Original subtitles

Narrator: the hindenburg...

The largest aircraft ever built,

An incredible feat Of nazi engineering.

That was certainly The most advanced airship

That had ever been built.

But in 1937, disaster strikes.

Man: The hindenburg is in flames.

Narrator: a raging fire tears Through the giant airship.

Morrison: Oh, the humanity!

This is the worst thing I've ever witnessed.

Narrator: The cause of the crash

Is an 80-year-old mystery.

In a matter of seconds, 245 meters of airship

Was reduced To just smoking wreckage.

Narrator: 35 people lose their lives.

What really happened That fateful night?

♪♪

Now investigators use Pioneering technology...

I don't think the flight crew Did the correct things.

Narrator: ...And innovative Forensic techniques

To unearth new evidence.

I can see the explosion Immediately.

We've got a whoomph, Didn't we?

You hear That chamber go.

Narrator: Using cutting edge 3-d graphics,

We will resurrect the hindenburg From the ashes.

♪♪

We'll reveal its inner workings

And the engineering That makes it fly.

We'll reconstruct The night of the inferno

To reveal the mysteries of this Incredible nazi flying machine.

--captions by vitac-- Www.Vitac.Com

Captions paid for by Discovery communications

♪♪

May 6, 1937.

Adorned with nazi swastikas,

Germany's hindenburg airship Flies over new york

After completing a three-day Crossing of the atlantic.

It makes the journey Twice as fast

As the quickest ocean liner.

♪♪

The hindenburg is the pride Of the nazi air fleet.

At over 800 feet long,

It's the largest aircraft Ever to fly.

♪♪

Under its aluminum-coated skin,

There's space for 61 crew And 70 passengers.

♪♪

It's a flying five-star hotel With bedrooms, dining hall.

Piano bar, and smoking room.

♪♪

Gigantic cotton gasbags Filled with hydrogen

Make this monster Lighter than air.

♪♪

♪♪

The hindenburg approaches Its final destination --

Lakehurst naval base, New jersey.

But as it prepares to land...

Morrison: It burst into flames!

And it's crashing! It's crashing terrible!

Oh, my! Get out of the way please.

It's burning, Bursting into flames,

And it's falling On the mooring masts.

This is one of the worst Catastrophes in the world.

Oh, the humanity!

I don't believe it. Oh!

I-I can't talk, Ladies and gentlemen.

[ woman screaming ]

You see this giant, Beautiful airship float in,

Know that it's filled With people,

And then all of a sudden It just bursts into flame.

Narrator: What causes one of the most

Notorious air Disasters in history?

♪♪

The enormous hangar one At lakehurst is where

The hindenburg is stored When it flies to the u.S.

♪♪

In 1937,

Hangar one is the largest Single room in the world.

It's 350 feet wide And nearly 1,000 feet in length,

As long as the chrysler Building is tall.

It's here where airship Historian dan grossman

Begins his search for the truth.

Grossman: This entire building

Would have been filled With airship.

And it kind of gives you a sense Of just how big the ship is.

This building had hindenburg From one end to the other end.

Narrator: The massive hindenburg

Erupts into flames Just overhead.

♪♪

Dan believes that the hangar Contains clues

To help solve this mystery.

We are standing where The control car crashed.

This entire area would have Been covered with nothing

But burning, Smoldering wreckage of airship.

Narrator: to this day,

Hangar one stores Charred traces of the airship.

Dan discovers evidence Of the fire's intensity

On these recovered Pieces of silverware.

Grossman: well, we can take A look at some of the items

That survived the fire.

You can see where metal Has melted

And dripped onto these pieces.

It was a horrific thing For people to go through.

There was a lot of tragedy Associated with this.

Narrator: In just 32 seconds,

The fire Consumes the entire hindenburg,

Killing 35 of the 97 crew And passengers.

But what can start a fire Ferocious enough to melt metal?

♪♪

Within hours of the disaster,

There are rumors that opponents Of hitler sabotaged the ship.

♪♪

The hindenburg is as large As the u.S. Capitol building --

Plenty of room for foul play.

[ ticking ]

♪♪

Is there a bomb Onboard the airship?

Fire and explosions expert Dr. Claire benson

Puts the sabotage theory To the test.

