Original subtitles

[dramatic music]

- [Narrator] They are giants.

Technological benchmarks of their time.

Statements of their era.

The most spectacular railway bridges in the world.

Monuments and indispensable infrastructures.

[dramatic music]

Hundreds of tons rush across them,

permanent, relentless, continuous strain.

And so they have to be serviced on a daily basis

under the most difficult conditions.

- You could slip on the cable and fall.

- [Narrator] They level the way for trains

in the most exposed of places,

often in areas with rough climatic conditions.

[dramatic music]

- In winter, temperatures can drop to minus 20 degrees.

- [Narrator] Construction is a huge challenge.

- Detonated and boom, the whole mountain lifted up,.

- [Narrator] A multimillion dollar game

that often never ends.

- It's a permanent construction site,

it's never really finished.

- [Narrator] The construction of the gigantic monoliths,

transcending borders and costing live.

- During the construction of the bridge,

there was many people unfortunately lost their lives.

- [Narrator] A high-risk race against time,

but when they're done, a new path open for so many people,

suddenly only magic and pride remain.

- This is the Forth Bridge and there will only be one Forth Bridge.

- [Narrator] A huge colossus.

The secrets behind the structures, spectacular buildings,

and the daily challenges of maintaining them.

[dramatic music]

Gigantic structures.

The most spectacular railway bridges in the world.

[upbeat music]

Majestic,

unique,

gigantic.

No matter what superlative we use, each is justified.

But without a few key milestones

in the history of bridge building,

they would all be unthinkable.

The Skerne Bridge in Darlington in Northeast England

is one of the first bridges for steam-powered railroads.

The first trains travel over in 1825.

There are all kinds of design for railway bridges

depending on distance and use.

Initially, the bridges are built of multiple steel trusses.

Also, brick structures with multiple arches are very common.

Dynamic effects are always the biggest challenge.

Beam and arch bridges best carry heavier loads,

with ever faster trains reaching speeds

of up to 350 kilometers an hour.

[rhythmic music]

It is no less than a masterpiece,

more than one and a half centuries old

and still state of the art.

The gulch style viaduct the largest brick bridge

in the world.

The gulch style viaduct is located in Saxony

in Eastern Germany.

Up to 100 trains cross the bridge every day.

Timbered construction withstands the heavy loads but only

because of daily maintenance.

[upbeat music]

Ulrich Scheffer and Marcus Fisher travel almost daily

to one of the most legendary railway bridges

in the world today.

Inspection of the Brickyard is pending,

wind and weather batter the brickwork.

[upbeat music]

- In most cases it's water that damages the bridge.

Be it either by penetrating the structure

through the leaky roadway

or heavy rain attacking the brick walls from the side.

- It was a real feat to build a bridge like that back then.

So now we make sure that it stays in good shape

as much as we can.

- Its a gem. - Let's go.

- [Narrator] With the so-called cat,

especially constructed service wagon, the men get going.

- So the bricks have been renewed before,

these aren't the original and are already damaged.

- [Narrator] Their mission,

find and replace broken bricks.

Always on hand, water, water, replacement bricks,

22 million bricks, hundreds of arches and vaults,

and a man who knows the bridge like no other

with his grandfather Fork Kercher

came along when the tracks were inspected on the bridge.

And then learnt masonry here today as an engineer,

he oversees their preservation.

- Steel as such didn't exist yet,

they knew about fire iron but couldn't build bridges

like this with fire iron.

During research, clay was found

and with clay you can make bricks.

- [Narrator] Back in 1851,

no one suspects what speeds and loads

the bridge would have to withstand.

All the more important today,

solid unimpaired bricks in sophisticated timbered masonry

able to shoulder trains thundering across

at almost 80 meters height.

- If you haven't been here for a long time,

you can get a queasy feeling.

- [Narrator] Marcus and Ish are now above the abyss.

Working at this height always makes the heartbeat faster.

No matter how often the men have been up there.

- You can't let it affect you.

It's an extraordinary job,

but you mustn't let it affect you.

- [Narrator] Even more disturbing than the height

is what the engineer discovers up here.

- The joints are all broken weathered.

This is as far as we can go.

- [Narrator] Through cracks in the brickwork,

water has penetrated deeply into the wall.

