Original subtitles

Weapons have existed as long as humankind.

(tense music)

For millennia they have determined

the destiny of generations.

Weapons bring suffering and death.

They show what humans can inflict upon other humans.

But they're also intended to keep the peace

and pave new ways for technology.

(dramatic music)

For thousands of years,

humans have fought to rule the seas.

Three weapons significantly altered war on water.

Using unique experiments,

we demonstrate how conflicts play out on the oceans.

The torpedo, an insidious and extremely effective weapon.

It changed warfare.

It allowed the little guy to sink the big guy.

Mighty ship cannons

rule the sea for centuries.

You can imagine the horror

of being on the receiving end of 50 of those balls.

This sort of war is no picnic.

The mysterious Byzantine

flamethrower, Greek fire.

It's gonna set you on fire,

it's gonna set your ship on fire,

it's gonna set your siege equipment on fire.

Greek fire destroys entire enemy fleets,

but how can fire burn on the water?

What's the secret to their formula?

(dramatic music)

677 AD, war over Constantinople.

Muslim Arabic invaders lay siege to the Byzantine capital.

Ships equipped with catapults block the city walls,

cutting off all supplies to citizens under attack.

The result, a famine.

In the seventh century, Constantinople is the city,

it's the largest city in the world,

it's the capital of what is still a very powerful

east Roman or Byzantine Empire.

And it's the gateway to Europe.

So, this is a very serious attack

which could've had enormous geopolitical consequences.

It's war of religions.

Since the death of the Prophet Muhammad in 632,

Islam had spread rapidly,

and in 635 Arab warriors conquer Syria.

In 637, they seize modern day Iraq,

followed by Persia, Palestine, and Egypt.

(dramatic music)

In the north, the Islamic push for expansion

clashes with the Byzantine Empire

and its capital Constantinople,

the bulwark of orthodox Christianity.

(yelling)

A brilliant inventor named Kallinikos

gives the Bynzantines hope.

No portrait of him exists,

but we know that he worked as an architect

and probably was from present day Lebanon.

(dramatic music)

He presents Constantine IV with a new weapon,

a mysterious substance that when ignited,

burns bright with a broiling heat, Greek fire.

With it, the besieged hope

that they can finally break through the Muslim blockade.

The exact composition of Greek fire is still unknown.

Weapons expert Stephen Bull

wants to determine the most probable formula.

One of our most terrifying and mysterious experiments

is Greek fire.

Mysterious because the original recipe has been lost,

and what we've had to do is bring together

some of the most likely ingredients.

(dramatic music)

In Byzantium,

the blend of the incendiary weapon was a state secret.

Historical accounts mention amounts

of sulfur, caustic lime,

saltpeter, and crude oil.

Which at the time was referred to

by its Greek name, naphtha,

and extracted directly from the ground

at sites in the Middle East.

Mankind has consumed crude oil for thousands of years,

using it early on for weapons as well.

The people of the Stone Age

attached arrowheads to their spears

using asphalt-like bitumen.

In ancient times, oil was used to seal boats,

and in Babylon, it was allegedly also used for illumination.

The great oil boom of modern times

begins in the middle of the 19th century

with the drilling of the first wells.

Initially, its most important use

was powering petroleum lamps.

As early as the 1910s,

experts believe that the oil era was coming to an end.

But even larger oil fields were discovered

across the globe,

and this oil makes a revolutionary

new form of transport possible, the automobile.

(dramatic music)

In the early modern era,

oil is also the fuel for war machines,

for tanks and airplanes.

Without oil, an army is just scrap metal

in the middle of nowhere.

The 20th century starts off

with the first motorized wars in history.

The demand for oil dramatically increases.

Enemy oil supplies are deliberately attacked.

(dramatic music)

When you look at history and recent times,

it's always the case that whoever controls oil wells

and supplies also has all the power

and the potential to wage successful modern mobile wars.

(dramatic music)

A world without oil is impossible to imagine.

