Abandoned Engineering (2016–…): Season 2, Episode 3 - The Italian Dam Disaster - full transcript
The Vajont Dam was completed in 1959 on the Vajont River, in the municipality of Erto and Casso. On 9 October 1963, during initial filling, a landslide caused a mega tsunami in the lake and 50 million cubic metres of water overtop...
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A colossal wall of
concrete, perilously wedged
between mountains...
Something so impressive
in the landscape to be built
is a real engineering feat.
..Five epic circular structures
mysteriously deserted.
Everything is curved.
There's no place you
can go and not be seen.
An American escape route
from nuclear armageddon.
You can almost envision
terrorised people trying to avoid
a nuclear explosion in a
large metropolitan area.
And an unsung
hero of world war ii.
The fact is it's got far
more historical significance
than you could ever imagine.
Once they were some of
the most advanced structures
and facilities on the planet...
At the cutting edge of
design and construction.
Today, they stand
abandoned, contaminated,
and sometimes deadly.
But who built them and how?
And why were they abandoned?
In northern Italy,
in the mountainous
province of belluno,
just 60 miles from venice is a
monumental feat of engineering.
Towering above the
town of longarone,
an 870 foot wall of concrete
spans the tree-covered cliffs
on either side of
this narrow gorge.
All of a sudden, you'd
come to an opening
with this big concrete
wall in front of you.
It's an astonishingly
impressive piece of engineering.
Even by modern standards,
it's still one of the
highest in the world.
627 feet wide at its summit,
the structure narrows
to just 89 feet at its base.
Here the wall is an
immense 72 feet thick.
Constructed using 1.3
billion cubic feet of concrete,
this fortress is not
holding back water...
But rather 9 billion cubic feet
of sedimentary rock and debris.
Standing at its
base, gazing up at it,
you would be
overwhelmed at its size.
You would be dwarfed.
But why did engineers
build this giant structure
in such a precarious location?
And why was it then abandoned?
Italy, at the end
of world war ii,
was a nation in tatters,
living under the
occupation of foreign armies.
The industrial heartland
in the northeast was vital
to the recovery of
its flagging economy.
But the region's factories
were chronically short of power.
In the 1950s, when
Italy was just coming
off the back of the
second world war,
its economy was in
a state of devastation.
Rising from the ashes,
the nation embarked
on a massive program
of industrialisation
backed by the us who saw Italy
as a valuable bulwark against
the threat of communism
from the east.
The program was
driven by hydroelectricity,
drawing on natural resources,
they harnessed the power of water
flowing from the Italian alps.
An abundance of
rivers, melting snow,
and high rainfall provided
perfect conditions.
Hydroelectric power
is incredibly attractive
in a mountainous
region because if you can
have a tight valley and
you can trap water high up,
you've suddenly got the ability
for that water to move downhill
very quickly and
generate free electricity.
In the shadow of
the mighty mount toc,
engineers identified the
deep and narrow vajont valley
as an ideal location
to store water...
Huge amounts of water
that could be used as part
of a vast hydroelectric plan.
The gorge itself was a
particularly attractive site
because of the sheer
height-ness of the gorge
and the amount of the volume
of water that you'd be able
to get for such a small
cutting off of the valley.
You can more or less throw a
stone from one side to the other.
At the core of this
hydroelectric network
was this...
The vajont dam!
A curved dam is a
very classical way
of structuring a
dam to make it strong
and resist the fluid forces
of the reservoir behind it.
It was designed to hold
a 3-mile long reservoir.
When you have a huge amount
of water pushing up against a dam
and the dam is in
the shape of an arch
and it's made from materials
that are really good in compression,
then what it means is that
the arch is really strong,
you don't need as much material
to resist that massive force,
and it stays stable.
And the clever thing is that
it channels all of that force
into the cliff faces
either side of it.
Employing over 400
labourers from the local area,
work started in 1957.
The dam was the centrepiece of
an ambitious hydroelectric network
that spanned the region.
Engineers hoped it would hold
over 6 billion
cubic feet of water
and feed 4 power stations
via 37 miles of water
delivery tunnels,
bringing much needed energy
to the cities of northern Italy.
For three years,
workers laboured
until the dam's
distinctive curvature
was finally in place.
For something that big,
something so impressive
in the landscape to be built
at that time is a
real engineering feat.
The filling of the reservoir basin
was underway in February 1960.
The moment of truth had arrived.
When you're filling
the dam up with water,
there's a lot of weight,
a lot of pressure
that's being exerted
on sides of the valleys.
But at the same time,
you're bringing water
into areas where it's not
normally there all of the time.
So, those two factors
clearly changed the way
the landscape was reacting.
For nine months, the
dam held its water level
at almost 600 feet,
part of a hydroelectric industry
that provided around
85% of the countries power.
However, a 6,000-foot crack
soon appeared across
the slope of mount toc.
And it was followed on 4 November,
1960, by a massive landslide.
24 million cubic feet of
rock slid into the reservoir
just under 2,000 feet
from the dam wall.
The water level
drastically increased
and it's threatened to
breach the crest of the dam.
Providing you keep enough space
in the level of the reservoir
and this slow rock
mass moves into it,
it would not necessarily be
a problem, they can control it.
Engineers lowered
the water level,
easing pressure on
the surrounding cliffs
and decided to employ a
fundamental principal of physics
to control any further
land movement.
So, if you imagine
taking a metal spoon
and then you bend it back
and forth a number of times,
eventually that
spoon is going to snap.
So, by raising and lowering
the level of the water
in the reservoir, they
changed the pressure
exerted on the soil.
Using the water level in a dam to
control the surrounding land mass
is a risky operation.
It makes it virtually
impossible to predict
how fast the
landslide might react.
But for three years, the
technique appeared to pay off.
The dam successfully supplied
water to four power stations,
producing much needed
hydroelectricity for the cities
of northern Italy.
In April, 1963, with
the landslide seemingly
under control, engineers
filled the reservoir
behind the dam to capacity
at 2,345 feet above sea level.
The lesson that civil engineers
are reminded of time
and again is to be acutely
aware of the natural surroundings
and the geology in which
you are building your structure
because, if you don't
take heed of those lessons,
the price you pay
could be devastating.
Disaster soon struck.
At 10:39pm on 9 October, 1963,
over 9 billion cubic feet
of rock broke away
from mount toc.
Hurtling down at 68 miles an
hour, the destructive debris smashed
into the reservoir below.
It wasn't just the mass
of earth that slid away
into the reservoir, it
was the ferocious speed
at which it came.
45 seconds for effectively
half of the mountainside
to drop into the water.
It cascades into the water
and causes big waves.
Now, if you imagine a bath,
you've got a wall on one side
of the bath and you've
got a lip the other side,
you jump into that bath,
you're gonna cause
waves in two directions.
One will hit the wall
and bounce back,
that's exactly what happened
in one part of the valley.
The other's going to
actually go over the rim.
It is literally like an
airborne Tsunami.
Over 800 million
cubic feet of water
became a massive wave,
a wave 820 feet high with
the village of longarone
directly in its path.
