All language subtitles for U-Boat.Wargamers.S01E03.The.Wrens.1080p.NOW.WEB-DL.AAC2.0.H.264-RAWR_track3_[eng]

- Bull's eye.

- Achtung! Achtung!

- Dive! Dive!

- Why the hell have you dived?

(clatter)

NARRATOR: Britain may have
dealt with Donitz' aces...

- No way back to Germany this time.

NARRATOR: ..but his U-boats
keep coming.

- Fire.

- New orders for Group
Paukenschlag.

- Attack at will in all coastal
areas.

NARRATOR: They sink ships
faster than Britain can build them.

- If we keep losing ships
at this rate,

the country will be down to
just a few weeks of supplies.

- People will be starving to death.

- Happy hunting.

NARRATOR: The Royal Navy turned to
retired war gamer,

Commander Gilbert Roberts...

...and a group of young women.

- Sir.

- Ladies, if we lose the battle of
the Atlantic, we lose the war.

Our job is to find a way to sink
the U-boats.

That is what we will do here.

- Sir, the board is set.

- By recreating battles and playing
through scenarios,

in a war game.

- Is that Donitz' master tactic?

- We need to work out how to destroy
them.

NARRATOR: Gilbert Roberts reports to
Western Approaches' command,

the Royal Navy's
Centre of Operations

for North Atlantic convoys,
in Liverpool, England.

- Gilbert Roberts could be doing
so much more at this point.

- Here's a man who's had two years
training in war games.

War gaming allows you to understand
how tactics work

and it allows you to explore
new tactics.

- Churchill couldn't be less pleased
with how the battle is turning out.

The fact that they're losing
hundreds of thousands of tons

of merchant shipping to U-boats.

- Enter.

- Churchill has to not just stay
in the war, but win it,

and you can only win it if you win
the battle of the Atlantic.

- Sir. Commander Roberts.

- Thank you, that will be all.

Commander Roberts retired.

I thought London was sending me
a Captain?

- No, sir, Sector Commander:

Portsmouth Naval Anti-Invasion
Battalion.

The Home Guard?

Instructions from the Admiral say
I'm to...

give you the top floor of the
exchange building. For?

- A school, sir.
- School?

- A tactical school.

The Prime Minister has asked me
to analyse U-boat attacks,

decipher their tactics and develop
counter tactics to sink them.

These would then be taught to Escort
Commanders at the school.

- We already have a counter tactic,
Roberts.

Buttercup, developed by our
own Commander Walker,

a man who has actually sunk U-boats.

Have you?
- No, sir.

And I'd very much like to begin with
Buttercup.

By analysing Commander
Walker's actions,

I can then play through other
scenarios in a war game

and identify any tactical
weakness that we -

- War game? Tactical weakness?

I'm sorry, but what does a Sector
Commander of the Home Guard

know of tactics?

- I spent two years at the
Portsmouth Tactical School, sir.

War gaming... (coughs)...

...before retirement.

- A school to play games.

- And I need men to staff the Unit
too, men with good analytical minds.

good with records, but mostly good
at playing the game.

- Commander, I'm in the middle of
fighting a war.

All my best men are at sea.

Might be able to find a couple of
our unfit for active service,

but if you need more to play your
game, you should speak to London.

- Thank you, sir.

- Oh, and Roberts, this school.

perhaps you can run occasional
courses

for half a dozen reserve
officers,

but don't bother me with it.
I'm a busy man.

Dismissed.

- Percy Noble isn't taking on board
the importance

of finding new tactical ways
forward.

- (coughs)

- Donitz is a tactical master.

This is a time where it's more
crucial than ever

that he listens to Roberts.

- Sir. Secrecy is paramount.

- Yes, quite right.

NARRATOR: And for the Royal Navy,

help arises from an American
tragedy.

After the attack on Pearl Harbour,
the USA declares war on Japan.

Four days later, Germany sides with
their Japanese ally

and declares war on the USA.

The Americans have already been
unofficially supporting Britain

through the war.

Now they mobilise at full strength.

- The idea was to get to Germany
to defeat it first,

but of course doing that meant
getting supplies and equipment

and now manpower as well
to the British Isles

in preparation for an eventual
invasion of Nazi Germany.

But the American involvement created
new opportunities

for the German U-boats to attack
American shipping.

Donitz saw this immediately.

