All language subtitles for impossible.engineering.s05e09.himalayan.mega.train.480p.webrip.x264.rmteam

This time on
"Impossible Engineering,"

the highest railway
ever built...

The engineering is mind-blowing.

It was almost impossible

to conceive of a railway
running at this altitude.

Constructed in
a remote, frozen wilderness...

It's definitely amazing.

It's a totally
different setting.

And the pioneering,
historic innovations...

We're at 30 meters.

One of the biggest changes
is my voice.

I speak in
a very strange manner.

I can sense the lack
of oxygen through my lungs.

Lightheaded. Do not feel great.

That made
the impossible possible.

Captions by vitac...
www.Vitac.Com

captions paid for by
discovery communications

this is Lhasa,

the spiritual home
of Tibetan Buddhism.

This city in the clouds
is one of the highest,

most inaccessible on earth.

Situated on the vast
Tibetan plateau,

it is surrounded by not one

but three
mighty mountain ranges.

Before the 1950s,
there weren't even any roads

to get to Lhasa...
Just meandering mountain paths

that took months to get through,
and only in good weather.

But the Chinese government
came up with an audacious scheme

to connect this ancient province
with modern China.

This is the highest
railroad on the planet.

Specially-designed,
high-altitude trains

climb to 16,400 feet
above sea level

to cross the Tibetan plateau...

The highest and largest
mountain plateau on earth.

Our locomotives
can pull 3,700 tons of cargo

or 20 passenger carriages.

It's the most advanced
technology in our country.

The engineering
is extraordinary.

675 Bridges and 10 tunnels

to cross the frozen wilderness

that's known as
"the roof of the world."

Whenever I see the train passing
through the Tibetan plateau,

I feel extremely proud.

From Beijing
and Shanghai in the east,

trains run
to the city of Golmud,

the start of
the high-altitude line.

From here,
they begin their climb,

crossing the formerly
impenetrable Kunlun mountains

to reach the immense,
frozen Tibetan plateau.

At this altitude,

the air oxygen content
is half that at sea level,

and temperatures can drop
below negative 20 degrees.

The railroad reaches
the world's highest station

at the Tanggula pass,

a staggering 16,600 feet
above sea level,

before making its way to Lhasa.

This is the Qinghai-Tibet line,

a railway which at first people
thought was impossible.

It's called the heaven road,

and, honestly,
that's what it is.

It's the most audacious
railway project ever imagined,

so it comes with some
enormous challenges.

Perhaps the biggest challenge

is how do you
keep everyone breathing?

At this incredible altitude,

oxygen is in short supply.

Dr. Zhu Xinxiang is in charge

of the railway's medical unit.

On the Qinghai-Tibet railway

between Golmud and Lhasa,

the average altitude
is over 4,000 meters.

It's an area of extremely
low atmospheric pressure.

There's only around 50% oxygen
in the air here

compared with the mainland.

The human body
is not designed to cope

with such low oxygen levels.

It can lead to potentially
fatal altitude sickness.

In severe cases where
the body's starved of oxygen,

it can cause swelling
of the brain or lungs,

which can be fatal.

These unique trains
are specially engineered

to protect their passengers

as they travel through this
beautiful but brutal landscape.

Ding Weiran
is the senior engineer.

In here is the oxygen generator,

which pumps oxygen
into the train carriages.

These prevent oxygen shortages
at high altitude

and make passengers
feel more comfortable.

Inside, there is an altitude
sensor to determine

the oxygen levels outside, and
oxygen concentrations sensors

to monitor the levels
in each passenger compartment.

The train is made up
of 16 carriages,

and each of these carriages

has its own
oxygen generator like this.

The passengers also
have access to oxygen masks,

which they can use
if they're having difficulties.

Well, if you're just sitting
here, then it's all right,

but if I climb to the top
of the bunk bed,

then I notice that I have
some shortness of breath.

As an extra precaution,

the railroad posts
a medical team on every train.

These extra measures onboard
ensure safe passage

for the 2 million travelers
who make the journey every year.

