,
pi times d...

♪

So...

That's about 750 miles an hour.

Now, the speed of sound
is about 740 miles an hour,

So that means those props

Are moving faster
than the speed of sound,

Making them supersonic.

Just like the concorde
created a sonic boom

When it broke
the speed of sound,

So did the margaret.

And the roar from
its supersonic propellers

Could be heard for miles around.

Warwick: The propeller tips
would break the sound barrier

Sometimes
coming into the terminals

When the pitch
changes suddenly,

So you could almost
hear them in France.

Chad: It didn't take long

For others to realize
the potential in such power,

And the innovations
pioneered by these hovercraft

Have been used
all over the world.

We're traveling fast!
This thing is moving!

From armed patrols
in the vietnam war...

[helicopter]

[gunfire]

To rescue craft
serving disaster zones...

And from tropical swamps...

To frozen tundra...

♪

Hovercraft have proved
a vital tool for the u.S. Navy.

Their ability to carry
huge loads at high speeds

Still makes them
ideal landing craft.

I'm off the coast of san diego,

On board their
landing craft air cushion,

Or lcac.

You know, this hovercraft
is so big,

And you're in
the vast ocean right now,

You can't see any land.

You really lose perspective of
how fast you're actually going.

And we're traveling fast!
This thing is moving!

And we've got
like 2-3 foot swells,

And you can't even
feel anything.

It feels like you're
riding in a cadillac,

Just, just moving along.

Lcacs like these

Have been in service
for over 30 years.

They're carried
by transporter ship

To within 80 miles
of the shore...

And then launched at sea.

Even when carrying 180 troops...

12 humvees...

Or 75 tons of humanitarian aid,

They're still
highly maneuverable.

This thing can turn on a dime

And deploy across
almost any terrain.

Now we're heading back
to the beach.

♪

Oh, man.

They give the u.S. Navy access
to 80% of the world's shoreline

And the lcac unit its motto:

"no beach is out of reach."

♪

It's stopping.

♪

That's spectacular.

♪

U.S. Lcacs have served
across the globe,

In iraq...

Somalia...

Indonesia.

And here in the u.S.,

They took part
in rescue operations

After hurricane katrina.

♪

Today, the lcacs operate
in extreme situations.

But in her prime,

The princess margaret's job
was to take tourists to France.

And now it's time
to rip out the passenger cabins

Where they sat.

Before we start,
I want to take a look around.

The margaret had two cabins,

Configured to seat 416 people.

Over their lifetimes,

The princess margaret
and her sister ship, the anne,

Carried over
11 million passengers.

And appropriately enough,

Seating was more like a plane
than a car ferry.

I can only imagine

What it would have been like
for the passengers

To be flying across the sea
in this huge hovercraft

Back in its heyday.

♪

Film narrator: Large windows
provide a panoramic view

For all passengers,

And the fully ventilated cabins
are light and airy.

Passengers relaxing in spacious
airline-style seating,

Perhaps sipping drinks
brought round by a hostess.

♪

Chad: Now all these seats
have gotta go--

Some to the museum,

The rest to auction,

Where they might be bought
for use in home movie theaters.

I brought my extra tool in case
we need some manpower.

[laughs]

Warwick: Ok, there it is.

There we go.

That's a lot easier.

Only another
150 more benches to do.

[laughing]

Chad: Oh, man.

Some of these have
been here a long time.

These are completely
corroded in.

Back in 1969,

Passengers paid around $13
to sit here.

That's about $90
in today's money.

Back then,

That was about the same price
as flying to France.

But the margaret
had one big advantage.

You could bring
your car as well.

Film narrator:
Cars enter the craft

By means of
the wide bow loading ramp

And are quickly positioned
with a minimum of fuss

Under the guidance
of car deck personnel.

Generous overhead clearance
in the car deck

Allows the craft
to cope with coaches,

Light commercial vehicles,

And holiday makers'
heavily laden cars.