Oil is used in the production of plastics,

medicines, cosmetics, and countless other products.

Global demand, around 15 billion

liters of crude oil per day.

It's no wonder that wars are waged over black gold,

because among other reasons,

armies themselves are some of the largest consumers.

Oil is also the basis of Greek fire.

For our experiment, Stephen Bull wants to check

the proportion of the ingredients.

(dramatic music)

So, let's light up this sample

and see how it works.

(dramatic music)

It's burning quite nicely.

But is this mixture really

the Byzantine's wonder weapon?

What happens when it comes into contact with water

like it did off the coast of Constantinople?

Obviously that would be a very foolish thing to do.

It seems to make the fire worse.

It splutters, fades, and then gets worse again.

Since oil is the main ingredient of the fuel

it really blazes,

and the ingredients make the whole thing very, very sticky.

So, that means that once you get it onto an enemy ship

or onto a person, it sticks, and then you start to burn.

And it's very difficult to get it off.

If a ship was attacked with Greek fire,

it could not be extinguished with seawater,

so what could stop this liquid fire?

Finally, something we would recognize

from fire buckets, sand.

So, we're gonna give sand a go.

(dramatic music)

Sand smothers the flames,

but due to the issue of its weight,

a large supply of sand was out of the question

for the Muslim warships.

To have this stuff burning your ship,

you've really got no option.

Abandon ship or die.

With their difficult-to-extinguish fire,

the Byzantines want to burn down the fleet of the attackers.

But they face another problem.

How do they manage to get the flames

to reach the enemy ships?

The solution is a primitive pump known as a siphon,

which normally would expel a jet of water.

Only instead of spitting water, it spits fire.

Stephen Bull had this kind of pump recreated for our test.

(dramatic music)

(dramatic music)

On the backside it has a container for the flammable liquid.

With a double cylinder pump the liquid moves through a pipe

or hose up to the nozzle.

With the help of a fire bowl, the liquid is then ignited.

So, now we're doing it for real.

We've got not just a small sample of Greek fire,

we've got a while siphon full.

And as you can see,

we're needing to take quite a few precautions.

We've got fire suits,

and we got a firetruck right on hand.

And I'm really not quite sure how this is gonna work out,

and to say the least, I am a little nervous.

How dangerous is

a replica Byzantine flamethrower?

(dramatic music)

(muffled speaking)

Everybody ready?

We're gonna go now.

We can see that the ignition system is blazing away

merrily at the front, there.

And we're ready to shoot.

Two people are necessary to operate the pump.

On one side, air is sucked in.

On the other, fire comes out.

The fiery jet only ends when the tank is empty.

(dramatic music)

Our Greek fire works.

The historic mess of fire doesn't go out,

even on the water.

That was pretty spectacular.

We were getting a range of about 10 meters,

and it takes an awful lot of effort to pump that fire.

You will also notice that my colleague

was readjusting the nozzle as we were going,

improving the aim.

There's still a little bit of interference

from wind, though, I would think.

Quite an experiment, and at least partially successful.

But the galleys have got to be pretty close.

Could this invention really have forced

the Arab fleet to flee?

According to ancient reports,

up to three Greek fire hoses were installed

on Byzantine warships.

(dramatic music)

With its ability to project sticky flames,

the Greek fire siphon brought a new dimension to warfare.

Flame could now be used at sea.

It was a terrible shock for the enemy,

and the siphon also became a morale weapon,

a weapon which would be kept a deadly secret.

(dramatic music)

But how long does it take

until a ship goes up in flames?

Our next experiment,

simulating an attack on a wooden warship.

The pressure seems to be good,

the wind seems to have dropped.

We're in with a fighting chance.

(dramatic music)

Will Stephen's mixture burn long enough

to ignite the ship's wall from 10 meters away?

In no time, the ship's wall is ablaze.

The burning liquid sticks to the wood.

All the crew could do was watch helplessly.

So we can definitely say that that one

was a complete success.

