Original subtitles

[dramatic music]

- [Narrator] They represent a unique kind of structure,

moving bridges, technological benchmarks of their time,

statements of their respective epoch.

The most spectacular moving bridges in the world,

monuments and indispensable infrastructure at the same time.

Every day, the sophisticated technology

paves the way for people and vehicles traveling from A to B.

They are however, tremendously maintenance intensive,

hundreds of tons of moving structures continuously.

- Without this, it's just a road.

This is what makes it a bridge.

- [Narrator] Its moving mechanism,

is from a technological standpoint, enormously complex.

Moving bridges must be constantly maintained.

The gigantic structures almost always boldly unique.

- There should be no construction

on either keyside, nothing at all.

- [Narrator] The construction is already a huge challenge.

- I was very skeptical as an engineer.

- [Narrator] A multi-million dollar game

that often drives engineers

and designers alike to the brink of bankruptcy and despair.

- It was extremely ambitious and at the time,

I guess expensive plan also.

- [Narrator] The gigantic structures cross borders,

let people doubt and wonder, the whole project,

a constant balancing act.

But when they are done and new paths open

for so many people, suddenly only magic and pride remain.

- So yeah, it's fantastic.

- [Narrator] Flexible giants,

the secrets behind the sophisticated technology,

the spectacular structure and the daily challenges

faced during maintenance.

Huge constructions,

the most spectacular moving bridges in the world.

[dramatic music]

[bright music]

Majestic,

gigantic,

[horn blows]

unique.

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 beginnings of moving bridges date back

to the Middle Ages.

Castle drawbridges and city gates protect against enemies.

The first real moving bridges are used in the lockup of

intersecting shipping lanes and in pool facilities.

Unique, they can be moved as a whole or in parts.

There are many types of moving bridges.

One of the most common, bascule bridges,

functional but mechanically demanding.

Late 20th century,

the bridges are more sophisticated and creative.

Milestones are the tipping bridge in Gateshead

and the vertical lift bridge in Bordeaux.

[dramatic music]

The Kaiser Wilhelm Bridge,

Europe's oldest and larger swing bridge.

The bridge was built in 1907 as part of the port expansion.

[dramatic music]

The Kaiser Wilhelm Bridge is located in Wilhelm's Harbor

in northern Germany.

It survives two world wars,

in spite of being the only connection

to Germany's largest naval port.

Some feat.

Since 1907, the same original drive principle,

nearly 440 tons of steel moves the mechanism opening a path

for passing vessels regardless of weather.

A great feat of engineering.

The engine for Europe's oldest swing bridge

sits under the bridge piers.

Rudiger Maher is maintenance chief

of the Kaiser Wilhelm Bridge.

He has been there for over 35 years.

The slewing gear,

the mechanism that moves the respective bridge wings,

must be serviced daily.

- [Voiceover] 109 years, they want to be oiled.

- [Narrator] Initially the bridge warden opens the bridge

with pure muscle power.

Since 1909, an electric motor drives the slewing gear.

- [Voiceover] Yes, it is really impressive

what was achieved back then when one considers

that the whole arch and pylons were still riveted here

on the landside or partly on site with steam rivets.

It is unimaginable what they were able to accomplish.

- [Narrator] Another important service is pending.

- [Voiceover] I'm going to uncouple this a half meter away.

Okay?

- Okay.

- [Narrator] The seam at the center back

has to be checked via the main console.

Colleague Cobbs can control the two wings.

To access the seams, he has to open the bridge slightly.

440 tons of steel are put into motion,

powered by two rotary units that sit under the 20 meter high

pillars in the middle of the two wings.

It's an ancient mechanism.

The Kaiser Wilhelm Bridge has a span of 159 meters

and a width of eight meters.

It weighs 440 tons.

The two supports are just over 20 meters high.

When the bridge moves, the bridge wings are set,

from traffic mode to operating position.

Relieving the pressure on the support bearings while forces

are diverted onto the so-called king and the wheels

during the turning process.

