NARRATOR: Almost a century since the outbreak of World War I,
archaeologists in Europe are uncovering
a unique time capsule from that conflict.
(artillery fire)
(explosions)
(gunfire)
For eight months, NOVA has been in Belgium
following a massive archaeological dig,
and it's revealing how World War I
became a technological arms race.
For four years, 70 million men fought
in the first ever industrialized war.
Nine million died as new and more powerful weapons
enabled both sides to fight each other
to a bloody standstill in trenches,
many of them stretching across France and Belgium.
(artillery fire)
(explosion)
It was a war that came to epitomize
man's inhumanity to man.
MAN: It must be a gas shell.
MAN: Phosgene is not an instant gas.
It can take 24 hours to come into effect.
A horrible, horrible,
and painful, agonizing way to die.
NARRATOR: The dig is on a site
where the entire history of that war
is uniquely captured.
We discover how the conflict went underground
to blast the w out of its trench-bound deadlock.
Stop, stop, stop.
Is it possible to turn the camera?
NARRATOR: It's here Allied troops
would secretly tunnel beneath enemy lines
and create the biggest explosion the world had ever seen.
(explosion)
NAATOR: With time and weather against them,
surrounded by unexploded ammunition,
can archaeologists tell the story
of this "Secret Tunnel Warfare"?
Right now, on NOVA.
Major funding for NOVA is provided by the following...
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Supporting NOVA and promoting public understanding of science.
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Thank you.
a region of Belgium on the border of France,
but almost 100 years ago,
the site of the biggest explosion
the world had ever seen.
(explosion)
During World War I, this was the Western Front,
where German and Allied soldiers faced each other
in a hellish killing field.
For over three years, the battle lines barely moved
as the war took lives by the hundreds of thousands.
(explosion)
The stalemate drove each side
to develop increasingly deadly weaponry,
triggering a high-speed, technological arms race
that gave birth to modern mechanized warfare.
Now, prompted by a project
to lay a two-kilometer pipeline around the town of Messines,
a team of archaeologists has been called in to clear a path
through the remains of these long buried trenches
where so many fought and died.
What they are discovering, buried in this unique site,
is a snapshot of the first modern arms race.
MAN: The round one here is German,
and the pointed one is British.
NARRATOR: Miraculously preserved for a century,
these trenches hold the entire technological history
of World War I, from horses to tanks.
Racing against the construction schedule,
they hope to preserve invaluable clues
and to discover which technological innovations
helped to finally break the deadlock.
Just outside Messines, work has begun on the new pipeline.
The undercarriages of the heavy equipment
are fitted with armor plating,
and the glass has been reinforced
because nearly 100 years after the war,
the ground here is still full of unexploded shells.
It is rich, if dangerous, pickings
for Belgian scientist Simon Verdegem,
who leads the archaeological dig.
Working alongside him are ex-Belgian military personnel
trained in bomb disposal.
But one of their first discoveries offers evidence
of the decidedly low-tech beginnings of the conflict.
SIMON VERDEGEM: It looks like the jaw of a horse.
You can see the jaw, the end of the jaw.
Here, you have the teeth.
This is the front.
There are some more teeth over here that came loose.
That one belongs here.
It's definitely from a horse.
NARRATOR: World War I began in August 1914,
when Germany invaded Belgium and France.
The Allies pushed the Germans back,
digging in at Messines and elsewhere.
At the beginning of the war,
the British army had 165,000 horses on its books,
and in the slaughter that followed,
it was not only the soldiers who would die.
(flies buzzing)
VERDEGEM: You can see a row of teeth.
NARRATOR: Horses and mules were used extensively in the war,
from pulling artillery
to carrying water to the troops at the front.
They were the war horses.
At the start of the conflict,
mounted cavalry were expected to lead the fight.
It was a British cavalry unit, the 9th Lancers,
who were holding part of the town of Messines
in the autumn of 1914.
The Germans who were approaching the town
were intent on removing them.
ALEXANDRA CHURCHILL: The Lancers are in trenches to the east of Messines,
and prior to the German attack, they were being heavily shelled.
(artillery fire)
(explosion)
It's quite a miserable position
for them to be in, because not only have they got
to think about themselves and protect themselves,
but they've got horses to look after as well.
