All language subtitles for Lost.Worlds.S01E08.Churchills.Secret.Bunkers.1080p.AMZN.WEB-DL.DDP2.0.H.264-BurCyg_track3_[eng]

NARRATOR: During World War II,
a vast complex of secret bunkers

was constructed under
the streets of London.

This world now lost to time
was once an important refuge

from the nightly onslaught
of Nazi air raids.

The subterranean labyrinth
kept the British government

led by Prime Minister
Winston Churchill

c through the darkest
days of the war.

It's the most dangerous
place in the world,

it's the most dramatic
place in the world.

And at the center of it all
is Churchill, who actually

is himself in the firing line.

NARRATOR: This secret network
also sheltered American General

Dwight Eisenhower, but
very little else has ever

been revealed to the public.

This is an immense effort that
never before had been set up

in the history of wartime.

And it's done while most
people above never realized

what is happening.

NARRATOR: Now we had underground
and bring this Lost World back

to life.

We will use cutting edge
computer graphic technology

to peel back the layers
and reveal a hidden city.

Deep below the sidewalk, we
will expose wartime secrets

we were never meant to know.

C is one of the world's most
densely populated cities.

And yet few people have any
idea that a secret world lies

beneath her streets.

Built during World War II
shelter Winston Churchill

and Dwight Eisenhower, this
underground government complex

actually had its origins
in an earlier conflict.

During the First World War,
Zeppelins and Gotha bombers

attacked London in
large quantities

and dropped bombs
on civilian targets.

This was a shocking
occurrence, and it gave Britain

a kind of pervasive fear of
what aerial bombardment could

do to them.

NARRATOR: For the British,
the rise of Nazi Germany

brought all these fears back.

During the 1920s Churchill
had thought that the no war was

going to be possible, but
when Hitler came to power

he saw the increasing
possibility of war.

He recognized the beast
in Germany. he, he,

he had a very
acute understanding

of what Hitler could do.

And in particular, he recognized
the threat that the Luftwaffe

would pose to Britain.

NARRATOR: Hitler's
aggressive foreign policy

led to paranoia in London.

The British believed
a new war would

lead to the dropping of bombs
and poison gas on their city.

London needed bomb proof
and gas tight shelters.

But building such structures
was an unknown science.

Civil engineers and
architects were recruited

to help with air raid planning.

At the outset
of the war, anyone

trying to design or build
a bomb resistant structure

was really getting into
very unfamiliar territory.

One fundamental question
really was whether to shelter

underground or overground,
and it's interesting

that in Germany at the time they
produced designs for some very

large heavily fortified
above ground shelters.

NARRATOR: But British
engineers influenced

by the trench experience
of World War I develop

their own ideas, they
would build below ground.

Those ideas and
developments from them

are beautifully illustrated
in a set of cartoons

that were put together by over
inflate engineer at that time.

NARRATOR: Starting
with an open trench,

the defenses got progressively
deeper and more elaborate.

Solid walls and reinforced roofs
proved capable of protecting

people in large numbers,
but not everybody

wanted to go below ground.

Churchill disliked the
idea of hiding underground.

He always had done in the First
World War, he despised it.

He regarded it as a sort
of form of cowardice,

and he would think of bunkers
as sort of funk holes not

what he wanted to do.

And the first of
these funk holes

that were suggested to him was
a place code named Paddock.

NARRATOR: Paddock was the
brainchild of Norman Hollis,

secretary of the Committee
on imperial defense.

In 1938 he was asked to find
the government a suitable bomb

and gas proof bunker.

After scouring basements,
tunnels, and disused subway

stations all over
London, he settled

on a cluster of
buildings in the suburbs

four miles from parliament.

This was the post
office research station.

It was the perfect mask
for a top secret government

installation.

To this day, it remains
largely ignored by the public.

None of the existing buildings
was large enough or suitable

for reinforcement.

So in February 1939, Hollis
ordered the construction

of a 50 room emergency bunker.

Excavation went 40 feet
down, then the bunkers

were built on two levels.

