Original subtitles

who have been inspired by the Thames.

in different directions. And that's what I'm working through right now.

So I can again turn these layers, you know, off and on.

The light is moving from outwards, in, across the piers.

It's sort of expressing the depth of the structure as well,

cos it really comes into vision, doesn't it?

You really get beautiful colours, actually.

Well, this bridge is... You know, it's so striking.

This kind of teal colour that it's painted is very specific.

And I just love this bridge. I mean, it's just so beautiful.

Every rivet, you know, I think is gorgeous.

So picking up the light and the way... When it rakes across,

you see each little detail in a way that you didn't really see before.

It's not just visual artists like Leo

So, in some cases, you know, we're moving light across, you know,

BOAT HORN HONKS

Over the years, composers too have fallen for London's great river,

and perhaps none more than George Frideric Handel,

with his 1717 masterpiece, Water Music.

MUSIC: Water Music

Commissioned by King George, it was not only inspired by the Thames,

but was actually first performed on the Thames.

In an outrageous display of showmanship,

a 50-strong orchestra was floated down the river,

with Handel himself conducting,

as the delighted king and his flotilla floated behind.

In the spirit of Handel, but with a modern twist,

and climbing gear... Yeah. ..changing the lights.

on first impressions it seems some of them aren't working.

With limited time left and the summer nights getting shorter,

I'm sure this is not the start Leo was after.

Well, we have the lights installed in the right locations.

So, right now, we have crews over there, pointing the lights,

which is also really important. Yeah.

So I can see there's a couple of lights not working,

and there's one that's slightly flashing.

Is that just all part of the teething kind of...?

You know, we're debugging now.

We can't put a curtain over it and do our work and then unveil it.

You know? Yeah, I can see there's people over there with flashlights

the Illuminated River Foundation has commissioned music to accompany

Just have to embrace that part of it.

Still, even with it in its partially-installed state,

I still can learn...

...things about what eventually will work.

I like Leo's optimism.

With just weeks to go, and short nights,

he's going to need to work hard to get the bridges ready.

Leo is using a state-of-the-art bespoke piece of software,

specially written for the project.

It gives him the ability to control each light node

to the desired hue, colour and brightness.

We still can control each one and create different relationships.

OK, so in this section there is this constant sound of metal being hit.

So this section, the violins are kind of playing this chugging part,

which I kind of wanted to imitate the sound

of an old steam train kind of chugging along.

TRAIN CHUGS AND HISSES

So I've come down a couple of nights this week to kind of see

the motions of the river and to watch the tide. And I've never...

never really realised how big it is.

And I'm hoping to replicate this in the brass.

BRASS SWELLS

They're playing these big crescendo chords, kind of...

...becoming more intensified.

This is to represent the sort of ebb and flow of the Thames underneath.

VIOLI NS PLAY RHYTHMICALLY

BELL CHIMES

And that was to represent the site of a medieval steel yard

where the bridge was built upon.

BELL CHIMES

We're now getting to what I think is the climax of the piece,

where we introduce this "ticking" sound...

ORCHESTRA PLAYS SHORT, RHYTHMIC LOOPS

...to represent the modern working day,

the importance of time for the workers that use this bridge

every day in the morning and the evening.

The collaboration of all these creative minds

is one of the things that really excites me about this project.

I found out that the name of Cannon Street

the river's new multimillion-pound lighting installation.

Students from the Guildhall School have been invited

to compose a piece for each of the four bridges

and, if chosen, will feature in a special app allowing users

to hear the composition when close to the bridge.

ORCHESTRA TUNES UP

Today, the school's orchestra are tuning up.

They're about to record a track by 22-year-old Sam Dingley.

He's taken inspiration from Cannon Street Bridge

and the adjoining railway station,

where he's recorded live sounds to enrich the piece.

When I first did my research into Cannon Street,

But, despite the effort of the team to get all the lights ready,

was taken from Candlewick Street,

which is a street nearby, where the candle makers used to work.

I decided to take this as inspiration

as the introduction of my piece.

So let's take a listen to that.

MATCH STRIKES AND FLARES

STRINGS BUILD STEADILY

So this is kind of representing

the start of the bridge's history being made.

SYNTH LOOP BEGINS We then kind of bring in this...

these electronics, this synth sound.