When the water freezes in winter and the masonry ruptures,

the bridge is in trouble.

- That is pretty extreme.

- [Narrator] The hollow sound not a good sign.

- The bricks are weathered all the way up

and you can see how they're falling apart.

The caulking is crumbling,

this should be done in the near future.

- [Narrator] Marcus and Lesh

are not equipped for such big jobs.

Scaffolding needs to be erected and like a few years ago,

a large construction site has to be set up.

- It's a permanent construction site,

it's never really finished.

- [Narrator] But it has to be preserved.

- You can really fall in love with this bridge

because it demonstrates such astonishing craftsmanship

from long ago,

and at the time when it was built

it is amazing that such a monumental structure

was built using such simple means.

- [Narrator] Extremely important for the construction

of the bridge is wood,

the densely forested region nearby

had to be partially cleared to build the bridge.

The centerings onto which the brick arches are erected

are made of wood.

Each arch needs its own centering.

77 arches rise in this way,

construction, a tour to force

up to 1700 people work simultaneously on the bridge

32 parish with completion in 1851.

It is the highest railway bridge in the world

and brings work to the region.

- Jobs were created during the railway construction period

when it was completed, industry skyrocketed,

people were employed.

The reason why they fought so hard for the railway.

- [Narrator] Construction of the Gulch Viaduct

connects an entire region to international trade.

The major transport link between north and south

is completed.

The substance of the bridge is actually very good.

Nevertheless, Marcus Fisher and his colleague

have to check each brick

in order to guarantee safe and secure train traffic.

The cornerstones are a particularly weak point

between two arches because they're exposed to the elements

with no protection.

In particular, the connection between platform and masonry

has to be repaired often,

frost destroys the top row of bricks again and again.

Marcus and Uli will not surrender to the weather,

the bricks they use are anything but standard.

- The bricks here are special,

they're exclusively made for this bridge,

they're made in the so-called cloister format,

which means that they're a little flatter

and a little bit longer than today's standard size bricks.

They're specially formatted to fit the old measurements.

- [Narrator] Masonry technique

has remained virtually unchanged

for one and a half centuries.

Quite the contrary,

the masons of the gal bridge worked with precision,

the workers today try to emulate them.

[upbeat music]

- Now we have to try to get back into the pattern,

watch out, we're taking off a bit.

It's a really cool building.

- [Narrator] [indistinct] Yeshiva is done for the day.

The bridge has 10 new bricks

and will be able to maintain its place in the Gulch Valley.

- The fascinating thing here is that

this bridge was built 160 years ago

and it is able to take on all the forces

and all of today's traffic without a problem.

And I wish for this bridge that it lasts another 160 years,

I can't wish for more.

[lighthearted music]

- [Narrator] The Gulch Town Bridge,

an iconic monument in 1851 for today and the future.

Another monument of bridge engineering

is to be found in Scotland.

A giant made out of steel.

[dramatic music]

50,000 tons of steel, the first bridge in the world

to be constructed completely out of steel.

Fourth bridge is an exceptionally

spectacular railway bridge.

5,000 workers work for eight years to complete

the steel colossus.

Today, spectacular maintenance missions happen

on a daily basis.

[dramatic music]

The Forth Bridge is located in the east of Scotland,

in Edinburgh.

More than 200 trains rush daily

along the Forth Bridge tracks.

Several teams are busy with a maintenance

of the living monument.

Cameron Miclar and Simon Tate prepare for their deployment.

One of the biggest bridge maintenance crews worldwide is

kept busy all year long servicing and maintaining it.

The two industrial climbers

have been working on the bridge for more than six years.

Just like every morning they start

with a mandatory safety check.

- Life jackets on.

[upbeat music]

- [Narrator] Working at 50 meters means extremely stringent

safety standards are required, not only for the workers,

nothing can be allowed to fall to the ground

or onto the tracks.

For Simon, the height is part of the job.

- But I respect the height, I'm not really afraid of it.

My job is to make sure they are doing everything safe,

everything is the way they're trained to do.

- [Narrator] The last fatal accident of a bridge worker

was five years ago.

That's not the only reason workers do not take any chances.

- That one's just a rescue bag.

It's should only be broke into if we need it for a rescue,

which finger shots we don't need to.