A massive amount
of water forced down
such a tight gorge, it
displaced all of that air
and it was almost
like a shockwave of air
hit the village directly
before the water did
and started destroying
some of the buildings.
And then next minute,
a wall of water hits you.
It's got rocks in it.
It's got trees in it.
It is like liquid sandpaper and
it just wipes the village clean.
Barely four minutes
after the landslide began,
most of the town was obliterated
by the subsequent wall of water.
It's one of the worst natural
disasters in European history.
Nearly 2,000
people lost their lives.
The tragic irony of this story
is that whilst the
villages below the dam
were completely destroyed
by the onrush of water,
the dam itself remained
completely intact.
I guess that's testament
really to the quality of the design
and build of the dam.
It was just a dam
built in the wrong place.
Ultimately, the reservoir
was filled with debris
and this spelt the end
for the great vajont dam.
It was then abandoned.
Today, the vajont dam stands
isolated in the rocky landscape,
scattered with hints
of its tragic past.
It forms a permanent reminder
of humanity's underestimation
of the forces of nature.
From an engineering perspective,
the vajont dam
should have become
one of the most
impressive dams in history.
Instead, it's become
one of the most infamous.
It's an unfortunate tragedy.
But from tragedy, we learn
about how the landscape can react
and, hopefully, we can
mitigate against such tragedies
in the future.
Nearly 5,500 miles
away on the Cuban island,
Isla de la juventud
or isle of youth
sprawls a group of
peculiar structures.
Laid out like five spots on
a die, these circular giants
are a 174 feet in diameter
and tower over a 4 million
square foot open plane.
If you were flying
over the island
and you looked down
and saw these five
yellow circular buildings,
you would think,
"what, is this some sort
of industrial beehive?
Is it a power plant?
No, it's not really shaped like
a conventional power plant.
What is it?"
The four outer buildings,
each 98 feet high,
consists of six levels, yet
inside there are no floors,
only a colossal empty space.
Light pierces the
dank grim interior
through 465
rectangular openings.
Had a pretty sinister reputation
amongst the local residents
and the conditions inside
were just atrocious.
The most bizarre feature
is a short lighthouse
like tower standing in
the centre of each building.
When you walk
inside, you're instantly
struck by the fact
that there are no
straight corridors,
everything is curved.
You are constantly in
view from somewhere else.
There's no place where
you can go and not be seen.
And that was all by design.
What happened in these
strange hollowed out structures
on this remote island?
And why was this site abandoned?
In the 1920s, Cuba
was experiencing
a period of economic development
set against a backdrop
of political corruption.
Cuban president Gerardo machado
had ordered a major
construction program
to modernise the nation.
He was also determined to
stay in power at all costs...
And maintain ultimate control
over his political opponents,
not only physically
but psychologically.
To help him achieve
this, the dictator turned
to this extraordinary
island complex,
presidio modelo,
Cuba's model prison.
It was created and
conceived by a Cuban dictator
who drew upon an 18th century
social reformer whole ethos
was that behaviour could
be modified via surveillance.
The brainchild of
English philosopher
and prison reformer
Jeremy Bentham,
it was part of his
panopticon theory.
It was a design intended
to rehabilitate prisoners.
Surveillance was conducted
from an observation tower
at the centre of the structure.
And this was key to
the building's design.
You have a central
observation tower.
And then you have
a circular structure
that surrounds that tower,
which is where all the cells are.
And the idea is that all
the prisoners in their cells
are not really sure whether
the guards are looking
at them or looking at
their neighbour downstairs
and so they have to be on
their best behaviour all the time.
That design inside the prison
certainly feels quite
menacing to me.
That central tower with
guards who theoretically
then can be observing
what's going on
in all of those prison
cells at any time.
I mean, it certainly
feels quite 'big brother',
something you might have
read in George orwell's '1984'.
Construction began in
1926 using inmate labour.
As each building was
completed, it was populated.
President machado's motive was
one of control rather than reform.
But as well as creating fear and
paranoia amongst the prisoners,
the structures also had
an engineering benefit.
This philosophy of
prisoner observation
actually lead to a very
interesting structural advantage,
and this advantage is the
fact that having a circular wall
going all the way round
meant that there was
an inherent stiffness
in the structure that meant
you don't need to put
intermediate floors in
to keep the structure stable.
By the 1930s, presidio
modelo was fully operational,
with each building
containing 465 cells,
the complex was designed to
house less than 3,000 inmates.
Every cell faced inwards,
pointing towards the
central guard tower
and most incredibly,
there were no cell doors.
The architecture itself
was designed to control
the behaviour of
those imprisoned.
Gualdemar llevaron
was a guard here
and kept watch
over the prisoners.
(Speaks foreign language)
Unseen by the captives
who never knew if and
when they were being watch,
guards entered the observation
tower through a 98 foot long
underground tunnel.
Hidden from view, the
guards could keep an eye
on the prisoners
through narrow slits
in the top of the tower.
You're constantly being watched,
not only by the prison
guards from the central tower
but other prisoners whose cell
was only a few feet from yours.
There's no privacy whatsoever.
And it must have generated
a whole lot of paranoia.
The large open space
within each building
made surveillance easy
and the result was the
inmates increasingly
policed themselves.
Even at meal times,
within the central dining hall,
there was no respite
from the constant silence
or watchful gaze of the guards.
You would think
that leaving your cell
where you're constantly
under surveillance
and going for a meal would
be a nice experience of chatting
with your fellow cellmates.
Not at all.
You went to a
building that was called
the hall of the 3,000 silences,
and it was aptly named
because you weren't
allowed to speak.
Imagine how
oppressive that would be.
You're being watched
all day in your cell,
and now you're having a
meal and you can't even speak.
Ironically, its cutting edge
design originally conceived
to rehabilitate convicts
earned the prison a reputation
for horror
and the prison relied on
more than watchful guards
to keep inmates under control.
There are all sorts of
legends about the prison,
including the fact that
there were crocodiles
in the ponds and lakes
on the perimeter
of the prison itself.
(Speaks foreign language)
President machado was
unable to hold on to power.
But the prison
continued for 27 years
and saw multiple regime changes.
But then in 1953, its
most notorious inmate
entered its doors.
The communist revolutionary
fidel Castro served two years here
for attempting to overthrow
the ruthless dictator
fulgencio Batista.
By his side was
his brother, Raul.
Though themselves treated
humanely as political prisoners,
fidel Castro witnessed firsthand
the psychological success
of the jail's design and
realised the potential
for control and paranoia.
It was knowledge and
experience he went on to exploit
when he overthrew Batista in
1959 to become leader of Cuba.
When he comes into
power, he doesn't, you know,
destroy the place, he
doesn't knock it down.
No!
He then sends his
political opponents there.
I think that's quite rich.
For eight years, Castro
used presidio modelo
to Bury his enemies.
But these political prisoners
posed serious threats to security.
One dramatic plan hatched
during the CIA-backed
bay of pigs invasion in 1961
involved destroying the prison
using the underground
guard tunnels.
There was actually
a plan to blow up
these structures
using that tunnel
by actually packing
it in with explosives.
And thinking about the sheer
size and scale of these structures,
the fact that they had this inherent
stiffness because of its shape,
I think it would have been
quite difficult to actually bring
that structure down.