Which then kind of brings in the string section.

to so many artists over the years.

The task ahead of him is to programme the 69,000 LEDs

on four London bridges to realise his artistic vision.

And, in four weeks' time,

his masterpiece will be revealed to London.

Leo is the latest in a long line of artists

who have drawn inspiration from the Thames.

From Whistler...

...and Turner..

...to Canaletto and, of course,

the beautiful impressionistic work of Claude Monet.

I'm taking this opportunity to learn more

about why London's great river has been such a consistent inspiration

Leo Villareal will be arriving in London.

Beautiful building, isn't it?

VOICEOVER: And, to do this, I'm meeting up with one of Britain's

most prolific contemporary artists, Stephen Wiltshire.

OK, Stephen. I think this is asked.

VOICEOVER: We've come to the sixth floor of the Savoy Hotel,

where Monet once painted his most famous Thames scenes.

That's a view, isn't it? Very nice. Incredible.

VOICEOVER: Stephen and I have come to try our hands at capturing

the view that the French Impressionist loved so much.

Which way should we draw, do you think, today?

Starting at the Royal Festival Hall, the London Eye in the middle

towards the Houses of Parliament and Big Ben. OK.

Hello. Are you able to put a different colour on for us?

Three, two, one.

But finishing the installation isn't the end of the work for some.

Before Leo arrives, the next step is to make sure

the lights are angled at the bridges correctly.

ON RADIO: Are we looking OK? It's a bit too high, I think.

That's not bad. I still think you could go a tiny bit lower.

Slightly between where we are and the ones in the middle between us?

Yeah. Doesn't make any sense at all, I know.

THEY LAUGH

With Leo not here yet,

I think I might have a go at lighting a London landmark myself.

I mean, how hard can it be?

Right, there's a chair over there. Shall we get that in place?

What colour would you like?

I would like, er...

Can you do green?

Can you do green?

Whoa!

What do you think?

I think I preferred the sort of pink!

Yeah, me too. I think we should go back to pink.

We're all agreed - I'll leave it to Leo.

There we go. There you go. It's voice-controlled.

This is easy!

In a few clays' time, renowned American light sculptor

Lovely. I think it looks better. CHARLIE LAUGHS

I've got some boats in there.

And when Monet went blind towards the end of his life,

he amazingly, like Stephen is today, painted from memory.

Come and have a look.

I sort of ran out of time.

And I sort of was going all right here...

...and then I sort of... It's got a bit sketchy over there.

It's sketchy. THEY LAUGH

The Houses of Parliament is...

It should be over there. Yeah, should be over there cos... God.

I know, it's very hard to...

Architectural sort of shape rendering. Lovely.

Have you got any boats on yours? Yeah. Yeah?

Yeah, I think you're right. Thank you for the lesson.

Yeah, you're welcome. Shall be have a look at yours?

Oh, my gosh.

So you looked at that view for about two minutes... Yeah, two minutes.

...and then you've drawn that. Yeah.

Beautiful. You've got the cars on the side. Yeah.

The buses on the bridges. Yeah, on the bridges.

God, you've done that so well. Yeah.

Well, that's incredible. Yeah, appreciate it.

That's an amazing skill. Pleasure. Amazing skill.

After years of planning, Leo has finally arrived in the UK

and is already down at Southwark Bridge.

to remember intricate detail,

Right, get yourself comfortable with that.

I'm going to sit over here.

VOICEOVER: At the age of three, Stephen was diagnosed as autistic

and didn't learn to speak until he was nine.

It was soon clear, however, that he was gifted

with an incredible ability to draw.

And now some of his panoramas can sell for in excess of £100,000.

Drawing's always been very important to you, hasn't it, Stephen?

Yeah, very important. What age did you really start to draw?

About five. Five years old, drawing London landmarks.

Big Ben, Houses of Parliament...

Stephen also has an extraordinary ability

But now, in the final countdown to the big launch,

and he's drawing today after only a quick glance at the view behind him.

You're not looking round and cheating, are you, Stephen?

No, of course not. CHARLIE LAUGHS

Despite being born 130 years apart,

there are some wonderful similarities

between Stephen and Monet.

Both had their prodigious talent spotted

before their sixth birthdays.