Rudiger Maher checks the bridge seams.

When it opens its wings,

four pins should slide apart here to ensure that it works,

even during strong North Sea winds.

And while pressure is applied on the heavy bridge wings,

they must be well greased.

- [Voiceover] You have to be free from giddiness,

and you should also be able to swim.

[Rudiger speaking in foreign language]

Retract that bridge again.

- [Voiceover] All right, careful.

- [Narrator] The bridge slowly closes again.

The pins engage, a steel giant that moves inch perfect

for over a hundred years now.

- [Voiceover] When I first pressed the button,

I was thinking, "What kind of monstrosity is this?"

- [Narrator] This monstrosity works with old,

but no less reliable mechanics.

The bridge wing is driven by a slewing gear that consists of

several units, four wheels, two wheel carts,

and two support rollers distribute the load

and open the bridge wings.

Wilhelmshaven becomes Germany's main naval base.

And for the bulky battleships, a swing bridge is imperative.

Engineer Oliver Leinette supervises the most recent bridge

renovation and is familiar with its history.

- [Voiceover] The steel and other construction materials

came by ship and were then assembled here

on a centering a wooden structure

and riveted like a plugin system.

While the bridge was being assembled,

the port was also under construction.

There wasn't water yet.

So in essence, the bridge was built on dry land.

- [Narrator] The contract to build the largest

swing bridge in Europe is awarded to MAN

from Gustavsburg near Mainz,

a company experienced in steel bridge construction.

In just two years,

the rivet steel construction is completed.

The steel elements are kept filigreed

due to the strong north winds.

The structure can resist strong winds while ensuring

structural integrity.

Over the years, however,

not only the rough climate poses a threat to the bridge.

- [Voiceover] Ultimately, luck played a role in the fact

the bridge survived two world wars.

These two devastating events did not leave

the structure unscathed though.

- [Narrator] The bridge survives around a hundred

air raids on Wilhelmshaven.

After 1945, the English occupiers want to dismantle

the bridge, remove and transport the coveted steel

back to England.

But the people of Wilhemshaven keep their landmark,

repair the damage and even today, more than a century later,

the bridge is as important as ever for maritime traffic.

[people speaking in foreign language]

- [Voiceover] Kaiser Wilhelm Bridge. Good morning.

- [Voiceover] Good morning. [speaker speaking in foreign language]

- [Voiceover] would like to pass through to...

[speaker speaking in foreign language]

- [Voiceover] Understood. I will open both wings.

- [Voiceover] Okay, thanks.

- [Narrator] Despite being more than 100 years old,

the Kaiser Wilhelm Bridge is a thoroughly living monument.

Several times a day, the wings open,

whenever a ship higher than eight meters

wants to pass through.

- [Voiceover] Attention, the bridge is opening.

Please leave the area.

- [Narrator] A marine tugboat waiting to enter the harbor.

At each opening, the bridge is closed to traffic,

which is why speed is essential.

Despite the bridge's fully automated capacities,

Rudiger Maher keeps a close eye on everything.

- [Voiceover] The controller can fail sometimes.

And now I have to make sure the wings go into creep gear.

- [Narrator] A tricky moment.

The rotation motion has to slow right down before the fully

open position and then halt.

The wings come to a stop at a 90 degree position.

Plenty of room for safe passage of the marine tugboat.

An accurate assessment of the morning's maintenance is only

possible during the closed phase.

Was it successful?

Around 2010,

Wilhelmshaven had its landmark renovated extensively

for more than 7 million euros.

Since then,

it must be able to operate in up to wind force eight gusts.

- [Voiceover] The bridge is pretty amazing.

It makes its own music down there in the wind formations,

the wind whistles through.

You can hear all the pitches down there.

Fascinating.

- [Narrator] After 10 minutes,

the marine tug is through and residents of Wilhelmshaven

have their Kaiser Wilhelm Bridge again, a steel landmark,

an iconic moving bridge.

[dramatic music]

A similar icon that has risen to landmark status

in a cosmopolitan city is in the US.