Dynamite couldn't destroy
presidio modelo but Castro could.
The prison had a
capacity for 3,000 inmates,
but he packed it with
double that number.
Something that was
originally designed
to house up to 3,000 prisoners
was now housing anything
from 6,000 to 8,000 prisoners.
Riots were commonplace,
fights, unsanitary conditions,
and the place was just hellish.
This measure of
overpopulation backfired.
Cramped, dirty, and overcrowded,
it encouraged growing resistance
from the inmates
and was increasingly
seen by Castro
as a security risk.
Cuba's model prison
closed its doors in 1967
and Castro's enemies were
dispersed to other prisons.
It just stops to function.
And it's a little bit
dilapidated anyways,
but the political
climate had changed
and it no longer had
a purpose to serve.
The unique design and
function of the prison
made the buildings virtually
impossible to re-purpose.
After 41 years of oppression and
paranoia, they were abandoned.
The gigantic circular cell
blocks of presidio modelo
are now decaying shells
and stark reminders
of Cuba's political turmoil.
While Raul Castro,
in early 2018,
remains president of Cuba,
the hospital building honours
its most famous inmate,
his brother, fidel.
But these structures
also represent the closest
anyone has come to
turning Jeremy Bentham's
panopticon concept
into a reality.
Today, the prison is a museum.
It's a school.
It's a research centre.
And that's about right.
Because what it really was,
historically, I think we look
back at it as an innovative
attempt at social reform.
It was all about surveillance,
and actually, it was
quite ahead of its time.
Over 2,000 miles away,
across the Gulf of Mexico,
a barren landscape hides
an enigmatic enterprise.
High above Los Angeles
is a closed off road,
winding 900 feet up in
the San Gabriel mountains.
It leads to a mysterious
masonry arch over 20 feet high,
driven into its slopes.
But what is this
an entrance for?
And where does it lead?
When you first see these
entrances opening up
on the sides of the
mountain, you can't fathom
why the effort was gone to to
build these huge big tunnels.
For me, you'd expect to see
some kind of railway or a road
or something coming out
of it, but none of that's there.
In fact, it becomes
quite mysterious.
A tiny light at the end of
the dark tunnel suggests
this structure runs directly
through the mountain.
As you're standing
there, you appreciate
what an impressive
feat of engineering it is
and how difficult it would
have been to have made.
The interesting thing
is there's a lot more
to this story than
meets the eye.
Why did someone go
to the trouble of building
this immense tunnel only
to seemingly down tools
and walk away?
Why was it abandoned?
In the 1950s, the
cold war loomed large
over a paranoid america.
The nation feared
not only an invasion
but nuclear attack
from the Soviet union.
La's many aerospace facilities
and military bases made
the city a prime target.
America's early warning
systems could recognise potential
threats hours before impact.
But in that small window of
time, how would the authorities
save the then population
of nearly 2 million people?
The la authorities began to
wonder how would we evacuate?
In the 1950s, there might
have been 20 minutes
or half an hour's warning of
an impending nuclear attack
on Los Angeles.
Any evacuation for the
people of Los Angeles
had to be prepared in advance.
(Siren blares)
Man: In this troubled
stage of the atomic age,
our very lives may depend
on always being alert.
If the Soviets launched a
nuclear strike on Los Angeles,
a credible escape plan
would need to be set in place
for its citizens.
To get out of Los Angeles,
you've got to get through
the hills and the mountains
and out the other side.
That means either twisting
and turning through canyons
or tunnelling right on through.
So, a 25-mile
shortcut was devised.
Designed to speed
the city's residents
through the San Gabriel mountains
via multiple tunnels to the safety
of the mojave desert...
This path to safety
was shoemaker canyon road,
better known as
armageddon highway.
The armageddon highway
would work in premise
that the entire
population of Los Angeles
would get in their cars
and exit away from the city
and the eventual
destruction that would happen.
This was part of the
culture at the time,
this fear that the other
guy has the technology
and can strike us and
that we need to have
some kind of way
to protect ourselves.
Once complete, these tunnels
were designed to form a costly
but potentially vital evacuation
route high above the city.
Given the cold war in the 1950s,
everyone was afraid of
nuclear war and in that,
the response of the
government was to drill a hole
through a mountain such that
the population of Los Angeles
could escape given
all out nuclear war.
One Soviet nuclear weapon
air bursted over Los Angeles
could kill more people than
were killed in Hiroshima,
Nagasaki combined.
(Loud explosion)
But carving a road
through a mountain
of hard rock is difficult
at the best of times.
And in the volatile region of
the San Gabriel mountains,
with severe heat in the
summer, avalanches in the winter,
and the continuous
threat of landslides,
the challenge was
all the more extreme.
Construction started in 1956.
To hold up in this
harsh environment,
interlocking steel beams
and moulded concrete
were needed to shore
up critical stress points
of the 1,000 foot long tunnel.
You would have thought that
a project of this importance
would have warranted
professionals.
But what they got
instead was a chain gang.
I mean, they literally asked
the inmates of nearby prisons
to go up into the
mountains, build a road.
Not only was their
heart probably not into it,
but they didn't
have the skill sets.
With unskilled workers
struggling to cut through solid rock,
the two-Lane escape highway
made agonisingly slow progress.
It was only completed in
1961, a full five years later.
The fact that they were prepared
to blast their way
through these mountains
just shows that level of panic
and urgency that was felt to give
the people of a major
us city a means of escape
and a means to get to safety.
To be inside of it, you
can almost envision
terrorised people trying to
avoid a nuclear explosion
in a large metropolitan area.
The route to salvation
had finally made progress
cutting through the mountains,
but engineers realised
there was a fundamental
flaw with their plan.
Predictably, progress
on the road was slow
and that led to la
authorities to say, "hang on.
Let's have a rethink."
"What we're really doing
is creating a potential
very huge traffic
jam in the future.
Do we really wanna do that?
It's going to be world war III
just trying to get to that road."
Given Los Angeles's
notoriously congested highways,
the premise that the
armageddon highway
would have been able to
safely transport the denizens
of Los Angeles to safety
is basically ludicrous,
especially when viewed
from a modern perspective
of gridlocked Los
Angeles highways.
And with the advent of faster
intercontinental ballistic missiles
giving even less warning,
escape from the Soviet nuclear
fallout became impossible.
La's evacuation plans
through shoemaker canyon
were now useless.
When you really think about it,
that given the warning
time, which is next to nil,
it's basically impossible to
evacuate major urban areas.
Now, I think, by the late
1960s, they're thinking,
"whoa, this is just a
whopping "waste of money.
It's just not worth it."
In 1969, 13 years after
the project commenced,
the Los Angeles authorities finally
called time on the escape route.
All that had been achieved
of the 25 mile shortcut
through shoemaker
canyon was a 4.5 mile road
and two tunnels
that led to nowhere.
Today, the road and tunnels
still stand on the slopes
of shoemaker canyon
but are rarely visited.
They survive as a monument
to cold war paranoia
and the real dangers felt
by the citizens of
la half a century ago.
Today, the most striking remains
of the road are its tunnels.