The side of the enemy ship was blazing,

the water was blazing.

There's little doubt that the Greeks

would've won this naval engagement.

At that time, for water to be burning,

would've been quite extraordinary.

It's like a nuclear weapon or something

in that it has a new effect,

something that people don't understand,

and it's gonna be absolutely terrifying.

Equipped with Greek fire,

in 678 AD Byzantine ships advanced to face the Muslim fleet.

Before the commanders could realize what's happening,

their ships have caught fire.

Panic erupts on board.

(dramatic music)

The Arab invaders are forced to flee.

Constantinople keeps its independence

for the next 750 years.

It's almost as if the Byzantines

had been forced to the very last extremity,

and they'd dug out of their catalog

the last, ultimate weapon,

because the only way to save this city

and the whole of their empire was to deploy this weapon,

and it worked.

(dramatic music)

Greek fire became one of the most

feared weapons of the medieval world.

Anyone would avoid a ship carrying this weapon.

The only known authentic depiction of Greek fire

dates back to the 12th century.

The picture shows a victory of the Byzantine fleet

led by Emperor Michael in the civil war

against General Thomas.

The secret of this wonder weapon

from the eastern Mediterranean was strictly guarded.

After the Ottomans conquered Constantinople in 1453,

the knowledge behind Greek fire was lost.

And now another weapon triumphs

and soon makes the era of British rule

over the oceans possible.

(dramatic music)

August, 1588.

Several naval battles are underway in the English Channel.

On one side, Catholic Spain ruled by King Philip II

with his Armada of 130 ships armed with heavy iron cannons.

Philip wants to force England

to return to the Catholic faith.

Above all, the Spaniards are feared

for their ability of capturing ships.

The Spanish built big ships.

They were relatively high out of the water.

The men who commanded the ships in battle

were not sailors, but soldiers.

So, the ships were fought essentially

as mobile fighting platforms for soldiers.

And the object was to close with the enemy,

board, and take his ship.

On the other side

Protestant England, ruled by Queen Elizabeth I.

Their more agile ships are equipped with bronze cannons

which can fire from a greater distance.

The English commanders know

they must weaken the Spaniards from a distance.

In close combat, they wouldn't stand a chance.

Today these kind of battles

can be simulated on a computer with authentic ship models.

But what effect did the cannonball of the time really have?

(dramatic music)

Stephen Bull wants to find out.

How effective were the cannons of the early modern era?

A model has been recreated based on historical examples.

(dramatic music)

The great powers of the time had an arsenal

that ranged from fairly light cannons weighing 200 kilos

to heavier examples weighing over five tons.

Developing over a period of 500 years,

the cannon was a defining technology

of the early modern era.

Cannon changed both fortifications and ships,

and in so doing helped project

European sea power all over the world.

(dramatic music)

In Lutsk, Ukraine,

specialists have researched the construction plan

of a ship cannon from the late 16th, early 17th century.

Pipe length 1.5 meters,

with an inner diameter of 10.6 centimeters.

What we're gonna reconstruct here

is a full-blown nine-pounder of the 17th century.

Some of the features of our cannon

will include a touch hole here and a taper bore.

So, the powder charge will be at this end of the barrel.

What is gonna be special about this cannon

is that it will be firing a ball with full charge.

And if this works, its effect on a ship target

could be spectacular.

Unlike 400 years ago,

our cannon is not cast, but milled.

This is done for safety reasons.

A faulty casting could cause the cannon to shatter.

(dramatic music)

Only our cannonballs are cast, weighing 4 1/2 kilos.

They cannot explode just as they couldn't

during the time of the Spanish Armada.

Explosive grenades were only used later.

(dramatic music)

At a test site, Stephen Bull

wants to find out how accurately it can hit a dummy ship

from a distance of 100 meters,

and how much damage it really does.

So, this is our magnificent reproduction

of a naval gun from the middle of the 17th century.