Both prolific painters of the London skyline -

Monet painted this view from the Savoy more than 100 times.

And, despite having different styles,

both artists are renowned for their incredible eye for detail.

Finally, the new look Thames at night is revealed

miles of cables,

tens of thousands of light nodes,

months of hard graft

and cost millions of pounds to get to this point.

But now, they're just a button push away

from changing London at night forever.

Four...

Three...

Two...

CHEERING AND WHOOPING

LEO: We're good, we're good.

SARAH: They're on! W000!

They're on!

It's taken years of planning, hundreds of people,

and each of the four bridges -

Millennium,

Southwark,

Cannon Street

and London -

are resplendent in their new colours.

While I've seen pictures of it on computer screens,

while I've seen little sections of the bridges lit

at different times during the testing,

to actually be here on the river

and to see four of these bridges lit up right down the Thames,

it's...

Eventually, the bus, and Leo, turns up.

But there's a problem.

We're here now, where are you?

I would be laughing if I weren't crying.

Due to a communication breakdown,

one of the buses seems to have gone on

a London by night sightseeing tour,

and on board is Leo, the light artist.

Who would think that the bus conductors thought

they were doing a scenic tour?

Anyway, never mind.

I so want a drink.

Without Leo, they can't turn the lights on.

It's wonderful. It's really a wonderful thing.

Did you go on the scenic route or did you come direct?

The scenic route! Oh, my God.

With everyone on board,

the boat takes its position downstream of London Bridge,

and the city awaits the big unveiling.

At 10 o'clock on the dot,

the time has finally come.

So, in a moment, we are going to light these bridges

with these buttons here,

and I'm going to ask Sarah Gaventa, Hannah Rothschild

and Leo Villareal to join me in pushing the buttons

that will light up the four bridges ahead of us.

I think there was a concern that by lighting four,

I mean, the lights went on. Do you like it?

Yeah, I love it!

I mean, you know, I'm the wrong person to ask, right?

But everybody else seems to love it. It's wonderful.

I am really, really happy. Really happy.

Slightly relieved?

I'm very relieved. Excellent.

I don't have to go and hide in the toilet, which is really good.

And, you know, now I'm just moving on with the next five, you know?

An amazing sense of dedication and focus on the prize.

I think it's been an incredible achievement. Thank you.

Thank you so much.

I feel really relieved.

and eventually 15 bridges,

with a single lighting scheme,

it might somehow lose the individuality of the bridges

but it's done exactly the opposite.

Somehow, what Leo and the team have done

is bring out the character of each of the bridges.

Almost make you see them in a new light.

I really like it, the people on the boat really liked it,

and now, I think, it's time for the people of London,

the people of this country, to come down here, see the lighting

and fall in love with these bridges all over again.

Subtitles by Red Bee Media

that you would get this incredible layering,

I love what it's doing to Southwark Bridge.

It just makes Southwark Bridge look so three-dimensional.

I think it brings out the real beauty, actually,

of Cannon Street Bridge,

which is, funnily enough, underneath those concrete collars,

a stunning bridge, and this really just sort of emphasises

the flat, linear quality of it.

And it's lovely to see the train moving across,

and the light gently pulsing, and the colours.

You can see the slight change in the colours.

Actually, the colours are rather beautiful.

I hadn't quite appreciated that that would happen -

she's commissioned a fleet of double-decker buses.

and actually the way that the light would sort of interact

bridge to bridge to bridge.

Is that something you were all over from the beginning,

or has this sort of evolved as you've been through it?

We knew that you'd be able to see one to the next

and that they would stack up in an interesting way,

but it is beyond my expectation.

That layering and...

There's also a sense of synchronisation,

so each bridge is sequenced on its own

but then there are these moments when they all align.

Sarah, tell me, how do you feel?

Hi, Eric. How are you? How you doing? Good, thank you.

was a real inspiration for it, wasn't it?

And I've always loved that concept. But it...

When you move the light down it, you really feel it.

It's really dynamic, in a way that it obviously isn't so much

in the day, when you see the whole bridge.

After nearly three years of hard work, planning

and installing the thousands of lights to our bridges,

the creative responsibility now lies on Leo's shoulders.

There is now just one week to perfect the look

of London's great river at night.