The foundations,
walls, and ceilings

were all made from
reinforced concrete.

c The building was
covered and then hidden

with the construction of
innocuous civilian buildings.

Paddock was one of the
great secrets of the war.

Lost under suburban
homes and gardens,

it was eventually discovered
by amateur detectives.

We can now enter the
shelters some 60 years

after the government
ordered it sealed.

This is the emergency
cabinet war room.

This is where the government
would have come from Whitehall

in the event of an
attack on central London.

Here they should have been
able to withstand a direct hit

from the largest
high explosive bomb

that the Germans had available.

c We're going down to the first
level of the bunker, about

15 feet.

After this point we're
coming into an airlock,

one of the major worries
was of a gas attack.

NARRATOR: The airlock worked
because the air pressure

in the bunker was kept
higher than the pressure

outside. c If someone entered
the bunker from outside,

the airlock would be sealed and
the high pressure would force

any gas back out.

The way would be
clear for people

to enter the bunker safely.

Poison gas was a very serious
factor in the government's

calculations, and
they produced millions

upon millions of gas masks.

At the beginning of the war,
about 85% of the population

could be seen in the streets
with their gas masks.

It was such a real fear.

NARRATOR: Despite the
enormity of this bunker,

it was built to
house 200 people.

Paddock was constructed
in complete secrecy.

Most work was done at night
under camouflage netting.

c The vast quantities of
spoil from the excavation

were allegedly removed
in bread delivery vans,

and local people knew
not to ask any questions.

No one wanted to be
suspected as a spy.

Now we're moving into the
inner sanctum of the bunker,

the basement where we are now
could have been sacrificed.

But downstairs in the
subbasement that's

where the government
would have been,

that's where Churchill
would have been.

There are three ways
down and each of them

is protected by a
heavy steel blast door.

c You turn the wheel and thick
metal bars would have pushed

into these openings here.

So this would have been
gas tight and blast proof.

As we go down the stairs,
this is floor level.

And between this floor level
here and the the subbasement

was five feet of
reinforced concrete

to give added blast protection
down in the sub basement.

NARRATOR: As the bunker was
designed to operate in the most

extreme of wartime conditions,
it had to be self-sufficient.

In case it was cut off from
main supplies by an air raid

it had its own water tanks.

There was a generator
capable of running everything

from the lighting,
teleprinters and radio

equipment to the ventilation
and filtration plant.

Paddock did not have
a heating system.

c It was assumed that
the warmth of 200 bodies

would have been sufficient
to heat the sealed bunker.

The trade off would have been
a humid and foul smelling

atmosphere.

However unpleasant,
Paddock had a vital role

to play when war finally
broke out in 1939.

c London braced itself
for Hitler's bombs.

As soon as Britain
was at war with Germany,

an air raid siren
went off in London.

It was a false alarm
as it happened,

but you've got an instant terror
hence the wearing of gas masks,

hence the evacuation
of people, hence

the moving of large quantities
of the population into bunkers.

The bombers didn't come at
first, but the fear of invasion

remained.

Should central
London be evacuated,

Paddock would be at the
heart of Britain's resistance

to the Nazis.

Right.

So we're coming into
the map room here.

This is the military
hub of the bunker.

This is where the war in Britain
would have been run from.

The would have been maps
on all these walls here.

And fluorescent light
fittings angle the light

onto these walls where
the maps were located.

we've got three offices, perhaps
one for each of the services,

the admiralty, the
Air Force, the army.

This is a vitally
important room,

this is where the war could
have been won or lost.

NARRATOR: In the end, the
order to evacuate London

was never given.

Paddock remained on
permanent standby.

Churchill did in fact, hold
one cabinet meeting at Paddock.

But it was an impossible
place to get at,

the cabinet got lost
as they went there.

And he dismissed it as a
piece of useless folly quite

unsuitable for his
Majesty's government.

NARRATOR: Although it never
fully served its purpose,

Paddock was important.

It helped engineers understand
how to build bomb shelters

and it served as a prototype
for many of Churchill's bunkers.

