Nazis, U-boats and the Battle for the Atlantic (2025) s01e02 Episode Script

1
The north coast of Ireland
has been a huge maritime highway
for centuries.
And that has meant that
we have one of the greatest
collections of shipwrecks
anywhere in the world.
This is such a special place
for divers.
The variety of sunken shipwrecks
here is unique.
I mean, there literally is
nowhere else that has submarines,
ocean-going liners, cargo ships.
You know, it's all here.
20 miles off the Irish coast
..a specialist team
are diving into history.
It's mind-blowing, the scale
of everything down there.
It's quite sort of scary
to see these things
and what they were built to do.
To rediscover the lost wrecks
These are really big things
and you just feel
..so small.
..of World War II's longest
and most critical battle.
The Battle of the Atlantic.
SIREN WAILS
Up!
By late 1942, war had been
raging at sea for three years,
with huge losses on both sides.
So many bodies washed ashore
that the local authorities
are talking about
reopening famine pits.
The deadly U-boat fleet, under
the command of Admiral Karl Donitz,
was still aiming to sever
the lifeline of convoys
between Britain and her allies
There was a sheer number of U-boats
now deployed to the Atlantic
and there was hardly any chance
to escape the searchlights.
It was just easy prey out there.
..whilst military strategists,
led by Sir Max Horton,
were desperately trying
to outthink and outmanoeuvre
the killer wolfpacks
of the German Kriegsmarine.
This room would have been filled
with men and women
and what they are doing here
informs their commanders.
And those are the people
who can order action
based on the intelligence
that is coming from this map.
A small city in Northern Ireland,
the most westerly port in the UK,
found itself at the heart
of the fight.
The hinge on which the
Battle of the Atlantic moved
was actually the City of Derry.
In this deadly game
of cat and mouse
The U-boats could hide themselves
in the dark
and attack whenever it suited them.
"The Hedgehog was the very latest
and the most desperately secret
"weapon designed for the
discomfort of U-boats.
"They never knew what hit them."
..the Allies and the Nazis were in
a race against time and technology.
It's not just one side
winning the whole time.
It was the punch and counter punch.
As the technology was introduced,
there's the reaction
from the Allies.
For both sides, the stakes
couldn't have been any higher.
Winning the Battle of the Atlantic
did not guarantee that the Allies
would win the war.
Total war means
there's nothing between
what the Nazis called
the final victory or total defeat.
Losing the Battle of the Atlantic
would have meant that the Allies
lost the war.
NEWS REPORT: Cruel is the
realisation of heavy losses at sea,
each sinking a toll
in arms, medicines, food,
robbed from a regiment in the field.
In late 1942, early 1943,
it certainly looked as if
the Battle of the Atlantic
was going the Germans' way.
In fact, the late Correlli Barnett,
in his history of the Royal Navy
in the Second World War,
actually describes that period
of late '42, early '43
as, "Donitz was torpedoing
his way to victory."
Three years into battle,
British naval leaders are locked
in a desperate struggle
against their German counterparts.
Vital convoys carrying supplies
of food, fuel and war materials
from America and Canada
are key to Britain's survival.
So the convoys were,
you know, they were the lifeline.
They were the lifeline.
But with nearly 2,000 ships sunk
and tens of thousands of lives lost,
this lifeline is in danger
of being severed.
If we cannot get ships and men
across the Atlantic Ocean
to physically fight the war,
there is no war.
Britain cannot fight any more.
And then there is no D-Day.
It could be the winning
or the losing
of the entire Second World War.
Western Approaches Command HQ was
based in Derby House in Liverpool.
This bomb- and gas-proof bunker
has been preserved exactly
as it was during the war.
This is the nerve centre
of what the Royal Navy is doing
in the Battle of the Atlantic.
And at any given moment during
that battle, from February 1941,
they can see what is happening
at sea.
When I started there,
those markers we used reminded me
of toys out of some children's game.
But soon they became U-boats
and ships carrying cargoes,
food and supplies and weapons
and men to use them.
The vast majority of staff working
around the clock in this room
were from the Women's Royal
Naval Service, known as Wrens.
What they are doing here
informs their commanders.
So the Royal Air Force
commanders are here
and the Royal Navy are there.
And the person in charge,
Admiral Max Horton,
Commander-in-chief
of Western Approaches Command,
whose office is just up there,
he's the one who can order
the big actions based on
what is happening in here.
This looks like a big map,
but there is actually a huge amount
going on on this wall.
So you've got the long,
coloured red strings -
that's depicting the route
that a convoy would take.
The little cards
with the names of the convoys
and the numbers of the convoys -
so that's telling you
where is the convoy coming from
and where is it going to.
The little coloured tabs
off the back -
they are telling you what kind of
naval escorts the convoys
have got with them. Is it
destroyers? Is it frigates?
The little white lozenges
are suspected U-boat sightings
and they are changed
to black lozenges
when it is confirmed
that a U-boat is definitely there.