It's taken the Illuminated River Project team,

and Leo, years to get to this point.

ls in it Anthony Caro who talked about sort of the bird in flight

In planning and instigating one of the biggest changes

to the bridges since they were constructed...

So it's 15 bridges in Central London. That's really nice.

...they've had to build vital relationships

with international companies...

...while trying to keep all the authorities happy.

Yeah, this is no good, is it?

We're being completely blinded by the lights under London Bridge.

It's not a pleasant experience, actually.

Now I'm under scrutiny here.

And all the time navigating the fragile wildlife issues.

Yeah, she's just down here.

To be able to, like, bring it to life.

I'm heading back to one of London's most famous bridges

to see how Leo is getting on.

Hello, Leo. Hey. How are you? Excellent.

Fancy seeing you here, um... at 10 o'clock on a Monday night.

Well, you know...

You know, after nearly three years of thinking about it

and simulating it and doing all this stuff,

to finally get to sit in front of the bridge, with the actual lights

and to be able to control it, is pretty incredible.

So it's kind of exciting to, you know...

to be able to work with something that, you know...

This stunning bridge, right?

Obviously, we can't work above, below, anywhere near her.

How many hours you think you'll be staring at this before you happy?

As long as I can withstand it, you know?

I'm on a nocturnal schedule

and, you know, I'm just waiting for the sun to go down,

and working as much as I can till it comes up, so...

The lights are now all up and running.

And, as I watch Leo work, there is a surprising animating effect

that the new lights have on the bridge.

I think it's pretty astounding. I really like it.

I think it's beautiful. Really beautiful. This is a good sign!

Yeah, it's a good sign. No, I generally think it's...

I know, cos... Anthony...

Are you excited or nervous?

make our way down to the river,

get on a boat and turn on the lights.

And I'm...

I've been involved in this project for just under two years

and I'm nervous, so I cannot imagine what it's been like

for the team who have been working on it for three, four, five years.

And the thing about a public piece of art

is that you can't hide it if it isn't any good.

It's out there.

After three years of planning for this day,

project director Sarah Gaventa is, not surprisingly,

feeling the pressure.

A couple of hours there and then we're going to

Completely anxious.

I really want it just to be over, to be quite honest.

Have you had a dress rehearsal and how did it go?

Well, we had an undressed rehearsal that didn't go so well.

It's going to be fine. It's going to be fine, Charlie!

Have you seen it on yet?

No. No? No. I've seen sections of it. Yeah?

And they better come on! Yes! They will come on.

For Sarah, work is not quite over.

She needs to get the guests from the reception venue

down to the river

and, to make the one-mile journey,

...and with concerned residents

Just let them go! Let them go! Let them go!

I've discovered some amazing history of our beloved bridges...

It's a model, but it's so evocative.

You can almost sort of smells the life - animals, people...

Wow. Look at this!

How do we move? Push. We push?!

Hey!

...and managed to access some in a way I never knew possible.

Inside London Bridge.

This is going to be attached to that thing.

After a race to get the bridges ready for Leo...

Right by the water. It does get quite close.

Yeah. No pressure!

keeping a close eye on the project...

We're hoping the colour schemes that we saw

maybe won't look as bright as we fear they'll look.

...it's now up to Leo to get it right for the big night.

Coming up next is the launch event.

How it's received by the critics and public alike

will all be revealed at the big switch-on.

This has to work.

On Wednesday evening this week, the moment finally arrived.

It was time for the big switch on.

This is the start of 500 guests

coming for a reception at the Guildhall.

Southwark Bridge will have slowly shifting lights

so I think our plan is to restore that in a way

that is very well engineered and very well designed,

replacing the existing lighting with more energy efficient

and durable LED lighting, but then adding an additional layer

of movement which is what the LED allows.

The Illuminated River Project is an ambitious £45 million scheme

to light 15 of London's most central bridges.

The cutting-edge LED technology will be subtly sequenced to change

in colour and fade in and out to Leo's artistic vision.

In the first phase of the project,

four of London's bridges will be given a new lease of life.

London and Cannon Street bridges are to have lights that reflect

the movement of pedestrians, vehicles and trains.

A lot of it is not functional,

that accentuate the beautiful arched metalwork below.

And the Millennium Bridge will realise the original idea

of becoming a blade of light spanning the Thames.

