Episode 3 Dig WW2 with Dan Snow

In the telling of the story of the Second World War,

Ireland is rarely mentioned.

But scattered across this landscape

and in the waters off these shores

are the relics and reminders of the greatest conflict in modern history.

As a military historian,

World War II is a story I thought I knew.

But now I've come to Northern Ireland,

where I'm discovering all sorts of incredible stories -

secrets, heroism,

suffering and valour.

This is the untold story

of how Northern Ireland played a pivotal role in the war

and how its people helped shape the outcome.

In our final programme, we search for an American bomber

which crashed in the mouth of Lough Foyle...

..we discover a farm in County Down

which gave refuge from the Holocaust

and an island on Lough Neagh where the troops left their mark...

..explore an underground bunker once occupied by the enemy...

..and find evidence of a U-boat graveyard off the north Irish coast.

Preserved for 70 years,

this is the story of Northern Ireland's war

told with what's left behind.

This is Lough Foyle where it meets the Atlantic.

I'm fortunate to be here on a calm day

because I'm in search of a special piece of World War II history

hidden beneath this seemingly-tranquil surface.

It was here in 1942 that an American B-17 bomber

carrying 11 members of the US Air Force

crashed on its way to a base in England.

'I've teamed up with divers from Inishowen

'who have located the bomber.

'This is an experienced group

'of wreck-diving specialists who know these waters well.

'Their knowledge is going to be vital to this salvage effort.'

Well, we're all kitted up now

and we're ready for the tide to slack off,

in other words, to get slack water

because we simply can't fight that current there at the moment.

The plane is 25 metres below the surface

and the Lough Foyle tide constantly throws up silt and sand,

covering the wreckage with every ebb and flow.

'We're being assisted by aviation expert Jonny McNee.'

-So the mud has preserved?

-Yes, preserves it excellently.

You can see that stencilling after 70 years

in the corrosive environment on the seabed. It's remarkable.

The plan is to retrieve what they can from the wreckage

before the tide turns against them.

The sight of an aircraft plummeting into the water

is seared into the memory of those who were there to witness it.

In 1942, on that particular Saturday,

it was a lovely day. It was a spanking breeze

and my mother said, "Let's go for a sail."

So we went out

and we heard this terrible noise

and looked up and to our horror,

we saw this huge plane

and it obviously was going to crash. It was diving down.

ENGINES WHINE

The sudden knowledge that it was going to crash,

I still remember vividly.

And the fright I felt for the people in it.

It's almost impossible to imagine

what it's like to crash-land a B-17 Flying Fortress on water.

But that was the reality for the pilot, Curtis Melton,

on the Saturday morning in September 1942

when he ditched his aircraft here into Lough Foyle.

Just hours before the crash here,

he'd been warming his engines on the tarmac

in Gander, Newfoundland, thousands of miles away.

All systems were go and his crew were ready

to fly to Europe and join the war effort.

Above all, they were preparing themselves

for the 12-hour flight across the Atlantic.

With a wingspan of more than 100 feet,

it weighed over 60,000 lb when fully loaded

and had an amazing 2,000-mile range.

They were the most heavily-armed long-range bomber

on either side of the conflict.

EXPLOSIONS

The B-17 we're going to dive on today was nicknamed The Melton Pot -

partly a play on words. Her captain was Curt Melton

but it was also a real melting pot. The crew were all American airmen

but they were from many different ethnic backgrounds.

Russians, Jewish, German,

some were southerners and some from the northern states.

They all had one thing in common -

they'd been trained to a very high level. They also shared a fate

that would see that training put to the test.

They took off from Newfoundland

at 9.30pm on September 12th, 1942.

This was the 11-man crew's first transatlantic journey

and expectations would have been high.

But it didn't take long for things to go wrong.

Just 45 minutes into the flight,

one of the four engines began to overheat

and Captain Melton was forced to shut it down.

90 minutes later, a second engine caught fire,

leaving Melton and his crew with just two.

They were now somewhere over the Atlantic, far from land

and past the point of no return.

Melton knew that their best chance of making landfall now

was to reduce the weight of the aircraft.

As the B-17 struggled to stay in the air,

Captain Melton ordered all non-essential kit to be jettisoned

and there was a lot of that on board - cartons of cigarettes,

Canadian winter jackets, a case of bourbon.

One guy played the saxophone with Tommy Dorsey before the war

and he brought 120 records from his collection with him on the aircraft.

It was all stuff to make wartime life in Europe

that little bit more bearable,

which is why most of it didn't get thrown overboard.

They smuggled it away in compartments.

The bourbon, however, they did get rid of.

They cracked it open as the plane lost altitude.