Chicago, the city of bascule bridges,

38 of them span the Chicago River,

but for Chicago residents,

there is only one queen among them,

- Michigan Avenue Bridge.

- Michigan Ave Bridge.

- I love the history about it.

- Right on Michigan, most iconic street in Chicago.

- [Narrator] The Michigan Avenue Bridge.

Embodiment of a metropolis.

The bridge breathed life into the city back in the twenties.

And is the Chicago we know and love today.

- Flag south over one. We're gonna go up three.

- [Narrator] Thanks to the folding mechanism,

the Chicago River is navigable at all times,

even for large sailboats,

because the legend is alive and well.

The iconic bridge is protected as an historic monument

since 1991.

[dramatic music]

Michigan Avenue Bridge connects the most important

areas of Chicago.

Today chief engineer, Dan Burke,

remembers how skeptical everyone was about the project.

- It was an extremely ambitious and at the time,

I guess expensive plan also.

So there was a lot of discussion and I think,

a lot of back and forth.

It's my understanding, the first bond approval didn't go through.

It took two tries,

but eventually they did get buy-in from everyone on it.

And I think people really recognized what an important asset

it was to the city.

This is our front door.

- [Narrator] The bridge is a double leaf construction,

functioning as two parallel bridges operating independently

of one another,

able to accommodate large ships.

In 2009, the bridge is elaborately restored.

Today almost 50,000 vehicles cross the historic

structure every day.

- The great thing was the people who designed it.

There was a lot of forethought into it.

It's a really heavy structure.

It's been able to accommodate today's loads and I think it

could take a lot more.

- [Narrator] An indestructible moving bridge,

becoming indispensable for thriving Chicago

shortly after its opening.

If Michigan Avenue breaks down,

chaos looms throughout the city.

The real challenge is the century old interior.

All gears and engine parts are custom made,

genuinely unique.

If a part isn't working,

it is expensive to replace or renew and the bridge remains

closed to maritime traffic.

During regular operation,

it opens every Wednesday and Saturday for passing sailboats

and cargo ships.

[dramatic music]

A two-man team ensures a smooth operation.

James Hoffman and Edwin Rodriguez.

- Got it.

- [Narrator] The two regularly check if the bridge motors

are ready and on standby.

- We're gonna have to maintain the bridges, grease 'em up,

make sure everything has proper grease, everything's moving.

And that's pretty much what we're doing today.

- [Narrator] As soon as the start button is pressed,

the motor drives these gears.

First, the smallest, then all the larger ones.

A kind of chain reaction.

At no point should anything scrape.

Abundant amounts of grease are essential.

- So yeah, this is very key for the operation of the lift

of the bridge.

Without this, it's just a road.

It becomes a road.

This is what makes it a bridge.

- [Narrator] The bridge's worst enemies,

moisture, rust, and heat.

After 100 years, wear and tear is commonplace.

The workers have to pay attention and be meticulous.

The Chicago River is the main artery

between the large bodies of water,

of the Great Lakes and the Mississippi River

for ships and boats.

The city of Chicago is very flat.

All the highways that pass over the river as bridges

are simply too low for most ships.

A major problem for the busy waterway.

The solution, bascule bridges like the Michigan Avenue.

In 1920, chief engineer William A. McKay,

creates the first double-decker bascule bridge

with two road decks.

A motor brings the gears into motion.

A counterweight provides a lever mechanism

that flips open the bridge.

[dramatic music]

And it's that time again today.

The bridge is opening shortly.

The first ships are waiting.

Kevin Sechison is the man who presses the key buttons.

In the observation tower,

he is always on high alert, full concentration.

After all, he decides who can drive or has to wait.

Not always a popular decision.

- We're over one to one. I'm in position when everyone's...

People jumping over gates.

I've almost seen fights down here because of people waiting.

- [Narrator] Let's see if it stays peaceful.

[bell dings]

- Bridge is going up, bridge is going up.

Clear the gate.

Get behind the gate.