And unlike most reproductions of cannons,

this thing can really fire

the solid round shot of about nine pounds.

And we're about to find out

what this could do to a ship of the period.

After four weeks, our cannon is ready.

The target, the ship structure 100 meters away.

From this distance,

can the cannon hit the side of the ship

with its first shot,

or at least strike the rigging and the mast?

Will the historical replica even work at all?

The principle behind cannons

and smaller, simpler firearms is actually very similar.

You have basically a tube that's closed one end,

and you put in black powder, for example,

a substance that can explode, and a projectile.

And then you ignite the whole thing

which results in an explosion.

Due to the sudden expansion in volume,

the projectile is shot through the tube very, very quickly,

and then keeps on flying in the same direction.

(dramatic music)

So, now we're preparing the powder charges,

and these are kept in this canister in one sealed bag.

In goes the charge.

1 1/2 kilos of gun powder

is necessary per shot.

So, here's the solid round shot

going down into the barrel.

It's a real moment of tension,

because I really don't know what's gonna happen next.

It's probably time that we fall back.

Well, I've never done this before,

and now they're taking aim over the barrel,

aim on the target.

So, it's imminent.

Now we'll find out if our cannon

can actually fire.

Go, go, go.

Will the amount of gun powder

be enough to shoot the 4 1/2 kilo ball 100 meters.

For centuries, gun powder

was the only propellant for firearms.

It was most likely invented in China in the 11th century,

where it was most commonly used for fireworks

as well as cannons.

In the 13th century the first gunpowder recipes

were recorded in Europe,

and after that this explosive knowledge

quickly spreads across the entire continent.

Gunpowder is one of those fairly basic things

that gets invented in two separate places.

The Chinese invent gunpowder

and use it to make rockets and fireworks.

The Europeans invent it and use it to make cannon

to knock down castles.

(pensive music)

Gunpowder ideally consists

of 75% potassium nitrate,

colloquially known as saltpeter,

15% charcoal, and 10% sulfur.

Demand increases rapidly due to

the mass use of firearms in the 16th century.

The main ingredient, saltpeter,

is so scarce that the profession of saltpeter makers

becomes more and more important.

Hundreds search on behalf of their respective countries,

despised by the locals.

Saltpeter is formed when animal

and human excrement mixed with the lime present in soil,

occurring frequently under stables or residential buildings.

(dramatic music)

You have to keep in mind that when

a saltpeter boiler arrives at a village,

there was always the fear that they would somehow

snatch part of your house away from you,

because it was clear they wanted the material.

And I wouldn't welcome someone as a friend

if they threatened my own home.

But in this case, of course,

the authorities also depend on the raw material.

At the end of the 19th century

gunpowder for firearms was replaced

by the low smoke option of cellulose nitrate.

Today we use gunpowder primarily as fuel for fireworks.

(dramatic music)

Our 4 1/2 kilo cannonball is ready to be shot

out of the cannon with 1.5 kilograms of gunpowder.

But will that amount be enough

for it to hit the target 100 meters away?

(dramatic music)

(cannon booms)

(dramatic music)

So, the gun has recoiled

all the way back from the gun port,

and if you look at the gun port,

it's actually damaged the gun port.

And even from this distance,

I can see a hole in the lower right hand portion

of the target.

I think we've gotta go and give that a closer look.

16th century ships

have varying wall thicknesses of up to 50 centimeters.

Not every shot would've been able to penetrate them.

So, the first shot is clearly a hit.

Clean through the target.

So, one shot may not sink a ship,

but you can see it's gone clean through the wood.

But even if the ball doesn't damage the crew,

then there's gonna be plenty of these.

Wood splinters flying around inside the vessel,

and these can cause horrible injuries.

Shrapnel could cause serious injuries,

deep wounds that later could also become infected.

Blood vessels could be ruptured,

or important organs could be damaged.

In naval wars the use of cannons

had a powerful psychological effect on ships crews.