Despite all the mechanical failures of the night,

there was optimism now. They thought they would make it

but then at 7am, with a terrible sound,

the third engine cut out.

The B-17 was now flying with just one of its four engines

and that was unsustainable.

The captain had no choice but to issue his final order -

"Prepare for ditching, prepare for ditching."

Incredibly, Curt Melton managed to ditch the stricken bomber

and all 11 crew survived.

As the crew looked out over the lough, sailing towards them

was the most unlikely of rescuers.

We saw yellow dinghies, inflatable things, floating

and we realised there were men in them.

So we sailed. When we got there,

my mother was able to bear down on it. We grabbed it

and I made it fast alongside.

And the men...

Well, the men didn't say anything.

I said, in a rather quavery voice, "You're all safe now."

So we just held on.

I think they must have been in shock in the boat.

Well, it must have been a terrible trauma for them

and they didn't say a word.

I often wondered if they thought I was speaking Irish

or what on earth they thought

because I did say, "You're all right," but there was no reaction.

I was very shaken, I think, but you don't think in these...

It's interesting, your reaction.

Something awful happens and you go and do something.

Just automatic, it was not brave,

you just did it because you were there

and you tried to help.

Now, 70 years later,

we're right above the spot where the aircraft went down.

There's still a mass of wreckage down there, waiting to be recovered,

but it won't be there forever.

It's a very tricky place to dive. There's a lot of tide here.

It really rips it out of Lough Foyle.

We've chosen a period of slack water

between the tide coming in and going out

so they've gone down the shot line, perhaps 20, 25 metres

to where the aircraft is on the bottom.

Visibility can be very poor here.

All the groundwater comes with its sediment out of the River Foyle

but they're taken some tools down there to rake through

some of the sand and mud that's filled up the fuselage

and hopefully find some of those personal items.

Apparently the visibility isn't too bad today.

-We have some finds from the bottom. What have you got?

-It looks like

one of the portable plug-in headsets they could move around,

from their own helmets or they would use as they moved around,

There's a jack they could plug into various points.

I love these finds that disappeared below the waves 70 years ago

and no-one would expect them to be seen again

and here they are, in our hands.

Looks like a bit of Perspex from one of the cockpit windows. That's good.

These are lifting bags, where air is attached to some heavy object

and that brings it to the surface. Let's see what we've got here.

Ooh.

Hmm.

'All the material that has been recovered is highly corroded.

'The job now is to get everything back on dry land

'and transport it to the nearby maritime museum

'where we can clean it up and examine it properly.'

-Coming up nice, isn't it?

-Yep.

This is very exciting.

We're rediscovering, we're reclaiming this machine gun,

this Browning machine gun, a 50-calibre Browning machine gun

and it's covered in sea life and barnacles

but actually, you can start to see the shape. There's the barrel there.

You can see where they put the belt of ammunition

here on the top.

Underneath these barnacles and this mud

it's in remarkable condition. We've found moving parts and everything

in pretty good working order.

These high-powered guns contributed to the fortresses' success.

The idea was that with the gun crews working in unison,

they'd be better able to defend the plane from all points of attack -

a potent defence against German fighters.

It's amazing to me they didn't jettison this over the Atlantic.

That's a heavy piece of equipment.

They kept it on board right till the crash.

You're right, normally the guns and the ammo are the first thing to go

but as I say, rumours are that the bourbon was much more exciting

and they thought, "If we're going to go, let's go happy,"

and everything else stayed on the aircraft

and they enjoyed a last drink.

Thank goodness they did.

There you go, unloaded,

as we've been told.

Look at that.

I mean, this is incredible.

After 70 years on the bottom of the ocean

in a pretty rough, pretty weather-beaten part of the world,

the breechblock still works

and you can still tell the internal workings of the gun.

It's just extraordinary.

What's this? Some kind of Perspex?

Yeah, one of the Plexiglas side windows, possibly from the cockpit,

-where the guys were down today.

-So that might be from the cockpit?

-Yes.

-That's so exciting.

He'd have been staring through that all the way across the Atlantic,

-begging for a sight of land.

-Yes, and suddenly watching the sea

get closer and closer through that piece of Perspex.

That's incredible, isn't it?

For me, what's so astonishing about this crash

is that nowadays,

that would be a momentous, life-changing event for anyone

but for these crewmen,

it was just another terrifying event they had to endure.

Just days after this crash, they were out flying combat missions.

Curtis Melton served with great distinction,

flying right across Europe, exposing himself to terrible dangers.

One other crew member became highly decorated

but had to bail out of an aircraft

and spent two years in a German POW camp

and four of the survivors from this crash ended up dying

when another bomber they were in crashed into the North Sea.