Chad: In the first six months,

The fleet of four hovercraft

Carried hundreds of thousands
of passengers and their cars

Across the channel.

Business continued to boom,

Until, in 1973,

Britain and america
faced the oil crisis.

Tensions in the middle east

Meant the oil supply
was cut off.

Film narrator: Traffic in the
cities was down by about 10%,

And garages
offered a regular service

Only to essential drivers,

Not those topping up
for shopping or the weekend.

Chad: The cost of a barrel
promptly quadrupled.

With the margaret burning
four tons of fuel every hour,

The hovercraft faced
commercial disaster.

But its engineering
came to the rescue.

Designers calculated

They could increase efficiency
and stay profitable

By making the craft even bigger.

Warwick: They stretched them,

So they cut them in half,
about where we're stood,

Added a 55-foot section,

And you could operate
the same engines,

Bigger propellers on the top.

For 10% more fuel, you could
carry double the payload,

So it revolutionized and gave
the hovercraft a future.

Chad: A new central section
was added to each vessel.

At the time,
it cost $12 million,

But it nearly doubled
their capacity

And ensured the future
of these two hovercraft

For another 20 years.

The extended version
was christened the superfour,

And it's the margaret
we see today.

Film narrator: Superfour,
with its payload of 90 tons,

Can carry 416 passengers
and 60 vehicles

In airline-style comfort.

♪

Chad: Next, I want to uncover
the hidden engineering

That made the princess margaret
unsinkable.

Wow!

The princess margaret
and the princess anne

Were in service for 31 years.

Together,
they each crossed the channel

Over 80,000 times.

That's more than
2.5 million miles--

100 times
the circumference of the earth.

Only once in all that time
did disaster strike.

It was in 1985.

The margaret
approaches dover harbor.

The pilot is fighting
near gale-force winds

And high seas.

There are
370 passengers on board.

Suddenly the hovercraft is blown
against the harbor wall.

[crash]

Reporter: The gaping hole

In the starboard side
of the hovercraft

Was an indication
of the force of the impact.

Chad: 50 people were injured.

Four died.

Reporter:
One of the first tasks

Was to try to get
underneath the skirting

To see if the missing bodies
were trapped under the wreckage,

But none were found.

Chad: It was a terrible tragedy.

But the accident
could have been much worse.

Reporter: They said
that if this had been a ship,

She would almost
certainly have sunk.

Chad: The reason
the margaret didn't sink

Was its unique construction.

And the secret
to that engineering

Is hidden below her car deck.

It's day four,

And this is the next innovation
I want to uncover.

The skirt and lift fans
make the hovercraft hover.

But because these vessels
operate at sea,

They're built with
a watertight hull for safety.

That means they can float,

Even without
the lift fans running.

This hovercraft is built on
a raft of 150 buoyancy tanks,

Which makes it 500% buoyant.

Basically, you'd have to stack
four hovercrafts on top of it

In order to make it sink.

These buoyancy tanks

Are built under the floor
of the cargo hold.

To reach them, I'm going to have
to smash through the car deck.

These chambers
haven't seen the light of day

Since it was built 50 years ago.

I'm gonna take one apart
and look inside.

♪

[buzzing]

♪

Wow! Ha ha!

I'm probably the first person
to be in one of these

In over 50 years.

[knocking]

These buoyancy tanks
are riveted together

And then sealed off

By the rigid floor
of the car deck.

It's like a giant raft
made of super light aluminum

And strong enough to support
130 tons of cargo.

Every tank is watertight,

So if one
is ruptured and flooded,

It won't affect
any of the others.

The side effect of this design

Is a giant hovercraft
that's actually ultra-buoyant.

There's 150 of these
on this hovercraft.

Now I can see why
it's virtually unsinkable.

So the construction on this,

You actually have
the wood top deck

Which is coated with
an anti-slip material.

Underneath the wood,

We've got two layers
of aluminum sheeting.

But what gives it its strength

So that you can
drive the cars on here

Is this honeycomb.