It's effectively like dragging a small child
around the Western Front because you've got to constantly
give care and attention to the animal,
but at the same time, you're still expected
to do everything that an infantry battalion is doing.
NARRATOR: Among the officers of the 9th Lancers defending the town
were two brothers in their early 20s:
Douglas and Lenny Harvey.
At dawn on the 31st of October,
the Germans launched their push for Messines.
(explosions)
CHURCHILL: For the 9th Lancers, it's just horrific.
The Germans successfully push the Lancers back,
and they're forced to retreat into the town itself.
And they're getting fired on
from in front, behind, to the side
from machine guns, rifles, and artillery shells as well,
so it's a pretty dire situation.
NARRATOR: The 9th Lancers regrouped at the cemetery
before being pushed from the town,
which then fell to the Germans.
(explosion)
The battle had claimed the lives
of both Douglas and Lenny Harvey.
The war was barely three months old.
Having taken Messines,
the Germans now set about consolidating their gains
by digging trenches to protect their troops.
The front line was etched into the battlefield.
Only days into the dig,
archaeologists uncover the floor of a World War I German trench,
part of a huge network which defined the war.
MAN: Both sides dug in.
They dug trenches to protect their troops.
The Germans dug in at Messines, and the British just below,
separated by just a short stretch of no-man's land
that could be just tens of yards apart.
And by early 1915, this massive network of trenches
now stretched from the North Sea coast
right through and down to the Swiss border--
450 miles of continuous trenches.
(explosions)
NARRATOR: Both sides tried with brute force
to break this deadlock on the Western Front.
When British troops went over the top of the trenches
at the Battle of the Somme,
they suffered nearly 60,000 casualties
on the first day alone.
At the battle of Verdun, over 700,000 fell
over ten months of fighting.
But for the time being, nothing defeated the trenches.
(engine whirring)
At Messines, the team has been struggling on the site.
A day's worth of rain
has transformed the dig into a quagmire.
It's a scene that would be all too familiar
to the soldiers of the First World War.
The archaeologists bail out the trenches
with their safety helmets,
as soldiers would have done with their steel helmets.
CHURCHILL: In the winter of 1914, '15,
if it wasn't raining, it was snowing,
so consequently, in the trenches,
it was muddy beyond belief.
They were sinking up to their knees
and some even deeper trying to get through them.
It got so bad that they had to abandon trenches,
and men were chancing
going over the top and risking sniper fire
to be able to not suffer the discomfort
of getting covered in this mud
and having to wade knee deep through it.
If we look at the map,
just ahead of us, probably on the rise...
NARRATOR: Helping the archaeologists at the Messines dig
is the discovery of a highly detailed German map
of the trench systems.
Marked on the trench map
in front of both the German and British positions
are belts of barbed wire.
Barbed wire was an unexpectedly effective and ferocious barrier,
feared and hated by the soldiers who had to get through it.
VERDEGEM: We've found this almost complete roll of British barbed wire.
REED: It's certainly fearful-looking barbs, but you're right,
it definitely looks like British wire.
Barbed wire was an American invention
used for agricultural purposes--
to contain cattle on the big, open prairies.
But by the American civil war, it had a military use.
It could be used to defend positions on the battle field.
And that use increased
throughout the course of the next century
until the time of the First World War,
when it was used on a massive scale,
literally thousands of miles of barbed wire fences.
A lot of people think,
when they find pieces of barbed wire like this,
"Is it modern agricultural wire?"
But as soon as you put your fingers on it, you can see,
because if it's a modern barbed wire fence,
we can probably get our whole hand in there,
but you can barely get two fingers
because they didn't want you to be able
to get some grip on it so you could cut it.
The Devil's rope, as it became known,
was used on an increasing scale.
There was some evil-looking barbed wire,
even razor wire being used by the Germans
in some parts of their line,
and troops became obsessed with it,
became obsessed with hanging on the barbed wire.
NARRATOR: Barbed wire would stop advancing troops.
There, they would face another American invention:
the Maxim machine gun, which was used by both sides.
The Maxim gun was the first self-powered machine gun.
When a bullet is fired, it produces a recoil.
A spring uses that energy to eject the spent casing
and to fire the next bullet.