- [Narrator] The rescue set includes

a special lifting device.

In emergencies, the worker can winch himself

or the injured person up.

The climbers work their way to the south tower.

A new work platform is supposed to be set up

every two weeks,

the supports have to be checked for loose areas,

not an easy task at 50 meters above the ground.

But height is not the only problem they encounter.

[dramatic music]

- The biggest challenge most of the time is the weather.

Because we're in a a big channel right up the Forth,

it gets the wind very, very, very badly.

- [Narrator] The first or Forth

is the river flowing underneath the bridge.

The problem wind speeds of 145 kilometers an hour and more.

- Yes, two abseilers can be working

on the five towers on the southeast leg over.

- [Worker] All covered cheers.

- [Narrator] The workers inform the coast guard

about the maintenance work,

understandable as they know that every second counts

in an emergency.

- My wife basically just tells me not to tell her

most of the time what I'm doing just to,

she tends to freak out a little bit about some of it.

But again, she's seen me at work a lot of the time,

and she knows how to do everything safely so,

she trusts that I do that and come home every day so.

- [Narrator] The complex construction of the bridge complicates

maintenance to check the scaffolding,

Simon and Cameron have to abs sail.

Every step must be well coordinated because mistakes

can cost lives.

But these two guys aren't intimidated.

- Yeah, there's certainly easier bridges to work on,

but again it's just another challenge

that we deal with on a daily basis.

- [Narrator] The strong wings also make it

extremely difficult for the 5,000 workers

during the construction of the bridge.

In 1890, nobody worries about worker protection.

73 people die during the seven year construction period.

Chief engineer John Andrew knows the dark side

of the bridge.

- During the construction of the bridge,

there was many people unfortunately lost their lives.

The bridge was designed functionally,

it did not, was not designed for safe construction at that,

in those days.

So many, many died.

- [Narrator] Among the 73 people

that perished in the construction of the fourth bridge,

the youngest victim was just 14 years old.

At the time the construction of railway bridges

and even using them were still very dangerous.

Sir Thomas vouch is originally intended

to oversee construction of the Forth Bridge.

His inspiration the Tay Bridge,

but it ends up crashing into the Forth River

during a storm, taking down a crowded train with it.

75 people lose their lives.

After the disaster, new architects

want to make it better and safer.

- The tape bridge did not take the loads

and strains that was put on it,

and the Forth Bridge is required to be a safe bridge

and a very stiff bridge and that's what it is.

So it looks massive

but in fact it's only there to fulfill

the purpose it was designed for.

This is the Forth Bridge

and there will only be one Forth Bridge.

- [Narrator] Benjamin Baker and John Fowler

have a revolutionary idea,

a cantilever bridge made entirely of steel.

The first of its kind,

so sturdy that no such tragedy will ever reoccur.

For the builders, architects and workers,

it's a huge challenge, but they master it.

The overall construction consists of approximately

50,000 tons of steel,

held together by 8 million rivets.

From the foundations three trusses rise

to an altitude of 110 meters.

Two hinged girders with a length of 107 meters each

connect the steel colossus.

The idea behind the Cantilever Bridge

to distribute the main burden

in the middle of the bridge onto the pillars

and foundations.

The truss is mounted on four feet each are set up first

and then connected with suspension girders.

The special thing about it,

the bridge can only be moved at this point.

[upbeat music]

The hefty winds across the river

complicate maintenance work for Simon and Cameron.

At 50 meters, there can't be any mistakes.

Today they have to inspect a recently erected scaffolding

for further work on the bridge.

[indistinct]

Individual screws loosened

due to the strong vibrations caused by trains.

If Simon doesn't tighten them,

it could lead to fatal accidents.

The climbers have a dangerous job,

there's no doubt about it,

but they wouldn't have it any other way.

- This bridge, it's an iconic building,

Oh, an iconic structure been having

mostly based on here now for quite a long time

and it's just the challenges that it brings

is really, really good fun, you know.

- [Narrator] Overall, a 50 person maintenance team

works continuously to keep the bridge operational

in these difficult climatic conditions.

- Run. - Good.

- [Narrator] Now it's time for the last

tough climb of the day to work their way out

of the busy landmark.

[upbeat music]

In the meantime, the legendary Scottish bridge

belongs to the UNESCO world cultural heritage,

for the climbers as well,

the bridge has its own special charm.