- [Narrator] While the bridge is open,

regular traffic on Michigan Avenue is at a standstill

for about 15 minutes.

[dramatic music]

- All right, rear lock's out. Over one.

We're gonna go up, break.

[dramatic music]

[gears creaking]

[bridge groaning]

- [Narrator] Unless there are large boats

waiting to pass through,

Kevin usually opens only one leaf.

Initiating a celebration as well.

- We got Michigan Avenue in the air.

Michigan's in the air.

Bridge is all locked out waiting for

the sailboat to come through.

- [Narrator] Depending on the season,

several hundred sailboats traverse

the main waterway.

Afterwards, Kevin does his best to get traffic moving

smoothly again.

[bright music]

Everything must be perfectly coordinated.

Everyone makes sure that his part of the operation works.

It is precisely this responsibility for the greater good,

which is the main reason the workers are fascinated and

proud of their jobs.

[bright music]

- I was born and raised here, so to be part of it,

just gives you more sense of pride

of where you're from.

And you cut yourself, you're like,

"Oh, I bleed for the city."

- [Narrator] The era of functionality endures.

But with a new millennium,

a whole new evolution has been ignited for moving bridges.

Spectacular and elegant.

Huge, yet delicate, is the credo now.

Gateshead Millennium Bridge is connecting

two cities in the UK in a way never seen before.

It is the only tilt bridge in the world which can rotate

around its huge horizontal axis.

Highly effective hydraulic cylinders push the construction

from its rest position.

Opening passage for sea vessels.

[dramatic music]

[dramatic music]

The bridge in northeast England connects

Gateshead and Newcastle.

Tony Hawkswell is bridge master

at Gateshead Millennium Bridge.

In a few hours the bridge will open.

That sounds like a lot of time,

but maintenance is still in full swing.

- [Tony] Hello, guys.

- [Speaker] Hi. - [Luca] Hello.

- Luca, how we getting on with the valves?

- All right.

- All the fishing gone well? - Aye, yeah, very well.

Very well. - Nice.

How many valves have you got to go in?

- Three more. - [Tony] Three more?

- [Luca] Yeah. - [Tony] Okay.

- [Narrator] Maintenance engineer, Luca Dirossa,

has to change oil, clean valves, and reseal everything.

For this overhaul service he is currently performing,

Luca needs several days.

- Yeah, it's a big maintenance.

Not every year, is every five years, six years.

Depends. Depends the pollution.

- [Narrator] The men have reached the last valve.

Tony is impatient.

He wants to know if the hydraulic seal is watertight before

the next opening.

A test run will determine whether the system is ready.

[gentle music]

[machinery whirring]

During the test, Luca relies on his hearing.

Tony, on his hands.

- All I'm doing is,

I'm just checking for the oil flow through the back

of this file through this fan,

just to see everything's through and all right.

And you can feel it from the vibration.

See? So everything's okay.

- [Narrator] The Gateshead Millennium Bridge

isn't the first bridge

that can be opened hydraulically,

but it is the first one that has the workings fully hidden.

[dramatic music] [birds squawking]

The foundations consist of 19,000 tons of concrete and are

buried deep in the riverbed.

They are the anchor of the pedestrian area,

the so-called deck and the huge arch,

which is a counterweight to the deck.

The heart of the construction is the huge hydraulic system

making it possible for the bridge to rotate on the

longitudinal axis of its anchor points.

As the bridge opens, the deck and the arch,

keep it in balance.

The London architectural office of WilkinsonEyre.

Here, the courage to start this bridge revolution

can be found.

Perhaps it is because it is the very first ever bridge

designed for architect Jim Eyre.

- There should be no construction on either keyside,

nothing at all.

So all the bridge construction had to be

contained within that gap.

I remember thinking, just thinking, "Well, a curve, a curve,

curve deck would go out just enough if you opened it up

to provide the clearance in the middle."

- [Narrator] Normally pedestrians cross the deck

at five meters above the river.

- [Tony] Well that's terrible, isn't it?