- The United States Navy should have
been prepared

for a submarine campaign,

but the problem they have
in early '42 is,

they have too few destroyers to
protect merchant shipping.

Most of them had gone to the Pacific
to fight the Japanese.

NARRATOR: This lack of protection

presents Donitz
with a golden opportunity.

e measures his U-boat captain's
success

by the number of ships they send
to the bottom.

- Admiral. Orders for
Group Paukenschlag.

Proceed to Naval square C-A-28,
New York.

- Yes, Herr Admiral.

- They knew the shipping would
concentrate off New York,

off Cape Hatteras; off Cape
Cod.

- American involvement in the war
gave the U-boats

a lot of new targets
off the American coast.

- Herr Admiral?

- Have the Americans learned nothing
from the British?

Very heavy traffic.
Mainly north-south.

Very many tankers,
Occasional neutrals.

- No surveillance.
- (chuckles)

- They're not even trying to protect
their ships.

- The United States Navy don't have
escort vessels they need

to establish a system of convoy,
so they decide not to do that.

There's a marvellous directive
from the Office of War Information.

Quite simply, "The Germans can
sink as many ships as they like,

really doesn't matter.
Because American industry

is just gonna bury them
in new shipping."

- All the more prey for the wolves
to feed on.

New orders for Group Paukenschlag.

Attack at will in all coastal
areas.

- January of 1942. They sank
41 ships, 250,000 tons

in just two weeks.

A lot of those sinkings were just
off the coast of the United States,

literally within sight of American
home territories.

- German success is so profound.
it's known as the second happy time

for the U-boat fleet.

- With the Americans being destroyed
in such numbers,

it's more and more important that
the convoys that do survive

are protected, that the Royal Navy
gets the ships across.

NARRATOR: The scale of the task is
enormous.

Every available man is put to work.
But there aren't enough.

- Without women, we realise we
can't win the war.

That is a whole new ball game for
men to get their heads around

and for young women to engage with.

NARRATOR: The Royal Navy are forced
to rely more and more

on Vera Laughton Mathews' Wrens.

- I do appreciate having your Wrens
here.

it's certainly brightened the place
up.

- They can do more than that.

Much more.

- To begin with, the Wrens have just
nine roles,

and they are fairly humdrum.

If you're lucky, you're a typist.
Or a driver.

Those minimal opportunities
expand to over 125 roles.

NARRATOR: One of those are as
codebreakers

at the highly secretive
Bletchley Park,

deciphering radio messages between
Donitz and his U-boats,

providing vital intelligence on when
to expect U-boat attacks.

But despite the best efforts of the
men and women of the Royal Navy,

they still haven't deciphered
the enemy's tactics.

- Even though Roberts initially
gets a very frosty reception,

he is delighted to be back.

He'd been cast out of the Navy due
to having TB four years earlier.

- (coughing)

- This was a man who had spent a lot
of time in the inter-war period

thinking about these problems.

He can use his skills, he can
contribute to Naval success

and if possible, he can contribute
to victory.

- As if to undermine Roberts'
position even further,

he isn't put in the main
headquarters.

His offices are in a building
which hasn't even been finished.

It's still under construction
AND it's been bombed!

- What's this?
(clatter)

- A gift from Hermann Goring.
Damage from an incendiary bomb.

- Needs to go. Arrange for it
to be cleared.

- Yes, sir.

- (coughs and wheezes)

I'll need battle reports.

Anything detailing a successful
U-boat kill,

including convoy HG76.

Commander Walker's Buttercup
triumph.

- Yes, sir.

- He needs as much information
as he can get

about what's really facing
commanders

when they're out in combat,

to figure out what the U-boats are
doing and how to defeat them.

- I'll also need supplies to build
the game board.

- Canvas sheet,;
roll of linoleum...

- Chalk, string, paint

and model ships, yes?

- Yes, sir.
- Very good.

- These requests raise eyebrows
at Western Approaches.

Here is this newcomer who wants to
play games

while battle rages in the Atlantic.

- Anyway, sir, all this tactics and
war gaming might be for nought.

We captured that Otto Kretschmer

and they already started
interrogating him.

Surely he'll spill the beans and
give up all of Donitz' secrets.

- Surely.

NARRATOR: From 1939 to 1941,

Kretschmer unleashed a reign of
terror against Allied shipping.