(dramatic music)

You can imagine the horror

of being on the receiving end of 50 of those balls,

and the sort of damage that it can do to a crew

when you're at sea,

and the primitive sort of medicine

that you might be lucky enough to receive.

This sort of war is no picnic.

For our next experiment Stephen Bull

wants to try a different cannonball.

Will it do more damage to the ship?

So, now we're gonna try something different,

something potentially more vicious.

This is actually what you call a chain shot.

It's effectively two half solid shots

linked by a chain.

And the idea is that the shot will whirl in the air,

and potentially you can cut things in half.

Whether this is rigging or a mast,

or even the human body.

This is a really vicious weapon,

and as far as I'm aware, it's never been test-fired.

They were used for close range attacks

against the deck or mast, or even against the crew.

Pirates, in particular, were big fans of this weapon.

With the next try,

the chain shot is aimed a little higher,

right at the rigging.

(dramatic music)

Actually, I'm quite concerned

about what's gonna happen now.

A lot will depend on whether the chain

stays in one piece as it leaves the barrel,

or will we land up with merely fragments

coming from the gun,

and will the aim be disturbed

by the fact that it is whirling chain.

Okay, we gotta fall back now.

Let's make it about 100 yards behind the bank.

Let's move.

(dramatic music)

The cannon is charged, the crew ready.

Time to fire the chain shot.

(cannon booms)

It's a hit.

(dramatic music)

The chain shot tore a huge hole in our ship's wall.

This is interesting,

because the shot was aimed higher,

but has actually gone in lower, closer to the waterline.

And I'm not sure whether the chain has whirled,

or whether we've got the chain and the shot

all going through together in the same spot.

But in any case, the hole is far, far bigger

than the hole from the solid round.

So, anything behind this chain shot as it goes through

is gonna be pretty badly damaged.

Both experiments have demonstrated

that even just one cannonball could seriously damage a ship.

And in historical naval battles, hundreds of these weapons

faced off against each other.

When the Spanish Armada encounters the English fleet,

they have over 100,000 cannonballs on board.

So why can't they manage to defeat the English?

Their downfall is a result

of their range and firing speed.

The Spanish cannons are stored on unwieldy racks.

In the narrow below-deck area reloading takes too long.

(dramatic music)

This is a key technical difference

between the English and the Spanish fleets

in the campaign of the Spanish Armada of 1588.

The English can reload their heavy guns

and fire them many times.

The Spanish load their guns, fire them, and that's it,

they're then left with only infantry weapons,

small guns, muskets.

And the English refuse to engage the Spanish

at close quarters.

They just hang off at a distance

and use range to bombard the Spanish

until they're disabled and have to retreat.

(cannons boom)

For several hours,

the Spaniards are constantly under fire.

Their strong ships receive countless hits,

but only five vessels sink during the fierce sea battles

off the south coast of England.

(dramatic music)

As they retreat,

the Armada is battered by a severe storm.

More than 10,000 Spaniards die

and only half of their fleet manages to return home.

In the decades to follow,

England replaces Spain as the world's leading naval power.

The British Crown secures their dominant position

through several naval wars.

And with control of sea trade

and an ever-increasing amount of income from their colonies,

the empire becomes the richest nation in Europe.

(dramatic music)

In 1805, after their victory

against Napoleon's fleet at Trafalgar,

England becomes the undisputed superpower of the seas

for an entire century.

The cannon continues to be

a decisive weapon for the Royal Navy.

The naval gun remained relevant until the 20th century

when heavily-armored ships began to be built.

(dramatic music)

Thousands of cannons were melted down.

Our replica will also be rendered harmless after filming.

(dramatic music)

A new weapon in competition with the ship cannon

hits its victims without a warning.

It approaches almost silently,

and then causes devastating damage, the torpedo.

February the 7th, 1945, near Bergen, Norway,

Operation Caeser, the most secret submarine mission

of World War II.

To this day it is the only known instance

of a submarine that was successfully torpedoed

by another submarine.