With Hitler's armies
triumphant in Western Europe,

it was inevitable that he would
direct his bombers at London.

What happened in one of these
bunkers would save Britain.

Hidden deep in the corner of
an Air Force base in London,

England is a top
secret military bunker.

60 years ago it was the hub of
Britain's air defense tasked

with stopping the most dangerous
threat the country had faced

in 1,000 years.

By the summer of
1940, Hitler's armies

had smashed their way
through Holland and Belgium

and had occupied
Paris in France.

He now set his sights on
Britain, just a short distance

across the water.

Britain was in huge danger
in the summer of 1940.

The Germans threatened to
bomb us into submission.

They were massing
on the continent,

they were assembling barges.

Hitler had planned an operation
which he called Operation Sea

Lion which was set for the
15th of September 1940.

And the British
thought that invasion

was a real possibility.

NARRATOR: Hitler now had
charge over French airfields

just 20 miles from
the British coast.

c His bombers and fighters
could now reach London,

and their lethal payloads
were forcing both the public

and the government to seek
shelter where they could.

His plan was to destroy
Britain's Air Force

and leave the island
open to invasion.

RAF fighter command
was a prime target,

and if it was to survive
the assault of the Luftwaffe

it would have to go underground.

These two items
about 40 German bombs,

they both weigh 1,000
kilograms that's around

about 2000 pounds.

This item here is a blast with.

About 80% of this of this
weapon contains explosives.

NARRATOR: Blast weapons
exploded upon impact

and caused maximum
damage above ground.

They were easily countered
by underground bunkers,

but such shelters were extremely
vulnerable to another weapon

in Hitler's arsenal.

This particular weapon
is called an easel.

Is a penetrating weapon designed
to penetrate bunkers or harden

targets.

It's got this Tonyan
strap system, which

means it's going to be
used by dive bombers that

can accurately hit the target.

80% of his weapon is
steel, only 20% explosive

NARRATOR: Although it
contained little explosive,

the pencil shape and extreme
weight of a penetration bomb

meant that it could burrow
through metal, brick,

or concrete before
detonating at high pressure

deep in the ground, the
original bunker buster.

The only response to
these penetrating bombs

was to take the bunkers
deeper underground.

Churchill was enormously
excited by warfare.

And the warfare that was
going on in the summer of 1940

was the Battle of Britain, the
airborne assault on Britain

and the bombing which got
slowly nearer and nearer London.

And Churchill he'd
like to do this,

he like to go to the front.

And the front line during
the Battle of Britain

was in the Underground
headquarters at Oxbridge.

NARRATOR: Oxbridge was
one of a new generation

of top secret deep level bunkers
that lay far below the range

of German weapons.

With special
military permission,

we can now head down 60 feet to
the operations room of London's

fighter command.

In the summer of 1940, this
room offered Britain a lifeline.

Buried deep in an
open excavation,

the Oxbridge bunker is a
simple thick walled box

on substantial
concrete foundations.

For added protection a six foot
slab of reinforced concrete

was laid on top.

Two exit passageways
were constructed,

and then the hole was
filled with sand and Earth.

It was designed to be virtually
invisible from the air.

The bunker comprised 40
rooms over two levels.

It was completely
self-sufficient

with its own generators,
ventilation system,

and telecommunications.

But the crowning glory of this
underground command center

was the plotting room.

Ready for action as
war was declared,

Oxbridge was for a time the
most important operations room

in Britain.

The Prime Minister was
a frequent visitor.

Joan Fanshaw serving
in the bunker in 1940

secretly recorded his visits.

It was quiet against
all rules and regulations

to keep a diary, but I
kept on throughout the war.

And I used to hide it in
my gas mask container.

NARRATOR: One particular
visit stands out.

September the 15th I
was on duty till nearly 1

because Churchill was upstairs
and we could not change over

in a blitz.

NARRATOR: That blitz was to
prove the heaviest daylight

raid of the war.

On September 15th 1940,
London held its breath.

200 heavily armed German
bombers were approaching.