- [Narrator] But Luca and Tony want to lift the bridge

to 25 meters.

But until then, there is still a lot to do.

- It's not the best job in the world,

but it needs to be done.

So off we go.

- [Narrator] The two need to lubricate

the large hydraulic cylinder

on the other side of the bridge.

- All right, can pump.

- [Narrator] The pump isn't ready yet.

- Oh, I lost the pressure in here.

Sometimes when the pill's getting lower and lower,

you lose a bit of pressure.

So you've got to force it down manual.

- [Narrator] When it comes to his bridge,

no task is too menial for Tony.

[dramatic music]

- Well, we do these bearings once a year

and give them a good coating just before the summer season

starts because the bridge is going up and down

three or four times a day.

So we like to get it greased in,

keep everything ship shape.

- [Narrator] Tony has been working for over 12 years

at Gateshead Millennium Bridge.

When the completely prefabricated bridge is delivered in

November, 2000,

the city witnesses a logistical master stroke,

Europe's largest floating crane,

the Asian Hercules successfully masters the mammoth task.

- It was an incredibly exciting time

when the bridge was going to be brought into position

because they needed a window in the weather.

They had to have the wind not too strong,

because they couldn't have it moving around.

We followed it.

We drove and kept going back to the river all the way up

to catch views of this bridge going up the river.

It was a surreal sight as you can imagine.

- [Narrator] The men on the crane have little water

under the keel.

They have to work against low tide and bring the 126 meter

long and 45 meter high arch centimeter by centimeter

into position.

- And so many people came to see.

There were thousands,

there may have been 30,000 people who came that day,

to see the bridge brought into position.

And then again, when it actually opened,

it was an extraordinary day, actually.

- [Narrator] Time for the next opening of the bridge.

So Tony closes the entries.

The excursion boat for tuna is traveling up river.

[bright music]

- Fortuna, Millennium Bridge.

- [Operator] Millennium Bridge, Fortuna.

- Give you a shout when we ready to go,

but we should be on time over.

- [Operator] Yeah, that's fine sir.

We'll just single up and steam in the middle.

- Thank you very much, sir.

- [Narrator] Time for everyone to get off the bridge.

- Good morning ladies and gentlemen,

and a very, very warm welcome

to the Gateshead Millennium Bridge.

The bridge will be tilting shortly.

Anyone wishing to cross the bridge,

do so now, please.

This is your last call for the bridge, ladies and gentlemen,

your very last call.

Clear the bridge now please. Clear the bridge.

Thank you.

- [Narrator] Over 800 tons of steel ready to move.

Luca and Tony are nervous.

The system is watertight,

but will it sink?

On both sides of the bridge,

three hydraulic cylinders push the structure

to a horizontal position.

Tony doesn't have the time to observe the imminent passage

of the Fortuna.

He is checking the parameters on his screen.

- Everything's running smoothly as it should be

at the moment.

We measure in the extension of the rams.

- We need to have the same extension on both side.

So it's why we are looking at all the pressure

and all the flow.

- [Narrator] With a difference of only 11 millimeters,

the bridge for safety reasons automatically stops.

Traffic would be blocked for quite some time,

if and when that happens.

[dramatic music]

It takes four and a half minutes to reach the full tilt.

The bridge is open with a deck at a 45 degree angle.

The Fortuna may pass.

[dramatic music]

Tony is still tense.

The bridge has to close again.

- There's nothing obstructing the rams at the moment because

we've done this maintenance.

I'm just basically just having a double check.

- [Narrator] The bridge can resume its normal position.

Tony gives the all clear for pedestrian traffic.

- Thank you very much ladies and gentlemen.

Open gates please.

- [Narrator] Now he can finally relax.

- Everything was brilliant.

I'm really over the moon with that.

'Cause sometimes you can get one or two little

blips here and there but that was spot on.

Spot on. I'm pleased.

- [Narrator] A long day draws to a close

at the Gateshead Millennium Bridge.