In the tumultuous wartime service of these men,

this crash barely gets a passing mention.

Theirs is just one of the countless stories

that connect Northern Ireland to the Allied air campaign against Germany.

Here on the western shores of Lough Neagh,

the connection runs especially deep.

It might look like a wasteland today

but 70 years ago, this was Cluntoe Airfield,

a massive 640-acre site

and a hive of Allied activity.

This was a military training base,

a place where pilots would come to hone their skills,

to make last-minute improvements to their technique

that could one day save their lives

and they'd need those skills because the air crew that trained here

were about to take part in the largest amphibious invasion

in history - D-Day.

If I'd been walking along this runway during World War II,

I'd have seen many of the iconic aircraft of that conflict,

like the mighty B-17 Flying Fortress

or Spitfires, Hurricanes

and even a huge Lancaster bomber.

Back then, this was Cluntoe Military Airfield

and it was a very busy place.

It was one of several key training bases dotted across Allied territory

where young pilots earned their wings.

Squadron leader Tom Long from Belfast

joined the volunteer reserve in 1939.

He trained at bases just like Cluntoe

and remembers his introduction to flight school.

We were delighted

when we got to flying training school

and then the butterflies started

because we knew

that about a third of us

wouldn't get through.

Of the 20 who became air crew,

only seven of us came home.

Built and operated initially by the RAF,

Cluntoe was handed over to the US in 1943.

At its height, it was home to 3,500 air force personnel.

There were only three airfields in Northern Ireland in 1939.

By 1945, there were 26.

As D-Day approached, these fields became vital in training the men

who would help to end the war in Europe.

Standing here, you realise just how rural this place was in 1939

and how extraordinary it was that

thousands of young men suddenly descended on it for their training.

Most of the men that came here were Americans

so they trained hard all day

and at night, they had money to spend

and they were keen to spend it.

They wanted to do as much socialising as possible

before they were thrown into the furnace of battle.

We were just a cross-section of young people at that time.

There were the serious types and the cheerful types and so on.

The idea was that

you had as good a time as you could,

that you went dancing, if that was your bent.

The only thing we had in common, I would say,

was our desire to become pilots.

Eventually, 120,000 US servicemen

came to live and train in Northern Ireland.

For the Americans stationed here,

there was no better respite from the rigours of military life

than here on Rams Island, a short boat ride across Lough Neagh.

The Americans would come to this island, not for training

but for rest and recuperation.

They'd steal a few hours, sometimes perhaps even a whole day.

It must have been a little paradise for them,

away from the sounds and smells of the vast military enterprise

and they showed their appreciation

by carving their names into these trees

and they're still here today.

There are little hearts on these trees, I think.

The closeness of battle

was making these soldiers think about what they were leaving behind.

A big "1944".

"NJK, 1944."

Here's his mark.

This is obviously where the guys came. There's a lot of graffiti.

Here's the best one yet.

"NNP, USA, 44."

That is a direct link with those US servicemen

that were here in the build-up to D-Day.

The Second World War left its mark on this landscape

in so many different ways.

It feels like there isn't a corner of this country it didn't touch.

This graffiti here is just so surprising.

I suppose it's just young men who on the eve of the liberation of Europe,

on the eve of D-Day, were terrified about not making it back alive

and were desperate to leave some sign of their existence.

I wonder how many of the guys who did carve their names in these trees

survived the beaches of Normandy and the fighting that followed.

We already knew

what we would have to do once we landed in France.

The thing that kept us going

in the Army, really,

was orders and training,

discipline and training.

While preparations continued at bases like Cluntoe,

the German soldiers in occupied Europe

were building a network of defensive fortifications

designed to be impregnable

from air, land and sea.

70 years later, evidence of their occupation remains,

now buried in the sand.

I've travelled to the beaches of Normandy

to uncover what the Germans had in store for the Allied forces -

a truly international brotherhood who would fight their way ashore.

We're digging on the site of what 70 years ago was a German bunker,

part of the Atlantic Wall, a long line of fortifications

that stretched not just along the French Atlantic coast

but all the way from the Spanish border in the south

right up to Norway in the north,

3,000 miles.

And along that wall were 15,000 of these bunkers.

On June 6th, 1944,

the Allied forces, including those from Northern Ireland,

combined all of their military might into one synchronised assault

involving over 200,000 men.

Known as Operation Overlord,

the D-Day landings were one of the biggest turning points of the war.