In the early months of 1943,
mounting Allied losses
were grimly reflected on the walls
of this secretive bunker.
That looks like a cluster
of colours on a plain old map.
But what it actually is,
is a depiction of a horrific
situation playing out at sea.
So you've got three suspected
U-boats - the three white lozenges.
But way more worryingly,
you've got two confirmed U-boats -
the black lozenges.
The convoy has come from Sydney
via New York
and it's heading to the UK.
But the two red crosses means
that two of those ships
have been damaged.
And the red boat beneath
is a ship that has been sunk,
so that is loss of life.
There are people in here who know
people who are on these convoys.
You have Wrens in here
who have brothers and cousins
and friends on those ships.
And they're looking at this map
and they are willing those
people to stay alive.
And they know that the work
that they are doing
will contribute toward that.
It is a big morale issue and it is
a very heavy place to work.
The most strategic port
in the fight against the U-boats
was Lisahally on the River Foyle
in Londonderry.
It's where a young
Bert Whoriskey grew up.
Lisahally was a very small village
at the start, you know,
but where you'd be looking up now
..you would be seeing lines
of battleships and destroyers
that were lying there all the time
during the war,
coming and going from the Atlantic
all the time
to be refuelled
and rearmed at Lisahally.
This is where it all happened
for them.
You had ships from America, Canada,
Australia armed to the teeth.
They had a thing
called depth charges
on the side of the destroyer,
and the depth charges were
just what you would look at,
like 50-gallon oil drums.
They went over to the U-boats,
they released them one at a time
and that's how they
attacked the U-boats.
It was unbelievable.
EXPLOSION
One major issue for the Allies
in the fight against
the Nazi U-boat threat
was the geographic
and political complexities
on the island of Ireland.
We're on the shores of Lough Foyle,
a sea estuary,
which during the Second World War
would have been busy
with escort ships from many,
many Allied nations
protecting the convoys
in the North Atlantic.
Straight across from us is County
Donegal, which is in Ireland,
and a separate jurisdiction.
On the same side of the River Foyle
is the city of Londonderry or Derry,
which is in the United Kingdom,
the most westerly port
in the United Kingdom,
and hence its critical importance
in the Battle of the Atlantic.
The island of Ireland
had been partitioned in 1921.
Northern Ireland, including Derry,
remained part of the UK,
but Ireland, then known as Eire,
declared its neutrality
at the outbreak of war in 1939.
NEWS REPORT: Thus, Ireland's unhappy
history under British rule
was an important factor in Eire's
decision to remain neutral,
a decision which the freedom-loving
nations of the world
found difficult to comprehend.
Geography shapes history.
Geography is destiny in a sense,
and it certainly did a lot of
shaping in the Second World War.
Irish neutrality meant that ports
once available to the British
were no longer accessible,
leaving Derry as the most
strategically vital location
in all of the UK.
While the city and its port
were critical to the escort ships
in the Battle of the Atlantic,
the area close by also provided
a number of airfields.
There were four of them in total.
Those airfields all played
a critical part
right throughout the war.
The quickest way out
into the open Atlantic
was due west from Derry
across County Donegal.
But technically, this would have
been a violation of Irish airspace.
The aircraft taking off from there
to fly out into the Atlantic
could fly out over Donegal,
and did without any protest being
made by the Irish government.
Every minute saved
getting to the Atlantic
was an extra minute added to
the patrol time over a convoy,
or in the area of the convoy, to
search for U-boats on the surface
or other German naval vessels
in the area.
With this short cut
into the Atlantic,
coupled with advances in technology,
planes providing air cover were now
able to fly further with convoys
to keep them safe from attack.
But deadly U-boat wolfpacks
knew the limitations
of the Allied air cover.
There was still a vast area
of ocean that planes couldn't reach.
So there was a dangerous area
that was called the Black Pit
by some merchant mariners,
where simply they had
no aerial protection.
Convoys had to rely on their own
destroyer screens defending them.
So that was where U-boats would wait
in wolfpacks to attack convoys,
and it's where some of the
biggest convoy battles
of the Second World War took place.
There was a sheer number of U-boats
now deployed to the Atlantic,
and there was hardly any chance
to escape these search lines,
which were spanning
all across the Atlantic.
So sooner or later, any convoy
would be located by a U-boat.
EXPLOSION
Convoys had nowhere to hide.
In March 1943, 95 merchant ships
were torpedoed and sunk -
one of the highest rates of monthly
losses since the conflict began.
To have any chance
of winning the battle,
the so-called Mid-Atlantic gap
had to be closed.
Through May 1943, you've got
these little merchant ships,
either grain ships or oil tankers,
which had their
superstructure removed
and a flat deck fitted to them,
and they can operate three
or four Swordfish biplanes.
And there were over 100 of them,
so every convoy after May 1943
has got air cover.
These merchant ships
converted to aircraft carriers
would be key in solving the crisis
in the Mid-Atlantic.
This open stretch of ocean was
about to be closed off to U-boats.