One last patrol,

then Tony Hawkswell calls it a day,

leaving behind one of the world's most spectacular bridges.

The Gateshead Millennium Bridge

is not the only unusual bridge.

A very unique specimen is located in France as well.

The Jacques Chaban-Delmas Bridge in Bordeaux.

It is the largest vertical lift bridge in Europe.

A masterpiece of technology and the only one of its kind.

It was designed by Michelle Vil Luger and the architectural

firm of Thomas Lavinian.

[dramatic music]

Jacques Chaban-Delmas is located in Bordeaux,

southwest of France.

The Pont Jacques spans the Garonne River in Bordeaux.

The bridge is designed especially for road transport,

but also has staggered bicycle and pedestrian paths.

[dramatic music]

The wide central opening allows large ships to pass.

Most fit under the roadway,

but some need a little more headroom.

For these ships,

the middle bridge section turns into a lift.

Each of the four towers has a cable construction,

which pulls the 2,750 ton centerpiece up.

The next vertical lift is pending in a few hours.

Sebastian Dufonne,

responsible for the lift and bridges technology.

[dramatic music]

Motors, gear boxes, machines.

The whole lifting technology lies here

deep down in the pillars.

That seems obvious, but it is not.

- [Voiceover] That is the difference

to the classic lift bridges.

The Pont Jacques Chaban-Delmas is a prototype.

It is the only one in this category where the motors are

installed below, not up on the pillars.

So pulling the load.

- [Narrator] For the construction,

designers use a common principle.

The 2,750 ton lift has four massive counterweights inside

the pylons with a total of 2,400 tons of counterweight

that move downward

as the main bridge section rises.

Massive pulleys distribute the load

on 11 steel cables per pillar.

The cables are under enormous tension.

- [Voiceover] Every three months,

industrial climbers check and grease the steel cables.

With a safety harness,

they descend and carefully inspect the cables

meter by meter.

This provides operational security both in the drive train

here as well as for the tension wires in the back.

- [Narrator] Each tower functions

like a gigantic elevator shaft.

The counterweights do the bulk of the work necessary

to raise the bridge,

the so-called hub.

Two support engines,

with 180 horsepower each, do the rest,

but the entire maneuver is not a surefire success.

- [Voiceover] We have to leave the bridge now.

We have a ship passing through this evening.

We need to prepare so that everything goes well

without a hitch.

- [Narrator] The whole effort happens mainly

for cruise ships like the Silver Explorer.

To enable ships to anchor near the city center of Bordeaux,

a movable bridge is necessary.

And even if the bridge is almost something of a landmark

of Bordeaux today, construction manager,

Michel Duchenne remembers the criticism

during the planning phase.

- [Voiceover] For opponents of the bridge,

the height was a problem.

Bordeaux is a very flat city,

but the bridge had to be built high up.

Finding a consensus was not easy.

- [Narrator] But the practical effect of the bridge is huge.

Bordeaux is growing from year to year.

More and more new neighborhoods are developing and the

bridge connects them and relieves inner city roads.

Pont Jacques is completed in 2013

after a construction time of three years.

Construction costs for the ambitious project,

over 150 million euros.

Most noteworthy moment,

delivery of a 117 meter long hydraulic lift.

President Francois Hollande comes to the inaugural ceremony.

- [Voiceover] The Jacques Chaban-Delmas Bridge

connects the districts,

but it does so in an agreeable manner.

We wanted a lively bridge you can stroll across

as well as being used by cars,

pedestrians and cyclists alike.

It's a symbol of the new city.

- [Narrator] In a few minutes,

Bordeaux citizens will have to let the bridge do its work.

A vertical lift is pending.

Sebastian Dufonne hurries to the control tower built,

especially for the upcoming task.

- [Speaker] Caution. The bridge is about to operate.

Please clear up the pedestrian sidewalk immediately.

- [Narrator] Cars aren't allowed to pass anymore and

pedestrians have to leave the bridge.

There's a time crunch.

The ship is ready to cast off.

- [Speaker] Caution. The bridge is about to operate.