- A hunter's moon.
Just as I like it.

Prepare for attack.
- Yes, sir.

- Fire bow torpedo.

NARRATOR: Sinking 47 ships
across the North Atlantic,

over 273,000 tons,

more than any other U-boat ace.

- That's as good as it gets.

NARRATOR: The human toll is
830 lives.

For his service to the Third Reich,

Hitler awarded him the Knight's
Cross of the Iron Cross,

with Oak leaves and swords.

- Danke schoen.

NARRATOR: At the time, Nazi
Germany's highest Naval award.

- Achtung! Achtung!

Dive! Dive!

- Why the hell have you dived?

Are you sure we couldn't have
got away on the surface?

NARRATOR: But in March 1941,
his luck ran out...

- Sir, we lost both thrust from the
propellers.

- Blow the ballast tanks, everything
we've got. We have to lose depth.

Prepare scuttling charges and
destroy all documents and ciphers.

No way back to Germany this time.

- Otto Kretschmer is this
extraordinary U-boat ace.

He's caught alive. That is such
a win for the Allies.

The MI9 have got hold of him.

MI9 is a unit established to
interrogate prisoners of war.

It's like a latter-day
Guantanamo Bay.

Here's your chance, boys.
Drill into him!

Download his microchip of knowledge

and you are gonna turn the tide of
this war.

- No, thanks.
- You speak English.

Would you rather we spoke German?
- No. English is good.

I might as well get used to it now

- Quite an impressive tonnage,
Commander Kretschmer.

Must make you very popular back
home. The Tonnage King!

Isn't that what Goebbels calls you?

- It's just propaganda. I'm a good
copy for the Nazi papers.

My picture gets more women
waving flags,

more men signing up to
the U-boat core.

What for? To sink more ships?

For Hitler?

Sorry if I don't seem
too enthusiastic.

I grew weary of this war long ago.

- You won't miss sinking ships?

- I have sunk enough ships.

The thrill of the hunt left me
long ago too.

- And how do you..."hunt"?

You've sunk more ships than anyone.

How do you do it?
What are your tactics?

- A U-boat captain, I mean
a real captain,

has to be able to take advantage of
whatever the passing moment offers.

You never know when you'll stumble
upon a convoy.

A real captain is born with
the intuition

to know when to attack

and how to press home
your advantage.

- Smashing.

- Do they get the key to Otto
Kretschmer's knowledge?

Do they find a way in?
Do they hell as like!

This guy ain't the top U-boat
captain for no good reason.

NARRATOR: Kretschmer reveals
very little to his captors.

Donitz' U-boat tactics remain
a mystery.

NARRATOR: At Western Approaches'
command,

Roberts tried to decipher them.

- Sir, the report you requested.
- Ah...

Convoy HG76.

Commander Walker's
famous Buttercup tactic.

- Thank you.
- Sir.

- A Report of Proceedings was
a standard report

that was written by anybody
in the Navy

who had encountered the enemy.

It explains what the enemy has done,

but it also explains what the
commander from the Allies has done.

- Buttercup astern!

- H276 is important because Walker
had some success during it.

He wants to understand why Walker
was successful.

(chink of glasses)
- Sir.

- What has he thought up?

Why did he behave the way he did?

But if you're looking at a report,
any kind of report,

they're very, very dry.

They don't really tell you anything
about the human side of decisions.

(knock on door)

- Enter.

Sir. Commander Roberts.

- What is it, Roberts?

Sir, I'd like permission to speak
with Commander Walker,

about convoy HG76.

- Don't you have his Report of
Proceedings?

- Yes, sir, I do.

- And you've read it?
- Yes, sir.

But to truly understand how
Buttercup works,

I need to speak with the Commander.

What assumptions did he make?

Why deploy his escorts when he did?

- Roberts, Buttercup works.
I's a sound tactic,

which is why I ordered it to be put
into group operational instructions.

- I'm aware, sir.

- Now our escorts are being fitted
with a new piece of technology.

Ship-mounted radar.

We'll be able to spot U-boats
on the surface miles away.

- That would be a great help, sir, undoubtedly.

But to complete my work, I will
still need to see Commander Walker.

- (huffs)
Very well.

When Walker gets back from sea,
if he can spare the time, you may.

- Thank you, sir.

- Now, if you don't mind...

NARRATOR: And Noble has another
reason to be confident.