But the team that built the line
didn't have these luxuries.

Construction
workers are at a high risk

of altitude sickness
and hypoxia...

A severe lack of oxygen.
Doing physical work

means your body uses up
oxygen very quickly.

That made this an extremely
difficult project.

At first, we thought there was
no way it could be completed.

They would need to
turn to a machine from the past

to defy nature and build
across the roof of the world.

Dr. Gary Smerdon
is in southwest England

at the site of Isambard
Brunel's masterpiece,

discovering how experts
in engineering and medicine

came together
to solve the problem.

So, here we have
the royal Albert bridge,

a fantastic feat of engineering.

Most of the people who travel
across the top of this bridge

do not have the faintest idea
about the effort

and the suffering that went
into building this bridge,

'cause the feat of engineering
to get that pier built

down into the rock bed
of the river

was very new at the time,
very dangerous,

and they didn't really
understand what they were doing.

These workers were moving
into a pressurized environment

every day to do their digging
and their engineering,

then coming back to the surface.

There were 25 workers.
One died, two became paraplegic,

and all of the others became ill

due to what became known
as caisson disease.

With 19th-century engineers

wanting to build
ever more impressive structures,

a way to treat workers who
came down with caissons disease

had to be found.

In 1876, American inventor
Daniel Kelly

submitted a patent in Chicago
for a compressed-air bath,

a machine that would
hold the key

to treating workers
with caissons disease...

Today commonly referred to
as decompression sickness

or the bends.

The body contains nitrogen gas.

When the pressure increases,

this gas dissolves
into the blood and tissue.

But when the body returns
to normal pressure,

it becomes a gas again.

If bubbles of nitrogen gas form,
they can gather in joints

and tissues,
causing serious problems.

Kelly's machine was a forerunner

of the hyperbaric chamber.

Any problems,
just put your hand up,

stay "stop,"
and we'll take it from there.

Lovely.
See you on the surface.

While the condition affecting
the caisson laborers

was very different

from what the Chinese workers
were suffering from,

this amazing machine
holds the key

to solving both problems.

An air compressor
creates pressurized air,

which is stored in a giant tank.

It's slowly pumped into
the hyperbaric chamber,

recreating whatever
pressure environment

doctors need
to treat their patients.

This was the key
to treating caissons disease,

giving doctors
the ability to reduce

those deadly bubbles
in the blood.

So, here we are.
We're in the chamber now.

The door is shut.

My colleague, Chris,
is at the controls,

and he'll soon be
pressurizing me

and getting me down
to the equivalent of 30 meters.

And the machine itself
can actually be used

to demonstrate the very problem
it was built to solve

with a simple experiment.

So, with me here in the chamber,
we have an empty bottle here

that's full of air

and another bottle
that's full of carbonated water.

The empty bottle contains air

at normal sea-level
air pressure.

So as the pressure
in the chamber mounts,

the bottle collapses.

But that's not
the only apparent change

in the pressurized chamber.

Okay, that's you
at 30 meters, Gary.

Okay.

Gary's vocal chords
are feeling the pressure, too.

And there we have a glass

of carbonated water.

The water, which was carbonated
at normal air pressure,

has completely lost its fizz.

That much pressure,
the gas molecules

are dissolved in the liquid,
but the gas is still in there.

This water represents
blood in the body.

So when we go back
to the surface, you will see,

bubbles will start to appear.

That's exactly
what was happening

to these caisson workers,

where bubbles will start
to appear in your blood

and in your tissues.
As a human, you're in trouble.

It was discovered that the key

to keeping bubbles from forming

was a slow ascent,

giving the body time
to equalize.

This machine allowed doctors
to simulate a slower,

controlled ascent, saving
the lives of caisson workers.

Likewise, the engineers
behind the Qinghai-Tibet railway

will take inspiration

from Kelly's rudimentary
hyperbaric chamber

to protect the workers

constructing this
impossible railroad.

In China, the team

building the
Qinghai-Tibet railway

realized that Daniel Kelly's
150-year-old

air-compressing chamber
could be put to a different use.