Eyewitness accounts At the time suggest

There was a quite A small fire towards the top

And the back of the hindenburg.

Narrator: Claire plans to detonate a bomb

Inside a model Of the airship

And analyze How quickly the fire spreads.

She works with pyrotechnics Expert matthew tosh.

We are modeling now

The individual reservoirs Of hydrogen gas.

We've got a cylinder here,

And claire is going to feed me Some hydrogen gas.

This replicates the hindenburg's Massive hydrogen-filled gasbags.

♪♪

Claire will analyze The explosion

And compare it To footage of the fire

That destroys the hindenburg.

Tosh: the explosive we're using On our model

Is black powder, gunpowder.

So this is the explosive Going in.

This is where Tensions start to rise sometimes

Because we're now going Into the firing system.

Narrator: Claire uses a slow-motion camera

To analyze the fire That the bomb sets off.

Tosh: right. Let's arm the system.

We're armed.

Okay. You ready? Here we go.

♪♪

In 3, 2, 1.

[ explosion ]

We got a whoomph, didn't we? You hear that chamber go?

Benson: yeah.

♪♪

Whoo!

All right.

Narrator: the camera footage Is downloaded,

And claire replays the explosion In super slow-motion.

♪♪

Benson: I can see the explosion Immediately,

And it seems to engulf The back third,

I would say, of the model Really quite rapidly.

Narrator: the hindenburg fire Last just 32 seconds.

But claire's experiment Suggests an explosive

Would have engulfed the airship In half that time.

Benson: an explosion happened Really rapidly

And then very quickly That fire propagates

Through the whole model And burns it up.

Narrator: despite the apparent Speed of the hindenburg fire,

Claire's experiment reveals In reality

The airship burns too slowly For the cause to be a bomb.

It's a breakthrough In the investigation.

She's certain she can finally Rule out the sabotage theory.

I think we can conclude From the experiment

That it's unlikely That the hindenburg disaster

Was started By an explosive device.

Narrator: a bomb did not bring Down the giant nazi airship.

So what else could it have been?

♪♪

Federal authorities discover That before the disaster,

The hindenburg's crew Gets sent threatening letters.

♪♪

As they examine the airfield,

Investigators find Suspicious tracks

That lead away From the crash site.

♪♪

There are rumors of a gun In the wreckage...

Fueling speculation of a shot From inside the airship.

♪♪

But even though investigators Name two suspects,

They eventually rule Out sabotage.

♪♪

The explanation of This disaster remains a mystery.

Today, in the search For answers,

Investigators turn to the Design of the hindenburg itself.

What clues does it hold To the cause of the catastrophe?

♪♪

Narrator: the nazi-built Hindenburg airship

Bursts into flames as it arrives At lakehurst, new jersey.

Sabotage is ruled out.

But what else could cause This disaster?

Now investigators look to the Hindenburg's design

For answers.

The hindenburg's skeleton

Is a complex web Of aluminum struts and braces.

It carries The ship's infrastructure,

As well as the engines, Passengers, crew and cargo.

♪♪

But its main job is to create A large empty space

For the mission-critical Components.

16 gigantic cotton bags...

That hold 7 million Cubic feet of hydrogen,

The lightest element In the universe.

The gas allows The hindenburg to fly,

But does it also cause Its downfall?

Hangar one at lakehurst is The hindenburg's american home.

The giant airship fills The vast space.

Today, it houses wreckage Of the disaster.

♪♪

Airship historian Dan grossman

Investigates one Of the surviving pieces.

Grossman: this is an actual Girder from the hindenburg

That was recovered After the wreckage,

And you can see in the bends

And the way this piece Was designed and fabricated,

That made it simultaneously Very strong,

But also very light because I can take this entire girder

And I can hold it With one finger.

Narrator: The hindenburg's designers make The frame as light as possible.

A light frame allows The fuselage to be supersized,

Key to carrying as Much hydrogen as possible,

Keeping the hindenburg Airborne.

But there's a problem.

Hydrogen can be very explosive.

Investigators want to know If that causes the fatal fire

Onboard the hindenburg.

Today fire and explosions expert Dr. Claire benson

Is taking a new look at how Hydrogen behaves when ignited.