The work of the Wrens is turning
Western Approaches' command

into an intelligence hub.

Up and down the country,

Wrens working in radio listening
sites known as Y-stations

are tracking U-boat positions.

- My first station was
on the Yorkshire coast,

not very far from Scarborough,

where there was a very big
listening centre.

NARRATOR: By comparing the bearing
of the U-boat's radio signal

with another Y-station, the U-boat's
position can be triangulated.

- U-boats of course very seldom
spoke,

but now and then one would come up

and would do a signal to its base
or to other U-boats.

When they did, it was a very, very
tense atmosphere

because they were such a menace
to our convoys and ships.

I was there when a U-boat came up

while they got the signal
from the U-boat down

and particularly the position of
the U-boat,

because they could then report this
back to Admiralty

and they might be able
to take action.

- Very good.

- That intelligence arrives
pretty pronto, via radio,

to Western Approaches, telling you
the real-time positions

of U-boat flotillas,
so you plot them, you mark them

on your giant map on the wall.

NARRATOR: And Western Approaches
are also benefiting

from long-range aerial photo
reconnaissance.

- A lot of the analysis of
these photographs was done by women.

They wanted to see for example the
U-boat pens along the French coast.

By looking at these sorts of images,

you had more of an idea of when they
were going to leave the pens,

when did they get back,
how long were they out at sea,

and what was their direction.

NARRATOR: It means Western
Approaches are much more aware

of when to expect attacks.

- Excellent, thank you.
That's good work.

NARRATOR:
But they still can't work out

how the U-boats are attacking
the convoys.

- Sir, this is the room.

Candidates will be with you shortly.
- Thank you.

- Before he could begin his work,
Roberts clearly needs a team.

- He needs people
who are "whip sharp".

He needs the finest brains, boys
who are gonna knock the tactics

back at the enemy.

- Please, take a seat.

- Lieutenant Commander Cousins,
DSC, sir.

- DSC?
- Distinguished Service Cross, sir.

Awarded for gallantry against
the enemy.

- I see. What experience do you
have of tactics?

- Tactics?

We smash the U-boats with depth
charges. That's all we need.

We hound them out of the Atlantic.

- I see.

Thank you.

- Thank you.

(knock on door)

(door opens)

- Lieutenant Commander Higham, sir.

- Your experience of tactics?

- Sir, I've served on both
submarines and ships.

- And tactics?
- My ship sunk.

I had to be hauled out of the water
on a rope! (chortles)

- Dismissed.

- Donitz is a genius. He needs men
who can think mathematically,

tactically; very clear-headed,
clear-minded.

These are clearly not
the sort of men he's going to need

to decipher Donitz' tactics.

(door opens)

- Commander Roberts.
Vera Laughton Mathews,

Director of the Women's Royal
Naval Service.

- The Wrens?

- I hear you're in need of staff.

- I can meet all your requirements.

I've been recruiting the people
you need for three years.

- Wrens?
I need Naval Officers!

- And how's that working for you, hm?

Wren Drake, please enter.

Please take a seat.

...Elizabeth Drake, the daughter of
an insurance actuary, yes?

- Yes. ma'am.

- Measuring risk must run in your
family, yes?

- Yes, ma'am.

- Thank you, Drake. That'll be all.
- Yes, ma'am.

- Sounds essential for your
tactical game, Commander.

Next!

- Wren Nancy Wales, sir.

- Wren Wales, what experience
do you have of tactics?

- Well, sir, I captained
the Yorkshire hockey team for years.

- An expert in team tactics.
Thank you, Wales.

Janet Okell. I hear you're
a formidable bridge player.

- Well, yes, ma'am.

- And what makes for
a formidable bridge player?

- Well, reading your opponent is
important, ma'am.

- Reading opponents.
And scenarios strategically?

- Ma'am, what is this all about?

- Thank you, Okell. That'll be all.

And finally, a real gem.

(knock on door)
- Wren Laidlaw, please enter.

- Good afternoon, ma'am. Sir.

- Wren Jean Laidlaw. Accountant.
- Yes, sir.

- I haven't met a woman accountant.

- I'm one of the first to qualify in
the United Kingdom, sir.

- I see... A keen mind for numbers,
I suppose?

- Yes, sir, very keen.

- Just what your game needs

to calculate those moves.

I suppose.

- Indeed.