The U-864, a long range submarine of the German Navy,

is headed towards Japan.

But it's detected along the way.

(yelling in foreign language)

Venturer, a British submarine

tracks a propeller noise of the Germans

to calculate the course of the submerged enemy.

They fire four torpedoes, and one of them is a hit.

All 73 crew members aboard the U-864 die.

This is the first effective underwater duel

in military history.

Weapons expert Stephen Bull knows

that the development of the torpedo

was a lengthy and technologically complicated process.

In its first decades,

the torpedo was extremely expensive

and barely provided any military advantage.

The torpedo is one of the most interesting weapons

of naval warfare.

In the 19th century it transformed strategy

because it gave small nations and small ships

the ability to take on the major fleets of the world.

The technology behind this weapon

is curious and fascinating.

From the beginning

there were many different versions of the torpedo.

For example, the German G7a torpedo of World War II

is over seven meters long and weighs 1.5 tons.

The only thing it has in common with other torpedoes

is self-propulsion and an explosive charge.

(dramatic music)

One precursor of the torpedo is the sea mine.

In the 18th century its aim

is to destroy enemy ships using a blast from below.

An attractive weapon option for countries

that are not the strongest at sea.

But the mines are not very effective.

They are stationary and will only explode

if a ship runs into them.

Contemporary experts refer to naval mines

as a sort of defensive torpedo,

but fleets all over the world

still long for a functional offensive torpedo,

an explosive charge that can precisely hit the enemy.

(dramatic music)

On February the 17th, 1864,

during the American Civil War,

a so-called spar torpedo was put into use.

A rod with an attached explosive device

that could be rammed into an enemy ship.

During the American Civil War,

the mine was also used as an offensive weapon

by mounting it on the end of a long pole.

The Confederate submersible the CSS Hunley,

which was essentially a man-cranked primitive submarine,

seven men sitting at a crankshaft

turning it rapidly to propel this thing

with a long pole on the front

and a mine on the end of the pole,

which was detonated by contact.

This makes the Confederate vessel

the first submarine ever to sink an enemy ship

with a torpedo during battle.

And after the successful hit,

the Hunley itself disappears without trace.

The ship wreckage is not found again until 1995,

when the mystery is finally solved.

The Hunley was too close to its own torpedo.

The shockwave of the explosion

destroyed the sailors' lungs.

The spar torpedo was a technical dead end

that killed more than just the enemy.

(dramatic music)

After the end of the American Civil War,

two Europeans contribute to the next phase of development,

British engineer Robert Whitehead and Giovanni Luppis,

an officer of the Austro-Hungarian Navy.

Together they equip the torpedo with self-propulsion

using a pressure tank of highly compressed air

as a energy source.

Now the torpedo should be able to head for its target

on its own.

It has a range of 300 to 400 meters,

traveling at a speed of only 11 kilometers per hour.

This early form of the torpedo

goes down in history as the Whitehead.

(dramatic music)

Indeed the torpedo, as we now know it,

was known as a Whitehead for the first 25, 30 years,

and everybody bought the patent to use the torpedo

from Robert Whitehead.

It changed warfare.

It meant that small vessels could sink

the biggest battleships.

It leveled the playing field

in the way that the longbow did in medieval warfare.

It allowed the little guy to sink the big guy.

(explosion booms)

Stephen Bull wants to find out

how a Whitehead torpedo works in practice.

Is it possible to precisely hit a target with this weapon

that is more than 100 years old?

As early as 1868 another innovation

was added to the Whitehead torpedo.

(dramatic music)

The fish behind me with the green and black markings

is the Whitehead torpedo of the late 1860s.

It has a hydrostatic pendulum.

The pendulum hydrostat includes a pendulum and a bar,

so when the torpedo changes its attitude in the water

the pendulum moves.

The pendulum activates a rod,

and the rod moves the hydroplanes at the end of the torpedo.

By doing this, the attitude of the torpedo

can be adjusted,

and its stability in the water much improved.