There was a very, very strong Northern Ireland influence

in Operation Overlord,

right from General Sir James Steele

who was in charge of the plans,

who came from Ballycarry in County Antrim,

General Montgomery, who commanded 21 Army Group

and, of course, on the ground, you had a unique situation

where you've both regular battalions of the Royal Ulster Rifles involved -

the Second Battalion coming ashore on Sword Beach

and the First Battalion coming in by glider on the evening of D-Day

and it's the only regiment in the British Army

that had both regular battalions involved in that operation.

The Allies chose five landing beaches along the Normandy coast,

each defended by the German occupying forces.

There were literally hundreds of aircraft that could be seen.

The sky was black with aeroplanes

and so forth, all heading inland.

We went in

and finally we sighted land

and it was very quiet, it was eerie.

There was a long beach and a wall

and there wasn't a sound

or a sight and you couldn't see anything.

It didn't enter our heads

that the Germans could stop the army, I don't think.

It seemed to be such an overwhelming force

that they were bound to get to their objective sooner or later.

EXPLOSIONS

When we first landed, it was almost like a training scheme.

But then we realised that...

this is for real - they're going to kill us.

Before D-Day, these beaches were tightly-controlled military areas.

Civilians weren't allowed anywhere near them

and they'd been littered with defences,

the concrete pillboxes

and gun emplacements slightly higher up the beach

but there were also minefields,

barbed wire, slit trenches and tank obstacles.

The Germans had had years to prepare these beaches

and the result was an absolute killing field.

The need to get across the beach to the bunker line quickly

was paramount at each landing site.

When that ramp went down

and we went through the water onto the beach,

we just ran and ran.

GUNFIRE

If you stop on the beach, you're dead. They'll kill you.

There was a lot of firing going on from the dunes

and we couldn't see them.

It was going on quite fiercely.

Two of my mates got hit

and going across,

quite honestly,

I was saying my prayers.

We'd never seen action before.

We'd never seen an angry shot.

I was shouting I wanted my mum...

..and I wasn't the only one.

Everyone was doing something similar.

It was just pure... Nobody knew what was happening

because there were bits of bodies lying all over the place

and people screaming.

And we lost quite a few.

It's amazing, the sand just reclaimed these bunkers.

This has been covered for nearly 50 years.

I'm very excited to see what we're going to find down here.

METER BEEPS

This tells us what the percentage of oxygen is down there,

just in case it is foul.

It'll just give us a readout and say if it's safe or not.

Bill's down there, checking there's enough oxygen for us to breathe.

It's been covered over for 60 years

so there could have been some kind of contamination or gas release

but so far, so good.

These really were the most formidable obstacles

for the Canadian infantry

but luckily, they weren't alone.

As this giant impact crater on the side of this bunker shows,

the infantry had some pretty heavy-duty support,

known to history as Hobart's Funnies.

They were the brainchild of a particularly innovative general.

One of the most significant and important figures

in the Allied success on D-Day

was Major-General Sir Percy Hobart

who came from an Irish family.

His mother came from Newmills, outside Dungannon in County Tyrone.

His father came from Dublin.

The Funnies weren't a particular kind of tank -

rather, an array of specially-adapted vehicles

designed to breach heavy defences.

They included flamethrowers,

amphibious assault tanks and mine clearers.

Hobart had thought about every possible scenario

that men taking a beach might encounter.

It was this combination of training, machinery and manpower

that allowed the Allied soldiers to fight their way off the beaches.

I think that Hobart's 79th armoured division,

if it had operated on no other day than the 6th of June, 1944,

would have repaid all of the investment and energy and coin

that the British War Office had put into it.

The German bunkers were eventually penetrated

'and now, 70 years later,

'we're about to do it once more.'

It's not easy digging out on your tummy, is it, Bill?

No, not at all, mate. Not when you're my size, anyway.

'The labyrinth of passageways seems endless

'and the build-up of sand over half a century

'has made them susceptible to collapse, so we have to be careful.'

OK. The wall's gone completely here.

So that blockage is in fact just a collapse, is it?

Yeah, it's a collapse in the wall

and it is very, very loose.

Erm, there's something...

something beyond it.

This just keeps going.

I think that might be an underground passage

all the way from this bunker system

to the observation bunker, right on the beach.

Yeah, it's going in the right direction.

It would have been a lonely place, in many ways,

to wait for the Allied invasion they knew was coming.

You very rarely hear about the experience

of the German soldiers that manned these fortifications.

Having built them, they would have waited for months and months

for the inevitable Allied assault,

praying it would fall somewhere else on the French coast, I'm sure.

The Germans faced a terrible choice between holding out desperately,

fighting to the last man

and almost certainly being killed by a flamethrower or explosive shell

or surrendering early and maybe saving their skins.

We felt that we were part of something huge.