- So no jobs, not two jobs are same.

Yeah, it goods fine.

[upbeat music]

- [Narrator] After the successful effort,

Simon signs off with the Coast guard.

- That's the ab sails finished on the five towers over.

- [Worker] Yeah, no problem man.

[bright music]

- [Narrator] Since 2002, the bridge

is on a new maintenance and restoration cycle.

Costs to date approximately 130 million pounds.

Built in 1890 in an extremely exposed position,

blustery winds and humidity,

yet still an indispensable and reliable thoroughfare

in Scotland, the Forth Bridge,

one of the world's most spectacular bridges.

[upbeat music]

Exceptional challenges arising from wind and weather,

but also from the choice of construction.

A railway bridge that breaks records

with a height of 190 meters.

The longest span of a bridge in Europe

used by trains and cars.

The 25th of April Bridge is located in western Portugal,

a main traffic artery, 160 trains daily.

Construction takes place in stages, first the road,

then the train connection.

The 25th of April Bridge,

a maintenance monster monitor day and night.

The north side of the bridge command central,

electricians, Antonio and Louise

are prepping for today's job.

It's no walk in the park.

The beginning is always a bit difficult

because of the altitude,

the winds and because the cables oscillate constantly.

- Fear, no, fear is my job.

- [Narrator] Maintenance is always in full operation.

Closing the bridge is unthinkable.

7,000 vehicles an hour, 150,000 a day.

The bridge in Portugal is the most important transport

connection from north to south.

Every three months the men have to climb

to the top of the pillars via the steep retaining cables.

This is still new territory for Louise.

He has only been working on the bridge for a year.

120 meters to the top, everything is on a narrow ledge.

On their way up to the top,

Lewis and Juan are secured by means

of a rope or cable system.

They must always be attached to the runner

on at least one side.

Several teams work parallel at different sites

on the bridge.

One level lower engineer Pedro and his team

are taking care of the additional loads

from the rail transport.

Because oddly enough,

the 25th of April bridge exists only since 1966,

yet the railway line goes into operation 33 years later,

Pedro and his engineers check

the railway construction today.

The extra weight of the passenger and freight trains

requires regular inspections.

When the railway line is planned in the fifties,

no one anticipates that current volume of traffic,

certainly not the enormous daily loads.

Nevertheless, it was already clear,

a gigantic bridge needs a secure foundation.

The 25th of April Bridge has the deepest foundations

in the world.

Two pillars support the structure standing

in the River Tay show,

not only a strong current, it is also very deep.

The rock bottom is 79 meters below the surface.

Engineer Pedro Abigail has been responsible

for the maintenance of the bridge for years.

He remembers the difficulties during construction.

- It was a big challenge, the technology was totally new.

The distances we are talking about here, never seen before.

Nothing comparable existed in Europe.

For the foundation we built individual elements

that we sunk and repeatedly kept putting new elements

on top of until we arrived at the bottom.

- [Narrator] About 300 people are employment

for the construction of the foundations over four months.

In cell design, big steel cylinders in blocks of concrete

are sunk up to 82 meters deep into the riverbed.

In this process, the cavities around the cylinders

are filled with concrete.

The weight of the element causes it to sink

just below the surface.

The next identical block is placed on top

and the procedure is repeated.

At the end hollow spaces are also filled with concrete.

The blocks are set one on top of the other

until they reach a depth of approximately 80 meters.

[upbeat music]

- Due to the width of the Tay shore,

which is still two kilometers across at its narrowest point,

it is clear that only a suspension bridge can work.

The material for the retaining cable

is supplied on huge rollers.

Each holding cable consists of over 11,000 fin steel wires,

which will be sent from one roller repeatedly

over the river back and forth

until the required diameter of just 60 centimeters

is reached.

The span of a little more than one kilometer

and the foundations are setting milestones

in construction technology.

- But the depth of the foundation

was not even the biggest concern at the time.

The main concern was that this foundation

was built in an area where seismic activity exists.

That was really the biggest concern of the people

who had the great earthquake of 1755 in mind.

- [Narrator] 30 Years after the opening of the roadway

construction on the railway line directly underneath begins.

It takes three years.