It's actually
very, very fragile.

You can kinda see...

[banging]

It's very easy to dent into it,

But what it does

Is it keeps the spacing between
these two aluminum sheets,

And with that spacing,
this stuff is rock hard.

This was what kept
the margaret afloat,

Even when the worst happened.

The tanks were a priceless
piece of engineering.

But today, their only value
is as recycling.

♪

With aluminum fetching
a dollar a pound,

The demolition team
wants to get back to work.

[clattering]

Before they do,

There's one part of the craft
we want to save for posterity--

The cockpit.

This is the man
who knows it best,

The princess margaret's
last ever pilot,

John hawkins.

How's it feel
to be back in here?

John hawkins:
Well, it's good.

It's still surviving,
isn't it?

[laughs]

It had to be
a little bit tricky.

I mean,
when you're flying a plane,

You don't have the lift fans
that you've got here.

And you've got
four different propellers

That could spin
all the way around.

John: Well, the beauty of it is,

It's set up to make it
very easy for yourself,

Because this yoke here--

If we were to do that,

All the pylons would
go to push you

In a certain direction,
that direction.

Chad: All at the same time?

John: Yeah.
Doing a turn, for instance,

You could do a turn
with the rudder.

You put the thing over.

Chad: Ok.

John: And the rudders
would go over to take you...

To starboard there.

Chad: Yep.

John: The beauty
of these things,

I've never known anyone
not to enjoy driving them.

Chad: John makes it
sound simple,

But flying these
took considerable skill.

To maneuver the craft,

The pilot could use the rudders,

Pivot the pylons and propellers,

Or adjust the pitch
of the prop blades.

He also had to
balance the vessel

By varying power
to each of the lift fans,

Or even pumping fuel
between the fuel tanks.

All this was controlled
from here in the cockpit.

It may seem complicated,

But the cockpit's design
worked so well

That it was never updated.

For me, that makes this
a piece of engineering history.

I'm delighted
it won't be scrapped.

Instead, it will be
saved and exhibited

In the local hovercraft museum.

But that means we have to
take it out in one piece,

Which could be tricky.

♪

So I'm only using a pickaxe

To make a starter hole
for the saw blade.

Once I get the blade in there,

I'm cutting through
the sheet metal

But not the structural supports.

We've got to make sure those
structural supports stay intact

'cause if we don't,

George and I
are both falling through.

[buzzing]

As we cut around the cockpit,

We're leaving four of these
structural support beams intact

To bear the weight.

Then we attach slings...

Let the crane
take up the tension...

And cut through
the last of the beams.

Now the crane takes

The full weight
of the cockpit...

[engine revving]

And we can lift it out.

Perfect.

Good job, george!

♪

♪

That's how you take a cockpit
off of a hovercraft.

As you can see,

We've a big hole
in the roof of the hovercraft.

We lifted it up,
it didn't buckle at all,

And now we've got a beautiful
cockpit for the museum.

The analog dials
and manual controls

In the margaret's cockpit

Are from another era.

But on this u.S. Navy craft,

Everything is state of the art.

I'm getting ready

For a once-in-a-lifetime
opportunity,

To take the controls
of this u.S. Navy lcac.

First, a brief from senior chief
petty officer eric crafton.

He's an lcac pilot

Who's served in iraq,
afghanistan, and haiti.

So what's it like to
actually operate this thing?

Eric crafton:
If you don't drive this craft,

It's going to drive you.

So, every slope,
the wind, the waves...

Everything is a factor.

Chad: You've got the lift,
you've got the propulsion,

You've got the bow thrusters.

It seems like
there's a lot going on.

Eric: It is very tricky.

You're using your feet
for your rudders,

Your left hand for the props,

And they're controlled
independently,

And your right hand
for your bow thrusters.

Chad: And if you combine that

With this thing not even
touching the ground...

You know, almost like
a frictionless surface,

I imagine that adds a layer
of complexity to it as well.