- Thank you, Laidlaw.
That'll be all.

- Yes, ma'am. Sir.

- Bright.

- All of them, Commander.

And they all bring a special set of
skills to the table.

- Exactly what the game needs.

- In the early war period, almost
every nation does not consider women

for these sort of roles.

The Wrens were a risk.

- The task these young women are set

is one of the most important in the
war.

If the battle of the Atlantic
is lost, Britain is lost,

and if Britain is lost, the Western
Allies will probably lose the war.

NARRATOR: In Liverpool,
Gilbert Roberts and the Wrens

begin the next phase of
their mission.

- What knot is that?

- It's a bowline, sir.

- Where'd you learn it?
- The Sea Rangers.

- The simplest and most resilient.

Very good.

Men, rig the canvas sheets around
the frames like these.

- Yes, sir. Sir, your linoleum,
string, paint, chalk

and model wooden ships.

- Excellent.

Any news of the great Otto
Kretschmer's interrogation?

Did he spill all their U-boat
secrets?

Of course he didn't.
That would be far too easy.

It's up to us to decode them,

and the first step for that is to
build the board for the war game.

- The board, sir?
- The board.

(coughs)
The board.

- Sir, are you all right?

- The board.

- This is the thing which is going
to win the battle of the Atlantic.

The idea is preposterous.

- And sir, Commander Walker's just
returned from sea.

He's waiting in your office.

- (angry) Well, why didn't you say?

Buttercup.

Wren Laidlaw?
- Yes, sir.

- Wait ten minutes, then join me
with Commander Walker.

- Yes, sir.

- Roberts wants to understand
how Buttercup works.

- Commander Walker.

- The chance to sit down with Walker

and actually try and get inside
his mind...

This is a crucial moment.

- What's this about, Roberts?

You want a debriefing on
Buttercup to help play a game?

- A war game, to play
through scenarios,

decipher Donitz' tactics and learn
how to sink his U-boats.

- (scoffs) Something I've actually
done, using Buttercup.

- Which is why I wanted to speak
with you.

Convoy HG76.

32 merchant ships
sailing homeward from Gibraltar.

19th of December. HMS Stanley is
torpedoed and you order Buttercup:

What happens then?

- Buttercup astern!

Well, I've... I've drilled all my
Escort Commanders

to go to battle stations on the
order Buttercup.

They turn away from the con...

- Ah, Laidlaw.
Please, take a seat.

Commander Walker, this is Wren
Laidlaw, member of my staff.

Laidlaw is a, is an accountant
by trade.

- I've never met a woman accountant.

- Laidlaw is one of the first in the
country to qualify,

so now you have.

- Uh, the Stanley was hit.

We can't be sure exactly where
the U-boat fired from.

They fired from outside the convoy
in.

Once a ship is hit, they escape
by motoring along the surface.

On the order Buttercup, all escort
ships turn outward

away from the convoy, full speed,

chase down the fleeing sub.

- Sir, how can you see the U-boats?

The attack was at night, wasn't it?

- We fire star shells.
Flares that light up the sea.

We search for 20 minutes, we spot
a U-boat,

uh, well, we destroy them.

Just find that damned hearse
and sink it.

Buttercup, starboard.

Come into our little trap.

Prepare to ram.

Buttercup has prevailed.

Dearest Buttercup.

- And it works?

- My dear, we only lost
two convoy ships.

I personally sank two U-boats

and three more were hit by other
forces under my command.

- Sir, HG76 had 16 escort ships

protecting 32 merchant vessels.

Is that a heavy escort?

- Uh, well, more than most
North Atlantic convoys,

but sailing out of Gibraltar, if you
don't go in heavy,

then you're asking for trouble.

- And how many escort ships
were lost?

- Two escorts.

- Including the aircraft carrier
HMS Audacity?

Buttercup works.

We sank five U-boats.

Admiral Noble even asked me
to write it up

for the Escort Group
Operational Instructions.

- Yes. So I understand.

Thank you.

- Everything they tried previously
just failed.

So this was really the first glimmer
of success.

It WAS a success.

Walker manages to sink two U-boats
himself and three others were sunk

in this whole operation,
but it was very, very costly.

- Everything's in place.
Roberts has got his game.

He's got his bits in order to make
his game work.

He's got detailed battle plans
so he can work out

what the U-boats have been doing.