Benson: this is a bag filled With pure hydrogen.

And inside Is an electrical igniter,

And we're going to see What happens

When we try To ignite pure hydrogen.

Arming.

And 3, 2, 1.

[ snap ]

Narrator: It won't set on fire.

A spark cannot Ignite the hydrogen.

The igniter went off,

But there was No combustion reaction inside.

But the hydrogen, because It's just pure hydrogen.

Narrator: But in certain circumstances,

Hydrogen will ignite.

Claire fills a second bag With hydrogen

Mixed with another gas That's all around us --

Oxygen.

Okay, arming. 3, 2, 1.

[ pop ]

Narrator: Together, hydrogen and oxygen Create an explosive cocktail.

But if they are kept separate, Then hydrogen is perfectly safe.

Benson: We have to manage it.

We have to make sure That we can contain it

And that we can keep it away From oxygen

That it could react with And from ignition sources.

[ pop ]

♪♪

Narrator: In the first world war,

German airship designers use Membranes from cows' intestines

To make bags That safely contain hydrogen.

♪♪

In the 1930s, They changed to helium --

A gas with less lifting power,

But also less risk.

♪♪

But the only place in the world That produces helium is america.

And the u.S. Won't sell helium to the nazis.

The hindenburg Must use hydrogen,

But can now afford To have nine extra cabins

As hydrogen Has more lifting power.

♪♪

The hindenburg's designers Also create a new way

To safely contain the gas.

They make airtight cotton Gasbags to hold the hydrogen.

They are so confident Their plan is foolproof,

They even allow passengers To smoke onboard the airship.

So why does the hindenburg Catch fire?

Claire believes there Can only be one answer.

Benson: on the hindenburg, If there was a leak

Or some kind of mixing Of the hydrogen with the air,

It's the mixing that Would enable the ignition

Of that reaction.

Narrator: could a deadly leak Of hydrogen play a part

In bringing down the hindenburg?

What sparks The catastrophic fire?

♪♪

Narrator: the massive nazi Airship hindenburg

Erupts in a raging fire.

Seven million cubic feet Of hydrogen are set aflame.

Within moments, Thirty five people are dead,

But hydrogen will only burn When mixed with oxygen.

It should be completely safe

Within the airship's Giant airtight gasbags.

Now investigators Want to know

How does this hydrogen escape?

Seconds before the disaster,

A witness sees The ship's skin fluttering...

...Possible evidence Of a gas leak.

♪♪

Right beneath this spot are Gasbags number four and five,

Each filled with half a million Cubic feet of hydrogen.

Could something Inside the airship snap

And tear the gasbags?

Now hydrogen can escape...

And mixed with oxygen,

Turning hindenburg Into a gigantic flying bomb.

But how could a section of the Hindenburg's structure break?

Dr. Praskovia milova Is an aeronautical engineer

From the université libre In brussels.

She examines the hindenburg's Design for clues.

Milova: we can see that the main Structure of the hindenburg

Was supported everywhere By still bracing wires,

Narrator: thousands of feet Of steel wire

Braces hindenburg's innovative Lightweight frame.

Steel wires surround all 16 Gasbags, securing them in place.

From this view, you can Imagine that the gasbag

Would be filling This whole space.

And even pressing Against the wires.

Narrator: But steel is prone to rust,

Milova: steel is a corrosive Material just by nature,

And rust then has A significant impact

On the strength of the material.

Narrator: Before the disaster,

The hindenburg makes 17 Round trips across the atlantic,

With each crossing taking An average of 55 hours.

♪♪

It flies at a cruising altitude Of only 650 feet,

Exposing it to moisture And salt from the ocean.

♪♪

To shield the skeleton under the Hindenburg skin from corrosion,

It is covered With protective paint.

♪♪

But the steel bracing wires Are unprotected,

And when exposed to salt And moisture, they can rust.

♪♪

Praskovia thinks there's Another threat

To the steel wires.

The airship's aluminum Frame bends and stretches

To cope with the challenging Weather conditions

Crossing the atlantic.

Milova: corrosion -- It's the material,

So it creates little cracks On the surface.