The flight crews for these
Fairey Swordfish biplanes
operated out of HMS Shrike,
based at Maydown Airfield,
just outside Derry.
It was home to thousands of men from
the British and Dutch Air Force,
and it's where Alex and Jennifer's
dad, Hugo Jellema, was posted.
Dad was born in Java
in the Dutch East Indies.
The Japanese
The Japanese invaded
the north of the island
and he and other people
were put on ships.
There were five ships went out,
and Dad's was only one of two
that survived that.
So from the outset, he was very
lucky to get away from Java.
19-year-old Hugo
joined the Dutch air arm
and found himself stationed
in Derry as a navigator.
And he needed luck on his side
because, as he soon found out,
protecting convoys
was a hazardous occupation.
The pilot tried to take off again,
but they clipped
the side of the ship
and they
Got ditched into the Atlantic.
And they were in the Atlantic for
about an hour, the three of them.
A budding photographer and artist,
he collated a stunning scrapbook
of personal photos and drawings,
detailing his life
protecting the convoys.
Yes. Oh, look. Oh, look!
Look at that. That's Dad.
That's a Swordfish.
And Dad painted that on the side
Oh, really?
..of their Fairey Swordfish.
And that's Dad. Yeah. Oh. Yeah.
And there he is again with his
gunner and his pilot probably.
Yes.
These aeroplanes were called
Stringbags, because they apparently
looked like they were just
tied together with string. Yes.
There were three seats
and the pilot was in the front.
Dad was in the middle.
And then this must be the gunner
because he looks like
he's facing backwards.
Dad said that when he
was navigating,
he was standing in this
little open cockpit.
In the middle of the Atlantic. Yeah.
Return convoy crossings
could take weeks,
and a Swordfish crew
would work on rotation,
keeping constant air cover
above the ships.
NEWS REPORT: Everyone
lends a hand in this vessel.
Ship's crew and ground staff
help with the aircraft.
The ship's doctor tests the wind
and the ship's engineer is in
charge of the arresting gear.
With average flights lasting
hours in minus temperatures,
it was gruelling yet vital work.
There was one time that they
almost ran out of fuel
and they managed to get
to Newfoundland.
Newfoundland. Newfoundland.
St John's.
Very, very luckily
flying up an inlet
and suddenly found an
In St John's. ..aerodrome.
Yeah. Very fortunate.
Very fortunate.
Also based at Maydown in Derry
was a young Wren from Belfast,
Mary Piper, who was keeping her own
record of life in Derry at the time.
There seemed to be lots of dances.
I'm not sure whether Mum
was organising them
or whether she was going to them.
But it was a dance here,
it was a dance there.
There was a dance there.
Mum was organising a 21st birthday
party in the White Horse Inn
and they'd invited,
I think eight of the officers
Six or eight, yes.
..from Dad's squadron
and Dad was one of them.
This blossoming wartime romance
between the young Dutch airman
and a Belfast Wren
is beautifully captured
in the pages of their scrapbooks.
Oh, look at this.
"A never to be forgotten
night at the club with Hugo.
"Back to Belmont in the pouring rain
in evening dress."
But given Hugo's critical job
protecting convoys,
finding time for romance
wasn't exactly easy.
"Received your letter.
No leave permitted.
"Any chance of seeing you? Hugo."
"All is well. I'm missing you
very much. Love, Hugo."
Oh, Dad. That's very sweet.
We have this amazing archive
of things which, really,
we never knew anything about
until more recent years.
No, we didn't.
And we can now see how, you know,
where they first met, how their
relationship was developing,
they became engaged
and then ultimately got married.
I think Dad wrote to Mum
and asked her to marry him.
And then they decided they'd better
go and see our grandfather.
Yes. Yeah. Who lived on the
Antrim Road in Belfast.
So this was coming to probably
Dad asking Grandpa Yes.
..if he could marry Mum. Yes.
After he'd asked her!
After he'd asked her, yes. Yes.
As well as discovering their
parents' incredible scrapbooks,
the sisters also unearthed
a rare film
which captures life on board
a MAC ship at that time.
The men were taking their lives
in their hands, guiding them in.
I love that, "Down a bit,
up a bit, down a bit." Yeah.
Yeah. Trying to Get your
head down! Yes, and then duck.
It's very hairy.
And the MAC ship is
It's not static.
A, it's moving forwards and
Sideways. And sideways.
So in bad weather, I think it was
a very hazardous thing to land.
There he is coming in.
There's a hook on the back of the
plane for There's the arrester.
Remarkably, it features their dad,
Hugo, and his crewmates.
That's Dad! There's Dad!
Oh! Oh, for goodness' sake!
He's chewing gum.
Just young lads larking around.
Look at that.
Oh, my goodness.
There he is.
They are really laughing.
I mean, they're forgetting
about the war and everything else
that's going on. They're
just having a bit of fun. Uh-huh.
Can you imagine Dad chewing gum?
No! Absolutely not!
No. Absolutely not. Especially
not as a dad and a father.
And, you know,
we don't even know him
as a young lad
larking about like that.