We did what we were supposed to do.

It was an experience not to be forgotten easily, you know?

Aye.

That's a day I'll never forget and I lost a lot of friends that day.

And I landed with a bunch of very good men.

And I'm very proud to have served with them.

And I'll never forget them.

In the days following D-Day,

the Allied forces pushed towards Paris.

There was ferocious fighting.

I'm heading to a village now called Cintheaux.

It's about 20 miles south of the beach

and here there was a particularly bloody firefight

but it's symbolic of all the battles

that were happening right across this landscape

as the Allies desperately pushed into France

and the Germans tried to hold them back.

From the second day onwards, it was... I just couldn't...

It was just hell upon earth.

ARTILLERY BOOMS AND ROARS

The men of the Royal Ulster Rifles were now moving inland,

going village by village, town by town, freeing each one as they went.

As we were advancing, my mate, he shouted to me,

"Bill, I'll see you afterwards,"

and I looked down and looked back again and he wasn't there.

He'd had a direct hit with a German 88 millimetre.

He was blown to pieces.

The casualties at the end of two days in Normandy

were almost 200 men killed, wounded or missing.

If you consider that the battalion's strength was about 760,

those are very, very heavy casualties indeed.

The fighting was so intense that the detritus, the waste of war,

littered the fields and streets.

Some people started picking it up.

Up here, there's a collection, said to be unique in France,

three generations of the same family

have gathered together evidence from the fighting in this area.

Where do you even start?

Everything in this room is from the fighting around this town in 1944.

It's just incredible.

Look at this, a Sten gun, classic shape.

This is the old infantry anti-tank weapon, the PIAT.

This must have been used by the Canadians fighting around here.

It's a PIAT anti-tank weapon. The infantry could carry it.

Designed by a British officer from Northern Ireland called Blacker.

Very important bit of kit.

Gave the British infantry a bit more teeth

when it came to taking on German armour.

And the human impact of these kind of weapons can be seen

by this shocking German helmet here,

the front of which has been completely vaporised, almost,

and you can imagine the injuries

the person wearing this would've sustained.

I have never seen anything like this.

This is the tail fin of an FW-190.

It was a German fighter that was shot down here, in 1944.

It was actually flown by an ace, a highly decorated German pilot.

Just extraordinary, not just because of the swastika motif,

but because it was graffiti'd by the locals after it crashed.

"Mort au Boche", which, in French means "death to the Germans".

The Allies were now taking more and more territory,

but not without cost. Even to those who survived.

I was a boy when I went out to France,

but within a couple of days, a man.

I've seen things that I'd never seen in my life before,

and I hope never to see again.

But unfortunately, I did see it again.

Back in Northern Ireland, there was a poignant reminder

of just why it was that we were fighting.

Just along the road down here there is a farm that,

from the outside, looks just like any other.

But actually, it's a very unusual farm with a particular history.

It's overlooking the sea, and, during the Second World War,

it became home to dozens of Jewish children,

brought from around all around eastern and central Europe,

who came here seeking a haven from persecution.

The farm, called Millisle, took in children from Germany, Austria

and Czechoslovakia, escaping what the Nazis called the Final Solution.

Among them was 15-year-old Walter Kammerling

who arrived from Vienna in 1939.

I remember we came to the farm.

We didn't have any buildings yet.

It was wooden buildings rather, on top of, not a hill, really,

it was a meadow going down.

I remember, when we went there,

everybody got a bottle of milk...

when we got on the farm.

That, I remember, as it was rather refreshing.

Though we lived together, we worked together, we joked together,

we realised that, though we live together,

we didn't know anything about each other.

It was almost like wounded animals, licking their wounds.

It all happened virtually overnight.

It seemed like an improbable picture -

a huge gang of Jewish children

dropped down in the middle of rural Northern Ireland.

The question is, why here?

In nearby Belfast, I met Professor Leon Litwack,

who told me about a programme called Kindertransport.

The story began in early 1939,

when there was a meeting in a pub, much like this one.

There was a meeting between a farmer from County Down

and a member of the Jewish community.

And there they developed a plan

that saved 30 or 40 children from the clutches of Hitler.

There was a scheme that was developed in Britain

to take children under 17 years old away from their parents

and bring them to the UK in order to offer them a new life.

And it must have been very, very difficult for them,

because their parents were left behind.

Sometimes, one child might have gone, another might not have gone.

I loved the harvesting work.

I loved all the other stuff - the work with the animals.

In the evening when we finished off, sometimes they had musical evenings.

The carpenter selected records, and records were played.

It was marvellous.

In total, 10,000 children were saved by the Kindertransport programme

and sent to refuges all over the United Kingdom.