And if Hitler could destroy
Churchill's air defenses,

the path to invasion lay open.

All records of
sightings were channeled

into the plotting room.

First reports of German aircraft
came from radar stations

on the coast.

These were then translated
into map positions

by plotters like John.

if it's the were
enemy aircraft,

it would say h,
hostile and it would

say how many aircraft there
were and at what height

they were flying.

As soon as they
touched the coast,

the observer corp took over
and picked up the aircraft

and they passed them to
fighter command headquarters.

NARRATOR: The station
controller reacted to the latest

information.

He sent up fighter squadrons to
intercept the German raiders.

Churchill knew it
was make or break.

This was the pivotal day
of the Battle of Britain.

Churchill sat there
absolutely enthralled

as the plotters pushed the
indicators across the board

and as the lights lit up
to show the Germans coming

and the British squadrons
rising to fight them.

You can imagine it would
become extremely busy

because then we come across
our own squadrons here.

3 and 3 has come from
North hote and that

means there are 22 aircraft
in it flying at 22,000 feet.

So the controller could get
them up to the ride height

to oppose the enemy
aircraft coming in.

NARRATOR: Facing over
200 German aircraft,

Oxbridge threw everything
it had into the fray.

It became almost impossible to
find space to put these blocks

all together, and the plots
were all getting mixed up

and you get mixed up with
your person next door.

It was a madhouse,
it really was.

At one crucial moment during
this extraordinarily tense,

dramatic time, air Vise
Marshal Park was in charge

of the whole operation told
him that there were no more

reserves.

NARRATOR: Every
available fighter plane

was committed to the battle.

Both the British and the
Germans suffered heavily

through the day.

There were wild claims from each
side over the number of planes

shot down.

Churchill was intensely moved
by the Oxbridge experience

and he went home excited,
elated, exhausted thinking

that the British claims
that we had shot down 185

German aircraft was correct.

It wasn't correct, we shot
down about a third of that,

about 60.

Nevertheless, it
was the culmination

of the Battle of
Britain, something

that he had witnessed
at first hand.

And it marked the end
really of the German attempt

to attack Britain by
air during the daylight.

NARRATOR: The secret
bunker at Oxbridge

was never discovered
by the Germans.

Without it, fighter command
might have been wiped out.

Because of it, Britain
retained control of the skies.

Hitler abandoned his
plans for invasion

and switched his tactics
from attacking the Air Force

to bombing civilians.

Churchill and his
government would now

be in the firing line.

They were in urgent need of a
bomb proof bunker in Central

London.

There began one of the most
incredible secret construction

projects of the war.

Under this building in Central
London is a massive bunker.

With over 200 rooms, it would be
the hub of Winston Churchill's

wartime world.

With German bombers wreaking
destruction on London,

this secret underground
complex would provide

a refuge for Churchill
and his government

in the most desperate of times.

London becomes a most
extraordinary focus

for world attention.

It's the most dangerous
place in the world,

it's the most dramatic
place in the world.

And at the center of it all
is Churchill who actually

is himself in the firing line.

NARRATOR: When the
blitz began, there

were loud calls to evacuate
the government from London.

But Churchill feared this
would lead to widespread panic.

He resolved to
stay in the capital

and see it through
with his people.

Churchill enjoyed the bombing.

It was a kind of huge
pyrotechnic display.

And sometimes in his
tin hat, he would

go up onto the roof of
what is now the Treasury

and look at this splendid
firework display,

puffing away at his
cigar throughout.

He realize of course
the horror of this,

but always in him there
was a kind of schoolboy

that was a delight in the
drama of action and warfare.

NARRATOR: But when his own home
took a direct hit Churchill,

reluctantly accepted the
need for bomb proof quarters.

Just 100 yards from the
Houses of Parliament,

a substantial
government building

with extensive basements
was identified as being

perfect for Churchill's needs.

On the first floor would
be his living quarters.

The basement would provide
protected office space

for political and
military leaders

and down in the
subbasement sleeping

quarters for his staff.