And it makes you appreciate
the fact that this is what
cold war paranoia
forced us to do.
Thousands of miles
across the Atlantic ocean,
on the south coast of
england is the seaside village
of littlestone.
In the rough seas of
the English channel,
a mysterious 200 foot long
and 32 foot wide steel structure
lies partially
submerged in its waters.
If you're one of the
thousands of holidaymakers
playing on the beach
at littlestone or even out
for an early morning walk,
you'd quite happily dismiss it
as part of a sunken
barge or something.
The fact is it's got far
more historical significance
than you could ever imagine.
At low tide,
a large 6,000 tonne block
of concrete is revealed.
Yet the object's humble
appearance belies
its engineering and
historic importance.
I can imagine that the
engineers at the time
were a little bit worried
that this was gonna be
a big risk to take.
But how did this
simple-looking structure
play a key role
in one of the largest
invasions in history?
Why is it here?
And why was it abandoned?
In 1944, a force of unprecedented
scale was being mobilised
across southern england.
Millions of soldiers backed up
by 12,000 aircraft and an armada
of 7,000 ships, all
preparing for d day.
It was a phenomenal
logistical undertaking.
And while the coastline was
heavily defended by German forces,
the challenge was not simply
landing this massive invasion force.
It becomes obvious
to the British,
to the Americans that
it's immensely difficult
to give an army the supplies
it needs to keep on fighting
once you've thrown
them onto a beach.
The allies developed a unique
and ambitious plan to ensure
they could maintain
the flow of supplies.
We, the allies, brought
together technology
from the field of civil
engineering, military engineer,
materials science
to create something
that had not existed
before, an entire harbour
that can 60 miles
to where it's needed.
Codenamed operation mulberry,
a critical element of these giant
floating harbours was
the Phoenix caisson.
The Phoenix caisson
is but a tiny element
of an incredibly complex
but at the same time
brilliantly simple plan
to take a self-assembling
floating harbour over to
the beaches of normandy
for the d day landings.
These watertight structures
were designed to provide
valuable protection
for the artificial ports.
(Gun fires)
But with wartime
steel shortages,
engineers turned to a more
readily available material.
The idea of using
floating concrete blocks
was actually nothing new.
Concrete vessels have been
made since the late 1800s.
What was different was using
them to create your own harbour
the size of any modern
international ferry port.
Each concrete block
was five storeys high,
intended to join
together in a chain,
they would serve
as a protective barrier
to the floating
mulberry harbours.
The purpose of the
Phoenix caissons
was to act as a breakwater
as the outer limits of the harbour
within which you'd have much
calmer waters to land the supplies,
the vehicles, and
the troops required
on the beaches of normandy
for the d day landing.
The caisson is made of a
reinforced concrete shell,
but nine hollow compartments
ensure its buoyancy.
Equipped with sea
valves, each compartment
can be flooded again and
the block sunk into position.
The Phoenix caisson
itself rates quite high
in terms of the
engineering ingenuity
involved in world war ii, right?
The engineers knew
they had a job to do,
and they solved it very
efficiently and very beautifully.
Construction began in late
1943, workers were tasked
with making 212 caissons
with only 6 months to complete
this colossal task.
At 12 different coastal
locations around britain,
45,000 labourers worked
in complete secrecy.
In total, this
endeavour required
over 8 million cubic
feet of concrete
and 31,000 tonnes of steel.
A lot of people would
be out there fighting
the wars and so on, so you
get the unskilled labour in
and you can
actually train them up
quite quickly to fix steel,
to pour the concrete
'cause actually
the process of doing that
is not terribly technical
or complicated.
While it was impossible
to fully conceal a project
of this magnitude from the
Germans, it was essential that Hitler
remain unsure of both when and
where the invasion would come.
To help keep these
preparations under wraps,
engineers used the caisson's
design and function to great effect.
To keep the plans
for the d day landings
a complete secret
from the Germans,
once the Phoenix caissons had
arrived at their assembly point
on the south coast, they
were sunk to keep them
out of view below
the water level.
The idea being then that
you'd pump the water out
to float them up before
being towed over to France.
In a mere 6 months,
212 Phoenix caissons
were successfully
built and many sunk
in the English channel
in preparation for d day.
Now, true to their name,
they were to rise again
to play their part in
the invasion of France.
Of course, there's
always the chance
that once you've
done the first sink,
it actually does what it's supposed
to do and sticks into the ground
and then stays there nice and
stable against the sea currents.
160,000 men crossed the
channel on 6 June, 1944.
Within 24 hours, the
beachheads were secured.
The allies now had
to land enough arms
and supplies to equip an
army that would liberate France
and ultimately Europe.
The Phoenix
caissons were refloated
and sailed across the
normandy beaches to create
the artificial ports that would
make this epic feat possible.
The Phoenix caissons
had a crew of six men.
I mean imagine that,
being a crewman on board
a floating piece of concrete.
As they were towed along
by tug boats on board,
there was a little
accommodation hut,
a life raft in case
anything went wrong,
but they also had anti-aircraft guns
just in case they came under attack.
At a rate of 3 knots, it
took 30 hours to float
146 of these giant concrete
caissons to the beachheads,
codenamed Omaha and gold.
Sunk into position, they functioned
as a 2 mile long breakwater
and outer wall of
the artificial ports,
fulfilling their crucial
role in operation mulberry.
The concrete boxes
of the Phoenix caisson,
in and of themselves,
are not terribly impressive
when described
as a concrete box.
But the usage of that
caisson in landing material,
men, and equipment
on the beaches of France
was tremendously important.
The mulberry harbour
made up an area of 500 acres
that was protected by a
ring of Phoenix caissons.
Critically, they calmed
the waters so boats
could safely dock
at the floating piers
whether at high or low tide.
Having taken the
Germans by surprise,
the Phoenix caissons
evaded serious bombardment.
Designed to last only 90
days, the mulberry harbour
at gold beach was still
going strong 10 months later.
With the help of the
Phoenix caissons,
the allies were able to unload
a staggering 2.5 million men,
0.5 vehicles, and 4 million
tonnes of goods and supplies.
For the engineers involved,
the mulberry harbours
were a phenomenal success.
The d day landings
have been described
as one of the most monumental
events in modern history.
The Phoenix caissons
are a huge part of that.
Yet not all the caissons
were successful.
Many didn't make it.
No matter how
hard engineers tried,
the caisson beached here
off the coast of littlestone
refused to budge and
remained fully submerged.
The only problem
was, in certain areas,
the seabed was extremely
sticky and, try as they might,
the Phoenix
caisson at littlestone
just couldn't be floated again.
Unable to rise from
its watery grave off
the shore of england,
it still lies abandoned.
These simple-looking
concrete blocks
played a crucial role
in the allies successfully
retaking France
and winning world war ii.
They are a monument
to military ingenuity
and inspiration to future
generations of civil engineers.
The story of the Phoenix caisson
at littlestone in a way
is a story of failure.
It never made its
way over to France.
But if you were able to get it
off the seabed today and float it,
it would still be able to do
the job it was designed to do.
And that's testimony
to quality engineering
and a sound plan.