Walter's family were less fortunate.

Both his sister and his parents died in Auschwitz.

It is quite amazing,

if I compare myself with youngsters at 15 now.

When I said goodbye to my father, he was in tears. That really choked me.

He obviously realised he may not see me again.

HE EXHALES

70 years later,

there's still some evidence of this building's wartime uses.

It looks like a little German graffiti here.

You can imagine the kids playing around, drawing on the walls.

The building's looking pretty dilapidated now, pretty unfriendly,

but, actually, that's the state that the Jews found it in,

and they turned it from this hostile shell into a happy, safe refuge.

The farm was a lifesaver, because where else would I be?

The mere fact that I was there,

that I had the facility to be there, where would I have been otherwise?

'Over 300 refugees took century at Millisle,

'brought by Kindertransport or other evacuation programmes,

'but even on this remote farm, the war was never far away.'

We are in the stable block now.

This looks like a sheep lambing pen.

And this whitewash doesn't look like it's been touched up

since the Second World War.

Up there is clearly a blackout blind.

It was slid along those rails,

now covered by cobwebs that must be 70 years old.

They were designed to shut out the light from the night skies.

The lights were burning in here.

These were living quarters in the war.

But that light couldn't escape out because it would give the Luftwaffe

a vital clue that they had hit the Irish coast

and they could home in on big bombing targets like Belfast.

I remember there was only once we were woken up at night

because Belfast, I think, was bombed,

and I remember people came out into the corridor and waited at night

and we saw, in the distance, fires, etc.

EXPLOSIONS

Belfast was just 20 miles to the west,

and remained a high-profile target throughout the war.

But it was not the only target in Northern Ireland.

To the west, the city of Derry,

where up to 140 warships could be moored,

was also a prime target for German bombers.

And when German aircraft did bomb Derry, just after Easter in 1941,

the wartime authorities were forced to act.

So it would have had some sort of...

'So they decided to construct, secretly, a series of decoys,

'known as Starfish sites, built to deceive the German bombers.'

Obvious why it was sited up here, isn't it?

'By setting ablaze this hillside a mile to the south of Derry,

'the soldiers inside this command and control bunker

'hoped to fool the German pilots

'that this was the city itself.'

So what are these platforms here?

These would have been beds for the generators

that provided the power for the equipment on the site.

Richard, why build this building on this windswept hill?

The whole point was that this was a starfish, a decoy,

and the reason for it

is that the city below us

was a major target for the Luftwaffe,

because it contained the Royal Navy's most important escort base

in the Battle of the Atlantic.

And the idea was that, if the bombers came back again,

fires were lit, and other lights were it further up from the Starfish site

and the bombers drop their bombs short of the city.

And that's because the city is blacked out.

So the bomber crews are looking for

anything on the ground to give them a target?

There should be no lights in the city.

It would've been blacked out completely.

Of course, once the fires light, the bombers home in on the lights.

So the idea is they drop their bombs

here in the country, where it doesn't matter.

They drop the bombs in the country,

where the only threat is to the personnel of the Starfish site,

and to the cattle and sheep and so forth

that are around in the countryside.

What about these guys in here? They've got a dangerous job,

sticking their head above the parapet, saying, "We're over here."

They have got a pretty difficult job. They are right in the front line.

This is a huge exercise, isn't it?

It just shows the importance

with which the British government viewed Derry.

Look at it in terms of the size of the city

in proportion to any other city in the United Kingdom

outside London.

This is the most heavily defended city,

which simply underlines its importance to the Royal Navy

and the Allies generally in the Battle of the Atlantic.

Donal Neill from Limavady is a pyrotechnician

who works on firework displays.

And he's going to show me

how it's possible to light a fire in a brazier very quickly,

in the same way that the troops did at the Starfish site in the war.

So the guys here would have had maybe maximum of an hour's notice

that the Germans were arriving.

-How do you make a huge fire very quickly?

-You make lots of little, small fires.

You put them all at a central point and start cutting them off

from one position.

So, you're in a central position, you wire it all up

and ignite them all separately.

-You load the fire.

-Yep.

'Fuel was sourced locally, to fill the braziers.'

There is no coal in Ireland. What do you use? You use peat.

'One memo talks of 600 tonnes of peat being ordered for the Derry site.'

At the bottom of this fire, we have what is called a portfire.

This is a device we use for lighting fireworks.

And how do you light those?

This would be sparked with a small ignition charge.

This will burn for two minutes.

So you can wire up the whole hillside from one central location?

From one central location.

This is the same sort of technology we'd use for a firework display.

Something like that, where you have more than one fire,

you just run it with a simple wire. Just two-core wire.