For many years, the
cabinet war rooms

were a closely guarded secret.

But studies of
declassified papers

now reveal the full story.

This is the way that
Churchill and those coming

to work in the cabinet war rooms
or to visit the cabinet war

rooms would have
arrived in the building

and he would have
walked up the staircase.

And ahead of them
they would have

seen a pair of glass doors.

As they got close they would
have noticed that there was

a small hole in the middle
with a machine gun pointing out

through it.

NARRATOR: Guarded by
heavily armed Marines,

the suite of first floor rooms
provided for the Prime Minister

was known as the Annex.

At one end where Churchill's
private map rooms, at the other

was his living quarters, a
dining room, a living room,

and a bedroom each for
Mr and Mrs. Churchill.

But these rooms were
not safe from bombs.

With Hitler intensifying
his night attacks

on London in late 1940,
Churchill and his government

took shelter in the
basement rooms below.

These offered some protection,
but they were still not

bomb proof.

Substantial reinforcement
was ordered.

What followed was one
of the most amazing

secret construction projects of
the war, the erection of a bomb

proof slab over the
basement cabinet war rooms.

Well, they started to
reinforce the cabinet war rooms

by putting in a
timber structure.

Eventually they changed it to
putting in a steel structure,

but that wasn't
considered safe enough.

And so eventually
they started to build

a massive concrete
detonator slab which

was thought to be proof
against 250 kilogram bombs.

NARRATOR: The principle of the
detonator slab was very simple.

A thick crust of concrete
lay above the basement.

Rather than penetrate
it, a bomb would explode

and the rooms below
would be shielded.

But the engineering
was more complex.

If you imagine a bomb
falling from maybe 15,000 feet.

It can reach a speed of
1,000 feet per second.

So that's an awful lot
of kinetic energy hitting

the roof of the shelter.

So if you actually
deal with that

and have a slap
of some sort that

will resist that
sort of impact this

is a big engineering challenge.

I'm sure a lot of
trial and error

went into establishing the
necessary thickness to defeat

the largest of the bombs
that might be directed

at an important target.

NARRATOR: The slab was laid over
a framework of steel beams cut

into the walls of
the ground floor.

In complete secrecy, some 900
beams each weighing over a ton

were lifted by hand
into the building.

On these beams a bed of
corrugated troughs was laid.

Then six feet of liquid
concrete was pumped in.

Eventually an area the size of
a football field was covered.

It was exposed
section of the slab,

you can see the
thickness of concrete.

You can also see the troughing
which supports the concrete,

and then the steel
beams underneath.

NARRATOR: This enormous
construction project

took 18 months to complete.

Work carried on 24 hours
a day around Churchill

and his government.

And while he hated the
constant banging and whistling

of the workmen, the prime
minister's fascination

in their work was noted
in his secretary's diary.

The PM appeared and bidding
may bring a torch led me

away to look at the girders
in the basement intended

to support the building.

With astonishing agility he
climbed over girders, balanced

himself on their upturned edges
some five feet above ground

and leapt from one to
another without any sign

of undue effort.

Extraordinary in
a man of almost 66

who never takes
exercise of any sort.

NARRATOR: Eventually
some 200 rooms

were reinforced
for government use.

Of primary importance
to Churchill

was the cabinet war room.

He regularly met here
with his ministers

and military commanders
to discuss strategy.

It was in this room that some of
the greatest decisions of World

War II were made.

But none of those
decisions could

have been made without up
to the minute intelligence

reports which came
from the map room.

This was the nerve center
of the basement complex.

This is where all the
information came in from all

the different theaters of war.

There were people sitting
around this table who

were on to the telephone
taking notes, ringing

and giving other people
pieces of information.

And the whole purpose of
it was that daily they

could make an assessment
of the state of the war.

NARRATOR: Around a
tight cluster of desks,

military staff
received and passed

on the latest information from
battle zones around the world.

It came in via radio,
telephone, and telegraph links.

All the information that
came in was plotted onto maps.