Although the Maxim gun was heavy and required water-cooling,
it could fire up to 600 rounds per minute,
equivalent to 30 contemporary rifles.
Stuck on the barbed wire, soldiers would be slaughtered
by the efficient killing machine.
At Bayernwald, a German front line trench
has been restored in the same spot
where it was first dug on the Messines Ridge
in November 1914.
MAN: This is a really good example of the kind of thing
that they would have to build and live in
on a day-to-day basis.
NARRATOR: Military historian Professor Peter Doyle
has studied the distinctive way
the Germans constructed their trenches early in the war.
DOYLE: The trenches themselves
had the sides held back by wattle and brushwood,
and what they would have done is to bind this wood together
to hold back the mud
which was continually collapsing into these trenches.
(explosion)
NARRATOR: Mud wasn't the German's only problem.
The British were constantly shelling the trenches,
and the real danger in this early war trench design
was when a shell fell right inside.
DOYLE: What we can see in this trench are some fatal flaws.
The trench is quite wide, which is good--
it gives real access-- but it's also quite long.
And if a shell exploded here,
the blast radius would kill most of the occupants.
So this is a pretty dangerous place to be.
I can't imagine that the Germans
would really like sitting in this trench,
waiting for this kind of thing to happen.
(artillery fire)
NARRATOR: Artillery was the biggest killer in World War I.
60% of all casualties were caused by shellfire.
For almost three years at Messines,
there were no major assaults; just the day-to-day bombardment
that slowly ground the soldiers down.
MAN: Total silence would have been very, very rare.
(explosion)
It's very difficult for people to imagine
just how assailed your senses would have been,
particularly with shellfire.
And a lot of nervous disorders suffered by Great War soldiers,
such as shell shock, were a consequence
not so much of mental injury,
but actually the way that shelling
affected the nervous system and indeed the mind.
NARRATOR: Something at the dig is becoming apparent.
Each of the circles being marked by spray paint
is the in-filled crater from an exploded British shell.
And the numbered markers show
they are getting closer together.
For the archaeologists, it's a clue they're closing in
on an important target for the British artillery.
The British were aiming for the German front line,
and as the team digs, they begin to unearth
a complete section of a First World War fighting trench.
DOYLE: It's just phenomenal.
NARRATOR: Professor Peter Doyle has come to the Messines dig
to meet Simon Verdegem and see the newly uncovered trench.
DOYLE: Just by excavating a trench as small as this,
we get a real sense of the true nature of trench warfare,
and it's pretty exciting to see that here.
NARRATOR: We know what the trench should look like
from this rare wartime photograph
of the trench that connects to it.
DOYLE: Shall we get out and look at the other side?
NARRATOR: But what the new trench reveals
is that unlike the trenches at Bayernwald,
this trench had been blown to pieces.
VERDEGEM: And the explosion actually pushed the side of trench
into the middle.
You can see some of the floorboards sticking out.
NARRATOR: The trench at some stage received a direct hit
from a British high explosive shell.
(explosion)
Amazingly, the top of the shell
is still lodged among the collapsed timbers.
Isn't that fantastic that an impact fuse...
And actually the result of the impact,
and it's frozen in time.
VERDEGEM: Everything that's underneath those boards
hasn't moved since the explosion.
REED: I've never seen anything like that.
NARRATOR: But why was only a small section of the trench destroyed?
This wartime reconnaissance film
shows that the trenches were constructed
with a series of rectangular switchbacks,
like the top of a castle wall.
It was a design adopted by both sides
to protect soldiers in the trenches on either side
of a direct hit.
DOYLE: This is a much more of a secure way of digging a trench
because any kind of explosion
would be kept in one area of the trench.
NARRATOR: In the stalemate of trench warfare at Messines,
the killing continued.
Among the graves in this cemetery
below the German trenches is an unusual marker:
that of Robert Cuthbert,
a former accountant and member of the New York Yacht Club.
He died when he was 47, old for a soldier.
Cuthbert was one of at least five Americans buried here
who had joined the Allied cause
more than two years before America entered the war.
The Germans were determined to hold on to the trenches
on the high ground of the Messines Ridge.
(artillery fire)
But the growing intensity of the British artillery bombardment
was forcing them to build stronger defenses
and entrench even deeper.