To help him, he's got his team of
brilliant minds,

these young, dependable women
from all sorts of backgrounds.

- So smart!

- Vera Laughton Mathews must be
incredibly proud.

She's hand-picked these young women
herself

and these women are not being asked
to do menial tasks

of answering phones or driving cars.

- This was taking the fight
to the enemy

and spearheading a mission
to save lives at sea.

This was using grey matter,
women's grey matter.

- Wrens, let's make a start.

Welcome to the Western Approaches
Tactical Unit.

WATU for short.
(door opens)

- Commander Roberts?
(door bangs shut)

Janet Okell.
Sir, I'm so sorry I'm late.

I took a wrong turn, and then
another, and another

and I couldn't find my way back.
- It's all right, Okell.

- So sorry, sir.

And I don't have a uniform yet.

- That's fine; I'm glad you could
join us.

The uniforms are here.
Please, collect yours.

This is Chief Yeoman Rayner.

He worked with me at Portsmouth.

He knows the game inside out.
- Sir, this isn't a Wren's uniform.

- You'll be working a lot
on the floor.

- Sir?

- Measuring on your hands and knees.
- Sir.

- For this work, the standard skirt
isn't exactly appropriate.

- WE'RE wearing the trousers now!

- (all chuckle)
- Indeed.

Ladies, if we lose the battle of
the Atlantic, we lose the war.

Our job is to find a way to sink
the U-boats.

But before we can do this, we need
to decipher Donitz' tactics.

That is what we will do here,
by playing through scenarios

and recreating battles...
in a war game.

This is our board.

The block for the convoy.

Model ships for the escorts.

The players are divided
into U- boat captains

and escort commanders.

The escort commanders stand behind
these screens

and view the board through
these lenses.

Wren Drake, would you...?

How much of the board can you see?

- Sir, I can't see anything.

- Ah, yes. Bit of a problem.

How about now?
What can you see?

- Not much. Just a few models.

- Just like at sea.
- Exactly.

It mimics limited visibility.
Just like a convoy,

stretched for miles
across the ocean.

- And the U-boat Captain,
Commander Roberts?

- The U-boat Captain sits
at the high table.

- There isn't a model for the
U-boat.

- No. The escorts can't see
the U-boats, just like at sea.

- So how do we plot their positions, air?

- Brown chalk.

Drake, can you see the U-boat track?
- Not a thing, sir.

- Brown on brown.
Thank you, Drake.

An adjudicator hands action events
to the players,

written on these chits.

U-boat contacts, aircraft sightings,
ASDIC pings, ships torpedoed.

The players are then given
two minutes to make their move.

They write down their instructions
on these movement chits -

course, speed,

ASDIC sweeps,
depth charges dropped.

They return them in silence so the
opposition doesn't know their plan

and the plotters move the models.

The aim of the game is to sink
the U-boats.

And the battle report
we'll start with...

is convoy HG76. Buttercup.

NARRATOR: Despite the Royal Navy's
confidence

that ship-mounted radar
and better intelligence

will turn the tide against
the U-boats,

they're still sinking ships faster
than Britain can build them.

More and more U-boats keep coming.

- Donitz developed the idea
that 100 U-boats

on active patrol
in the North Atlantic

could all but shut down
trans-Atlantic shipping.

NARRATOR: In April 1941,

Donitz had only 28 U-boats
hunting at any one time.

By the beginning of 1942,
that number has exploded.

- How many boats do we have at sea?

- 88, Herr Admiral.
- 88?

That's close to the 100 we need
to shut down the Atlantic.

What is the monthly tally
from Group Paukenschlag?

- Paukenschlag?

- A five U-boat wolf pack.

23 merchant ships sunk

for 150,000 tons in the last month,

and they ran out of torpedoes.

- But they are just five U-boats.

This is a feeding frenzy.

They are gorging themselves off
the coast of America.

- Fire!

- The German U-boat crews are having
a field day

off the American East coast.
There were so many available targets

that U-boat skippers could pick out
the most useful ones.

- This led to a kind of
specialisation on hunting tankers,

the most valuable prizes,

because fuel meant war.

- Britain's war machine runs
on oil

and very little oil is making it
across the Atlantic.

Without fuel, Britain dies.
The war effort stops.

This is a very productive
hunting ground.

Let's go for the jugular.