With aircraft that could now spot
and attack U-boats
anywhere in the Atlantic,
the Allies were beginning
to wrestle back advantage at sea.
But wary of the Nazis' ability
to quickly develop
their own technology, the Royal Navy
were about to introduce
a brand-new weapon named Hedgehog.
A depth charge is one of the weapons
they have been utilising
against U-boats,
but you have to be
directly over the U-boat.
There have to be perfect conditions
for that to strike successfully.
A Hedgehog, on the other hand,
doesn't need those conditions.
Originally, depth charges
were rolled off the stern of a ship
or they were fired by mortars
off the side
or over the stern of the ship.
This new system, erm
..Hedgehog, was an array of,
I think it was 24 small mortars,
launched basically simultaneously
and firing forward
over the bow of the ship.
You've got seconds when a U-boat
is about to dive.
You need something that
can make contact with it
and explode very quickly,
and that is what a Hedgehog is.
HMS Broadway, based out of Derry,
was one of the first
Royal Navy escort ships
issued with this new weapon.
Commanded by Irishman
Evelyn Chavasse,
his mission was to keep convoys safe
and vital supply lines to the UK
open at all costs.
Evelyn Henry Chavasse
was a regular Royal Navy officer.
Very, very professional as
the Royal Navy's officers were.
Born in County Waterford,
he left to attend naval college
in England at just 13-years-old.
Even though his country of birth
was neutral in the war,
he, like tens of thousands
of others from Ireland,
was proud to fight on the side
of the Allies.
It's one of those complications
of being Anglo-Irish.
And I mean, the thing about
the Anglo-Irish is the fact
that the Irish think we're English
and the English know we aren't.
We were brought up to be Irish, to
respect everything about the Irish,
but we were open
to what was happening
to our nearest neighbours as well.
Evelyn's unpublished memoir
from his time
during the Battle of the Atlantic
details the new weapon
they had been supplied with.
"The Hedgehog was the very latest,
and at the same time
"the most desperately secret weapon
"designed for the discomfort
of U-boats.
"If you had made a good shot,
"one or more of them would plunge
down on to a U-boat with a bang
"and punch a neat hole in it.
"If you missed,
there would be a sad silence,
"but the U-boat would not
realise it had been shot at.
"You could then have another go."
Despite showing its capability
in Navy tests,
the Hedgehog was failing
to live up to expectations
in the immediate months
after its introduction,
leading some in the Admiralty
to question its effectiveness.
Evelyn Chavasse would be the man
to prove its worth
on a critical convoy
from Halifax to Liverpool.
That's the first convoy
that was ever supported
by an aircraft carrier for the
entire crossing of the Atlantic.
Convoy HX 237 consisted
of 46 ships with eight escorts.
On the 12th of May 1943,
it was attacked by a wolfpack
of U-boats in the Mid-Atlantic.
"The pace was beginning
to hot up a bit."
I mean, there were a lot
of U-boats around them.
"And it's clear to me
that by this time
"several U-boats were in touch
with the convoy, mostly astern."
One of those was U-89,
with 48 sailors on board.
U-89 was then engaged by Chavasse's
destroyer, HMS Broadway,
and a frigate, HMS Lagan.
U-89 did all sorts of changes
of depth and direction
to try to avoid being hit.
One, at least, of the 24 Hedgehog
mortars fired by HMS Broadway
hits U-89 and sends U-89
to the bottom.
We do know this was the first time
that Hedgehog
had actually been guaranteed
or certified to have had a hit
and to have sunk a submarine.
The convoy lost three ships,
but would ultimately
make it to Liverpool
with most of its
vital supplies intact.
A combination of aircraft
and escorts equipped
with the new Hedgehog mortars
sank three U-boats
in that one attack.
In the space of just a couple
of months, it seemed the Allies
were beginning to turn the tide
against the U-boats.
The Nazis were fiercely determined
to win back the advantage at sea,
but their losses were mounting.
May 1943 saw the culmination
of all these efforts
on the British side and on the
Allied side to defeat the U-boats.
So the U-boats were rather surprised
to find aircraft in the
middle of the Atlantic,
and these aircraft were, of course,
equipped with highly effective
anti-submarine weapons
and the results came in quickly.
It saw the loss of almost
40 boats in one month.
That is almost one third
of the total boats
operational at that time
in the Atlantic.
This is Black May
to the Kriegsmarine.
You know, it's had many periods
of success through the conflict,
but this is one where, to Donitz,
Vice Admiral Donitz,
the head of the U-boats, that
this looks like they've had it.
Nearly 2,000 men perished
aboard U-boats in May 1943.
Amongst them was Admiral Karl
Donitz's 21-year-old son, Peter.
One of the main problems
the Kriegsmarine
was suffering during the war
was the deprofessionalisation
of its crews.
The number of trained U-boat men
aboard newly built
or newly constructed boats was just
reduced to four or five at maximum.