It's a fact borne out
by the archaeologists' latest discovery:
an extraordinarily well-preserved trench
leading to a concrete structure-- a German bunker.
The bunker's walls are over 30 inches thick,
strong enough to shelter infantry
from all but the biggest shells.
If the Allies were to take the ridge,
dozens of bunkers like this would have to be neutralized.
But for Simon Verdegem and the team,
the most exciting discovery is the best-preserved
and deepest trench ever uncovered in Flanders.
VERDEGEM: We are standing in the main trench
leading towards the entrance of the bunker.
We are actually standing on the original floorboards now,
which are in a remarkable good condition.
It's amazing, the condition of this trench.
I've never seen an original trench of this depth
ever uncovered on a battlefield, or ever been in one.
VERDEGEM: Over here, we have two things which are very special.
On our left side,
we have a board to put rifle butts in.
So this is a rifle rack?
Yeah, exactly.
It's a rifle rack which could hold six rifles,
which we think indicates that
this bunker had room for six soldiers.
REED: Incredible to see here
these original boards and the original steps
going down into this First World War
dug out with the floorboards still there.
Incredible.
NARRATOR: In one of the trenches,
the archaeologists find evidence that the Germans
were fully expecting to fight at close quarters.
VERDEGEM: It looks like hand grenades,
German hand grenades.
We have one, two, three, four, five, six, seven, eight, nine,
at least ten hand grenades.
NARRATOR: Because the grenades are still live,
Verdegem calls the Belgian bomb squad,
who will come and make them safe.
100 years on, these weapons are still lethal.
ALEX TURNER: Hand grenades were the weapon of choice for an infantryman
in the First World War in the attack,
and here we have a German stick grenade,
known as a potato masher, and same nickname in German--
"Kartoffelstampfer."
And it has an explosive charge on the end of a wooden stick
which allows you more leverage in the throw
and allows you to lob it more accurately.
NARRATOR: The stick grenade was introduced in 1915,
d its simple design lasted into World War II.
It works by placing a detonator in an explosive charge
packed within the head.
The detonator is attached to a cord
which runs through the hollow base.
Pulling the cord set a five-second fuse burning.
It has an idiot's guide on the handle
which tells you how long the fuse is going to last
once you've initiated it.
You unscrew the base and a little string emerges,
which when tugged effectively strikes a match
in the base of the grenade head there
and gives you five-and-a-half seconds
to lean back, take an aimed throw,
and lob it in the direction of attack.
(explosion)
NARRATOR: But there was one weapon used at Messines
that more than any other would come to symbolize
the real horror of the First World War.
VERDEGEM: It might be a gas shell.
NARRATOR: In June 1916, the Germans released phosgene,
a type of poisonous chlorine gas,
from canisters sited here above the dig.
Heavier than air, it flowed down the 500 yards of no-man's land
towards the British trenches
at the bottom of the Messines Ridge.
Just after midnight, British sentries observed
the gas clouds in the bright moonlight.
(rattling)
The noise of the gas rattle
alerted the British troops that an attack was imminent.
They would have had just minutes
to put on their protective gas hoods
equipment which would bring its own set of problems.
MAN: It's absolutely terrible.
You can't see-- it mists up almost instantly.
The eye pieces go everywhere,
and as soon as you breathe the wrong way, it steams up.
It's already hot in here now.
You've lost all your side vision.
You can't see any more than what's right in front of you.
You'd be turning to your right, turning to your left
to try to see where the enemy is coming from.
NARRATOR: The release of gas usually preceded a German attack.
So that night, British artillery laid down a barrage
in order to prevent any German troops
from reaching their lines.
(artillery fire)
David Whithorn is a military historian.
What he has just done-- removed his gas hood--
is exactly what some of the British troops did that night,
some 20 minutes after the gas release,
believing the attack to be over.
Unbeknownst to the British,
the Germans were about to launch a second wave of poisonous gas,
this time catching many soldiers unaware.
By the time they got their gas hoods back on,
for many, it was too late.
The first thing you did,
you could deposit the contents of your stomach,
vomiting into your gas hood.
So your gas hood would be half-full of your own vomit,
and maybe the breathing tube
would be blocked with your own vomit.