Now abandoned, they were once
on the cutting edge
of human engineering.
Within these decaying structures
are the echoes of history.
They speak of war and
terror but also of exploration
and human endeavour.
Captioned by
ai-media ai-media. TV
---
A colossal wall of
concrete, perilously wedged
between mountains...
Something so impressive
in the landscape to be built
is a real engineering feat.
..Five epic circular structures
mysteriously deserted.
Everything is curved.
There's no place you
can go and not be seen.
An American escape route
from nuclear armageddon.
You can almost envision
terrorised people trying to avoid
a nuclear explosion in a
large metropolitan area.
And an unsung
hero of world war ii.
The fact is it's got far
more historical significance
than you could ever imagine.
Once they were some of
the most advanced structures
and facilities on the planet...
At the cutting edge of
design and construction.
Today, they stand
abandoned, contaminated,
and sometimes deadly.
But who built them and how?
And why were they abandoned?
In northern Italy,
in the mountainous
province of belluno,
just 60 miles from venice is a
monumental feat of engineering.
Towering above the
town of longarone,
an 870 foot wall of concrete
spans the tree-covered cliffs
on either side of
this narrow gorge.
All of a sudden, you'd
come to an opening
with this big concrete
wall in front of you.
It's an astonishingly
impressive piece of engineering.
Even by modern standards,
it's still one of the
highest in the world.
627 feet wide at its summit,
the structure narrows
to just 89 feet at its base.
Here the wall is an
immense 72 feet thick.
Constructed using 1.3
billion cubic feet of concrete,
this fortress is not
holding back water...
But rather 9 billion cubic feet
of sedimentary rock and debris.
Standing at its
base, gazing up at it,
you would be
overwhelmed at its size.
You would be dwarfed.
But why did engineers
build this giant structure
in such a precarious location?
And why was it then abandoned?
Italy, at the end
of world war ii,
was a nation in tatters,
living under the
occupation of foreign armies.
The industrial heartland
in the northeast was vital
to the recovery of
its flagging economy.
But the region's factories
were chronically short of power.
In the 1950s, when
Italy was just coming
off the back of the
second world war,
its economy was in
a state of devastation.
Rising from the ashes,
the nation embarked
on a massive program
of industrialisation
backed by the us who saw Italy
as a valuable bulwark against
the threat of communism
from the east.
The program was
driven by hydroelectricity,
drawing on natural resources,
they harnessed the power of water
flowing from the Italian alps.
An abundance of
rivers, melting snow,
and high rainfall provided
perfect conditions.
Hydroelectric power
is incredibly attractive
in a mountainous
region because if you can
have a tight valley and
you can trap water high up,
you've suddenly got the ability
for that water to move downhill
very quickly and
generate free electricity.
In the shadow of
the mighty mount toc,
engineers identified the
deep and narrow vajont valley
as an ideal location
to store water...
Huge amounts of water
that could be used as part
of a vast hydroelectric plan.
The gorge itself was a
particularly attractive site
because of the sheer
height-ness of the gorge
and the amount of the volume
of water that you'd be able
to get for such a small
cutting off of the valley.
You can more or less throw a
stone from one side to the other.
At the core of this
hydroelectric network
was this...
The vajont dam!
A curved dam is a
very classical way
of structuring a
dam to make it strong
and resist the fluid forces
of the reservoir behind it.
It was designed to hold
a 3-mile long reservoir.
When you have a huge amount
of water pushing up against a dam
and the dam is in
the shape of an arch
and it's made from materials
that are really good in compression,
then what it means is that
the arch is really strong,
you don't need as much material
to resist that massive force,
and it stays stable.
And the clever thing is that
it channels all of that force
into the cliff faces
either side of it.
Employing over 400
labourers from the local area,
work started in 1957.
The dam was the centrepiece of
an ambitious hydroelectric network
that spanned the region.
Engineers hoped it would hold
over 6 billion
cubic feet of water
and feed 4 power stations
via 37 miles of water
delivery tunnels,
bringing much needed energy
to the cities of northern Italy.
For three years,
workers laboured
until the dam's
distinctive curvature
was finally in place.
For something that big,
something so impressive
in the landscape to be built
at that time is a
real engineering feat.
The filling of the reservoir basin
was underway in February 1960.
The moment of truth had arrived.
When you're filling
the dam up with water,
there's a lot of weight,
a lot of pressure
that's being exerted
on sides of the valleys.
But at the same time,
you're bringing water
into areas where it's not
normally there all of the time.
So, those two factors
clearly changed the way
the landscape was reacting.
For nine months, the
dam held its water level
at almost 600 feet,
part of a hydroelectric industry
that provided around
85% of the countries power.
However, a 6,000-foot crack
soon appeared across
the slope of mount toc.
And it was followed on 4 November,
1960, by a massive landslide.
24 million cubic feet of
rock slid into the reservoir
just under 2,000 feet
from the dam wall.
The water level
drastically increased
and it's threatened to
breach the crest of the dam.
Providing you keep enough space
in the level of the reservoir
and this slow rock
mass moves into it,
it would not necessarily be
a problem, they can control it.
Engineers lowered
the water level,
easing pressure on
the surrounding cliffs
and decided to employ a
fundamental principal of physics
to control any further
land movement.
So, if you imagine
taking a metal spoon
and then you bend it back
and forth a number of times,
eventually that
spoon is going to snap.
So, by raising and lowering
the level of the water
in the reservoir, they
changed the pressure
exerted on the soil.
Using the water level in a dam to
control the surrounding land mass
is a risky operation.
It makes it virtually
impossible to predict
how fast the
landslide might react.
But for three years, the
technique appeared to pay off.
The dam successfully supplied
water to four power stations,
producing much needed
hydroelectricity for the cities
of northern Italy.
In April, 1963, with
the landslide seemingly
under control, engineers
filled the reservoir
behind the dam to capacity
at 2,345 feet above sea level.
The lesson that civil engineers
are reminded of time
and again is to be acutely
aware of the natural surroundings
and the geology in which
you are building your structure
because, if you don't
take heed of those lessons,
the price you pay
could be devastating.
Disaster soon struck.
At 10:39pm on 9 October, 1963,
over 9 billion cubic feet
of rock broke away
from mount toc.
Hurtling down at 68 miles an
hour, the destructive debris smashed
into the reservoir below.
It wasn't just the mass
of earth that slid away
into the reservoir, it
was the ferocious speed
at which it came.
45 seconds for effectively
half of the mountainside
to drop into the water.
It cascades into the water
and causes big waves.
Now, if you imagine a bath,
you've got a wall on one side
of the bath and you've
got a lip the other side,
you jump into that bath,
you're gonna cause
waves in two directions.
One will hit the wall
and bounce back,
that's exactly what happened
in one part of the valley.
The other's going to
actually go over the rim.
It is literally like an
airborne Tsunami.
Over 800 million
cubic feet of water
became a massive wave,
a wave 820 feet high with
the village of longarone
directly in its path.
A massive amount
of water forced down
such a tight gorge, it
displaced all of that air
and it was almost
like a shockwave of air
hit the village directly
before the water did
and started destroying
some of the buildings.
And then next minute,
a wall of water hits you.