So to replace those crews
that had been lost,
the Kriegsmarine was forced
to introduce untrained personnel
from other branches
in the Kriegsmarine.
So the casualty rate for the
U-boat crews in particular,
this really came on
in the latter part of the war
as the Allies got on top.
It was the highest of any
armed service in any nation.
It was absolutely incredible.
So every able bodied person
was drafted in.
On 24th of May 1943,
Donitz stopped the tonnage war
in the Atlantic.
He stopped wolfpack tactics
in the Atlantic
and then he ordered his boat
to move further south
in order to find the so-called
"soft spot" in the central Atlantic,
or even in the South Atlantic.
But what he had not foreseen
was that, even in these areas,
there were no longer
any more soft spots.
Germany's shocked
that they didn't expect
the Allies to be so successful
in May 1943 against the U-boat.
And Willie Warnock, who was
the Irish minister in Berlin,
reports back that Germany is looking
for some new form of weapon,
some new form of tactics
to meet the Allies.
20 miles off the Irish coast,
the sunken wrecks of battle
are giving up their secrets,
revealing how the Nazis were
rapidly developing technology
to try and regain the upper hand.
As with all of the
Battle of the Atlantic,
there's the punch and counter-punch.
Technology introduced,
there's the reaction from
the Allies, and vice versa.
Every time there was an advance
by one side,
the other sought to counter it.
An expert team of divers,
led by world renowned underwater
cameraman Rich Stevenson,
are exploring U-218.
Originally designed to lay mines
in coastal waters,
its mission became
increasingly difficult
due to advances in radar
and air cover.
But the Kriegsmarine believed a new
piece of technology named "snorkel"
could change how a U-boat operated
and give them back their advantage.
When we dived U-218,
Barry pointed out the snorkel.
Again, it looked like
the day it was made.
It was in a really
incredible condition,
given the amount of years that it's
been lying there on the seabed.
A snorkel would extend
to a length of 8.5 metres
from the deck of the boat,
effectively allowing it
to breathe underwater.
The introduction of the snorkel
was a huge leap ahead
for the German submarines
because they didn't have to surface.
And not having to surface then made
you much, much less vulnerable.
The snorkel turned
these submersibles
into complete submarines.
In terms of that they could stay
submerged for longer periods,
could reload their batteries
and could travel being submerged
at periscope depth.
So once the U-boats
were able to stay submerged
with the help of the snorkel,
their chances to be located
by enemy aircraft was almost nil.
And then, typically at night,
they would come up and start
to engage targets.
EXPLOSION
And this came very much as a
surprise to the British Admiralty
because thanks to the snorkel,
they were now able to stay
unmolested in these areas
and even they achieved some success.
Traditional U-boats
retrofitted with a snorkel
would still have a significant role
to play in the battle,
as the Allies would soon find out
to their cost.
But the Nazis were also
secretly developing
a completely new type of U-boat.
Their most effective
killing machine yet.
This bunker stands for what
the Germans call the Total War.
Total War means
there's nothing between
what the Nazis called
the final victory or total defeat.
They named this project Valentin.
And it was located at the River
Weser in the north of Germany,
and it was huge.
This concrete superstructure
with a seven-metre-thick roof
extended to the length
of four football pitches.
It was here that this
brand-new type of U-boat
would be constructed
in total secrecy.
The Type XXI,
dubbed the Elektroboot.
The hope of the Nazis was to
mass-produce Type XXI submarines
on a really new system
of assembly line.
The idea was to put out
one submarine each 56 hours.
If you compare this
to 12 months building
in the previous times
with a conventional boat,
the production figure was immense.
So it would have increased
the number of U-boats available
to the Kriegsmarine
to a very large number.
Plans for the Elektroboot
were finalised in 1943,
and the first vessels
went into production
at various locations
across the Reich.
It was the first U-boat that could
truly be called a submarine,
able to spend most of its time
operating below the surface.
It did this with the help
of a massive battery compartment
in the hull.
The new Elektroboot types were,
in a way,
revolutionary in terms of design.
They applied for the
first time streamlining.
They had high underwater speed.
They had very effective
weaponry and detection systems.
You've got this submarine
that doesn't have to surface.
It can stay submerged and fire.
It's got more advanced weaponry.
Its guns can be reloaded in quarter
of the time they could before.
It's an impressive feat.
Convinced of the new vessel's
potential,
Grand Admiral Karl Donitz
wanted this vast bunker complex
to house a mass production facility.
He gambled that the sheer number
of these technically advanced boats
rolling off the assembly lines would
ultimately overwhelm the Allies.
The problem was that these
constructions were only able
with the help of slave labour
and prisoners of war at that time,
because the Germans were completely
exhausted in terms of labour.
It's very peaceful, it's very quiet,
and especially today
with the sunny weather.
But it looked completely different
80 years ago
because we are now standing at
the beginning of what was the
..landscape of different camps where
the forced labourers were put.
So there were barracks
all over the place.
There were guards
all over the place.
Barbed wire, military structure
to put people
kept from different countries
and for different reasons,
sent here to work.