It must have been absolute hell of earth.
Wearing this, fighting for your breath,
awful smell inside, fear of the gas,
fear of the Germans coming.
You then seriously consider ripping this from your head,
and when you did so, you'd be then obviously faced
with the toxic gases in their purest form.
Some soldiers fought so much to get their gas masks off
that they tore their own throats apart.
Phosgene is not an instant gas.
It can take 24 hours to come into effect.
It's slow, it's insidious, it worsens.
You drown on dry land.
You know you are going to die.
A horrible, horrible, painful and agonizing way to die.
NARRATOR: Of the 500 casualties of the German gas attack,
many are buried here, just yards from where they fell.
At the dig site, Simon Verdegem and the team
have uncovered something completely unexpected.
Here just below the surface
are the remains not of a trench, but a tunnel.
VERDEGEM: The tunnel was completely a surprise for us.
We didn't know about the existence, wasn't on any map,
neither on any aerial photographs,
so it was actually kind of luck that we even found it.
NARRATOR: The tunnel is a sign that the Allied attempt
to break the impregnable German defenses at Messines
had moved into a much more deadly phase.
The team removes the roof to enter the tunnel
for the first time since it was abandoned.
VERDEGEM: The tunnel is in almost perfect condition.
The walls, the roof, the floor is as it was 100 years ago.
You can even see on some points the nails sticking out
to put some kind of lights on there.
It's an amazing feeling to be able to walk through a tunnel
that had been there for over 100 years
and probably not been entered since 1917.
These are the roof parts from the tunnel behind me.
Yeah, they're extremely thick pieces of timber,
incredibly good condition.
Yeah, it's amazing and it's still heavy
so it didn't dry out or anything.
Pre-made by the look of it.
All pre-made, so they all have the same size.
They are all as long and as wide as the others.
The construction system that the Germans have used here
to build these tunnels is to dig underground.
This isn't cut and cover,
they've actually tunneled underneath the surface--
in this case, part of the battlefield,
part of the road-- and constructed a tunnel there,
which has then been lined
with these prefabricated timber sections.
A section to go on the floor, two uprights, and then a roof
so it can be put in place very quickly.
NARRATOR: The sophisticated prefabricated tunnel
is evidence of a widespread underground war,
which reached its peak here in Messines in 1917.
It was a type of warfare the Allies would develop
on a massive scale.
What they were trying to achieve by going underground
was to blow up the enemy
basically to try and destroy strong-points.
NARRATOR: If the Allies were going
to break the deadlock of trench warfare
they would have to take the German strong points.
We're just moving up from the British frontline
in front of the hills of Messines--
this is the Messines ridge.
And as we rise up this slope, we can really get the sense
of where the Germans were sitting at the top of this ridge
and they would have been looking down upon the British below
and any of the enemy that wanted to try and attack
these German trenches would have to labor up this slope
just as we're trying to labor up it in a modern car.
NARRATOR: So in January 1916, the Allies forged a new plan.
If they couldn't get across no-man's land,
they would go beneath it.
They would dig tunnels towards key targets
and plant explosives below them.
Then, they would simultaneously detonate the charges
right under the Germans.
It was called "earthquaking the ridge."
DOYLE: The British were in a really good situation
because they were in the lower ground
and the Germans were in the high ground.
That meant that for the British, all they had to do in effect
was dig in a straight line.
And if they could go in a shallow tunnel downwards
they could undermine the Germans.
NARRATOR: The plan called for up to 49 tunnels dug under the ridge,
ending in 25 mines placed under the German strongholds.
The British tunnelers-- called moles--
included many ex-coal miners.
All were volunteers,
but because they were specialists
working at an unusually perilous job,
they were each paid three times more than an ordinary soldier.
DOYLE: They were using a technique called clay-kicking.
The man who was doing the kicking--
that is doing the digging--
would lie back on a wooden construction.
He would be starting at the base of a face
and using a tool called a grafting tool,
he would sort of work out a clod of earth, clod of clay,
which would then be taken away.
And the British used it to great effect here in Messines.
NARRATOR: The tunnelers experimented with various charges
before settling on a new explosive called ammonal--
a mix of aluminum powder the fuel for the explosion,
and ammonium nitrate,
the chemical combustion that powers the blast.