Please clear off the pedestrian sidewalk immediately.

- [Narrator] The pressure is on in the control tower.

- [Voiceover] Hello, harbor. Can you help us?

- [Voiceover] Yes, okay.

- [Voiceover] We wanna start.

- [Voiceover] Yes, okay.

The path is clear. A small boat was blocking it before.

- [Voiceover] When all the pedestrians have crossed,

we will lift the bridge.

Have a safe trip.

- [Voiceover] Good. Okay.

- [Narrator] But suddenly there is a problem.

There are still people on the bridge and the cruise ship

is already underway.

[horn blows] [dramatic music]

The lift is delayed and the engineers in the control deck

are nervous.

The engineers are waiting to trigger the lift mechanism with

a foot peddle,

but there are still pedestrians on the bridge.

- [Speaker] Caution, the bridge is about to operate.

Please clear off the pedestrian sidewalk immediately.

[speaker speaking in foreign language]

- [Narrator] Finally, bridge clear. It's a go.

[siren sounds]

The lift begins moving with a click,

15 seconds after ignition.

2,500 tons of steel rising.

[dramatic music]

- [Voiceover] All parameters are in place.

That's imperative.

- [Voiceover] The bridge is up. The ship can pass.

- [Narrator] Each vertical bridge lift

is an event in Bordeaux,

an average of only 30 larger ships per year pass by.

[dramatic music] [horn blows]

All goes smoothly.

The Silver Explorer passes through safely

with significant reserves on top.

Even taller ships can anchor here in Bordeaux.

- [Voiceover] There is no routine here.

If it becomes routine, then we've lost control.

The most important thing for us here

is to stick to the schedule.

We always focus on the time and that's

our guiding principle.

- [Narrator] The ship was early so the crew

can lower the bridge sooner than expected.

The maneuver takes 11 minutes.

Now Sebastian and his crew can call it a day.

Relax until the next time.

The people of Bordeaux have their spectacular

bridge back again.

The UK has one place where pedestrians never have

to relinquish their bridge because the Scale Lane Bridge

is the only moving bridge in the world that is never closed.

The bridge looks like a stealth bomber

and is exceptional in many ways.

[dramatic music]

Scale Lane Bridge is located

in the city of Kingston upon Hull in northern England.

It is the only swing bridge in the world

that is always open to traffic,

regardless of whether it is turning or not.

The bridge crosses the River Hull of the eponymous city,

and encourages passers by to come along for the ride

before it starts its journey.

It works like this.

A glockenspiel announces the next maneuver.

Passersby cross the bridge as it rotates.

Coming from the city,

you can climb aboard at any time.

The 350 ton boom can take up to 1,000 people

during a rotation.

A ride takes 100 seconds.

The barrier opens and then the bridge is in place again.

Ships can sail the river only during high tide.

Right now it's low tide.

The best time for Scale Lane Bridge

to undergo maintenance.

Six hours from now,

it has to be ready for a tanker to pass by.

Bridge technician Neil Wales and apprentice, Henry,

want to use the time until the next maneuver.

- Let's go check the rolling wheels. Grease them.

Check the hydraulic fluid.

- [Narrator] They climb down to the bridge's foundation

where the turn mechanism is located.

[dramatic music]

- [Neil] You got some rags on the screen there?

- [Narrator] The roll wheels and runway are not sealed,

so are prone to dust and dirt.

- Can you check the trap for any debris?

I've just noticed there's some there,

an old rusty screw.

- [Henry] Yeah.

- Okay and if you can give the track a bit of a clean here,

there's quite a bit of grit that's come onto it.

- [Narrator] Grease in conjunction with sand and dirt,

is toxic for sensitive, rolling mechanisms.

The men have to step up more often than expected

to service the bridge.

And there are always surprises.

- I must admit it's the first time

I've noticed some bird's nests down here.

They start coming down here, we've got problems.

We'll have to keep an eye on it.

Make sure it's all removed.