It's got rocks in it.
It's got trees in it.
It is like liquid sandpaper and
it just wipes the village clean.
Barely four minutes
after the landslide began,
most of the town was obliterated
by the subsequent wall of water.
It's one of the worst natural
disasters in European history.
Nearly 2,000
people lost their lives.
The tragic irony of this story
is that whilst the
villages below the dam
were completely destroyed
by the onrush of water,
the dam itself remained
completely intact.
I guess that's testament
really to the quality of the design
and build of the dam.
It was just a dam
built in the wrong place.
Ultimately, the reservoir
was filled with debris
and this spelt the end
for the great vajont dam.
It was then abandoned.
Today, the vajont dam stands
isolated in the rocky landscape,
scattered with hints
of its tragic past.
It forms a permanent reminder
of humanity's underestimation
of the forces of nature.
From an engineering perspective,
the vajont dam
should have become
one of the most
impressive dams in history.
Instead, it's become
one of the most infamous.
It's an unfortunate tragedy.
But from tragedy, we learn
about how the landscape can react
and, hopefully, we can
mitigate against such tragedies
in the future.
Nearly 5,500 miles
away on the Cuban island,
Isla de la juventud
or isle of youth
sprawls a group of
peculiar structures.
Laid out like five spots on
a die, these circular giants
are a 174 feet in diameter
and tower over a 4 million
square foot open plane.
If you were flying
over the island
and you looked down
and saw these five
yellow circular buildings,
you would think,
"what, is this some sort
of industrial beehive?
Is it a power plant?
No, it's not really shaped like
a conventional power plant.
What is it?"
The four outer buildings,
each 98 feet high,
consists of six levels, yet
inside there are no floors,
only a colossal empty space.
Light pierces the
dank grim interior
through 465
rectangular openings.
Had a pretty sinister reputation
amongst the local residents
and the conditions inside
were just atrocious.
The most bizarre feature
is a short lighthouse
like tower standing in
the centre of each building.
When you walk
inside, you're instantly
struck by the fact
that there are no
straight corridors,
everything is curved.
You are constantly in
view from somewhere else.
There's no place where
you can go and not be seen.
And that was all by design.
What happened in these
strange hollowed out structures
on this remote island?
And why was this site abandoned?
In the 1920s, Cuba
was experiencing
a period of economic development
set against a backdrop
of political corruption.
Cuban president Gerardo machado
had ordered a major
construction program
to modernise the nation.
He was also determined to
stay in power at all costs...
And maintain ultimate control
over his political opponents,
not only physically
but psychologically.
To help him achieve
this, the dictator turned
to this extraordinary
island complex,
presidio modelo,
Cuba's model prison.
It was created and
conceived by a Cuban dictator
who drew upon an 18th century
social reformer whole ethos
was that behaviour could
be modified via surveillance.
The brainchild of
English philosopher
and prison reformer
Jeremy Bentham,
it was part of his
panopticon theory.
It was a design intended
to rehabilitate prisoners.
Surveillance was conducted
from an observation tower
at the centre of the structure.
And this was key to
the building's design.
You have a central
observation tower.
And then you have
a circular structure
that surrounds that tower,
which is where all the cells are.
And the idea is that all
the prisoners in their cells
are not really sure whether
the guards are looking
at them or looking at
their neighbour downstairs
and so they have to be on
their best behaviour all the time.
That design inside the prison
certainly feels quite
menacing to me.
That central tower with
guards who theoretically
then can be observing
what's going on
in all of those prison
cells at any time.
I mean, it certainly
feels quite 'big brother',
something you might have
read in George orwell's '1984'.
Construction began in
1926 using inmate labour.
As each building was
completed, it was populated.
President machado's motive was
one of control rather than reform.
But as well as creating fear and
paranoia amongst the prisoners,
the structures also had
an engineering benefit.
This philosophy of
prisoner observation
actually lead to a very
interesting structural advantage,
and this advantage is the
fact that having a circular wall
going all the way round
meant that there was
an inherent stiffness
in the structure that meant
you don't need to put
intermediate floors in
to keep the structure stable.
By the 1930s, presidio
modelo was fully operational,
with each building
containing 465 cells,
the complex was designed to
house less than 3,000 inmates.
Every cell faced inwards,
pointing towards the
central guard tower
and most incredibly,
there were no cell doors.
The architecture itself
was designed to control
the behaviour of
those imprisoned.
Gualdemar llevaron
was a guard here
and kept watch
over the prisoners.
(Speaks foreign language)
Unseen by the captives
who never knew if and
when they were being watch,
guards entered the observation
tower through a 98 foot long
underground tunnel.
Hidden from view, the
guards could keep an eye
on the prisoners
through narrow slits
in the top of the tower.
You're constantly being watched,
not only by the prison
guards from the central tower
but other prisoners whose cell
was only a few feet from yours.
There's no privacy whatsoever.
And it must have generated
a whole lot of paranoia.
The large open space
within each building
made surveillance easy
and the result was the
inmates increasingly
policed themselves.
Even at meal times,
within the central dining hall,
there was no respite
from the constant silence
or watchful gaze of the guards.
You would think
that leaving your cell
where you're constantly
under surveillance
and going for a meal would
be a nice experience of chatting
with your fellow cellmates.
Not at all.
You went to a
building that was called
the hall of the 3,000 silences,
and it was aptly named
because you weren't
allowed to speak.
Imagine how
oppressive that would be.
You're being watched
all day in your cell,
and now you're having a
meal and you can't even speak.
Ironically, its cutting edge
design originally conceived
to rehabilitate convicts
earned the prison a reputation
for horror
and the prison relied on
more than watchful guards
to keep inmates under control.
There are all sorts of
legends about the prison,
including the fact that
there were crocodiles
in the ponds and lakes
on the perimeter
of the prison itself.
(Speaks foreign language)
President machado was
unable to hold on to power.
But the prison
continued for 27 years
and saw multiple regime changes.
But then in 1953, its
most notorious inmate
entered its doors.
The communist revolutionary
fidel Castro served two years here
for attempting to overthrow
the ruthless dictator
fulgencio Batista.
By his side was
his brother, Raul.
Though themselves treated
humanely as political prisoners,
fidel Castro witnessed firsthand
the psychological success
of the jail's design and
realised the potential
for control and paranoia.
It was knowledge and
experience he went on to exploit
when he overthrew Batista in
1959 to become leader of Cuba.
When he comes into
power, he doesn't, you know,
destroy the place, he
doesn't knock it down.
No!
He then sends his
political opponents there.
I think that's quite rich.
For eight years, Castro
used presidio modelo
to Bury his enemies.
But these political prisoners
posed serious threats to security.
One dramatic plan hatched
during the CIA-backed
bay of pigs invasion in 1961
involved destroying the prison
using the underground
guard tunnels.
There was actually
a plan to blow up
these structures
using that tunnel
by actually packing
it in with explosives.
And thinking about the sheer
size and scale of these structures,
the fact that they had this inherent
stiffness because of its shape,
I think it would have been
quite difficult to actually bring
that structure down.
Dynamite couldn't destroy
presidio modelo but Castro could.
