01x01 - Grey Wolves

[bunniefuu]

The Atlantic Ocean,

the scene of one of
World w*r II's bloodiest battles,

the Battle of the Atlantic.

This is the forgotten front line.

It's a battleground that saw the deaths
of thousands of British sailors.

And here, danger was everywhere.

Not only do they have the harsh
Atlantic weather to contend with,

beneath the waves
could be a German U-boat,

ready to fire a torpedo.

The Battle of the Atlantic is much more
than just a single battle.

It's a bloody and
devastating campaign.

In this w*r, we can't just survive it,
we have to win it.

Britain's forces risked
everything they had.

The w*r was an extraordinarily
bloody conflict.

As an ex-Marine, I'm going to reveal

how British troops coped with the
constant threat of German U-boats.

Over the course of just a few months,


And as an engineer,

I want to get to grips with these
incredible k*lling machines.

What made them so deadly.

The more ships it took down,
the greater the fame and accolade.

And how they were eventually defeated.

This time, the Nazis strike first
in this bloody conflict.

Well, the British were devastated.

If one submarine can get in,
can others?

Churchill is overwhelmed
by the growing death toll.

I can't stress enough
how shocked Churchill was.

He just couldn't believe it.

Until the Royal Navy fight back
with deadly countermeasures.

It's a numbers game.

The more depth charges you can deploy,

the more relentless that battering
from the shockwaves is.

And the British forces make a discovery

that would change the w*r forever.

This is the campaign that decides
the outcome of World w*r II.

The Battle of the Atlantic begins

on the very day Britain and France
declare w*r on Germany.

And it starts with an attack
on a defenceless ship.

The passenger liner, SS Athenia,

is travelling across the Atlantic.

There are 1,103 passengers on board.

On 3 September at 11.15am,

it's over 200 miles into its journey

when Prime Minister
Neville Chamberlain's speech

is broadcast over the radio.

A state of w*r would exist between us.

Chamberlain is announcing that Germany
has not responded to Britain's ultimatum

and have failed to withdraw
troops from Poland.

And that consequently,

this country is at w*r with Germany.

Six hours after Britain's
declaration of w*r,

the passengers are sat down for dinner

and where the outbreak of w*r is,
the hot topic of conversation.

They were ordinary people making
an ordinary transatlantic crossing.

They had sailed
before w*r had broken out

and were well under way, so

there wasn't necessarily any expectation

on the passengers that

this was going to be anything
other than a normal crossing.

And as the food is being served,

nobody on board suspects
that their ship is being stalked.

Lurking beneath the waves
is a 65-metre-long German U-boat.

The U-boat has been stalking
the SS Athenia for over three hours.

Then, as dusk falls,

it strikes.

At first, there's utter chaos.

People don't know what to do.

After all, this was a civilian vessel,
a passenger liner.

It shouldn't have been attacked.

Nobody's quite sure what's happening.

The ship is lurching from side to side.

People are screaming.

There would have been a considerable
amount of shock damage.

People would have been picked up
and thrown across the ship

and may have suffered
severe injuries or even death.

There's panic on board.

Passengers are racing
from their cabins to the deck,

where lifeboats are being
frantically loaded and launched

into the freezing cold Atlantic Ocean.

Hidden in the darkness,

watching the mayhem
as the cruise liner sinks,

is the German commander
of the U-boat that torpedoed it,

Fritz Julius Lemp.

Only 26 years old, Lemp has built a
reputation as a hot-headed rule-breaker.

Lemp was one of the pre-w*r
U-boat regulars.

He was very experienced

and he had been given
very clear instructions.

No sinking merchant ships
without warning.

It takes at least 14 hours
for the Athenia to sink,

with the loss of 118 lives.

With the ship a confirmed k*ll,

Lemp sneaks away
to hunt other targets.

But if Lemp thought he was
going to return home as a hero,

he was very much mistaken.

All hell breaks loose.

He gets sent to Berlin

to possibly be court-martialed,

because the Germans have already
gone on the record saying,

it wasn't us, it's the British.

Hitler still hopes
the British won't follow through

on their declaration of w*r.

So sinking the Athenia
is a huge mistake.

The Battle of the Atlantic has begun.

In London, the British w*r machine
is getting into first gear.

But out in the Atlantic,

the Germans have already made
a key strategic decision.

The Nazis knew they couldn't compete
with the Royal Navy on the surface.

On the whole, the German ships were
inferior in firepower and in number.

So instead, they put their faith
in the subsurface U-boats.