And then because the whole Structure is flexible,

The steel wire Would be repetitively

Tensioned and relaxed,

Tensioned and relaxed, And eventually it breaks.

♪♪

Narrator: each cotton gasbag Is reinforced and sealed

By a thin layer of rubber.

Could a snapping steel Wire puncture one of the bags?

♪♪

The cause of the leaking Hydrogen is a mystery today.

Praskovia is finally putting

The suspect gasbag material To the test.

She prepares samples Of the rubberized cotton

With lab technician Inge desmet.

Milova: We chose the pointed needle Because if the wire broke,

It would have had The sharp edges,

And the pointed needle would be

The best to assimilate That broken wire.

♪♪

Narrator: The machine ramps up the force.

♪♪

Milova: This sample was punctured.

You can see the hole.

The puncture resistance Is around 40 newtons.

Narrator: Praskovia's test reveals

How little it takes to pierce The material.

Milova: the gasbag material Could have been

Pretty much easily broken By a broken wire.

Narrator: all the vital Forensic evidence

Is destroyed In the intense fire.

But with the results Of her test,

Praskovia is now certain

A tiny piece of metal Is the most likely culprit.

The cause of The hindenburg disaster

Is finally getting clearer.

♪♪

But the leak Still needs a spark.

What starts the mighty fire?

Narrator: may 1937.

The wreckage Of the airship hindenburg

Lies burning On a new jersey airfield.

Now investigators believe A broken steel wire

Has ripped open a gasbag,

And half a million cubic feet Of hydrogen leaks out.

But the highly flammable Mix of hydrogen

And oxygen needs to be ignited.

So what sparks The deadly fire?

[ thunder rumbles ]

The hindenburg lands at Lakehurst during a thunderstorm.

Eyewitnesses report Dim blue lights

Rippling across its aluminum Coated skin.

Are these the sparks That ignite the hydrogen

And bring down the hindenburg?

Dr. Chris gould is An electrical engineer

From staffordshire university In england.

♪♪

He investigates If a thunderstorm

Can produce a spark powerful Enough to start a fire.

Gould: What we're trying to test here

Is how can a spot be created

Within the hindenburg structure?

Narrator: Thunderstorms produce millions

Of volts of electricity.

The hindenburg Is electrically charged

Flying through The stormy conditions.

But dropping its Mooring ropes for landing

Should safely discharge The airship.

♪♪

The mooring ropes Should channel

Any electrical charge to earth,

Eliminating the risk Of potentially lethal sparks.

How is a spark created On the hindenburg?

Chris and technical assistant Suhil want to find out.

They use a replica of the Hindenburg skin to investigate.

This model represents The main components

Of the hindenburg -- The airframe and the outer skin,

Which has a woven fabric Painted with aluminium powder.

And we have this aluminium bar,

Which represents The metal structure

Of the airship airframe.

Narrator: the mooring ropes Are only attached

To the airship's aluminum Alloy frame.

The skin is separated from it By wooden dowels.

Chris suspects this separation Means the skin

Keeps its electrical charge

When the airship drops Its mooring ropes.

The electrical current Then flows across the gap

In the form of a spark.

If we can create the spark In that gap,

Then potentially That can lead to ignition.

Narrator: Flying through the storm,

The hindenburg's outer skin Gets covered in water.

Chris and suhil recreate The same conditions

On their model.

Gould: the water that we poured Onto the fabric of the airship

Is replicating The pools of water

That have formed as the airship

Has been traveling through The poor weather conditions.

Narrator: suhil connects The high-voltage generator

To the wet skin...

And grounds the inner frame

Exactly like the hindenburg Moments before the disaster.

Gould: I think we're ready to go.

Narrator: chris's equipment Can produce up to 50,000 volts.

The experiment must be done Inside a cage for safety.

♪♪

1,000. One and a half.

2,000 volts.

We can see a spark. We've got a spark.

♪♪

Chris creates a spark In the exact conditions

The hindenburg faces.

His findings are conclusive.

Chris believes it's a discovery

To finally solve An 82-year-old mystery.

The test reveals a fatal Design flaw in the hindenburg.

Wooden dowels insulated skin From the metal frame

And the mooring rope.