The one on the wall
is the convoy map

and you can see from all the
thousands of pinholes in it

where they were following
all the different movements

of the ships across
the different oceans.

NARRATOR: There were
literally hundreds

of maps on the walls covering
up to the minute land and Naval

operations across the globe.

Operating 24/7 irrespective
of air raids, the map room

was Britain's eye on the
world that never slept.

There was office space allocated
to dozens of secretaries,

clerks, telephonists,
and guards.

The cabinet war rooms could
sustain the essential machinery

of government underground.

And in order to work around the
clock sleeping accommodation

was provided.

Senior staff enjoyed private
quarters at basement level,

but the Junior staff had
to descend 20 feet further

into the dock.

This was a claustrophobic warren
of rooms in the subbasement.

And it's exactly the
same layout of rooms

as you had above, but you had
a very much shorter headroom

as you can see from this
mind your head sign.

And so people would
come through here

and then go off into
their dormitories.

NARRATOR: Just four feet
high in places, the dock

was damp and infested with rats.

But it did at least offer a
safe berth away from the bombs.

Churchill and his government
now considered themselves

safe in their
basement war rooms,

but there was a real danger that
the Prime Minister would be cut

off from the outside world.

The intense bombing was tearing
London's communication system

to shreds.

One of the first targets that
an enemy tries to hit in a war

is your communications center.

If they can knock out
your radio transmitter,

if they can knock out
your telephone lines,

if they can knock
out your telegraph,

they're going to do it.

NARRATOR: London's cables were
being cut as fast as they could

be laid.

Churchill was safe
in his bunker but he

knew that without communications
he could not direct the war.

The remarkable tunnel system
that he ordered in response

to this threat remains a
state secret to this day.

One of the great secrets
of Churchill's lost world

remains under central London
today classified and fully

operational.

Nightly German bombing raids
were tearing the city's

communication system to shreds.

This secret tunnel network
was built deep underground

in response.

German bombers are trying
to take out not only people.

They're trying not only to
terrorize the population,

they're trying to take out
the main command and control

points that link London
with the rest of the world.

What's important is not only
the population hold out.

It's not only important
that Churchill survives,

but Britain's communications
survive the blitz.

NARRATOR: If Hitler's severed
London's telephone, telegraph,

and radio networks,
Churchill's voice

would be cut off from
the rest of the world.

The fight was on to protect
the capital's communications.

London's international radio
telegraph and telephone network

stemmed from the
Faraday exchange,

the hub of a
network of landlines

350,000 miles in length.

By securely connecting the
cabinet war rooms to Faraday,

Churchill would enjoy
direct communications

with his armed forces and
over 70 countries among them

the United States.

But Faraday lay over two miles
away and cables at street level

were vulnerable.

Churchill urgently needed
a bomb proof system

to get his cables
safely across the city,

and this spawned a remarkable
deep level tunneling project.

Hidden under Whitehall far
below unsuspecting Londoners

lies the first phase
of this secret project.

Still classified and a
potential terrorist target,

we can only piece
together this tunnel story

from fragmentary evidence.

We're here in
Trafalgar Square,

the tourist heart of London.

Down there, we have
Whitehall, which

is the heart of the
British government.

Under Whitehall is a
tunnel, a top secret tunnel

built during the
Second World War

to house and secure the
government communications.

NARRATOR: C Building a two mile
tunnel from Churchill's war

rooms to Faraday was beyond
Britain's wartime resources.

But a shorter 800
yard tunnel was

begun between Trafalgar Square
and the Houses of Parliament.

It would carry government
communication cables deep

under the street.

Initial excavations 100
feet down in the clay soil

were consolidated by cast iron
segments bolted into rings.

Section by section, the
12 foot diameter tunnel

progressed along Whitehall.

It was to carry a total of
40,000 government telephone

and telegraph wires toward
the National Network.

Starting in late 1939,
miners and engineers

protected from air raids
worked day and night.

They completed the
tunnel in just 18 months.

As well as cables,
the large bore tunnel

provided workspace for
hundreds of telecoms operators

and engineers.