As an engineer,

I've always been fascinated
by these aquatic k*lling machines.

But I've always struggled to grasp

why the Germans thought their U-boats
would win the Battle of the Atlantic.

To help understand,
I've come to Birkenhead

to meet author and journalist
Simon Parkin

and a real-life U-boat.

Oh, here we go, Simon.

It's actually pretty big, these U-boats,
weren't they?

Yeah, this is like
a particularly large version.

But yeah, it gives you a good sense
of the scale of the thing.

Yeah, it absolutely does.

So tell me, what was it
that made these German U-boats

such deadly weapons of w*r
during the Battle of the Atlantic?

What made them so deadly
was their ability

to move very quickly
on the surface of the ocean.

When surfaced on the water,

the U-boat was very difficult

to be detected by early sonar

that the British were using in the first
part of the Battle of the Atlantic.

So it could really evade detection.

It strikes me then, stealthiness
and speed were real features

that made them such deadly
adversaries to the Allies.

Well, let's have a little look
at some of the weaponry

that these U-boats carried,
Simon.

On a Type 7 U-boat
could carry 14 torpedoes,

or eels, as they were known,
to the crew.

In the early stages of the w*r,

the detonation mechanism
would come in two varieties.

There was either one that would
explode on impact…

and then a second version which was based
on a sensor for magnetic field changes,

which would be able to essentially

recognise when there was
a ship's hull above it.

A captain would try to aim the torpedo

underneath the hull of a ship

so that it detonated in
key location right underneath.

And in this way, a single torpedo
could take down a very large ship.

Back in London,

the reality of the U-boat threat
has hit home and sent shockwaves

through the British government.

Prime Minister Chamberlain knows

that someone of experience is needed
to head up the Navy during the w*r.

So he calls on a backbench MP
to be his head of the Admiralty.

And that person

is Winston Churchill.

Churchill becomes
First Lord of the Admiralty

at the outbreak of
the Second World w*r.

It's a position he held
at the outbreak of the First World w*r,

which he left under a very large cloud,

having made a complete mess
of running the w*r at sea.

And it was his ambition, I think,

to return to that office
and vindicate himself.

Churchill's all too aware of the
seriousness of what Britain faces.

The Navy must keep
control of the Atlantic.

If Hitler's allowed to take over
this vital supply route,

Britain will be starved of food
and materials to make weapons.

And if that happens,

Britain will have no choice
but to surrender to the Nazis.

Supplies start arriving
from all over the world,

predominantly from the US,

but the Empire
also plays a vital role.

And the ability to keep
these supply channels open

is what the Battle of the Atlantic
will be all about.

For the last 200 years,
Britain has depended on imported food.

It depends on imported raw materials
for its industrial output.

And if it's waging w*r,

it depends on imported
high-end products,

military hardware,
specialist equipment.

And in order to feed and arm
and equip Britain,

the sea is absolutely fundamental.

Those who controlled the seas

would ultimately determine

how the battles in Western Europe
would be fought

and who would win those battles.

One week into the
Battle of the Atlantic,

and the Allies have
already lost 16 ships

and thousands of tonnes
lie on the ocean floor.

Yet no U-boats have been destroyed.

Britain is unprepared
for the scale of the U-boat attack.

And Churchill immediately pushes for armed
escorts to accompany the supply ships,

and this does help
slow down the losses.

But on the north coast of Germany,

a plot is being hatched that will strike
at the very heart of the Royal Navy.

The Battle of the Atlantic begins on the
very first day of the Second World w*r,

and Churchill knows it's imperative

Britain takes control
of the Atlantic waters

so that food and other vital supplies
reach British shores.

Now, the Nazis are planning
a daring U-boat mission

to strike at the very heart
of the Royal Navy.

In charge of all U-boat missions is
a rising star of the Third Reich Navy,

Rear Admiral Karl Dönitz.

Dönitz is a critical figure
because he's the one officer

actually who believes that
the U-boat is the decisive weapon,

not a decisive weapon,
but THE decisive weapon.

He's also a convinced n*zi.

The U-boat crews respected him.

He was seen as the kind of
father of the service,

the lion, as they called him.

He was very trusted,

but very ambitious for his men,
very ambitious for the service.

Dönitz's view of how a future w*r
should be conducted was very simple.

It was essentially,

give me enough submarines and
we will starve Britain out of the w*r.

And he had a very simplistic view of
what those submarines were going to do.

They were going to sink ships.

Eventually, they run out of shipping
and they run out of food

and they run out of
raw materials and they surrender.