The frame loses its charge

When the mooring rope Drops down,

But the skin remains charged And can still trigger sparks.

♪♪

Chris is convinced this is The cause of the deadly fire.

Gould: that spark would be Enough to be able

To ignite a leaking hydrogen Mixture from the hindenburg.

Narrator: investigators discover That an electric spark

Ignites the hindenburg.

62 of the 97 onboard

Survived the resulting fire.

How can so many people Escape the inferno?

Narrator: the hindenburg airship Leaking hydrogen

And electrically charged by A huge thunderstorm

Approaches Lakehurst, new jersey.

♪♪

During the landing, most Passengers are in the lounge.

They have no idea what's Happening 400 feet behind them.

A spark ignites a gasbag In the tail

And turns it into a fireball.

A huge flame blasts Through the central walkway.

Fire engulfs five crew In the central control rooms

And traps nine crew In the bow.

The nose becomes A giant blowtorch,

And the ship starts to crash.

How can 62 of the 97 people On board survive this inferno?

Airship historian Barbara waibel hunts for answers

In the town Where the hindenburg is built.

Friedrichshafen, germany.

The zeppelin museum houses A full-scale replica

Of the hindenburg's interior.

[ speaking german ]

Narrator: the trip across The atlantic takes three days.

♪♪

A round trip cost $720.

♪♪

Not much today, but in 1937,

It's half the average U.S. Worker's annual salary.

The need to save weight Is the biggest priority.

Each cabin only contains What is absolutely essential.

The hindenburg Makes its final approach

Towards lakehurst, new jersey.

Most passengers are in one Of the two lounges

Enjoying the dramatic views Of new york city.

The hindenburg is designed With vast windows

Along the length of each lounge,

Reconstructed here At the museum.

As the hindenburg Descends to the airfield

At lakehurst naval base,

The large windows in the lounges

Are the most popular place To be,

But the passengers here are

The first to notice The disaster.

♪♪

The windows not only Help alert passengers

To the unfolding disaster...

They help with a hasty escape.

The hindenburg catches fire 200 feet in the air

Before it crashes to the ground.

People escaping must wait

For exactly the right moment To jump.

[ indistinct shouting ]

But not all passengers are In the lounges during landing.

Many are in their cabins Preparing to disembark.

They face greater danger.

♪♪

The cabins' modern Minimalist design

Lacks one crucial feature --

A window.

All the cabins are situated In the center of the airship

With no views to the outside.

Passengers in their cabins

Are unaware of the disaster Unfolding around them.

It takes just 32 seconds from The first flames being spotted

To the giant airship Hitting the ground.

[ indistinct shouting ]

Passengers still in their cabins Have no time to escape.

No one in their cabin Survives the disaster.

23 passengers do escape.

Every one of them Are in the lounges.

However, the crew are spread Throughout the airship,

14 of the 61 crew onboard

Are killed almost instantly In the fire.

The rest have a chance To make their escape.

♪♪

At the time of the disaster,

The captain is overseeing The landing

From the hindenburg control car.

The control car is far away

From the start of the fire At the tail.

The captain and 11 of the crew Here escape

When the airship crashes To the ground.

♪♪

But this is not the end Of their ordeal.

♪♪

Now on the ground, They must find their way

Through the burning wreckage.

Two of the crew In the control car die

Trying to escape.

The captain survives,

But is severely burnt Fleeing the wreckage.

Other members of the crew Are luckier.

♪♪

The engine cars are far away From where the fire starts,

And 9 of the 11 crew there Escape.

♪♪

With the tail virtually Touching the ground,

All four crew in the rear also Walk away virtually unscathed.

In total, 39 of the 61 crew Survived the disaster.

But could the entire Catastrophe have been averted?

What can the captain Do differently

To stop the disaster?

Narrator: lakehurst, new jersey, May 1937.

The wreckage of the hindenburg Lies scattered on the airfield.

35 people are dead.

♪♪

Can the captain of the airship

Do anything to stop The disaster?

♪♪

Mats backlin is A retired airship pilot.

Mats programs This state-of-the-art simulator

To exactly replicate The conditions

On the day of the disaster.

In the search for clues,

He's re-created the hindenburg's Precise flight path.