A touch of liquid fuel is added to help the combustion.

One side goes to one terminal of the battery.

And then the other side goes to the other terminal of the battery.

You have now completed the circuit. Once you touch the wire to it,

you can run down, as quick as you want,

and have fires going all over the hill.

Let's go for it.

Nice. That sounds hopeful. Ooh, look at that.

'And true to his word, Donal's fire is ablaze in seconds.'

Look at it. That's really going now, and that's seconds.

Just brilliant, isn't it?

And from 15-20,000 feet, that would look like,

a settlement, or it might look like fires started by bombings,

so the rear bombers would think, that's the place to drop them.

I'm just amazed at the speed

with which you can set an entire hillside on fire, effectively.

Derry was never bombed again and the Starfish site would remain untested.

To tell the final chapter of this country's role

in what was a global conflict,

we are heading back underwater, to the hunting grounds

of one of the most feared German war machines the U-Boat.

The hidden menace that tried to starve us into submission.

Just off the north coast lies a submarine graveyard,

where over 100 of the vessels that formed Germany's backbone

during the Battle of the Atlantic now lie broken and in ruin.

The Battle of the Atlantic

was the longest continuous battle of World War II.

It stretched from the earliest days of September 1939

right up until early May 1945,

just before the final German surrender.

Throughout this battle, Allied convoys feared U-Boats

like no other weapons system.

Hunting alone or in wolf packs, they would prey on Allied shipping

and sent numerous vessels to the bottom.

GUNS BOOM AND ROAR

But by the spring of 1945, the Nazis were on their knees,

and as the noose tightened around Berlin,

the German High Command had no choice but to put an end

to its naval campaign.

For the U-Boats, it ended here in Northern Ireland.

On May 5th, 1945, just five days after Hitler had died in his bunker

in Berlin, Admiral Karl Donitz, who was now the supreme commander

of the German Armed Forces, issued the following order.

"All U-Boats, cease fire immediately.

"Stop all offensive actions against Allied shipping."

This was total defeat.

The German fleet was made to surrender formally in Londonderry,

the city that had played such a huge part in the battle against them.

Able seaman Tex Beasley was among those tasked with ensuring

that all enemy crews yielded without incident.

We went out in early May

to meet up with these U-Boats that were surrendering.

Behind were many other U-Boats.

I don't know how many. Quite a few.

So the skipper said, "Right begin actions now, over."

So we jumped from our boat onto the U-Boat.

I said to the, I presume he was the commander,

I said, "Guten Morgen, sprechen Sie Englisch?"

And he said, "Yes, rather well, I think!"

And the other diver came up, had an American accent, but...

HE MIMICS THE ACCENT ..a German-American accent, you know what I mean?

That sort of thing.

And he said, "What would you do," he said, "if I...?"

"I just did. I told the crash divers to shoot you right between the eyes."

This remarkable structure is all that's left of the naval escort base

built at Lisahally during the war, just a few miles north of Derry.

It's here that the U-Boats were moored alongside

and here that, on 14th May 1945,

the German Navy ceremonially signed its final surrender.

Over the next few months, more than 50 U-Boats came up the River Foyle

where they were stripped of anything valuable still on board.

Locals came from miles around to have a look

at the world's most famous submarines.

Once the U-Boats were alongside here, the crews were marched off,

taken along the pier

and put on waiting trains, then transferred to PoW camps.

For the commanders, it must've been a terrible humiliation.

For the locals watching these men as they shuffled off into captivity,

it must've been hard to believe that this was the force that,

just a few years earlier,

almost brought the Allied navies to their knees.

For the U-Boats that remained tied up in Derry,

their fate was swift and deliberate.

As part of Operation Deadlight, 116 surrendered U-Boats

were towed into the north Atlantic, off Malin Head.

Some of them didn't even make it.

They were barely seaworthy after such a long war.

But those that did were used as target practice

by Allied ships and aircraft.

The task of dragging them out to sea took three months.

One by one, 116 of these once-proud members of the wolf packs

were systematically destroyed.

70 years later, we're looking for one in particular. U2511.

This was a Type XXI craft, the most lethal U-Boat yet designed.

It was quicker, could fire faster

and dive for longer than any of its predecessors.

Dive supervisor Geoff Millar is leading a group of divers

with a combined 100 years' experience working in these deep waters.

These U-boats were deliberately sunk to be forgotten

and only now are advances in diving technology re-opening this extraordinary sight.

We're diving in the low-water slack,

so the depth of the water is 67 metres.

From the top of the submarine there's approximately 62 metres.

The hardest thing about it is trying to hook on the submarine.

You're just a straight pipe more or less.