Ammonal was three times more powerful than gunpowder,
and considerably less volatile.
It could not be set off by fire or bullets.
Detonators were placed in some of the boxes,
which were electrically fired from back in the trenches.
The shockwave from the initial explosions
would set off the other ammonal charges.
The drawback with ammonal
was that it degraded when it was wet,
so the explosive was sealed in rubberized tins and boxes
before being laid in vast quantities
at the end of the tunnels.
The farm of Petite Douve is just 500 yards from the dig site.
During the war, Petite Douve was a stronghold
on the German frontline.
It was also the destination for one of the British tunnels,
which branched under the farm, its ends packed with explosives.
Where I'm stood now is on the old German frontline
on the western extremity of the Petite Douve strong point.
The British frontline was 500 meters or so west,
just below those farm buildings,
and that's where the British started their mine
in and among where those farm buildings are now
And they would have kicked and dug underground
pretty much beneath our feet as we are now, 520 meters
for the principle charge
just over my left shoulder under the strong point.
NARRATOR: But here at Petite Douve in 1916,
the British tunnelers weren't having it all their own way.
The Germans knew of the underground plan
and were digging their own tunnels
in an attempt to kill the British miners.
JOHAN VANDEWALLE: These are all pieces of bricks from the farm.
NARRATOR: Johan Vandewalle is Belgium's leading expert
on the underground war.
Oh, I think this is the place.
So what have we got here then, Johan?
What's this, is this the shaft?
This is the spot.
Literally here is one of the German countermining shafts
that goes straight down-- what, 20 meters?
Exactly.
Okay, that's it.
NARRATOR: The team is here to explore the opening
to the last surviving German mineshaft
from the Messines battlefield.
So this is the first time that anyone has really--
since the war-- done any work on this,
tried to identify how deep it is, what was going on.
It's like an exploration into the past isn't it?
Yeah.
NARRATOR: As the British were tunneling towards Petite Douve,
the Germans were sinking vertical shafts
to get beneath the British tunnels,
where they would lay their own explosives called camouflets
in an attempt to kill or disrupt the British working above them.
DOYLE: Petite Douve is an interesting aspect of the Messines battle
because here we can see the Germans seeking out the British.
This is a rare survivor.
Really we're not going to get this chance again.
NARRATOR: The German mine shaft could be as deep as 25 meters,
but what the team doesn't know is whether it will be blocked
or if the water will be clear enough to actually see anything.
DOYLE: It's so tantalizing
just to get things appearing out of the murk.
Yes, what is that?
NARRATOR: As the camera descends,
from the gloom emerges the timber sides
of the German mineshaft.
DOYLE: We're just seeing the shaft as we go down
and we're getting some idea of features in the side wall.
It's a real testimony to the men who built this
that its still here and it's still in good condition.
Nobody was before here.
So nobody has ever seen this kind of thing,
this is the first time anybody's ever seen this since 1917.
This is interesting this is porcelain for electricity?
MAN: Yes.
NARRATOR: The mineshaft would have had electrical lighting,
and pumps to keep the water out.
They also find pipes used to take fresh air
to the German miners below.
Are we seeing the ladder there, do you think?
NARRATOR: Attached to the wall is the steel ladder
used to descend to the bottom of the shaft.
From there, tunnels would lead underneath
the British miners close by.
VANDEWALLE: Can you imagine a ladder?
With your muddy hands pulling down on a steel ladder.
You couldn't really imagine descending on that ladder,
could you, down to 20 meters.
Stop, stop, stop.
Is it possible to turn the camera?
NARRATOR: As they reach the bottom of the shaft,
Johan thinks he has found something.
So we are on the west side now this is the west.
Try to keep this depth, but just try to..
DOYLE: Gently turning it around so that we might...
This looks like for me the gallery to no-man's land.
It is possible to come a little bit back?
Stop because this is to no man's land
So this is the direction towards the British.
NARRATOR: This tantalizing glimpse into the darkness
reveals the entry of the German's fighting gallery:
an offensive trench dug to try and attack the British miners
in this underground war.
The British miners finished the main tunnel at Petite Douve
in August 1916,
placing 25 tons of ammonal beneath the farm.