On the 29th of June, 2001,

the build began of the
highest section of the railway.

This was the base hospital
for the construction team.

We provided a lot of
medical personnel and support.

This hyperbaric chamber
was used frequently.

The construction team
went through 120,000 bottles

of oxygen each year,
but even that wasn't enough.

There were many
critically ill patients

during the construction
of the railway.

These chambers were vital.

They saved patients' lives.

When you're working
at 4,000 meters altitude,

getting back down
to sea level isn't easy.

But by placing workers suffering
from altitude sickness

into hyperbaric chambers,
they could effectively simulate

a move straight back
down to sea level,

meaning treatment
could start immediately.

Engineers installed 25 chambers

at strategic locations
along the line.

During
the construction of the railway,

the success rate
for saving lives

from acute altitude sickness
was 100%.

There were no fatalities.

This line is a milestone
in the history of railways.

I'm proud of it,
and I'm very proud

of being part of the medical
team during its construction.

This machine helped
keep the 100,000 workers,

who spent five years

building this inspirational
railroad, safe.

Mount Everest is the
highest mountain in the world,

with the Himalayas
making up the Southern edge

of the world's largest
mountain plateau.

Stretching 620 miles north,

the Tibetan plateau
is the breathtaking setting

for the highest
railroad on earth.

In the past, people thought
a railway to Lhasa

could never be done.

It's one of the most
remote cities in the world,

but this didn't stop
the Chinese engineers,

and the engineering challenges
they faced were immense.

The city of Golmud
sits at over 9,000 feet

in the foothills
of the Kunlun mountains.

To link it to Lhasa,

engineers needed to find a way
to run rails

across the permafrost,
permanently frozen ground

of the 965,000-square-mile
plateau beyond.

Wang Jinchang
is professor of engineering

at the railways
research institute

that was tasked
with achieving the impossible.

He regularly makes the 8-hour
round trip from Golmud

to the heart of the plateau

to monitor
the ground conditions.

The area we're in now is typical
of the Tibetan plateau.

It's called "no man's land."

2 or 3 meters beneath us
is permafrost,

which is permanently
frozen ground.

It's incredibly cold here.

Building anything
in this environment isn't easy.

Frozen ground
can actually provide

the perfect foundation
for building on,

but with one
important condition...

It must remain frozen.

If the ground melts
below your foundations,

you're in real trouble.

A railway line
is at risk of collapse,

derailing any trains
trying to use it.

So how do you keep
hundreds of miles of ground

frozen solid enough to build on?

For inspiration, the engineers
turn to another frozen territory

4,300 miles away.

Known as the last frontier,

Alaska is America’s
northernmost state.

Straddling the arctic circle,

it covers a staggering
656,300 square miles.

When the largest oil field
in north America

was discovered in Prudhoe bay,

an 807-mile pipeline down
to the Southern port of Valdez

was required to export the oil.

The problem, just like in Tibet,
was that they needed to build

on endless expanses of hard
but unstable permafrost.

Local civil engineer
Doug Goering

is aware of just how hard
this can be.

Trying to build any
kind of engineering structure

on this type of permafrost
results in major challenges.

If you try to build a warm
structure like a house

or a building, you can imagine
that the heat from that building

is gonna work its way
into the ground.

It thaws the ice
in that ground out,

and it becomes a mushy mess.

The house foundation
typically fails.

And when you're trying
to build a pipeline

that will carry warm oil,
those problems are compounded.

Normally, an oil pipeline
would be buried,

but anywhere where
the ground is frozen,

the pipe has to be physically
separated from that frozen soil

because, of course,
it carries warm oil.

That warm oil would melt
the frozen ground

and cause structural problems...

Cause the pipe
to deform, buckle,

and probably would have
caused oil leaks.

So they built it above ground.

This is
the trans-Alaska pipeline...

An $8 billion creation

that carries up to 2 million
barrels of oil a day

across the entire state.

The design focused
on an elevated pipeline

to keep the warm pipe
away from that frozen ground.