Dönitz doesn't have the number
of U-boats that he would like

and is constrained by Hitler's caution,

but he's still determined
to escalate his attacks

and he devises a plan to strike
at the very heart of the British Navy.

On the 8th of October, 1939,

a U-boat leaves
the German port of Kiel

and heads north.

It will take five days for U-boat 47
to reach its destination.

A large section of water in the Orkney
Isles that leads out to the Atlantic.

Scapa Flow.

Scapa Flow is the main base of
the Royal Navy's home fleet.

A very large, very powerful fleet.

Fabulous harbour.

It's one of the finest
that you can find,

certainly anywhere
in the Northern Hemisphere.

U-boat 47's mission is to get in
and destroy the fleet harbouring there.

In the early hours
of the 13th of October,

over 50 ships are moored there,

ready to head out into the Atlantic
when the order comes.

And none of them
have the faintest idea

that a U-boat is
prowling beneath them.

For the German U-boat crew,

striking Scapa Flow is more
than just a tactical decision.

It's personal.

Scapa Flow is a name that is absolutely
reviled by the German people

because this is where the
German fleet had to surrender

and was incarcerated
at the end of the First World w*r

until the whole fleet is scottled
and sinks there.

So Scapa Flow was a humiliating
location for the Germans.

So the opportunity to get the U-boat
into Scapa Flow of all places

and do some damage in there,
this is absolutely immense.

This daring mission is given to one of the
Third Reich's rising U-boat commanders,

Gunther Prien.

Prien is described as clean-cut,
c*ck and a fanatical n*zi.

He's already sunk three ships
during his first patrol in the w*r

and is deemed to be the perfect choice
for this audacious assignment.

Prien was highly trained,
very motivated,

with a well-trained
and well-disciplined crew.

Prien, what can only be described
as an extremely brave

and professional piece of
seamanship and navigation,

manages to penetrate one of the
passages into Scapa Flow

that has been partially blocked.

Having reached their destination,

Prien orders his crew to set
the U-boat down on the seabed.

He and his men then
sleep through the day.

They'll attack at night,
under the cover of darkness.

Late into the night,

U-boat 47 silently rises to the surface,

ready to start its attack.

Prien lines himself up…

and fires.

One torpedo from his salvo
hits the very bow of the Royal Oak,

in the vicinity of the paint locker.

The crew
think it's an internal expl*si*n.

Prien
reloads his torpedoes and fires again.

And this time he gets three hits
on the side of the Royal Oak.

Pretty much blows
the side of the ship in.

Prien's attack kills over 800 people,

and 700 of the bodies
have never been recovered.

With the attack complete,

Prien now has to escape

the largest fleet in the British Navy.

They must be expecting,
at any minute,

that the Royal Navy's defences

are going to absolutely
galvanise into action.

The shore battery is opening up,
you know, and they don't.

There is just no reaction.

He must have been a very relieved man

to have got U-47 in, out, succeeded
with the task that he was given,

and then submerge again
into the North Sea and disappear.

Prien returns to Germany
to a hero's welcome.

He receives a medal for bravery.

The knights cross with oak leaves and
instantly becomes a national hero.

Going into Scabber Flow
and sinking a British battleship

looks good on the news reel.

It gives them a big shot on the up.

So the U-boat becomes,

in many ways, a poster boy
for the party and the party's w*r.

The U-boat is a kind of
n*zi w*r machine.

Well, the British were devastated.

This was their main fleet's
operating base.

If it's not secure, where do they go?

And if one submarine can get in,
can others?

Churchill and the Navy
had been caught napping.

But immediately, Churchill orders
defences to be built around Scabber Flow,

so something like this
never happens again.

And he goes one step further, too,
by putting together a naval task force

with the job of hunting down U-boats
anywhere in the Atlantic.

Churchill wanted everybody
to get on a horse

and chase off after the enemy.

And as far as he was concerned,
if the enemy's out there,

you go and hunt for him.

The Navy said,
this is a waste of time.

Looking for a submerged submarine
in the Atlantic, it's a joke.

What we need is to be
in the right place at the right time,

so when the eagles come to feed,

we're right there to intercept them.

That's how we deal with this.

Less than two months into the w*r,

and nearly 400,000 tonnes of ships
have been lost to U-boats.

g*ns are fitted to merchant ships,

and Churchill pushes for more naval
vessels to escort the Atlantic convoys

across that massive stretch of ocean.

And most importantly,

the naval ships are now fitted
with a piece of equipment

that has the ability to defeat U-boats.