But there remain the problem
of the last mile and a half

to reach the Faraday exchange.

The solution the
tunnel engineers found

was as simple as
it was brilliant.

C We have a cable
tunnel running all the way

along Whitehall from
parliament to Trafalgar Square,

but that's no use
unless it can talk

to the rest of the network.

In London we have a
large tube network

waiting to carry cables.

It's called the
London underground.

So if you can link from
the communications tunnel

into the London underground, you
can get pretty much anywhere.

NARRATOR: The extensive tunnels
of the London underground

were perfect for connecting
Churchill's communications

to the outside world.

Cables from the
cabinet war rooms

fed directly into
the Whitehall tunnel

where they traveled
to Trafalgar Square.

There they connected with
a tube tunnel heading

South under the River Thames.

At Waterloo station,
they switched tunnels

and headed North again
back under the river.

At Faraday telephone
exchange they

surfaced in a specially
constructed shaft.

This is Faraday building.

By linking across from Whitehall
through the tube tunnels

to Faraday, Whitehall was
now in touch with the world.

NARRATOR: But getting the
cables safely across town

was not the end of the story.

The Germans understood the
significance of Faraday

and targeted it heavily.

In one night in December
1940, almost 25,000 bombs

were dropped in the area.

The exchange urgently
needed protection.

A bunker was planned.

But we're not talking about
an underground bunker here,

we're talking in
terms of a citadel,

a bomb proof citadel being
built on the surface simply

to protect what was
inside that building.

NARRATOR: A huge
concrete fortress

began taking shape next to
Faraday to house an emergency

telephone exchange.

Built above ground
to save time, it

had foundations 10 feet thick
with walls and roof to match.

It was windowless.

Its steel doors
weighed four tons

and it was gas proof
and bomb proof.

It could hold out for
months under attack.

Under this formidable
concrete shield,

government communications
were patched into the National

Network.

They were then sent
back out of the city

via the underground railroad.

The Whitehall tunnel
and Faraday citadel

were immensely successful
in keeping Churchill's

communication channels open.

As Britain gained allies in
Russia and the United States,

this was ever more important.

But the arrival of
American troops in London

brought further security risks.

In 1942, President Roosevelt
since his commander, the man

who will lead Allied forces to
retake Europe, General Dwight

Eisenhower here to
London to run the war.

But London is one of the
most dangerous places

to be on the face of the Earth.

How do you protect
your commander?

There has to be a safe point
that will protect Eisenhower

and his communications.

NARRATOR: A new
generation of Nazi weapons

were set to flatten London.

If he was to survive and
lead the allies to victory

in Europe, Eisenhower would
need a different kind of bunker.

Far under central London is
the deepest underground bunker

built in Britain
during World War II.

This awesome bomb shelter
safely housed General Eisenhower

after his arrival in Britain,
and was the focal point

of Churchill's new
alliance with America.

For two years Britain had
fought the war on its own,

but after Pearl Harbor
Churchill wanted

to build that special
relationship with Roosevelt

into something which is a
political and strategic plan

to defeat Germany,
Japan, and Italy.

To do that, he needed to build
that informal relationship

into something where he could
have access to the President

day in day out.

NARRATOR: Eisenhower was the
key to Britain and America

fighting a successful
war as Allies.

He set up his headquarters in
the shadow of the US embassy

in Grosvenor Square.

But intelligence reports
in 1942 suggested

that the Allied Supreme
Commander would not be safe

there.

Germany had developed
lethal new rocket weapons.

Soon they would be able
to release them on London.

The effect would be devastating.

The V1 one was the first of
the German revenge weapons.

It was in all essence,
an unguided aircraft

and used a post jet
engine for propulsion.

It carried a war of
around about one ton.

It was not enormously accurate,
but it was well able to hit

a large target like London.

You could hear the
V1 coming, which

was a distinctive
nickname of the doodlebug.

It was vulnerable to being shot
down by aircraft, in particular

the latest jets.

It was also vulnerable to
anti-aircraft artillery.