It was really like
a concentration camp system.
Among the 10,000 men sent
to the camps at Bremen-Farge
were 32 Irishmen
who had been captured
on British Merchant Navy ships
in the years before
and taken prisoner.
They belonged to the first groups of
the people who were forced to work
within the project of the Bunker
Valentin construction site.
The Irish seamen would be
kept here for two years.
The men were from both sides
of the Irish border,
but German officials eventually
declared them all to be Irish.
Now classified as civilians
from a neutral country,
their prisoner of war status
was removed
and they were offered
contracts aboard German ships.
When they refused to cooperate
with the Nazis,
they were sent to the
punishment camp at Bremen-Farge.
The youngest of the group
was 19-year-old Harry Callan
from Derry,
the city at the heart of the battle
against the U-boats in the Atlantic.
A seaman doesn't have a passport.
What a seaman has
is a discharge book.
And so here's the very first ship
he went on, the Culebra in 1940.
But this one then shows
the Afric Star.
This was the ship
that he went down on.
And in this case,
on the 29th of January, 1941,
they were discharged at sea
because that's when they were
captured and the boat was sank.
And then his next voyage is 1946.
Nobody in the family
ever mentioned the war
or being a prisoner of war.
It just wasn't done.
People came back from the war
and they were all damaged people.
It was only when Harry
was in his mid 80s
that Michele finally got him
to talk about his experiences.
He found out that he was
actually the last survivor.
I asked him to please, please talk
to us because you're the last one.
And if you die,
nobody is going to know anything
about what happened to you guys.
So you do need to talk.
And once I started down that road,
it was like a tap opened.
That's when it all came out.
What he saw, the beatings,
the people being shot,
the bodies in the open graves.
And
..it was really difficult for him.
As thousands of forced labourers,
including Harry
and his fellow Irishmen,
continued to toil
on the bunker construction,
the Nazis were increasingly
pinning their hopes
on the Elektroboot to turn
the tide in their favour.
Because post Black May of 1943,
Allied convoys were crisscrossing
the ocean relatively untouched.
That all changed in September 1944,
just off the north coast of Ireland,
when a lone U-boat fitted
with the new snorkel device
wreaked a deadly havoc
and rocked the confidence
of the British high command.
We're diving on a wreck
called the Empire Heritage.
So the Empire Heritage was
originally built as a factory ship,
a whaling factory ship
in South Africa,
so she's known as the Tafelberg.
So in the Second World War,
these were really valuable
because they were so versatile.
The massive ship, one of the
biggest sunk during the war,
was making its 10th crossing
of the Atlantic,
carrying war supplies
and sailors back to the UK.
This is a huge ship.
You know, you're coming down and the
first things that'll come up to you
are the huge twin derricks, these
masts coming up to nearly 40 metres.
The ship isn't sitting up
like you might classically
imagine a ship - like this.
It's done that and then everything
has just slid off to one side.
The Empire Heritage was loaded
with 16,000 tonnes of fuel oil
and a valuable cargo
of Sherman tanks and trucks
that were destined
for the war in Europe.
The D-Day landings had taken place
two months before
and the Allies were gradually
pushing their way through France.
It's one of those sites where
I don't think it actually hits you
until you've got out the water
and you watch the footage back
and you see someone swimming next
to a full-sized Sherman tank.
And they're just scattered in such
random directions and positions.
You know, it's not just
the Sherman tanks.
There's these 20-tonne trucks.
Cab is gone, but the chassis
is there, the engine is there.
Double axle at the back,
double tyres on each axle,
and the tyres are still inflated.
It's mind-blowing to think about
how big that ship would have been
to be carrying so many tanks
and trucks,
and then the destruction
to then sink it - it's incredible.
It's really quite an emotional
process that I go through
when you consider how these things
get to lie on the seabed.
After the Germans had lost
their French bases,
they had to transfer
all boats from these bases
to their new Norwegian bases.
And the range of most
of the Type VII boats
was not long enough to go into
operations in the open Atlantic.
So Donitz had the idea to send
all these snorkel-equipped boats
into the coastal waters
around Britain.
One of those boats was U-482,
commanded by Graf von Matuschka,
a young commander
on his very first patrol.
Operating with the snorkel,
he was able to hide undetected
close to the Irish coast.
In the week before he spotted
the Empire Heritage,
he had already sunk three ships
in the same area.
Oftentimes, individual initiative
and the willingness to take risks
was an important mark of
a successful U-boat commander.
He was highly praised
for the conduct of his operation
because he went right into
these heavily covered areas
and he never made some second
thoughts about being endangered.
He just said,
"Well, I'm going to attack,
"and sooner or later I will escape."
And as matters turned out,
he was successful in this role.
As the Empire Heritage sank,
U-482 lay in wait
as a rescue ship, the Pinto,
plucked survivors from the water.
So she came alongside to try
and pick up sailors in the water
and she too was torpedoed.
She had about 60 people on board,
of which 20 drowned.