There's not an awful lot to catch on.

With the shot line successfully attached, the team descends quickly,

knowing that at this depth they only have 25 minutes

on the bottom to gather photographic evidence confirming this as U2511.

The technology of this rare type of U-boat was highly prized.

Those that were still operational were divided up

between Britain, France, the Soviet Union and the US.

Several of them even saw service for those countries after the war.

After 19 minutes of decompression time, the divers surface safely.

Geoff and I review the material they captured back at the dock.

What's on this screen here?

This is U-boat 2511.

-Is this the conning tower?

-Yes, that's the conning tower.

-So that the periscope, is it?

-Yes, that's the periscope.

-It's amazing.

To the inexpert eye this looks like a big pile of rusted metal.

How can you tell what it is?

Obviously you can see here the huge propeller and there's the rudder.

-Oh, yeah!

-The submarine's actually lying on its port side.

-I see. The propeller's great.

-It's hopefully intact.

These are storage pods and this one's completely opened.

-If you look closely here, you see this black and yellow?

-Yeah.

This black rubber, that's the remains of one of their life rafts.

No!

-An inflatable boat.

-That's amazing.

Their visibility is incredible. How do you know what kind of U-boat this is?

The telltale sign is the streamlining and the shape of it.

The Type XXIs had a huge conning tower compared to the ordinary subs.

Either side of the conning tower was just completely straight.

-Also the Type XXI had six torpedo tubes on the bow.

-Ah.

I never thought anything like this existed in UK or Irish waters.

What's especially remarkable about U2511

is that it's one of only two Type XXIs that actually saw active service.

Launched too late to have any impact, it never even fired a shot.

The sinking of the U-boats as part of Operation Deadlight

marked the end of the Battle of the Atlantic.

It was a campaign which thrust Northern Ireland to the heart of the action,

defending the convoys at sea and from the air.

CHATTERING

At the start of this series,

we recovered the wreckage of a wartime Spitfire which had crashed in a bog

while providing cover for a convoy off the coast of Northern Ireland.

Let's have a look.

The Spitfire's RAF pilot was an American called Bud Wolfe

who bailed out of the aircraft before it crashed.

This is something I never believed that we would find.

Bud Wolfe's original flying helmet, worn by him on that sortie,

still attached to the original oxygen mask,

it's survived underground for 70 years.

70 years later, Bud Wolfe's daughters have come to Derry

to see for themselves the remains of the aircraft their father flew.

Then you had your oxygen...

They unveil a plaque at the City of Derry Airport in memory of their father

and the other pilots who flew from here when it was a wartime airfield.

We just want you to know that we're so honoured

by the folks of County Derry.

All the work that's gone into excavating the aeroplane

and all the research that's gone into finding out things

and teaching us things about our dad that we didn't know, we appreciate so much.

The trip has also given Bud Wolfe's family the chance to visit

the crash site where five months earlier the Spitfire was unearthed.

We're exactly 70 years almost to the very minute

when Bud was... bailed out of his crashing Spitfire.

So we know this is a very emotional time for you, Barb, and for Betty.

And it's this peat bog here that's given up its secrets

after 70 years.

Now perhaps it has given you

an insight into the secrets of some of the things

and the exploits and bravery and the heroism of your father.

Heavenly Father, we thank you that through the enthusiasm...

Bud Wolfe, the young American pilot,

bailed out of his stricken aircraft here

while defending Derry and the convoys steaming off the coast nearby.

So it's appropriate the remains of his Spitfire

should go on display in the city he defended so bravely.

It's absolutely amazing.

Another thing which Barb has mentioned is this dilemma about how to represent our dad

on our return because Dad would not be sitting up here.

TEARFULLY: Where Dad would be today would be out there with that engine.

Um...

He would want to hear about the process of retrieving it.

He would want to lay hands on it, he would want to hijack that

and keep it in his living room.

Bud Wolfe died in 1994, but through the remains of his Spitfire

the memory of his bravery and that of the others

who flew here in the Second World War will not be forgotten.

What I've experienced in this series

shows that Northern Ireland's influence stretched right across the war.

The land was home to hundreds of thousands of Allied soldiers,

sailors and airmen.

And their story remains carved into the landscape.

I've seen 70-year-old fighter planes reclaimed from the hillsides,

visited coastal defences buried by the sands of time,

fired 70-year-old guns once buried in peat.

And ridden in tanks that took our fighting men into the heart of battle.

But it's perhaps this extraordinary U-boat graveyard

hidden for the last 70 years which will ensure that

Northern Ireland's role in the Second World War

will never be forgotten.

Subtitles by Red Bee Media Ltd