Depth charges.

Now, I was a marine for five years,

so I know my way around
expl*sives and weapons.

But how do you attack something
when you can't even see it?

Nick Hewitt, head of collections at
the National Museum of the Royal Navy,

can explain just how these U-boat
k*lling weapons worked.

It's very like a mine.

It's an expl*sive device
to go off under water.

You can set them
for a particular depth,

you deploy them by various means.

The idea is that they will go off in the
water and the shockwave will break,

bust the seams of the submarine and
cause it damage and cause it to surface.

So you're not trying to actually
hit the submarine with this,

you're just trying to have it
go off somewhere near it.

How close would they have to get
to the submarine

to sort of pop rivets within it, then?

Yeah, pretty close.

Meters, really.

And you also need an awful lot
of them to do any damage,

so it's a numbers game, really.

The more depth charges
you can deploy,

the more relentless that kind of
battering from the shockwaves is.

The most common way of deploying
them is off the back of the ship,

so you have depth charge rails on
the stern and you kind of literally

drop them over the back
as you pass over.

Later in the w*r, they had to introduce
a forward-firing anti-submarine weapon,

but it has to fire forward far enough

that it doesn't cause damage
to your own ship,

because if you just fire
something off the front,

you're going to go over
the top of it as it blows up,

which is going to wreck your ship.

Hang yourself from your own petard.

It's a mortar, basically.

It's the same technology
that the military use on land

and that fires a mortar b*mb

far enough ahead of the ship
to do this kind of damage.

The expansion of the
use of depth charges

starts to make a difference
in the Battle of the Atlantic.

And by the end of 1939,

the Allies sink nine U-boats.

This is positive news that Churchill is
keen to announce to the nation.

He tells Britain that he's pretty sure

half of Germany's U-boats
have now been sunk.

An incredible achievement,

except that it's not true.

Churchill's exaggerated U-boat kills
are wishful thinking.

Many more U-boats are attacked
than are ever sunk.

To be sure that you've sunk a U-boat,

you have to retrieve
critical information.

Even a slick of diesel oil is not enough.

What you actually need
is some human remains.

You need the doctor on the ship

to pick up something
and identify it as human.

It's usually the spine and rib cage.

That's your confirmed k*ll.

Churchill knows his speeches

are powerful pieces of propaganda
for the British population.

And even as the Battle of the Atlantic
swings in favour of the Nazis,

his speeches become
more and more positive.

But even if Churchill is

truly hopeful of fighting back
against this U-boat menace,

he's blissfully unaware that the Nazis
are about to take a huge step forward

in their domination of the Atlantic.

By May 1940,

the Battle of the Atlantic
has been raging for eight months.

Winston Churchill has been in charge of
the Navy since the beginning of the w*r.

But the country has lost faith
in its Prime Minister,

Neville Chamberlain.

And he's replaced by Churchill.

He had a real chance

to make life-or-death speeches
in the Commons,

to set the tone.

He was the right person
to kind of whip up the oratory

around this patriotic w*r
and taking a fight to the enemy.

He was the obvious choice
in many respects.

Being all too aware of the dangers
faced in the Atlantic,

Churchill is now in the position

to divert more resources
to defeating the U-boats.

But a major event in Europe

is about to change everything.

The fall of France.

On the 25th June,

France surrenders to the Nazis.

Churchill must focus
all military resources

on the upcoming Battle of Britain.

I can't stress enough
how shocked Churchill was

by the rapidity with which
the French went down.

He just couldn't believe it.

It was over.

The fall of France
changed Winston Churchill's plans.

France was now
part of the Axis powers.

The front line wasn't
in Europe any more.

The front line now
was the English Channel.

The front line now
was the North Sea.

It was in the Atlantic Ocean.

Churchill says that during the w*r,

the only thing that really ever
scares him is the U-boat peril.

These fearsome vessels
stalk their prey

and attack without warning.

Before the fall of France,
to reach the Atlantic,

German U-boats needed to risk travelling
through the narrow English Channel,

where they were easier to locate,

or take the long way round
past the top of Scotland.

Now, Admiral Doenitz can move his
U-boats into French ports and bases,

giving him a clear gateway
to the open ocean.

Doenitz believes that access
to these new bases

will tighten the Nazis' grip
on the Atlantic.

It absolutely turns
a w*r at sea on its head.

From the British and the French
pressing down on Germany at sea and

basically isolating
and squeezing Germany,

all of a sudden, Germany is in a position
to do exactly the same to Britain.