But the foundations
for the support columns

still needed to rest
on solid, frozen ground.

If it melted, whole sections
of pipeline could collapse.

Luckily, one man had an answer.

In 1963, nuclear physicist
George Grover

developed a system
to transfer heat

that would be crucial

for engineers trying
to build on permafrost.

You can see that each of these
vertical support members

are capped
by two finned sections.

Those fins sit on top of a
device known as a thermosyphon.

These thermosyphons are used
to ensure that the ground

that the vertical support
members go into remains frozen.

The vertical
support members rely

on that frozen ground strength
to hold the pipe up.

A thermosyphon
is essentially an empty tube

which goes through the marshy
bog down to the frozen ground.

At its base is
a liquid refrigerant

with a low boiling point.

When the temperature rises
in the ground,

the liquid absorbs the heat,
starts to boil,

and then evaporates,

dissipating the unwanted heat
through the tube

and into the atmosphere,

keeping the ground around
the foundations cool.

What I have here
is a canister of butane,

which is similar
to the refrigerant

that's used in the thermosyphon.

And what I'm gonna do here
for a demonstration

is get a little bit of liquid
butane into this plastic bag.

So you can see that I have
liquid in the bag, here.

What happens at the base
of the thermosyphon

is that liquid boils.

And you can see that
when I add heat

by putting my fingers
on this bag,

that I get pretty vigorous
boiling of the butane.

This is the same thing
that's happening

at the base of the thermosyphon.

In this case, the butane is
collecting heat from my fingers.

In the case
of the thermosyphons,

the refrigerant collects heat
from the permafrost

and pulls heat out of it...

Dumps that heat
into the atmosphere.

Over 100,000 thermosyphons

help to keep the oil flowing.

This pipeline project
really is an engineering marvel.

It's been stable for
on the order of 40 years.

Really, I think it's safe to say
that the engineers

who designed this
solved the permafrost challenge.

The permafrost challenge
has not beaten the team

in Tibet, either.

Here, they've used thermosyphons
on a massive scale,

stretching as far
as the eye can see

to cross over 310 miles
of permafrost.

These thermosyphons are the
best way to solve the problem.

It's a great solution.

Its main function is to decrease
the temperature of the ground

and prevent the permafrost
from melting.

This is the part
that releases heat.

This is the middle section,

and the working part
is underground.

We use two rows of thermosyphons
on the side facing the sun

and one row on the side
which doesn't face the sun.

Over 25,000 thermosyphons
have been installed.

But with the heat generated
from passing trains,

the thermosyphons alone aren't
enough to keep the ground frozen

and the foundation solid.

The track is also raised
off the ground

on a crushed rock embankment.

This low-tech engineering works
by letting the cold wind

flow through the gaps
between the rocks,

dissipating any heat
coming from the trains above.

By using these
measures, we protect the railway

by keeping the ground cool up to
15 meters away from the track.

This prevents the permafrost
from melting

and sinking the railway.

But for a 7.3-mile long stretch
of the permafrost zone

in the heart of the plateau,

neither of these measures
could help.

To make this unbuildable
stretch buildable,

engineers would need
to make the impossible possible.

We're now at the Chumaer river
upland plain natural reserve.

This is all wetlands.

The biggest feature here
is the hydrothermal lakes.

This is a natural occurrence
of frozen soil.

While in the winter
this area is frozen solid,

the heat from
the hydrothermal lakes

means it's all a boggy marshland
come summer.

So this is the
incredible solution.

At over 6.8 miles,

it's the longest bridge
over permafrost in the world.

Most of
the frozen soil is melted here.

A rock embankment wouldn't be
stable, so we built a bridge.

The bridge is supported
by pile foundations,

which were inserted
deeply into the ground.

In this environment, a bridge
is a much better solution

than an embankment.

The biggest difficulty for us
building this kind of bridge

is working in winter.

During summer, the atmospheric
temperature is too high.

If we built during this season,
we would risk

causing the permafrost to melt,
making it too unstable.