That led directly to the
development of the V2

its big brother weapon.

This only carried the same size
warhead as a V1 but it's one

massive advantage was we could
not hear this weapon coming.

It was launched into
the stratosphere

and would re-enter after
the engine had burnt out.

The first indication
of a V2 attack

would be the explosion as
a weapon hit the ground.

NARRATOR: The massive potential
these rockets had for blast

and penetration caused great
concern amongst Britain's

engineers.

They feared that London's
underground shelters

were no longer safe.

One effect of detonating
occurring deep in the soil

particularly in something
like London clay

was that it confines
the explosion

and thereby intensifies, it
makes it much more powerful

than it would be if the same
explosion was to take place

in the open at ground
level with pulse of energy

this ground shock wave rushes
out at supersonic speed

away from the center
of the explosion.

So in a way London was its
own worst enemy you might say.

It had soil conditions
that allowed bombs

to get deep and also
soil that transmitted

the effects of the
explosions very efficiently.

NARRATOR: With the lethal threat
of V weapons hanging overhead,

Eisenhower was provided with
the first of a new generation

of ultra deep bunkers.

With rare permission
to gain access,

we can reveal the full extent
of Ike's London bunker.

Prewar plans to enlarge an
underground station close

to the American
embassy were co-opted,

and using established
deep tunneling techniques

a tubular bunker was developed.

Using a pair of
concrete blockhouses,

parallel shafts were dug by
hand through the London clay.

c They went to a
depth of 120 feet.

Small bore access tunnels were
then dug away from the shafts

before two large tunnels 16 feet
in diameter were constructed.

Again, the work
was done by hand.

These two larger tunnels
provided the main body

of the shelter.

Divided into two floors
they could accommodate

as many as 8,000
people Eisenhower

took possession of his bomb
proof bunker in late 1942.

60 years later, it remains off
limits and just as impregnable.

It is now London's
deepest and safest store

for confidential documents.

It hasn't changed since
Eisenhower occupied it.

This is the lift, the lift
that Dwight Eisenhower had

installed to make sure he was
safe in supervising the war

effort from this
bunker in London.

Not only is this one of
the most central points

for communications, this is
one of the deepest points

in London.

You're 120 feet
underground here.

There's no way that
the personnel can

be killed or captured.

This becomes the unseen command
post, the unseen headquarters

for Eisenhower the rest of
the American staff linking

the Americans with
their British Allies.

Eight men from the 318
special service battalion

were brought here working
through these tunnels.

In 29 days they put in
1,400 communication lines.

In normal conditions,
three months.

In less than half that
time these eight men

set up the vital link that
allows Eisenhower to reach out

to Churchill and Roosevelt and
establish the winning strategy.

NARRATOR: With sensitive
transatlantic telephone lines

passing through his bunker,
Eisenhower installed SIG Sally,

a high tech voice
scrambling system to ensure

that conversations were secure.

A hot line from the
White House was set up

to link Roosevelt directly with
Churchill in the cabinet war

rooms.

It was disguised as
Churchill's private bathroom.

Thanks to Ike's bunker the
President and Prime Minister

enjoyed unbroken and secure
communications on a day

to day basis.

This tunnel provides
the center, the center

for what will become
the unseen effort to win

the war in Europe.

NARRATOR: Ike's bunker
provided a springboard

from which he orchestrated
the fight back against Hitler.

After D-day, Allied forces
pushed into northern France.

They captured the airfields
and rocket launching sites

that had terrorized London.

From his secret
underground world,

Churchill had saved Britain
and with General Eisenhower led

the Allies to victory in Europe.

This Lost World has retained
its mystery for 60 years.

Largely absent from
the history books,

the secrets of its wartime role
are only now giving themselves

up.

Who knows how much remains
classified or to what extent

this world of
bunkers and tunnels

was extended after the war?

With the British government
facing new threats in the form

of nuclear, biological,
and chemical weapons,

and the very real dangers
of global terrorism,

it is likely that any further
secrets under London streets

will remain buried for
many years to come.