They are closer to the convoy routes
to their bases now.

It's an absolute godsend
for Doenitz and the Nazis,

and therefore a disaster
for the British.

Access to the French coast
has given the Nazis the edge

in the Battle of the Atlantic,

and they're making
the most of their advantage,

attacking convoys and ships at will.

Certain U-boat captains become
household names in Germany.

One of the most famous amongst them
is Commander Otto Kretschmer,

also known as Silent Otto.

Some say he earns his nickname by use
of the silent running mode of operation

when he's on a mission in his U-boat,
making it much more difficult to detect.

He's also ruthlessly efficient.

Where some commanders might fire

multiple torpedoes at a target,

Kretschmer becomes
famous for his phrase,

one torpedo, one ship.

Now, the manufacturer's
guidelines on submarines

was fire from a kilometre away from
the vessel you were trying to attack.

Otto turns that rule book on its head,

and in order to only expend
one torpedo taking out a vessel,

you need to be as near
to that vessel as possible.

On the 25th July, 1940,

Otto takes his U-boat
out into the Atlantic.

Within a few days,
he's attacked and sunk four ships.

Then, on the 31st July,

he spies a convoy.

Kretschmer takes his U-boat
right into the centre of the convoy.

He takes out one ship,
which goes down in flames.

Then he waits for his opportunity.

About an hour later,
fires a second torpedo at another ship,

then waits again
and then fires his third torpedo.

So within one evening,

within just a few hours overnight,

he has devastated this convoy

and left unscathed
with a minimum of fuss,

the minimum of torpedoes fired

and really the maximum effect
on the shipping.

On this one patrol,

Silent Otto has either sunk or damaged

seven ships and taken 16 lives.

It was an incredibly effective tactic

and it really heralded the start of
what the Germans called the Happy Time.

I mean, around 18 U-boat commanders
doing untold damage to Allied shipping.

The Nazis' dominance in the Atlantic
has grown through the year

and by the start of 1941,

Churchill has decided
enough is enough.

So he creates the
Battle of the Atlantic Committee

to plan a fight back.

And with more and more ships
heading to and from Liverpool,

they decide to open
a command centre there.

Secret construction begins

and on the 7th of February 1941,

Western Approaches is open.

Beneath the ground of
this side street in Liverpool

is hidden this top-secret
naval operations base.

It was called Western Approaches

after the area of the ocean it would
oversee in the Battle of the Atlantic.

Simon, what is this place?

So this is the Western Approaches
command centre.

The key location from which the
Battle of the Atlantic was orchestrated.

Here we have the plot,
the main plot.

This is really, I suppose,

the equivalent of a live traffic map
that we might have today.

It was updated once
every two hours by Wrens,

who would ascend the ladder there,

and they would place little
pin tokens onto the sea,

showing the location of convoys
of the Royal Naval ships that were

protecting them, of U-boats,

in order to give a sense of the
current state of the Atlantic w*r.

How many people worked here?

I think there were around 200 people.

That was primarily Wrens,

young women of the
Royal Naval Service.

And then also officers who had perhaps
been passed over for a promotion,

or who had some reason why they
couldn't be serving on the ships at sea.

Presumably it must have been
quite crowded.



it's kind of rabbit warren of corridors

and stairways, alleyways and things.

It certainly is warren-like, and I think
there were at the time around 80 rooms.

Hitler suspected that the headquarters

from which the Battle of the Atlantic was
being orchestrated was in Liverpool,

and so sent his planes,

and that was one of the primary
motivations for the bombing of Liverpool.

Really?

Blimey, they were trying to find this
place, and did they ever get close?

Yeah, so an incendiary b*mb, I think,
struck the building outside,

but the bombers wouldn't have
known that they'd hit their target.

Oh, of course.

And how important was
the work they were doing?

It was of extreme importance.

The Battle of the Atlantic was really

the foundation on which Britain's
w*r strategy was built,

because Britain is an island nation.

Without imports of food,
fuel and supplies,

we could no longer have
continued to be involved in w*r.

It was that serious.

Churchill understands that the key
to winning the Battle of the Atlantic

is not through brute strength,
but through statistics.

And those inside Western Approaches
are there to crunch the numbers.

Churchill desperately hopes
that these people can help turn

the Battle of the Atlantic around
in favour of the Allies,

because if this doesn't work,

Britain won't just
have lost the battle,

they'll have lost the w*r.

A month after the opening
of Western Approaches,

a convoy comes under attack
by five U-boats,

two of which include legendary
commanders Kretschmer and Preen.