In total, 130 men
lost their lives in the tragedy.
The sinking of the Empire Heritage
and the Pinto
was a stark reminder to the Allies
that the battle was not yet won.
The Nazis were determined to keep
fighting until the bitter end.
When I film shipwrecks that
have had a loss of life on them,
you have to be respectful for that,
because that is
literally somebody's grave.
And in the same way
you wouldn't just carelessly walk
through a graveyard
standing on people's graves,
in some respects, whilst we
swim over these locations,
we're kind of doing
exactly that in a way,
so you have to be mindful
and respectful at the same time.
There would have been shock and
surprise at the fact
that convoys were being attacked
in coastal waters.
That was not expected.
But clearly, you know,
in this case a lot of bravery,
but different tactics
and clever tactics.
The introduction of the snorkel
proved that U-boats
with advanced technology
could still pose
a significant threat.
The Kriegsmarine were convinced
that the new Elektroboot
would be a game-changer
in the Atlantic theatre.
By late 1944,
hundreds of these new boats
were being manufactured
at shipyards across Germany.
Designed in nine separate sections,
the ultimate plan was to transport
these sections to one location,
Bunker Valentin, where they would be
assembled, completed and launched.
The idea of this bunker was
to mass-produce these submarines
on a kind of assembly line.
And they would have worked
on 12 boats at the same time.
As far as we know,
6,000 people would have worked
inside the bunker each shift,
as you can imagine,
because they needed so many
of these boats so fast.
Desperate to ramp up this
modular mass production model,
the Nazis were pouring
all available resources
into finishing construction
of the bunker.
But just a few months
from completion,
the Allies were preparing
to make their move.
They had the means
of air reconnaissance
over almost all of Germany,
and so they sooner or later detected
that there was something
going on at this site.
And they realised that the Germans
were building something
really, really great.
On the ground at the bunker site,
Harry Callan and the other
Irish seamen
were enduring ever more
difficult conditions
at the hands of brutal SS guards
and a sadistic camp commander.
It was pure terror.
Every day was terror.
The roll call in the morning
where they'd have to stand in rows
of five in the yard and be counted,
and he would just pick on someone.
One day he picked on a man
and had him run backwards and
forwards and backwards and forwards
and picked shots at him
until the poor man just
dropped down to his knees.
And then he just shot
and killed him for no reason.
The threat of death was constant
for the thousands of men
continuing the construction work.
And as the bunker neared completion,
it was thought to be
impenetrable to attack.
The final idea was to bring
all walls and the whole roof
up to seven metres of concrete.
The Minister for Propaganda,
Joseph Goebbels, visited
the construction site in November
'44 and he said, OK, the works
are so far that no Allied bomb
can do any harm to this project.
The Allies knew they couldn't risk
allowing the bunker to be finished
and these advanced weapons
to make it out into the Atlantic.
They made very clear photographs
of the site.
What they were interested in was
how far is the production
of the roof, because on the one side
of the bunker the roof is
seven metres, but on this side,
it's only, it's "only" 4.60.
Just months after Goebbels
made his bold claim, two RAF planes
from 617 Squadron, known
for their Dambusters mission
two years earlier, launched
a daring raid on the site.
One attack, two bombs,
this one and one at the back.
That was the end of all works
on this construction site.
After 24 months of building,
Grand Admiral Donitz's dream
of unleashing a wave of
technologically superior U-boats
was no more.
Thousands of prisoners died
in the Bremen-Farge camps,
including five Irishmen.
One of the oldest of the group,
58-year-old Patrick Breen,
was beaten to death by the guards.
He was in the camp on his own most
of the time because he wasn't
physically able to work,
and they came back one day,
they found him outside the barracks,
beaten up
..and he was dead.
Harry and his fellow Irishmen
were the longest-serving prisoners
in the camp.
27 of them managed to survive.
In March 1945,
they were still being held captive,
but things were moving quickly
and freedom was close.
With the loss of the bunker and
no prospect of assembling
the much vaunted Elektroboot
in the numbers needed,
the U-boat campaign in the Atlantic
was doomed to fail,
but the Nazi high command were
determined to fight on,
no matter the cost.
At the end of the war, the German
U-boat arm was mostly made up
of reserve officers.
All of them lacked the essentials
in training,
and this is one of the reasons
why the loss figures
in the year 1945 rose to figures
unheard before,
so there were months when there were
60% of the boats sent out
did not return.
NEWSREEL: The convoy comes through.
The supplies reach Britain, but
one more U-boat goes to the bottom.
At the end of March 1945,
even German U-boat command realised
that these kind of figures
could not be tolerated any more.
On 30th of April 1945,
Hitler died by suicide in Berlin.
He was succeeded by the head
of the German Navy,
Grand Admiral Karl Donitz.
Just days later, the man
who had masterminded the overall
U-boat strategy in the Atlantic,
and who had now lost his two sons
in the battle, ordered his men
to surrender.
They say, well, six years
of fighting are over now,
and you have still to continue
and to obey orders.
They had to surface.