Working through winter

at temperatures
down to minus-22 degrees,

engineers achieved
the impossible

and completed the final,
most difficult part

of the line to Lhasa.

Building a railway

in the permafrost
of the Tibetan plateau

was one of the biggest
engineering challenges

in the world.

It was almost impossible
to conceive of a railway

running at this altitude.

It's an extraordinary feat
of human ingenuity.

To construct
this $5.2 billion line

to run at high altitude,

engineers overcame huge hurdles,

but they also had to specially
engineer the locomotive itself.

Across most of the China
railway network,

electric locomotives are used,

which draw their power
from overhead cables.

The Shanghai to Lhasa express
uses these

for the first part
of the 47-hour,

2.6-thousand-mile journey
across the country.

But when the train reaches
Golmud, it runs into trouble.

In the isolated,
high-altitude plateau,

extremely low
winter temperatures

combined with lightning storms

means that electricity supply
cannot be guaranteed.

So they can't install
the overhead cables

necessary to electric trains.

Normally, railroad engineers

would turn to
a regular diesel locomotive.

Combustion engines need
fuel and oxygen to work,

but at these altitudes,
there's just not enough oxygen

to give enough power
to the engines

to haul the huge trains
up the steep gradients required.

Internal combustion
engines draw air

into the combustion chamber
to mix with fuel.

The piston compresses it.
Then the spark plug ignites it.

This controlled explosion

forces the piston
back down the cylinder.

But as oxygen levels drop,

so does the force
of the explosion

and the power produced.

Regular locomotives just
wouldn't be able to cope

with the lack of oxygen.

They wouldn't get
anywhere near Lhasa.

To get trains to run
at such high altitudes,

the engineers needed
to look to the skies.

Mechanical engineer Dan Dickrell
is exploring pikes peak,

one of the highest points
in the rocky mountains.

It was here in 1918
that a landmark experiment

changed engine design forever.

Driving this really muscley car

up one of America’s
most iconic highways

is quite exciting
from both an engineering

and an auto-enthusiast
perspective.

But as the road climbs,

the amount of oxygen
in the air falls.

I've reached
the halfway point up pikes peak.

I can feel that lack of oxygen
at this altitude,

and so the automobile.

At the bottom,
it was really snappy.

It's starting to get
a little bit more sluggish.

At the 14,115-foot summit,

the oxygen is almost 50% lower
than at sea level.

All right.

I can really, really feel it.

Lightheaded. Do not feel great.

And on the way up,

the internal combustion engine
inside my car,

it could feel it, too.

This problem plagued
early aircraft pioneers,

who found the higher
they took their machines,

the more their engine's
power faded.

And during world war I,
the ability to fly high

became a matter
of life and death.

The higher a plane could get,

the smaller the chance of
it being detected by the enemy.

They had to find a way
for their engines

to cope with lower oxygen levels

so they could go higher
than ever before.

And the solution they landed on

just might hold the answers
for the team in China.

For a solution to their
low-oxygen, high-power needs,

the engineers behind
the Qinghai-Tibet railway

must turn to an innovator
of the past.

During world war ii,

aircraft designers
needed to maintain engine power

at increasingly high altitudes
to avoid radar detection.

To help the U.S. air force
solve their lofty problem,

they drafted in steam turbine
engineer Sanford moss.

Sanford moss developed a
revolutionary piece of machinery

that would force more air
into the airplane engine,

essentially turbo-charging it.

Moss' turbocharger
was a total game changer.

Instead of just being wasted,
the engine's exhaust gas

is used to spin a turbine,

which in turn powers
a compressor,

which draws in air,
compresses it, cools it,

and pushes it into
the combustion chamber.

This high-pressure mix,
when ignited,

dramatically increases
the engine's power.

To demonstrate
the difference it makes,

first we need to see how
an engine performs without it.

This is gonna serve
as my cylinder.

Inside the cylinder, we're gonna
put a mixture of fuel and air.

Instead of gasoline,

I'm gonna use butane.

Now, what I'm gonna do is
I'm gonna take this butane...

And inject it into
my cylinder...