In our test, we want to hit a dummy ship

25 meters away.

To match the early torpedo,

Bull operates it at low speed.

The rudders of the Whitehead replica

must be adjusted in advance.

They can't be corrected after the launch.

(dramatic music)

The weather's quite good at the moment,

but there's a bit of a current.

And it's causing the target to drift

and the torpedo to drift,

and we're going to try to get the two into alignment.

When they're in alignment we can press the button

and the torpedo can run.

I think we look ready.

Yeah, we look ready,

then we're ready to start. Okay, we're ready to go.

Torpedo run!

(dramatic music)

Will the Whitehead torpedo hit our dummy ship?

It's drifting off to the left somewhere.

The torpedo can't hold course

even on a calm sea.

A diver heads out to recover it.

In the early days of the torpedo

it was actually very difficult to hit a ship.

Now, this is one reason that they would launch

several torpedoes at once.

A group of torpedoes moving across the ocean

has a much higher chance of hitting a ship.

And your chances are better still if it's a group of ships.

The early torpedoes of the 19th century

still had a long way to go

before becoming a war-deciding weapon.

Theoretically a Whitehead torpedo

is capable of hitting a target from a distance

using self-propulsion and depth control.

But even a slight current diverts it from its course.

I think it's most unlikely

that this would've been a very successful weapon of war,

so the idea that they changed the system

within two or three years is really no surprise to me.

It only takes two years

before the next phase of development begins.

And the solution that will revolutionize the torpedo

comes from the civilian sector, the gyroscope.

Invented in 1810 by Johann Gottlieb von Bohnenberger,

a professor of physics, mathematics,

and astronomy at the University of Tubingen.

(dramatic music)

In 1870 a gyroscopic instrument

was first added to a torpedo.

The Howell torpedo, named after John A. Howell,

an American rear-admiral,

uses a gyroscope for stabilization.

The principle of the gyroscope

depends on centrifugal force.

So, providing some force,

the gyroscope spins,

and now it maintains its stability and direction.

(gentle music)

Due to the rotation,

an equal force acts outwards at every points on its axis.

This keeps the gyroscope stable.

In a torpedo the gyroscope is attached to the rudder

via a rod system.

When the current pushes the torpedo to the side,

the gyroscope automatically corrects the course.

Modern torpedoes have a computer chip

with a built-in gyroscope function.

Similar technology was used in all sorts

of navigational equipment,

and even today an electronic version

is still in the smart phone,

which knows which way its facing however you hold it.

(dramatic music)

Our next test, a gyroscope-controlled torpedo.

The silver torpedo here in front of me has a gyroscope.

So, in theory this torpedo

will be much more accurate than the old example.

The question is, will this experiment demonstrate the point?

(dramatic music)

So, the torpedo's pointed at the target

and we're gonna start it off.

We're ready to go.

Go!

(dramatic music)

It's moving a little faster this time.

Thanks to the gyroscope,

the torpedo cannot be swayed from its course.

Actually, this is looking good.

It's pretty straight.

Three, two, one.

Actually an excellent shot, even though I say it myself.

The decisive stage of development

with the addition of the gyroscope,

the torpedo will become a strategically vital weapon

over the coming decades.

For the first time,

submarines equipped with torpedoes

are used in large numbers during World War I,

particularly by the German Empire.

From 1914 to 1918,

German submarines sank a total of more than 6,000 ships.

One of the countless human tragedies

is the sinking of the British Lusitania.

On May the 7th, 1915,

the German U-20 attacks a passenger ship with a torpedo.

Within only 18 minutes the 239 meter long ship sinks.

Close to 1,200 people perish.

Only around a third of the passengers manage to survive.

Among the victims are many Americans.

This only increases the will

of the United States of America

to enter the war against Germany.

There is only one way to hunt the German submarines,

intercepting the radio traffic,

a task of the secret services.

Intelligence has been a critical part of war

since the dawn of time.