- [Narrator] Keeping everything clean and greased

is not all that needs to be done.

The 350 ton jib and counterweight loads directly onto the

rolling wheels and the runway.

It seems to be too heavy of a load for the screws

that secure the runway.

- [Neil] Can you get in there to check that one for me please?

Last thing we want is the track working loose.

- [Narrator] This inspection demonstrates

that Neil and Henry need to check more often in the future

so that the bridge functions smoothly.

- Usually it's every six months.

And what happens when it all dries out,

you get a noise through the bridge

and there's no smooth movement.

What we need is a smooth movement of the bridge.

- [Narrator] Scale Lane Bridge also serves

as a tourist attraction.

Not too many of those in Hull.

The construction of the bridge is delayed repeatedly.

First plans are in 2008,

but it takes until 2013 until the bridge is completed.

Not only is the design unique,

the Scale Lane Bridge has exclusive features

such as a lighting concept,

and especially composed sound system.

[instruments sound]

During the planning period,

the bridge has a lot of opponents

because of the many features.

Bridge engineer, Peter Curry.

- I was very skeptical as an engineer,

because of the art side of it with the lights,

the sounds and everything, it made it very complex.

But when it was completed,

I was on site as a resident engineer for a lot of years

while they were building it.

And when it was complete,

I thought it was fantastic and people enjoy coming here

and for a ride on the bridge.

So yeah, it is fantastic.

- [Narrator] The recreational aspect is good,

but the waterway is paramount and the water rises.

Neil and Henry still have to check the hydraulic system

at the front of the boom.

If it doesn't work, the bridge can't push off.

- This is the hydraulic pack that operates

the lifting rams at the far end of the bridge.

- [Narrator] Narrow, a lot of steel and pipes.

Here in the boom,

the bridge almost feels like a submarine.

- What we also do is a visual inspection on the pipe

where connections make sure there's nothing leaking

and they're all clean, okay.

- [Narrator] Not good if you have claustrophobia down here.

- Weight tapers down to the end of the bridge.

it's a smaller area to work in and you get used to it.

- [Narrator] The inner life of the bridge,

almost as complex as its moving mechanisms.

Three pressure cylinders lower the end

of the cantilever platform.

This lifts the other end of the bridge and allows it

to float freely.

Three electric motors pivot the bridge arm at a rate

of about half a meter per second.

In 100 seconds,

the bridge is fully open.

After three years in operation,

The first signs of wear and tear.

But that is normal with moving bridges.

- The lifespan of this bridge,

it should be about 150 years.

During that period, we will have to do maintenance.

The bearing that it runs on will have to be replaced.

That has a 50 year life.

So there is ongoing maintenance of the hydraulics

and stuff like that will change.

The computer may change,

but the structure itself has got a lifespan of 150 years.

It'll certainly be around after I've retired.

So, yeah.

- [Narrator] In the meantime,

the water has risen high enough.

The tanker is waiting for passage.

Bridge operator, Dean Sizens,

prepares the opening of the bridge.

He gives the command via these remote controls

from the outside.

[dramatic music]

- [Dean] All right, it's about five minutes now.

- [Narrator] One thing that's important

prior to every opening,

that there is no blockage in the area

in front of the entrance.

Tanker and pedestrians waiting for it all to start.

The spine of the bridge arch rotates

by means of an electrical drive mechanism.

It's central tenon, annular rail, bogeys,

and the hydraulic pipes in its cantilevered section

are all below deck level.

[dramatic music]

Neil Wales monitors the function of the freshly lubricated

rolling wheels inside the foundation.

The smacking sound means all is well.

[instruments sound]

Just a few more seconds and the tanker can pass through.

[dramatic music]

The spectacle is over three minutes later.

The bridge and its passengers can return

to the starting position,

which is what makes the Scale Lane Bridge so unique

for pedestrians and passengers.

- [Worker] There you go.

- [Narrator] Even when Scale Lane Bridge is resting,

it always looks ready to go.

A gigantic structure,

one of the most spectacular moving bridges in the world.