And two metal electrodes
are gonna serve as a spark plug.

I'm gonna introduce
two alligator clips

that will provide electricity.

In three, two, one.

Cool.

All right, now we're gonna
repeat the same demonstration,

except this time, I'm gonna
turbo-charge the cylinder.

To do that,
still need some fuel.

Now, this time,
we're gonna introduce

a slightly different cork,

'cause this one
as a valve in it.

That's gonna allow me
to pressurize the cylinder,

just like a turbocharger would.

We lock down...

Give it a few good pumps...

And now I've got
my pressurized cylinder.

Let's repeat

and see what the effect
has on it.

In three, two, one, go!

Whoa! Nice!

Oh, that one flew
much, much higher.

The turbocharged cylinder
worked much better

in terms of explosive
release of energy,

just like a turbocharged
engine would.

In 1918,
moss and his team came here

to carry out their first
high-altitude test.

He put his new turbocharged
engine on the back of a truck

and attached it
to a giant propeller.

The output had been
230 horsepower.

But with his new invention,

it was boosted
to 356 horsepower.

Three years
afterwards, a biplane fitted

with a moss device
broke the altitude record,

flying higher than any other
airplane had flown before.

Turbochargers exist
all over the place.

Really impressive pieces
of technology.

In China, engineers
have fitted moss' turbocharger

to special locomotives
to give them the power

to cross the high-altitude
Tibetan plateau.

At Golmud station,
locomotive engineer Shen Dezhi

is supervising the switch-over.

This train has just arrived
from Beijing to the east.

It's an electric locomotive,

powered from
the overhead cables.

After the crew have
disconnected all the wires,

it will be pulled out so that
the new locomotive can come in.

With the passengers
eager to continue

the next 14-hour leg
of their journey to Lhasa,

the train crew
must move quickly.

This is our solution
to the high-altitude problem.

It's a tailor-made
plateau diesel locomotive,

especially designed
for the Qinghai-Tibet line.

It's about to be connected
to these carriages.

These turbo diesel
engines provide 6,000 horsepower

to pull either
20 passenger carriages

or a whopping 3,700
tons of freight

at speeds of up
to 75 miles an hour.

I had the honor
of driving the first train

to cross the plateau to Lhasa.

So whenever I see this
incredible, advanced locomotive

coming into Golmud,
I feel excited, very excited.

If we don't manage to build
this turbocharged locomotive,

so many people just wouldn't
be able to get to Lhasa.

I feel very proud
of this solution.

But the engineers
still face another major hurdle.

The single-line design

makes reliable
communications essential.

With high-speed trains traveling
in opposite directions

in some of the most
remote locations on earth,

how do you ensure you can
communicate with them

to keep them safe?

The highest
railroad in the world

runs to Lhasa station.

Trains on this line
are specially engineered

to cross the frozen tundra
of the Tibetan plateau.

Undercarriages are sealed
to protect against frost damage,

and even the windows
are specially designed

to cope with subzero
temperatures.

The windows are equipped
with a special heating device.

It prevents the glass
from freezing and cracking

as the train travels
along the cold parts

of the Golmud to Lhasa line.

These incredible advances

make this previously impossible
journey possible

for passengers like Gregor and
Marianne, tourists from Holland.

Yeah, it's definitely amazing.

I'm reading a book right now

about a woman
who's traveling in Tibet

I think about 20 years ago,

and it was so different.

You had to do everything by foot
or with a Jeep.

And if there were mud floods,

then you couldn't go
any further.

It's really
a totally different setting

to just cruise through
the mountains in warm trains.

The 710 miles
of high-altitude railroad

between Golmud and Lhasa

includes a staggering
675 Bridges

and almost 6 miles of tunnels,

including the highest
railroad tunnel in the world...

The 4,400-foot-long
Fenghuoshan tunnel,

drilled through
a permanently frozen mountain.

Building this line really pushed
the boundaries of engineering.

But with a £3 billion price tag,

they simply couldn't afford
to build two lines side-by-side,

one for each direction,

so they had to settle
for a single line.