The prison had a
capacity for 3,000 inmates,
but he packed it with
double that number.
Something that was
originally designed
to house up to 3,000 prisoners
was now housing anything
from 6,000 to 8,000 prisoners.
Riots were commonplace,
fights, unsanitary conditions,
and the place was just hellish.
This measure of
overpopulation backfired.
Cramped, dirty, and overcrowded,
it encouraged growing resistance
from the inmates
and was increasingly
seen by Castro
as a security risk.
Cuba's model prison
closed its doors in 1967
and Castro's enemies were
dispersed to other prisons.
It just stops to function.
And it's a little bit
dilapidated anyways,
but the political
climate had changed
and it no longer had
a purpose to serve.
The unique design and
function of the prison
made the buildings virtually
impossible to re-purpose.
After 41 years of oppression and
paranoia, they were abandoned.
The gigantic circular cell
blocks of presidio modelo
are now decaying shells
and stark reminders
of Cuba's political turmoil.
While Raul Castro,
in early 2018,
remains president of Cuba,
the hospital building honours
its most famous inmate,
his brother, fidel.
But these structures
also represent the closest
anyone has come to
turning Jeremy Bentham's
panopticon concept
into a reality.
Today, the prison is a museum.
It's a school.
It's a research centre.
And that's about right.
Because what it really was,
historically, I think we look
back at it as an innovative
attempt at social reform.
It was all about surveillance,
and actually, it was
quite ahead of its time.
Over 2,000 miles away,
across the Gulf of Mexico,
a barren landscape hides
an enigmatic enterprise.
High above Los Angeles
is a closed off road,
winding 900 feet up in
the San Gabriel mountains.
It leads to a mysterious
masonry arch over 20 feet high,
driven into its slopes.
But what is this
an entrance for?
And where does it lead?
When you first see these
entrances opening up
on the sides of the
mountain, you can't fathom
why the effort was gone to to
build these huge big tunnels.
For me, you'd expect to see
some kind of railway or a road
or something coming out
of it, but none of that's there.
In fact, it becomes
quite mysterious.
A tiny light at the end of
the dark tunnel suggests
this structure runs directly
through the mountain.
As you're standing
there, you appreciate
what an impressive
feat of engineering it is
and how difficult it would
have been to have made.
The interesting thing
is there's a lot more
to this story than
meets the eye.
Why did someone go
to the trouble of building
this immense tunnel only
to seemingly down tools
and walk away?
Why was it abandoned?
In the 1950s, the
cold war loomed large
over a paranoid america.
The nation feared
not only an invasion
but nuclear attack
from the Soviet union.
La's many aerospace facilities
and military bases made
the city a prime target.
America's early warning
systems could recognise potential
threats hours before impact.
But in that small window of
time, how would the authorities
save the then population
of nearly 2 million people?
The la authorities began to
wonder how would we evacuate?
In the 1950s, there might
have been 20 minutes
or half an hour's warning of
an impending nuclear attack
on Los Angeles.
Any evacuation for the
people of Los Angeles
had to be prepared in advance.
(Siren blares)
Man: In this troubled
stage of the atomic age,
our very lives may depend
on always being alert.
If the Soviets launched a
nuclear strike on Los Angeles,
a credible escape plan
would need to be set in place
for its citizens.
To get out of Los Angeles,
you've got to get through
the hills and the mountains
and out the other side.
That means either twisting
and turning through canyons
or tunnelling right on through.
So, a 25-mile
shortcut was devised.
Designed to speed
the city's residents
through the San Gabriel mountains
via multiple tunnels to the safety
of the mojave desert...
This path to safety
was shoemaker canyon road,
better known as
armageddon highway.
The armageddon highway
would work in premise
that the entire
population of Los Angeles
would get in their cars
and exit away from the city
and the eventual
destruction that would happen.
This was part of the
culture at the time,
this fear that the other
guy has the technology
and can strike us and
that we need to have
some kind of way
to protect ourselves.
Once complete, these tunnels
were designed to form a costly
but potentially vital evacuation
route high above the city.
Given the cold war in the 1950s,
everyone was afraid of
nuclear war and in that,
the response of the
government was to drill a hole
through a mountain such that
the population of Los Angeles
could escape given
all out nuclear war.
One Soviet nuclear weapon
air bursted over Los Angeles
could kill more people than
were killed in Hiroshima,
Nagasaki combined.
(Loud explosion)
But carving a road
through a mountain
of hard rock is difficult
at the best of times.
And in the volatile region of
the San Gabriel mountains,
with severe heat in the
summer, avalanches in the winter,
and the continuous
threat of landslides,
the challenge was
all the more extreme.
Construction started in 1956.
To hold up in this
harsh environment,
interlocking steel beams
and moulded concrete
were needed to shore
up critical stress points
of the 1,000 foot long tunnel.
You would have thought that
a project of this importance
would have warranted
professionals.
But what they got
instead was a chain gang.
I mean, they literally asked
the inmates of nearby prisons
to go up into the
mountains, build a road.
Not only was their
heart probably not into it,
but they didn't
have the skill sets.
With unskilled workers
struggling to cut through solid rock,
the two-Lane escape highway
made agonisingly slow progress.
It was only completed in
1961, a full five years later.
The fact that they were prepared
to blast their way
through these mountains
just shows that level of panic
and urgency that was felt to give
the people of a major
us city a means of escape
and a means to get to safety.
To be inside of it, you
can almost envision
terrorised people trying to
avoid a nuclear explosion
in a large metropolitan area.
The route to salvation
had finally made progress
cutting through the mountains,
but engineers realised
there was a fundamental
flaw with their plan.
Predictably, progress
on the road was slow
and that led to la
authorities to say, "hang on.
Let's have a rethink."
"What we're really doing
is creating a potential
very huge traffic
jam in the future.
Do we really wanna do that?
It's going to be world war III
just trying to get to that road."
Given Los Angeles's
notoriously congested highways,
the premise that the
armageddon highway
would have been able to
safely transport the denizens
of Los Angeles to safety
is basically ludicrous,
especially when viewed
from a modern perspective
of gridlocked Los
Angeles highways.
And with the advent of faster
intercontinental ballistic missiles
giving even less warning,
escape from the Soviet nuclear
fallout became impossible.
La's evacuation plans
through shoemaker canyon
were now useless.
When you really think about it,
that given the warning
time, which is next to nil,
it's basically impossible to
evacuate major urban areas.
Now, I think, by the late
1960s, they're thinking,
"whoa, this is just a
whopping "waste of money.
It's just not worth it."
In 1969, 13 years after
the project commenced,
the Los Angeles authorities finally
called time on the escape route.
All that had been achieved
of the 25 mile shortcut
through shoemaker
canyon was a 4.5 mile road
and two tunnels
that led to nowhere.
Today, the road and tunnels
still stand on the slopes
of shoemaker canyon
but are rarely visited.
They survive as a monument
to cold war paranoia
and the real dangers felt
by the citizens of
la half a century ago.
Today, the most striking remains
of the road are its tunnels.
And it makes you appreciate
the fact that this is what
cold war paranoia
forced us to do.
Thousands of miles
across the Atlantic ocean,
on the south coast of
england is the seaside village
of littlestone.