Kretschmer sinks one ship
immediately before disappearing.

Preen also attacks and damages a ship,

which Kretschmer later sinks.

After receiving the alert
from Western Approaches,

naval ships race
to attack the U-boats.

HMS Wolverine claims to have
engaged Preen's U-boat.

The attack goes on for something
like four hours.

People watching see this huge
orange glow beneath the ocean

and apparently even breaks up
onto the surface.

Exactly who or what was hit
underwater is later disputed.

Either way, Preen,
his crew and his U-boat

are never seen again.

Silent Otto manages to avoid
detection for another nine days

before he's finally discovered,

depth-charged and forced
to scuttle his ship

before he's captured
and taken prisoner.

Churchill announces the capture of
Kretschmer in the House of Commons.

That's how important it is
to our British morale

to know that one of
Germany's most lethal

has been removed
from the equation.

Churchill is delighted.

He knows that the Atlantic
will now be a little bit safer.

Doenitz is forced to turn to one of his
more maverick U-boat captains,

Captain Lemp.

Lemp narrowly avoided a court-martial
after the sinking of the SS Athenia.

But now, nearly two years later,

Doenitz needs his captain to step up

and become a poster boy
for the Third Reich.

Lemp's rebellious nature has been
one of his greatest strengths,

but it's about to be responsible
for his greatest downfall.

By the spring of 1941,

the Nazis are winning
the Battle of the Atlantic.

Their U-boats are hunting down ships
and destroying vital supplies

heading for the British coastline.

And in May 1941,

there is one attack that has a huge
impact on this brutal campaign.

Commander Lemp,

who began the Battle of the Atlantic

by sinking the SS Athenia,

is on a mission.

Lemp is seen as one of the U-boat aces.

He's one of the faces
of the U-boat service.

And he is out on patrol

looking for merchantmen
to take out and destroy.

Lemp is tracking a large convoy,

and after two days, he's ready to strike.

U-boats usually use
the cover of darkness to attack,

but Lemp isn't a usual
U-boat commander.

Around midday,
Lemp fires four times,

hitting twice.

There's confusion
among the Allies' vessels,

as two ships start to sink.

But as Lemp makes his escape,

he and his crew hear the sound
that all submariners dread.

The repetitive ping of a sonar.

A warship has found them.

So Lemp would have been using
every bit of experience and guile

that he could to try and twist and
turn his way out of the sonar beam.

Lemp and his crew
hear the warship pass overhead.

You will hear the thrashing of the
destroyer or frigates or corvettes,

propellers, as they pass
over the top of you.

And then you will hear,
possibly for the last time,

cataclysmic series of explosions

as the depth charges
go off around you.

In Lemp's case, the depth charges

didn't sink the submarine,
they crippled it.

And it limps to the surface in
pretty much a sinking condition.

It's fired upon almost
immediately by British warships,

with shells and with b*ll*ts.

Crew abandon ship and make their way
over to the British destroyers.

Many of them are taken on board
and taken prisoner.

But Lemp isn't amongst them.

He's nowhere to be seen.

Later there are conflicting reports that

perhaps Lemp had been
fired upon and shot in the water,

but the British sailors are adamant
that this didn't happen.

But what that means is that
there's a submarine out in the water,

bobbing up and down
in these rough seas,

and there's an opportunity.

The commander of the escort fleet orders
a search party to board the U-boat.

They're not sure what they're
going to find underneath.

Maybe there are German submariners there
waiting for them, to surprise them.

The team form a human chain,

taking as much info as they can
up to the surface.

Maps, files, books, code sheets.

In they go to the radio room

and there's this really
weird-looking typewriter,

and when you press one button,
another button lights up.

They send that back up,

and of course that eventually becomes

known as the Enigma machine.

This device is the Germans'
top-secret code-maker,

the encryption machine that has
infuriated the Allies throughout the w*r,

as it was proving
impossible to crack,

until now.

And not just an Enigma machine,

but it's rotors and, most importantly,

all of the rotor settings,

so you can actually read

what the Germans
have already sent.

As well as what they're going to send
in the future.

What they also managed to do,

is to get this without the Germans
realising they've done it,

because otherwise that knowledge
would have gotten back to Germany.

So not only has Lemke lost his boat,

but he's also given away
the crown jewels.

But it's not until this material
is brought back to the Admiralty

and really studied in detail,

that the profound implications of
what they have found become clear,

that potentially it's going to change the
course of the Battle of the Atlantic,

and change the course of the w*r.