They then set about digging a branch tunnel
to lay a secondary mine nearby.
But using sensitive listening equipment,
the British tunnelers picked up the unmistakable sound
of German voices only yards away.
TURNER: The British heard them.
This is a blind form of warfare digging towards one another
detecting purely by sound.
So the British heard they had been detected
and blew what's called a camouflet, a disruption mine,
which was only moderately successful,
and of course that provoked a response.
NARRATOR: The Germans responded with their own explosive charge,
claiming the lives of at least three tunnelers,
whose bodies still remain entombed under the farm.
Their names are recorded on the Ploegsteert Memorial close by.
Of the 25 mines planned by the British under the Messines Ridge
Petite Douve was the only one lost to enemy action--
a fact that still resonates today.
TURNER: The main charge at Petite Douve, all 50,000 pounds of it,
was never blown, it was abandoned.
So it's still lying dormant 25 meters below ground
very close to where we're stood now.
NARRATOR: The unsettling fact is that beneath this small Belgian farm
is potentially the world's biggest unexploded bomb.
Earthquaking the Messines Ridge with mines
was part of a much more ambitious plan.
British high command believed that the key to unlocking
the Western Front lay here in Flanders.
Breaking through the line at Messines
would be the first part of an operation,
which they hoped would lead to the defeat of Germany.
In his preparation for the battle,
the British general Sir Herbert Plumer
was leaving nothing to chance.
TURNER: He pulled in 2,250 artillery pieces,
which for a seven-day bombardment
consumed three-and-a-half million shells.
You had 31,000 people--
that's a third of the modern British army--
employed solely on road building duties.
NARRATOR: 9,500 motor vehicles were amassed.
173 miles of railway were laid.
Plumer would have more aircraft over Messines
than the Germans had over the entire Western Front.
And the days of horses leading the attack were over.
Tanks had been first used in the autumn of 1916
with limited success.
(loud explosion)
Early versions had been slow, unreliable, and unbearably hot
for the crew who operated them.
For the impending battle of Messines,
Plumer took delivery of 72 of the latest model: The Mark IV.
CHURCHILL: This was the one that the tank drivers had been waiting for.
There were bits of it they really liked.
I think they liked that they'd moved the fuel tank
away from the drivers,
which obviously if you're under shellfire is beneficial.
They've taken those stabilizers off the back.
These little wheels on the back of the tank,
which were supposed to help steer it,
but really they were just getting caught in everything.
NARRATOR: Although impervious to small arms fire,
they were vulnerable to artillery
and were prone to catching fire.
And there were other shortcomings.
They were hoping that when the Mark IV came out,
it would just be one driver required to driver it.
But actually it was four.
And it was done through this sort of insane system
of banging on the engine casing and hand signals
to try and steer the thing.
And it took four men to get it across a battlefield.
NARRATOR: The Mark IV was a heavily armored vehicle
designed to plough through
the previously impenetrable belts of barbed wire
while protecting the infantry following closely behind.
While rudimentary, the tank offered a way
of punching through the German defenses.
Below the town, the dig offers a grim memento
of the bitter fighting to come:
the helmet of a German soldier,
and nearby, an ammunition box
containing the belt of a British Vickers machine gun.
The Vickers gun was built on the success
of the earlier Maxim gun.
As well as being lighter,
it featured a new muzzle booster,
a cup at the end of the barrel.
This captured some of the exploding gas from each shot
and pushed the sliding barrel backwards,
adding to the energy of the recoil that powered the gun,
making it less likely to malfunction.
But it was the big guns--
(loud explosion)
heavy artillery that began General Plumer's battle
to take the German bunkers and strong points
on the Messines Ridge in the summer of 1917.
On the evening of June 6, Allied soldiers assembled
on the low ground beneath the ridge.
The mines containing over a million pounds of explosives
were now ready under the German strong points.
Still fearful that the Germans might discover them,
the tunnelers prepared for their simultaneous detonation
in the final few hours.
TURNER: The troops moved into position, in darkness
quietly as possible into taped positions in the open.
They were told to lie in the open and wait.
And waiting like that is a nightmare,
it's interminable.
Troops just want the attack to happen.
And they lay down in the open on their tapes waiting to go
resting, head on the forearms with the helmet,
dozing, and imprisoned really by their thoughts.