This presented engineers
with a new challenge.

With high-speed trains traveling
in opposite directions

in some of the most
remote locations on earth,

how do you ensure
you can communicate with them

to keep them safe?

So how could an innovation from
19th-century railroad pioneers

help inspire
the engineers in China?

Engineer Kate Mulcahy
is at miniatur wunderland

in the German city of Hamburg...

The largest model railroad
in the world.

1,300 trains
with over 10,000 carriages

crisscross this huge attraction,

where they have
a similar problem...

Keeping trains safe.

Luckily, an ingenious,
new form of technology

was about to change
the way the world communicated,

setting in motion
a telecommunications revolution.

In 1837,
William Fothergill Cooke

and Charles Wheatstone struck
upon a brilliant concept...

Electromagnetic deflection.

They found that when they
created a complete circuit,

magnets reacted
to each other predictably,

even across great distances.

Cooke and Wheatstone
built this instrument...

The five-needle telegraph
arranged on a grid of letters.

Now, in my version,
my construction here,

this bit represents
the sending element,

and then this bit over here

represents
the receiving element.

These rods in the middle
represent wires.

Now, because this telegraph,
the sending one,

is connected in the circuit
to this telegraph,

when I move this needle one way,

the action is mirrored in the
receiving telegraph over here.

So, for example,
if I wanted to spell out,

say, the word "stop,"
I start with the letter "s."

So, on my sending,

I'll move this needle so it
points towards "s,"

and I'll move this needle
so it points towards "s,"

and then the person
on the receiving end

will look for where the points
of those needles converge.

I then need to move the needles

so that I can get them
to converge on "T."

This device enabled
its users to spell out words

and send them down the wire.

Their feat
of engineering brilliance

was to send the first
communication

electronically on the railways.

The needle telegraph started
a telecommunications revolution.

Adopted by the rail
network initially,

it was quickly
implemented worldwide.

In China, they've taken
this 180-year-old concept

and given it
a 21st-century makeover.

Third-generation
railway man Wang Jinchang

manages the Golmud
train station,

and the technology he uses
to signal trains

on the Qinghai-Tibet railway
is a far cry

from the 19th-century innovation
that inspired it.

Between Golmud and Lhasa,

we use satellite
positioning signals.

You won't see a single trackside
signal on the Golmud-Lhasa line.

We use the
satellite positioning signals

due to the tough
weather conditions

and 4,000-meter-high altitude.

This is a great piece
of technology.

It's a massive leap forward.

The train control system is run

from a control room
at Xining station.

With global
positioning satellites

determining the train locations,

all signaling is virtual
instead of wayside signals

used by Cooke
and Wheatstone's system.

All information is communicated
directly into the train cab,

where an onboard
computer terminal

displays up-to-the-second
information to the driver.

The advanced technologies
implemented along this line

are unique in this country.

They are the only reason
that we can provide Tibet

with the heaven road railway
that's been so important

for their economic growth
and social development.

The Golmud-to-Lhasa
line has transformed travel

across the Tibetan plateau.

Business increased quickly

once the Golmud-to-Lhasa
line opened.

Just in the last year,

we've dispatched
over a million passengers,

and the goods we have
transported by rail

have sharply reduced the number
of lorries on the road.

Lifestyle products,
building materials,

and daily necessities
such as oil

are basically all
transported by rail now.

Building a railroad line
across the roof of the world

was never going to be easy.

When we were young,
we didn't think

there would ever be a railway
between Golmud and Lhasa.

I think it's a milestone in
the history of global railway.

The unprecedented
and ambitious project

stands as testament
to the tenacious perseverance

of the human spirit.

If this special
locomotive didn't exist,

so many passengers wouldn't
be able to get to Lhasa,

so I feel very proud
of this train.

Go!
Whoa! Nice!

By building on the work

of the inspirational pioneers
of the past, upscaling,

and breaking
new ground themselves,

the engineers have succeeded

in making
the impossible possible.

The Qinghai-Tibet railway is the
greatest engineering achievement

in the world.