Eric: It does.

You have to be in control to
make the craft do what you want.

Chad: Gotcha.

It certainly doesn't sound easy.

But what better way to learn

Than from this elite
u.S. Navy lcac crew?

It's safe to say
I'm pretty excited.

Oh, man!

Man: Welcome to the forward con.
Chad: Woo hoo hoo hoo hoo!

Man: All right. Let's do it.

Chad: Oh, it's not every day

You get to drive
a $30 million hovercraft.

Right now, the lcac's
floating on its hull.

But as soon
as I give the order...

Engineer, bring us on cushion.

Engineer: All right, got ya,
con. Bring on cushion.

Chad: The lift fans kick in.

The skirt inflates.

And in less than five seconds,

We're floating
on a cushion of air.

Bow thrusters forward.

Woman: Bow thrusters
are forward.

Chad: As the engines rev up,

The 120-ton craft
begins to glide forward.

♪

Seconds later,
we're pushing 20 miles an hour,

Then 30...

40...

50 miles an hour
in a 120-ton craft,

Loaded with six humvees
and a dozen marines.

Incredible!

Yeah!

Ha ha ha!

It feels amazing!

♪

I am flying a hovercraft.

Wow!

This is at least
three times faster

Than a conventional cargo boat.

Low cushion.

Man: Low cushion? Gotcha, con.

Chad: Ha ha ha! Wow!
Man: Hope you enjoyed it.

Chad: Yeah, that was awesome.

As soon as we kill the fans,
the skirt deflates

And the lcac lowers
onto its watertight hull.

I had four engines
at 4,000 horsepower each,

And we were doing
about 40 knots,

Which is probably around
50 miles an hour.

And it felt like we were
just gliding on air.

It was amazing.

♪

The lcac uses the same
principles as the margaret

But is only one-third its size.

The engineering
has been refined

To create more power and lift

From smaller engines

And just two propellers.

But the margaret had four props

And four lift fans.

These giant moving parts
were all joined together

By one final piece
of engineering.

And it's buried deep inside
the superstructure.

It's the innovation
I want to uncover next,

Before my final goodbye
to this engineering legend.

[crunching]

♪

Just like peeling an onion,

Layer by layer.

♪

Ok.

There it is.

The drive shaft.

This is just part
of a huge drive shaft.

It rotated at high speed

To deliver power

From the engines
at the rear of this hovercraft

To the propeller and lift fan

Via the pylon,

All the way at the front.

This drive shaft
had to be 140 feet long.

It was the biggest
aviation had ever seen.

And the margaret
had two of them.

This is one of the gigantic
140-foot drive shafts

That connect
to the forward pylons.

And together they're some of
the most valuable recycling

On the hovercraft.

No one is quite sure
what it's made of.

My bet is aluminum,

Which is very light
and very strong.

We're not sure
how to get it out, either.

Roy's just going to have to
grab a section and pull.

So what do you think, roy?

You think you could
get the drive shaft out?

Roy: Yeah, we'll have a go.

I'll grab it in the center there
where the joint is.

Chad: Yep.

Roy: And it should
snap the bolts off then.

♪

♪

Chad: Wow!

Let's see.

Oh, ho ho ho ho!

Alright, moment of truth.

I have a magnet here,

And it's definitely not steel.

I'm not sure if that's
the bolts or the flange,

But this is definitely aluminum,

And this is worth
a lot of money.

This is just one section
of the drive shaft.

The whole thing weighs
2,500 pounds.

And remember,
there's two of them.

Together, they could be worth
up to $5,000 as scrap.

But to get every piece out,

The demolition team will have to
tear the margaret to shreds.

There's no turning back now.

♪

The hovercraft boom years
did not last.

By 1994,
their future was under threat.

Conventional car ferries
had become faster

And could carry more cars.

Budget airlines
offered cheap flights.

And a new tunnel
under the seabed

Was about to connect
England and France by rail.

Meanwhile,
margaret's fuel consumption

Was costing up to
$7 million a year.