NARRATOR: The moon came out at midnight,
and it was said that in Wytschaete Wood near Messines,
nightingales could be heard singing.
(birds chirping)
The tunnelers checked their watches
and the leads to the explosives.
At ten past 3:00 that morning,
19 mines under the Messines Ridge
were simultaneously detonated.
(loud explosion)
TURNER: The troops would have been presented by the blast
where I'm standing now,
which was the height of St Paul's Cathedral
rearing right up above them-- these huge tongues of flame
and incredible clods of earth
the size of carts, huge lumps, raining down.
The commanding officers and the company commanders
would have said, "Right lads, we're off, let's go.
Get up everybody, get up."
And they would have advanced up the hill,
marching into this inferno.
The Germans on the ridge--
if they haven't been obliterated by this blast--
they rush into position.
As soon as they get into their fighting positions,
they're just... just raining of shells coming down.
They talk about the fact that they were "virtually deafened,
useless, indifferent to their fate,"
one German officer describes it.
NARRATOR: Detonating the mines on the Messines Ridge
created the biggest explosion the world had ever seen.
Some estimates say 10,000 German soldiers
were killed in the blasts.
From the moment the mines detonated,
it would take New Zealand troops just over an hour
to reach the outskirts of Messines.
By the end of the day,
the Allies had achieved all their objectives.
General Plumer was delighted
with how low the casualties had been in the initial offensive,
although by the end of the battle seven days later,
24,000 Allied soldiers had been killed, wounded or were missing.
The German casualty figure was as much as a third higher.
But after nearly three years at Messines,
Plumer had broken the deadlock of trench warfare.
DOYLE: The Battle of Messines has got to be considered
as one of the most successful battles
the British army ever fought.
The combination of the mine warfare, the artillery assault,
and the infantry assault makes this battle unique
and makes it-- in my opinion anyway--
the most successful of the British army's activity
on the Western Front.
NARRATOR: In Flanders, nearly a century later,
the craters from the detonated mines are still clearly visible.
They stand as a reminder of General Plumer's bold plan
to drive the Germans from the Messines Ridge.
TURNER: It was a stellar achievement
to breach such an impregnable objective,
but it was unrepeatable,
and its planners never envisaged that it would
bounce straight into some kind of incredible breakthrough--
troops flooding across the Northern plains
and on to Berlin.
NARRATOR: In fact, the Allies advanced barely ten miles
into German territory before faltering.
The three-and-a-half million shells fired
during the Messines offensive
had not only destroyed enemy trenches,
but had churned up the ground ahead,
making it all but impassable.
Now one of the grimmest campais of the war,
Passchendaele,
would claim over half a million casualties in a sea of mud.
The long awaited breakthrough had failed to materialize.
Messines may have fallen, but it would take another year
of bitter fighting before the war was over
and the armistice signed.
CHURCHILL: When we look at World War I, we spend a lot of time
concentrating on the people that died in the war
and we don't often think of the people they left behind.
One story that's really touched me is the story of two friends
named Robert Irvine and John Corrie
from a small town in Dumfriesshire
who served together throughout the war.
John was actually killed near here in the Battle of Messines.
After the battle, a New Zealand soldier
was walking back across the battlefield,
and he actually found a diary lying on the ground.
And when he opened it up and went through it,
he saw that there were a number of letters, and photos,
and personal mementos
and he saw it belonged to John Corrie,
and he thought it would be the right thing to do
if he sent it back to Lizzie, John's sweetheart.
Lizzie came to Belgium after the First World War
to visit John's grave.
She never married, and when she eventually died
aged nearly 100 in 1991,
she was buried with a photograph of him in her hand.
NARRATOR: Although the Germans had been driven out
of their trenches at Messines,
it would take the arrival of American troops
joining the Allies to finally bring Germany
to its knees and end the war.
The archaeological dig has unlocked
a hundred-year-old time capsule of the First World War.
The horses and trenchehe
the bombs and the bullets,
and the underground tunnels
snaking beneath the killing fields of Flanders
all tell of a war of huge technological change.
(explosion)
But above all, the dig is a timely reminder
of the human sacrifice
that more than anything else has come to symbolize
the horrors of the First World War.
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