- With everything in place,
Roberts and his team begin.

The first thing they're gonna do is
look at Buttercup

and the HG76 convoy engagement.

- The first time that they actually
set up for the war games,

they don't play a game itself:

This exercise is really for Roberts
to get all of the ducks in a row;

all the pieces on the board,
to figure out what happened.

Every single thing they know,
step by step.

Where did the convoy go?
Where were the escorts?

Where were the U-boats sunk?

- It provides Roberts and his team
with a bird's eye view.

That is gonna give them a real
advantage in understanding

what went right on the side of the
Royal Lena,

but also what the German U-boats
themselves are most likely doing.

- Sir, the board is set.

- Excellent.

Let's begin.

- Convoy HG76. 32 merchant ships
with an escort screen of 16 ships.

- The escorts form
a protective perimeter.

A merchant ship is hit.
What position?

- The merchant ship, sir?
Not the escort, HMS Stanley?

- No, the merchant ships are
our lifeblood.

I want to see how they're targeted.

- The SS Annavore, convoy position
five-three.

- Fifth column, third ship.

- Now what?
- Commander Walker orders Buttercup,

The escorts turn outwards
at full speed

and fire star shells
to illuminate the sky.

- They speed AWAY from the convoy,
to try to spot the U-boat.

- Walker manages to sink a U-boat
earlier at the rear of the convoy.

- The stern of the convoy.
- Astern.

- Good. At Least one U-boat down.

Proof they attack
from outside the convoy,

like Commander Walker said.

Is something wrong?

- A merchant ship was hit
in the centre.

Can they even hit...

What's the range of a torpedo?

- Uh...

- Leave the board as is.
I need to make a phone call.

- Operator?
- Flag office, Submarines, London.

- I'm connecting you now.

- Roberts has an old friend
who's based at Submarine Command.

So he puts in a call.
To his surprise,

it's answered by the Commander,
Submarines for the Royal Navy,

That's Sir Max Horton.
(telephone rings)

- Admiral Horton?

- Apologies, sir. I was hoping to
speak with your Chief of Staff.

- Captain McIntyre isn't present.

You're through to the Flag Officer
himself. Who is this?

- Max Morton is a big

He is the head of the Royal Navy
Submarine Arm.

He was a submariner
in World War One.

He knows everything there is
to know about submarine warfare.

- Sir; it-it's Commander Roberts

of the Western Approaches
Tactical Unit.

I wanted to speak with Captain
McIntyre on submarine tactics.

- I served in subs during the first
war. What do you need?

- Oh, thank you, sir.

What is the range of
a German torpedo?

- A G7E? Roughly 5,400 yards,
but that's the limit.

Effective rang,
expect to halve that.

- Now, remember, the ship that was
sunk in HG76,

that ship was in the middle of
a convoy.

A convoy is 10,000 yards across,
How does that make sense?

- Commander, are you still there?

- Yes, sir.

One more thing, if I may.

During the first war, would you ever
fire from inside the convoy?

- Of course.
It's the only way of being accurate.

- They're inside...

- They're bloody well inside.

- Roberts, does this answer your
question?

- Yes, sir. More than you can know.

Commander Walker,
the Royal Navy,

they believe the U-boats fire
from outside the convoy.

But what if they're wrong?

What if they're firing from INSIDE?

- The U-boats Walker sank.

- It would mean Buttercup is based
on a false assumption.

The Royal Navy are relying on luck
to protect the convoys.

- The Navy knew all along, but they
forgot they knew.

- Is that Donitz' master tactic?

- It's getting late.

Wales, Drake, you're dismissed
for the evening. Get some sleep.

Laidlaw, Okell, Rayner.
I want you to stay.

- As long as you need us, sir.

- We need to find how the U-boats
are getting inside the convoy...

and find a tactic to destroy them.

- Mein Fuhrer,
I can strike a decisive blow,

but I need more U-boats.

- U-boat destroyed.
- How?

Run the game again.
We need to be sure.

- Who devised this tactic?
- Wren Jean Laidlaw, sir.

- And do you have a name for it?

- Raspberry. As in, blowing
a raspberry at Hitler, sir.

- Well, let's hope it works at sea,

because now Donitz has
his 300 U-boats,

and he'll be hell-bent on
using them to turn the Atlantic

into a convoy graveyard.

- Imagine the carnage we will sow!

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