Knowing what your enemy knows,

and making sure he doesn't know what you know

gives you an advantage.

World War II begins in 1939.

Intercepting German radio traffic is no longer possible.

The Nazis use a cipher machine

that was developed by Arthur Scherbius in 1918,

its name Enigma.

(dramatic music)

In the Second World War,

we come to the German Enigma machine,

which was invented to deal with the problem

that the British had broken German radio signal codes

in the First World War,

and had used them very effectively.

So, this mechanical electrical encryption system

was designed to be unbreakable.

Encryption techniques had been used before,

but the Enigma combines different mechanisms

into a single complex code.

A very simple encryption technique

is to just move along in the alphabet,

so A becomes B and B becomes C.

But this is very easy to crack.

Enigma had a different method.

Every letter was replaced by another letter,

but you didn't always move

the same number of letters forward.

Enigma itself was a machine similar to a typewriter,

and it had three rollers that rotated

a little bit further with each input.

So, if you knew the exact position of the rollers,

you could calculate how much forward or backwards

you needed to move and you could decode a text perfectly.

For months Allied specialists

have tried in vain to crack the Enigma code.

Capturing the crew of a German submarine

and with the help of Polish specialists,

they are finally on the track of the mystery.

A few radio transmissions are decrypted,

but it still takes too much effort and too much time.

At this rate, there is no way

that they'll stop the terror of the German submarines.

(dramatic music)

An invention from a reclusive mathematician

ultimately turns the tides in the brutal battle

of the Atlantic.

Alan Turing develops a highly complex deciphering machine

nicknamed the Turing Machine.

It can crack the daily new Enigma encryptions

much faster than any other device,

making it a predecessor of the modern computer.

In the battle of the Atlantic,

the critical battle of the Second World War

which kept Britain in the war,

what the British did initially

was to use that information not to fight the enemy,

but to make sure the enemy couldn't find the convoys.

They would move the convoys away from the submarines.

Once they knew where the submarine was,

they moved the convoy.

(dramatic music)

If the ship changes position,

the torpedo can't hit anything.

Its course can't be changed.

The next leap in technology is a torpedo

that can self-correct its course.

During World War II,

the so-called passive process was developed.

The torpedo was able to detect

the sound of a ship's propellor and steer towards it.

Active tracking is perfected during the Cold War arms race.

The torpedo itself generates sound waves,

and heads towards the echo

that bounces back from the target.

But the torpedo is also a safety risk

for the carrier ship.

Many accidents occur.

On August the 12th, 2000,

the loss of the Russian nuclear submarine Kursk

is most likely the result of a defective torpedo.

118 people die.

Various carrier systems including surface ships,

airplanes and helicopters all play a role

in the history of the torpedoes.

But submarines are certainly the most important of them all.

The US Navy deploys them in formations

known as battle groups,

a complete squadron of combat ships and submarines.

In coordination with an aircraft carrier,

they can control entire strategic sea zones.

(dramatic music)

The aircraft carrier is the ultimate naval weapon system.

It's a mobile airfield with 50 or 60

or even 80 frontline combat jets on board.

It can move hundreds of miles in a day.

It's capable of operating at sea for long periods.

Today, further torpedo developments

focus primarily on speed.

Now effective countermeasures like decoys

or anti-torpedo weapons are available.

But the faster a torpedo reaches its target,

the harder it is to fend off.

(dramatic music)

In the future the navies of the world's superpowers

are betting on

a completely new technology, supercavitation.

(dramatic music)

With the help of this futuristic technology,

torpedoes and potentially even entire submarines

will be able to race through the seas

at the speed of sound.

It utilizes a physics phenomenon,

a bubble filled with water vapor

almost completely envelopes the underwater vessel

up to the tip,

greatly reducing the flow of resistance.

The Russian Navy already has a torpedo

with this technology in use,

which can achieve a speed

of more than 300 kilometers per hour.

And so, the race for the most

destructive weapon at sea continues.