The Assassin (Sha ren zhe Tang Zhan)

Today, on "Impossible Engineering",

the Panama canal expansion,

one of the largest infrastructure projects

in the world.

This is one of the biggest projects ever made.

It is a big challenge, but that's what we pilots like.

We like challenge.

This expansion takes engineering to new heights.

The gates are enormous.

The gates are like an 11-story building.

Relying on pioneering innovations of the past...

It feels more like a cathedral than a functional structure.

...It took revolutionary engineering

to make the impossible possible.

Captions paid for by Discovery communications

Panama.

For more than 100 years, the Panama canal

has provided a vital shipping link

between the pacific and Atlantic oceans.

But by 2006,

engineer Luis Ferreira and his colleagues

find themselves in a massive predicament.

The problem with the original Panama canal

is that the ships are growing,

and the ship cannot fit through the existing canal.

Since the original Panama canal

was completed in 1914,

ships have increased around three times in size.

Many are so immense,

they simply cannot squeeze through the original canal,

forcing these big ships on a costly two-week detour

around south America,

wasting a million extra gallons of fuel.

We need a bigger canal.

The solution?

An engineering project of epic proportions...

the Panama canal expansion project,

one of the biggest infrastructure projects

in the world.

This massive construction

includes six new lock flights,

each one spanning the length of four soccer fields.

The gates separating each chamber

reach the heights of an 11-story building.

To make way for them,

a staggering 5.3 billion cubic feet of earth

must be dredged.

A whopping 155 million cubic feet of concrete

encase over 215,000 tons

of structural steel.

The result is a 48-mile-long canal

that can finally accommodate

some of the largest ships in the world.

But building it is no easy feat.

We have big challenge here.

You have to understand, the canal

has to go over mountains in order to do this.

For chief engineer Ilya De Marotta,

expanding this iconic canal is a tall order.

The Panama canal is a canal

that moves ships from one ocean to the other one,

pacific-Atlantic or Atlantic to pacific,

through a mountain range,

so you have to put a ship through the mountains.

So what do we do?

Overcoming this massive obstacle

would be impossible

without the great innovators from the past.

Engineer Dr. Rhys Morgan is exploring

the Loire valley in France

to examine an innovation

that changed water transportation forever.

At the start of the 17th century,

king Henry iv of France had to rebuild a country

that was ravaged by decades of religious wars.

Facing widespread food shortages,

the king wanted to connect the north with the south

and build a canal to link the Loire and the seine.

But between the two rivers,

a Ridge rises up 130 feet,

making the link seemingly impossible.

To make boats sail uphill,

31-year-old hydraulics engineer Hugues Cosnier

developed an ingenious solution.

Here in the village of Rogny-Les-Sept-écluses

is the most extraordinary example

of what Cosnier achieved.

It's a staircase lock,

the first of its kind in Europe.

Seven interconnected chambers enable the boats

to rise up the steep terrain.

It's a wonderful and beautiful example

of engineering.

To traverse the slope, Cosnier's staircase

used a sequence of lock chambers

to lift boats 10 feet at a time.

Well, prior to this, there was a method

of doing this called a flash lock

which involved a single step

from the lower level to the higher level,

but it was very dangerous.

As soon as the gate was removed,

there would be a torrent of water,

and the boat had to be pulled up through it

and then the gate closed behind it quickly.

You can see the obvious dangers in this,

and the boat could get damaged. The goods would be damaged.

It was just a terrible way

to lift the boat over the terrain.

Cosnier's ingenious idea was to introduce a second gate...

...so that there would be a series of isolated chambers

in which the water levels could be equalized

and adjusted as appropriate.

The boat would come in from the lower level,

and the gate would be closed behind it,

sealing it into the chamber.

The next stage was to slowly bring in the water...

...until they will naturally equalize.

Now the door could be easily opened

without any water flushing through,

and the boat could safely travel through.

By using a total of 36 lock chambers,

Cosnier surmounted the 130-foot-high watershed

and made the entire canal system possible.

It must have been such a sight,

a truly pioneering feat of engineering.

To build the Panama canal over the mountains,

engineers super-size Hugues Cosnier's lock staircase

on an epic scale.

Workers construct a total of six giant chambers,

three on each side of the canal,

requiring a stunning 120 million cubic feet of concrete.

Building the new locks had a lot of great

technological challenges.

Needless to say, the structures are massive,

unique designs.

We have three chambers.

Each raises the vessel 9 meters.

So the vessel goes 27 meters high

through an artificial lake,

and it goes down the same three steps down the other side.

But getting ships through the mountains

is only half the battle.

The new locks require more than 20,000 workers

excavating well over 2 billion cubic feet

of rock and earth.

That's 2.6 million dump-truck loads.

There's a lot of excavation that had to be done.

It's a lot of earth moving.

And not only was the earth moving,

but the geology of the area,

because you're going from sea level up to the mountains.

However, contracts manager Jorge De la Guardia

must modify the landscape not only above the water,

but also below the water.

We are looking, here, at the approach channel.

Deepening and widening the channels for navigation

presented quite a big engineering challenge,

'cause you have very hard rock,

and there are areas where you just have,

like, a muddy surface.

So that was the big challenge that we had.

To dig this deep, engineers must rely on...

The D'Artagnan,

one of the world's biggest cutter suction dredgers.

And at the pacific side of the canal,

this machine faces one tough problem...

rock-solid bedrock.

We had to prepare the navigational channels for ships

that are bigger and are deeper.

To cut out this roadblock, D'Artagnan uses

a computer-controlled rotating cutter tool

like those employed on tunnel-boring machines.

This enormous cutter smashes

the bedrock to smithereens.

Then the D'Artagnan sucks up the detritus

with a giant pump.

But the dredging and excavation

produce huge amounts of waste material,

creating a seemingly impossible problem.

We needed a place to deposit

the material that we were excavating,

but to find areas where we could,

you know, deposit 50, 60 million cubic meters of material

is not an easy thing.

Compounding this problem is an altogether unusual one.

The adjacent wastelands are deadly.

This was a contaminated area.

This was not a place where you could walk or use it,

because it was with unexploded ordinance.

This former U.S. army firing range

is littered with live ammunition.

To dispose of the 2.1 billion cubic feet of earth

on these treacherous lands,

the engineers must draw on one of history's great innovations.

The Panama canal expansion project...

spanning 48 miles, it's one of the biggest

infrastructure projects in the world.

But disposing of the immense quantities of bedrock

in the nearby wastelands is a deadly prospect.