♪♪

Backlin: There are major differences Between airships and planes,

But the trickiest part Of any operation is the landing.

The ground can be Very unforgiving

If you hit it the wrong way.

Narrator: the hindenburg is Flying through a thunderstorm.

It charges the airship With lethal electricity.

And puts it hours Behind schedule.

The captain decides To land fast.

He uses a quick And efficient method

Called a flying moor.

In a flying moor,

The hindenburg drops Its ropes at a high altitude

And is winched to the ground.

But only the airship's frame

Is safely discharged Of electricity.

While it's 200 feet in the air, The height of the airship

Increases the electrical charge Of the skin,

Causing the catastrophic spark.

The captain's choice to land Using a flying moor

Is the catalyst For the disaster.

Mats thinks there's A safer way to land.

We're going to try The approach at a lower level,

Narrator: airships can also land Like conventional aircraft,

Slowly reducing speed And altitude

Until coming to rest On the ground.

♪♪

A low landing is much slower And harder for a pilot to do,

But it dramatically reduces The risk of a disastrous spark.

[ thunder crashes ]

Mats attempts to land Like an aircraft

To see if the captain can do it And avert the catastrophe.

♪♪

Backlin: The flight crew has more tasks,

More conditions to deal with.

If you're very low, you can Easily post the tail

To strike a tree Or even the ground.

Narrator: mats approaches Lakehurst airfield

And begins the critical stage Of the landing.

♪♪

Backlin: we're coming into The final approach.

Try to avoid hitting pine tree On the right here.

Narrator: Mats safely brings down

The massive airship Onto the airfield.

We're now going to be Settling down to the ground.

Narrator: Mats' new experiment proves The disaster is not inevitable.

The captain could have chosen The slower but safer option.

♪♪

The hindenburg disaster Is seen around the globe

And shocks the entire world.

The catastrophe brings an Abrupt end to the airship era.

♪♪

Astonishingly, Dr. Praskovia milova believes

That despite the tragedy, Hydrogen-filled airships

Could grace our skies Once again.

Hydrogen's amazing Lifting power

Means it could be the perfect Green alternative

For moving cargo.

Praskovia and her team Are building a brand-new airship

They hope will avoid The mistakes of the past.

We've spent so much time by now Designing and researching

All the components Of the airship model

Due to the disasters That happened in the past

With the hydrogen airships.

Narrator: they develop a 50-foot Prototype model

To test their technology.

The airship is built From carbon-fiber tubes

That are corrosion resistant.

We are using carbon tubes,

Which are light, Which are strong,

And they are also Electrically conductive,

Which is very important For a hydrogen airship,

Narrator: Praskovia needs to test

The most critical component Of her design --

The material that makes up The hydrogen gasbags.

She's discovered A brand-new fabric

She thinks will prevent Any possible leak.

Milova: the solution is to have Two layers of plastic film

For even more gas-tightness, Plus carbon fiber,

Which is a synthetic material To make it even more strong.

Narrator: praskovia tests Her new material.

Will it be stronger than the Hindenburg's original fabrics?

She's using a machine that will Test them to destruction.

Basically pulls away Until the sample is broken,

And then the force is measured.

Lab technician inge desmet Loads the tension machine

With the material used In the hindenburg

And sets the test running.

♪♪

The force ramps up...

And rips apart the cotton.

It gives us around 200 newtons Of force to break it.

Narrator: Praskovia runs the same test On her brand-new material.

♪♪

It doesn't rip Until 700 newtons.

Her modern fabric Is much stronger.

Compare it to the cotton-based Material

Used in hindenburg,

This is 3.5 times more strong.

Narrator: praskovia is confident She's found a material

To safely contain hydrogen...

♪♪

...And our skies Could soon be filled

By a fleet of brand-new Hydrogen airships.

♪♪

The crash of the hindenburg

Is one of the most spectacular Aviation disasters in history.

Modern investigations reveal A punctured hydrogen bag

Creates an explosive gas

And a spark of electricity That ignites it.

♪♪

35 people die In the catastrophic fire.

♪♪

But new discoveries From the tragedy

May mean a new age Of hydrogen airships is dawning.

♪♪

♪♪

♪♪

♪♪

♪♪