In the rough seas of
the English channel,
a mysterious 200 foot long
and 32 foot wide steel structure
lies partially
submerged in its waters.
If you're one of the
thousands of holidaymakers
playing on the beach
at littlestone or even out
for an early morning walk,
you'd quite happily dismiss it
as part of a sunken
barge or something.
The fact is it's got far
more historical significance
than you could ever imagine.
At low tide,
a large 6,000 tonne block
of concrete is revealed.
Yet the object's humble
appearance belies
its engineering and
historic importance.
I can imagine that the
engineers at the time
were a little bit worried
that this was gonna be
a big risk to take.
But how did this
simple-looking structure
play a key role
in one of the largest
invasions in history?
Why is it here?
And why was it abandoned?
In 1944, a force of unprecedented
scale was being mobilised
across southern england.
Millions of soldiers backed up
by 12,000 aircraft and an armada
of 7,000 ships, all
preparing for d day.
It was a phenomenal
logistical undertaking.
And while the coastline was
heavily defended by German forces,
the challenge was not simply
landing this massive invasion force.
It becomes obvious
to the British,
to the Americans that
it's immensely difficult
to give an army the supplies
it needs to keep on fighting
once you've thrown
them onto a beach.
The allies developed a unique
and ambitious plan to ensure
they could maintain
the flow of supplies.
We, the allies, brought
together technology
from the field of civil
engineering, military engineer,
materials science
to create something
that had not existed
before, an entire harbour
that can 60 miles
to where it's needed.
Codenamed operation mulberry,
a critical element of these giant
floating harbours was
the Phoenix caisson.
The Phoenix caisson
is but a tiny element
of an incredibly complex
but at the same time
brilliantly simple plan
to take a self-assembling
floating harbour over to
the beaches of normandy
for the d day landings.
These watertight structures
were designed to provide
valuable protection
for the artificial ports.
(Gun fires)
But with wartime
steel shortages,
engineers turned to a more
readily available material.
The idea of using
floating concrete blocks
was actually nothing new.
Concrete vessels have been
made since the late 1800s.
What was different was using
them to create your own harbour
the size of any modern
international ferry port.
Each concrete block
was five storeys high,
intended to join
together in a chain,
they would serve
as a protective barrier
to the floating
mulberry harbours.
The purpose of the
Phoenix caissons
was to act as a breakwater
as the outer limits of the harbour
within which you'd have much
calmer waters to land the supplies,
the vehicles, and
the troops required
on the beaches of normandy
for the d day landing.
The caisson is made of a
reinforced concrete shell,
but nine hollow compartments
ensure its buoyancy.
Equipped with sea
valves, each compartment
can be flooded again and
the block sunk into position.
The Phoenix caisson
itself rates quite high
in terms of the
engineering ingenuity
involved in world war ii, right?
The engineers knew
they had a job to do,
and they solved it very
efficiently and very beautifully.
Construction began in late
1943, workers were tasked
with making 212 caissons
with only 6 months to complete
this colossal task.
At 12 different coastal
locations around britain,
45,000 labourers worked
in complete secrecy.
In total, this
endeavour required
over 8 million cubic
feet of concrete
and 31,000 tonnes of steel.
A lot of people would
be out there fighting
the wars and so on, so you
get the unskilled labour in
and you can
actually train them up
quite quickly to fix steel,
to pour the concrete
'cause actually
the process of doing that
is not terribly technical
or complicated.
While it was impossible
to fully conceal a project
of this magnitude from the
Germans, it was essential that Hitler
remain unsure of both when and
where the invasion would come.
To help keep these
preparations under wraps,
engineers used the caisson's
design and function to great effect.
To keep the plans
for the d day landings
a complete secret
from the Germans,
once the Phoenix caissons had
arrived at their assembly point
on the south coast, they
were sunk to keep them
out of view below
the water level.
The idea being then that
you'd pump the water out
to float them up before
being towed over to France.
In a mere 6 months,
212 Phoenix caissons
were successfully
built and many sunk
in the English channel
in preparation for d day.
Now, true to their name,
they were to rise again
to play their part in
the invasion of France.
Of course, there's
always the chance
that once you've
done the first sink,
it actually does what it's supposed
to do and sticks into the ground
and then stays there nice and
stable against the sea currents.
160,000 men crossed the
channel on 6 June, 1944.
Within 24 hours, the
beachheads were secured.
The allies now had
to land enough arms
and supplies to equip an
army that would liberate France
and ultimately Europe.
The Phoenix
caissons were refloated
and sailed across the
normandy beaches to create
the artificial ports that would
make this epic feat possible.
The Phoenix caissons
had a crew of six men.
I mean imagine that,
being a crewman on board
a floating piece of concrete.
As they were towed along
by tug boats on board,
there was a little
accommodation hut,
a life raft in case
anything went wrong,
but they also had anti-aircraft guns
just in case they came under attack.
At a rate of 3 knots, it
took 30 hours to float
146 of these giant concrete
caissons to the beachheads,
codenamed Omaha and gold.
Sunk into position, they functioned
as a 2 mile long breakwater
and outer wall of
the artificial ports,
fulfilling their crucial
role in operation mulberry.
The concrete boxes
of the Phoenix caisson,
in and of themselves,
are not terribly impressive
when described
as a concrete box.
But the usage of that
caisson in landing material,
men, and equipment
on the beaches of France
was tremendously important.
The mulberry harbour
made up an area of 500 acres
that was protected by a
ring of Phoenix caissons.
Critically, they calmed
the waters so boats
could safely dock
at the floating piers
whether at high or low tide.
Having taken the
Germans by surprise,
the Phoenix caissons
evaded serious bombardment.
Designed to last only 90
days, the mulberry harbour
at gold beach was still
going strong 10 months later.
With the help of the
Phoenix caissons,
the allies were able to unload
a staggering 2.5 million men,
0.5 vehicles, and 4 million
tonnes of goods and supplies.
For the engineers involved,
the mulberry harbours
were a phenomenal success.
The d day landings
have been described
as one of the most monumental
events in modern history.
The Phoenix caissons
are a huge part of that.
Yet not all the caissons
were successful.
Many didn't make it.
No matter how
hard engineers tried,
the caisson beached here
off the coast of littlestone
refused to budge and
remained fully submerged.
The only problem
was, in certain areas,
the seabed was extremely
sticky and, try as they might,
the Phoenix
caisson at littlestone
just couldn't be floated again.
Unable to rise from
its watery grave off
the shore of england,
it still lies abandoned.
These simple-looking
concrete blocks
played a crucial role
in the allies successfully
retaking France
and winning world war ii.
They are a monument
to military ingenuity
and inspiration to future
generations of civil engineers.
The story of the Phoenix caisson
at littlestone in a way
is a story of failure.
It never made its
way over to France.
But if you were able to get it
off the seabed today and float it,
it would still be able to do
the job it was designed to do.
And that's testimony
to quality engineering
and a sound plan.
Now abandoned, they were once
on the cutting edge
of human engineering.
Within these decaying structures
are the echoes of history.
They speak of war and
terror but also of exploration
and human endeavour.
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