Since the expansion the contact point of the road

on the pillars is one of the critical sections

of the structure.

Engineer Pedro checks whether the carrier

still has enough leeway.

The road is not supported.

- Here, if something blocks

it could happen that the pillar breaks.

If something breaks and the road doesn't have enough give,

then it might bend slightly or even break at some point.

- [Narrator] You can clearly see the extreme loads

and the supports when a train passes,

the road gives under the weight,

which is how the engineers intended it to be.

- The bridge, even if it is made of steel,

is very flexible and elastic.

That means it deforms when there is a heavy load on it

and then comes back to its initial position.

- [Narrator] Which is why the road doesn't rest

on the buttresses it's secured by the cables.

One can observe this underneath the pillars

when trains pass,

here the road runs on rails on the pillars

and thus can slide back and forth.

The support gives up to one meter 50 engineer Antonio

and his colleagues measure the distance to the pillar.

If it's less than one millimeter, it is critical.

Every four weeks they take a tolerance measurement.

Various thick metal rods are used to measure the gap.

- So here on the list it says there was 1.6 millimeter

last time, let's see if anything has changed

in the past month.

The distances remain the same.

- [Narrator] Good results for the 25th of April bridge.

The securing cable gets the job done as planned.

[dramatic music]

Up on the cables,

electricians Antonio and Louise are working

their way upwards.

They have to climb up to a height of 190 meters.

For this job, they have had climbing training,

after 35 minutes climbing on the long cable,

they arrive at the top of the bridge.

- We have strict rules, for example, when it's too wet,

when it rains, we cannot go up

because there is not enough grip.

You might slip on the cable and injure yourself

despite all safety precautions,

and this is not exactly the easiest place for a rescue.

Of course, we must also monitor the wind speeds,

which can change very, very quickly here.

- [Narrator] Via a catwalk the two reach the other side

where today's task awaits.

The signal lamp on the highest point of the bridge

must be inspected regularly.

The proximity to the airport makes this work very important.

Electrician Antonio checks whether the bulb is still okay

or needs to be replaced.

They cannot fail, the bridge is in the flight path,

therefore it relies on early detection.

[upbeat music]

- I like my job to work with electricity.

That's what I can do.

It's what I've done since I'm 13 years old, now I'm 62.

I've been doing this for such a long time

and then the whole thing in such a place with this view

that's just great.

[lighthearted music]

- [Narrator] The workday on the 25th of April Bridge

is almost over.

On one of the very few suspension bridges worldwide

of this size also designed for heavy trains

and for automobiles.

A workday on one of the most spectacular railway bridges

in the world.

Another amazingly spectacular railway bridge

can be found in the mountains of Montenegro.

The Mala Rijeka Viaduct,

the highest railway bridge in Europe,

and quite possibly one of the most exciting.

The Mala Rijeka Viaduct is located in Montenegro

in the southeast of Europe.

The construction of the viaduct at the end of the sixties

is one of the most daring projects in Europe until today.

Its maintenance is a balancing act.

The highest where we bridge in Europe,

the main hub between Serbia and Montenegro

for over 40 years.

However, it has never been renovated,

yet the heaviest trains thunder over

the weakened 64,000 tons steel colossus.

[train engine rolling]

Closing the bridge would immediately bring

one of the most important railway routes

in former Yugoslavia to a standstill.

Since the bridge was never extensively restored,

it is closely monitored.

Selja Lekovic and Stravrako Metza

belong to the maintenance team and drive 20 kilometers

each day to the Montenegrin capital of Podgorica

where the bridge is located.

Spectacular as the tracks wind their way

through the mountains of Montenegro.

- The terrain is very difficult.

In the summer, rocks repeatedly fall onto the tracks

and there are strong winds,

and in winter there is so much snow

that may damage the bridge and the tracks.

A few years ago,

an avalanche paralyze the entire rail system.

- [Narrator] From the train,

Stratco and his colleague tried to identify any damage,

for maintenance supervisor Medeneza a daily adventure,

especially when his train nears the legendary

Mala Rijeka Bridge.

[train hoots]

- Every time I come out of the tunnel

and see the bridge in the amazing valley below,

it's like an incredible adrenaline rush.

- [Narrator] Rightly so,

because almost half of the long steel structure

lies at a height of 201 meters

underneath the bridge Just a deep canyon un rugged terrain.