They had to show a black flag
as a sign for surrender.
And then they had to steer
for certain harbours and places
that had been named by the British.
When they intercepted the signal
that Donitz sent
on the 4th of May 1945,
he told his submariners
that they finished this war
undefeated.
This happened at the end of the last
war, that the Germans were convinced
that they weren't defeated.
If any part of the German forces
believes that it wasn't defeated,
then we could have
the same trouble again.
Admiral Sir Max Horton was taking
no chances, and he decided
that the entire remaining U-boat
fleet would officially surrender
in a formal ceremony.
And he decided that
the most important base
in the Battle of the Atlantic
had been on the River Foyle.
They would surrender at Lisahally
on the 14th of May 1945.
NEWSREEL: They came some
way up the River Foyle.
A great day for all who saw them
and, by no means least,
for Admiral Sir Max Horton,
commanding the Western Approaches.
The number of German U-boats had
not yet been accounted for.
This was really the end, at last,
of one of the most bitter
and dangerous struggles
of the whole war.
Time and time again, the very issue
of the war depended
on the breaking of
the U-boat blockade.
As British Admiralty debated what to
do with the surrendered U-boats,
the young German submariners
were kept as prisoners of war,
close to where
a young Bert Whoriskey lived.
There was a
prisoner of war camp now,
where we're standing now,
where those pylons are.
That was where
the prisoner of war camp was.
You know, when you looked at them,
they were young lads.
There were very few of them
in their 30s, you know.
They were all young fellas.
They worked on the submarines
during the day,
emptying the submarines.
And they marched down at night.
And the Germans didn't march
without singing.
It was so exciting.
I was marching along with them,
and one of the officers
threw me a cap,
and I don't have that cap today.
In the six months the Germans
were kept prisoner,
they worked to strip their boats
of all materials onboard.
There was a wee miniature
railway line come right down
to behind our houses, nearly.
And when they were emptying
the U-boats,
they brought the stuff down,
you know.
So, us, as a crowd of young fellas,
we were going through
what was on the thingummies,
you know, every day.
We weren't stealing anything.
We were borrowing it, you know.
I would say everybody in Lisahally
had a German blanket!
In effect, these boats were
a source of technical features.
And then, it was investigated
in very great detail
if there were any technical
inventions that could be made use of
in the Royal Navy or in the US Navy.
German U-boat design and technology
would form the basis of the next
generation of submarine in navies
of America, Britain and Russia.
But for the boats tied up in Derry,
their time was up.
The U-boats had been collected
into Loch Foyle
and into Loch Ryan in Scotland.
And it basically was a question of,
what do we do with all of this?
And so the plan was developed
to sink,
scuttle these boats,
in a big operation.
Operation Deadlight in November 1945
is designed to remove,
once and for all, remove the U-boats
as a threat against Great Britain
and her allies.
So all of the boats, and there
are about 60 tied up at Lisahally,
along the River Foyle,
were towed out into the Atlantic.
Quite a few of them actually broke
the tows and sank themselves.
Others were shot up by destroyers
or other warships,
and some by aircraft
firing rockets at them.
And basically,
apart from a few U-boats,
all of them went to the bottom
of the sea.
A lot of convoys had gone out
over the northern tip of Ireland,
and they had gone
from or past Derry.
So this is a significant place
to scuttle these U-boats,
and there's something
almost poetic about it.
There was no escape, like
it had been in the First World War.
At the end of the Second World War,
the U-boat arm was utterly defeated.
These sunken relics,
whether scuttled in a symbolic act
of victory
or condemned to the depths
by enemy torpedoes,
remind us of the all too human
cost of war.
During six years of intense fighting
at sea,
over 100,000 people
lost their lives.
Grand Admiral Karl Donitz was tried
at Nuremberg
and served ten years in prison.
He was released in 1956 and lived
a quiet life in rural Germany.
He remained unrepentant
right up until his death in 1980.
But the battle and its aftermath
lives on in the minds of people
who are still trying
to make sense of it all.
People like David Brew,
who has spent a lifetime
searching for traces of
the father he never knew
..and Bert Whoriskey,
the Lisahally boy who bore witness
to the historic events taking place
on his doorstep.
For others, treasured family
archives hold precious memories
of their loved ones'
honoured service
..like the young navigator
Hugo Jellema
and his wife Mary, a Wren,
who met during war and lived
a long and happy life together.
And of Evelyn Chavasse,
whose memoirs revealed a faith
which sustained him through
the darkest months of battle.
He gave up his Navy career to become
a Church of England minister.
For those who survived
the worst of conditions,
life went on.
Young Harry Callan finally made
it home to his family in Derry,
four and a half years
after being taken prisoner.
Despite everything,
he returned to sea.
So, he actually filled out
this piece of paper.
"The period between 1940 and 1945,
"I was a prisoner of war
in Germany."
And he signed it, Harry Callan.
And he would just hand that
to the captain,
and the captain would say,
"Oh, OK, right. That's fine."
No questions asked.