On top of that was the bill for
routine maintenance and crew.

It all added up to an annual
running cost of $18 million

For a single hovercraft.

To stay profitable,

The operators needed to sell
more than just tickets.

That something was alcohol.

Just like
international airports today

Make money selling
duty-free alcohol,

Cigarettes, and perfumes,

So did the princess margaret
and the princess anne.

Film narrator: Duty-free
facilities on board a hovercraft

Do not require lengthy queueing
by the passengers.

Instead, they enjoy
a pleasant and efficient service

In the comfort of their seats.

The cheerful cabin staff

Can bring round drinks
and duty-free goods,

Ensuring that
everybody is served

During the 30-40 minute flight.

♪

Chad: Ticket prices were dropped
to around a dollar.

For that,
you could travel to France

And stock up on cheap alcohol.

The trip became known
as a booze cruise.

Soon, the hovercraft's
huge running costs

Were paid for almost entirely
by profits from cheap alcohol.

It's hard to believe
that a hovercraft this big

Survived from duty-free.

Warwick: Yeah, and in fact,
on some of the trips,

If they were going
a bit too quick,

The stewardess would call up
to the captain on the bridge

And say, "slow down, we're
still selling the duty-free,"

So we'd do a little nip and turn
and slow it down a bit.

But, yeah, duty-free

Was the saving grace
of the hovercraft.

And towards the end,

It was very much people going
for a day to get duty-free

And not paying a premium.

They'd pay a pound
for a day return

And come back laden
with duty-free.

Chad: Then, in 1999,

The eu abolished duty-free
between european states,

Including
the united kingdom and France.

With no way
to cover the huge cost

Of running these machines,

The writing was on the wall

For both the princess margaret
and the princess anne.

Warwick: The duty-free ending

Really spelled the end
for the hovercraft.

It competed for ten years
against the channel tunnel.

That didn't kill it.

They survived an accident,
they survived price wars,

They survived
an awful lot of things.

But the death knell was
the abolition of duty-free

In the year 2000.

And overnight,

The hovercraft was no longer
a viable concern.

Chad: Less than a year after
the abolition of duty-free,

Both the margaret and the anne
were permanently retired.

[ship horn blows]

The era of giant hovercraft
on the english channel was over.

The princess anne
and princess margaret,

Two extraordinary pieces
of engineering

Run aground by economics.

And now
it's because of economics

That the princess margaret
is being torn to pieces

And recycled.

The demolition team

Has already shredded
the 30-ton rubber skirt.

They've ripped out and sold
the four lift fans.

One of the giant props has been
preserved for a museum,

Along with the seats
and the cockpit.

But now it's time
to really cash in

With what's left of
the 300-ton princess margaret.

Melted down, it will be worth
around 40 grand.

All together, that's a total
of about $175,000

For five days of salvage
and three decades of history.

♪

The princess margaret

Was born in a moment
of inspiration...

♪

Developed for a decade...

♪

Only to be launched
and made even bigger...

♪

Before making its name over
millions of miles of service.

♪

Now it's being transformed,

Bite by bite,

From a legend of engineering...

Into a pile of scrap,

Ready for recycling...

♪

Perhaps even to become
part of the next generation

Of mighty machines.

♪

The margaret
is now gone forever.

And with it,
cockerell's vision

For a hovercraft
to serve the masses.

But his inspired idea
for an amphibious craft

Lives on.

Not as a huge passenger vehicle,

But as a tool for the military

And emergency
and rescue services.

Today, hovercraft
can be found working

In some of the most extreme
conditions in the world.

They all started
with the princess margaret.

♪

Although we scrapped it,

Thankfully some of the parts
are going to be used

To preserve this incredible
craft behind me.

Being here has given me
a chance to explore

Just how the giant
hovercraft worked,

To uncover the wonders
of its engineering

And the genius
of its simplicity.

And it's genius
that is at the heart

Of every incredible invention.