The maintenance team has to inspect

the single track railway line carefully.

The heat sometimes warps the steel in the summertime,

but today, at least from the train, everything looks intact.

But of course,

Stratco and his colleague inspect the bridge

and the surroundings from up close again.

[upbeat music]

- Not only do I have to inspect the tracks,

but also the bridge and the maintenance scaffolding

for rust, with the scaffolding,

you can repair the lines anywhere on the bridge

and that's why it always has to be at hand.

- [Narrator] The rust is the worst enemy

of the highest railway bridge in Europe,

everywhere it eats its way through the more

than 3 million kilograms of steel

used to construct the viaduct.

Vera Vujivic is a civil engineer

and collects all the important facts

about the bridge for maintenance purposes.

The extreme temperature fluctuations here in the canyon

make it tough on the bridge, especially in extreme heat,

42 degrees, the tracks often expand

a few centimeters causing cracks.

- Measuring the rail temperature

is very important because the temperature changes

with the seasons.

In winter, we're at minus 20 degrees

and in summer sometimes up to 55 degrees.

It's crucial, we know if everything is working properly

and that the train tracks remain intact.

- [Narrator] Almost every single step during construction

is a major effort in the rugged mountains.

The structural stability of the viaduct

is the greatest problem.

Both bridge pillar stand at an extremely steep angle

to the deepest point of the valley.

In order to anchor them securely,

four meters of brittle sands donor excavated

and subsequently replaced

with 8,000 cubic meters of concrete.

Feline Concic was a geological supervisor

during construction,

at just 25 he was the man responsible

for all detonation operations.

- We drilled a 15 meter tunnel into the rock,

T-shaped and we used tons of plastic explosives.

Then we closed the tunnel from the outside

and remotely detonated.

[narrator speaks in a foreign language]

Boom, the whole mountain lifted up for a second

and then crashed down again like a small earthquake.

- [Narrator] Construction begins in 1969

with the help of two large cranes,

the workers mount the steel girders

onto the concrete pylons.

A total of 3,342 tons of steel.

250 construction workers work around the clock

with Stan wind and weather, two men are killed.

- The north wind was so strong during construction

that we held each other's hands on the bridge.

Formed a human chain.

And that chain is what prevented us

from falling off the bridge.

- Calculations on the structural stability of the bridge

are of paramount importance.

Even though the single track route

is only used by 12 trains a day.

Vera Vukovich has for years accumulated

all facts surrounding the bridge.

Measurements are taken mechanically

by means of a classical plum line.

It's way to suspended from a pier or abutment head,

which points to a scale on the bottom

of the integrated container.

Red at regular intervals it determines if

and how much horizontal movement has occurred

through a shifting of the foundation.

Since the Mallory has never been renovated

since its completion.

Close monitoring of the bridge is crucial

as it is one of the most important landmarks of Montenegro.

- My first encounter with the bridge was in middle school.

At that time I would not have thought it possible,

but my life's dream was to work on the bridge Mala Rijeka.

- [Narrator] Until renovation can finally begin,

Maintenance Chief Stratco menza inspects the bridge daily

for corrosion damage.

These include the views from the top

and the functional control of the service carriage.

For today, the check is done.

Everything looks good, despite its considerable age,

the bridge is in perfect condition.

- The bridge is in good shape,

it was designed to have a really strong

and rugged construction.

All of the pillars and the lattice structures

are strong elements that can permanently support the bridge.

- [Narrator] For today, the job is done

and railway traffic on the highest railway bridge in Europe

can continue to run smoothly.

[dramatic music]

The latest evolution in railway bridges inspire engineers

in recent years,

not without reason as trains are getting faster.

Especially in Germany, construction focus,

the ICE route between Nuremberg and Air Airport,

the most spectacular railway construction line

were revolutionized rail traffic in Europe.

The Grumpental Bridge lies in the middle of Germany,

and is one of 37 viaducts over 515 kilometers long.

The project a mega challenge.

The goal, the most modern high speed railway line

in the world,

9,000 workers are laying more than

two 2000 kilometers of track.

The Grumpental viaduct in Turan,

trains traveling at over 300 kilometers an hour

will speed by.

Today is one of the last monitorings before the opening.

This inspection will indicate whether any damage was caused

to the bridge's interior

during the exhaustive construction work,

which also involved extensive blasting.

Engineer Sebastian Sebastian Self and his colleagues

want to take a closer look at the bridge.

The engineer's job to check for any defects in the structure

which could jeopardize startup operations.

- You can go up.

- [Narrator] The men are on a work platform

allowing them to go right under the arch apex.

After all, it was constructed quite some time ago.

- Now, after six or seven years,

we check again if any cracks have formed

or if load shifts have taken place.

Trains going 300 kilometers an hour

are supposed to pass through here.

- [Narrator] Especially the heavy construction vehicles

working on the bridge above cause damage.

- Here for example, we have a small crack 0.1 millimeter,

which is not bad

but I wouldn't notice it from this distance.

Therefore, we must examine it extremely close.

- [Narrator] This means the entire concrete structure

must be carefully examined in 50 centimeter gaps.

From the tower engineer's Fen

checks the sidewall of the huge concrete arch for cracks

and any other changes.

Below the work platform Sebastian checks

for defects and damage.

- We have a few open anchor sleeves.

I would like to have them closed

because we have already discovered small trees

and grasses growing in other large viaducts.

Vegetation growth is definitely unfavorable for a structure.

- [Narrator] The damage is photographed

and ends up in a report,

Self and his team have hardly discovered any damage.

A miracle, especially for the extremely large arch,

the construction of which was a real challenge.

Trek director Martin Schellhardt was there

during the entire construction period.

- The construction of the 270 meter long span arch

was a challenge because the construction company

had chosen a method that was rather unusual

for arch support structures.

- [Narrator] The giant arch is built in sections

with the support of eight, eight pillars

and a so-called form work.

For the construction of the record arch

it must be drained in order to rebuild for the next hop

to be heaved to the next section repeated

over and over again.

This method is used globally for the first time

for a concrete arch.

Once the arch arch is sealed in this way,

the supporting piers must be blasted a critical moment

when the total weight is transferred onto the arch.

[dramatic music]

Engineer Martin precisely recalls the day of the blast.

- A small crowd had formed mostly residents

who live here and they were all quite anxious

whether the pillars would fall in the direction

that they were supposed to.

Of course, it depends on the experience

of the demolition expert to make it fall

into the right direction.

[bomb explodes]

- [Narrator] A big risk with a new arched bridge,

in 1088 bore holes around 70 kilograms

of explosives are distributed throughout the pillar.

In the end, all goes well, but has the blast,

the so-called load redistribution damaged the arch.

- We have no cracks here because of load redistribution,

which happened through the auxiliary supports

that were here,

then we're blown up with a controlled blast.

Now the load redistribution is directly in the arch.

We could expect cracks on the narrow side,

but there's nothing here which shows good quality.

- Pressure to find even the smallest piece of damage

is that much higher because bridges

for the new high tech tracks are extremely

low maintenance.

The next inspection is not for another six years.

- This is a beginning stage,

we recognize this as early as possible

and then determine that these sections should be renovated.

[worker speaks in a foreign language]

When steel rusts, the grid expands

and presses from the inside against the concrete.

Resulting in pieces of it breaking off.

- The rusty area measures one meter 20,

that's more than just a trifle.

The damage must be repaired before it spreads,

but even more importantly is finding answers

to the question

where is the moisture coming from

that led to this corrosion?

- Should, we look here?

There seems to be water inside.

- [Narrator] The record, breaking arch is hollow

and completely walkable.

[upbeat music]

A hatch leads to the interior of the gigantic structure.

Seft believes that water is penetrating it

and some rust spots suggest the same.

[upbeat music]

A workplace that not many people have been to previously

before Seft and it probably will remain that way.

[upbeat music]

Clear the arch is completely dry from the inside.

The rust seems to have formed due to a different reason.

- We are only here every six years,

if a pillar with frost and everything else

that comes with it is taking on water,

then of course that is very damaging.

- [Narrator] For the grump Andile bridge,

everything looks good.

It has passed the inspection with flying colors.

Nothing stands in the way of start of startup operations.

Now it too will join in an entire high speed rail line

revolutionizing rail traffic in Europe.

Not least due to this particularly spectacular bridge.

[upbeat music]