While the work to get the lights ready for a Leo to programme

presses on, I'm taking a chance to see one of my favourite bridges

like I've never seen it before.

So, I'm very privileged, actually,

because I've been allowed to poke around

and explore inside London Bridge, so currently,

we are inside the downstream arch of the mighty London Bridge,

the one that opened in 1973.

And it has got...

from colliding with whatever or whoever is dangling from the bridge.

he's having to abseil to the problem cable 30 feet above the river.

Are you looking after him?

Sometimes, you just have to get the right man to fix the problem...

...even if you have to drag him there.

But over on Millennium Bridge, work is waiting to begin.

So, this is one of the strangest jobs you have to do

when working on a bridge in Central London.

If you want to dangle over the side of the bridge,

like Steve, Angel and Ian want to do,

you have to hang a bale of straw off the side to the same height

that you're going to work according to bylaw 36.2.

This genuine bylaw is to stop passing riverboats

VOICE ECHOES: "the most fantastic acoustics.

And that makes it OK to hang off the bridge.

Don't say it's not a weird country, because that's quite weird.

The race is now on to get all the work done in readiness

for artist Leo Villareal to start programming the lights.

We are behind in terms of the dates we thought that it would be,

but, you know, which project...?

When you're doing a kitchen, you never get it done on time.

And then Leo arrives in five clays, so this will be his first visit,

the first of the two kind of sequencing visits.

Currently 2,000 miles away in New York with his team of programmers,

Leo's had to do all his work so far on computer-generated models.

A lot of the lighting on the bridges on the Thames is somewhat haphazard.

which is where the railway trains run.

but to my mind, they are far more than just romantic walkways.

For me, the real excitement lies in their design.

Now, if you ask someone to draw a bridge,

they're pretty much always just going to draw an arch

and whilst we all know what an arch bridge is

and it's the kind of thing you've known all your life,

actually there is something quite magical about the way they work,

so I'm going to just use Blackfriars Rail Bridge to try

and explain what I understand about how these wonderful structures work.

So what you've got are a series of large stone piers

set in the river.

And over the top of that, you've got a deck,

Bridges have always held a special place in people's hearts,

But crucially, you've got an arch,

a series of arches spanning over the river.

Now, when you put a load on that bridge,

you've got weight pushing down onto the bridge

and what you need to exert is an equal and opposite force

up through the piers to support that bridge.

Now, the really clever thing that an arch does

is it takes this force and it pushes it sideways.

As the middle of the bridge tries to push down,

it starts to push outwards because it can't go straight down

because of this arch shape and then the curve of the steel

directs that load down into the base of the pier.

Ho-ho-ho! Whoa!

It's quite an extraordinary expefience

as you walk through the arches. You feel a bit like Alice in Wonderland,

as the spaces get smaller and grow as you move through these bulkheads.

And the other thing that I love is that you can see

the imprint of all of the grain

that was used to make the timber formwork back in the day

and some of the nails that were used to build up the timber framework

to fill it with concrete.

The bridge was designed with these voids

which allow for repairs and maintenance.

It's a concrete labyrinth where you're not quite sure

what lies around the next corner.

More used to having his feet firmly on the ground,

That's fantastic.

So I've now come up between the two main structural elements.

The Thames below us.

I mean, it's a really secret,

hidden space that I imagine very few people know about.

The other thing that you really realise

when you get up close to a structure like this is the scale of it.

I mean, everything about it is vast

and it's very easy to lose sight of that

when you see it in the context of the city.

But when you're down here,

you can't help being impressed by its heroic scale.

They are an incredible showcase of the very best of British design

Seal, look. There. Oh, my God.

...protecting the fragile ecosystem will be paramount.

Fish don't like light. Right, so this is really not good.

And with the big switch on happening this week...

Well, we had an undressed rehearsal that didn't go so well.

It's going to be fine, Charlie.

...can the artist behind the project pull off the feat of turning

the Thames into a river of light?

Three, two, one...

CHEERING

I'm Charlie Luxton, and like most people,

I love the bridges that span the mighty Thames.

And with the Thames home to an array of endangered species...

and engineering for the past 150 years.

So when it was announced that they were going to be subject

to one of their biggest makeovers since they were built,

well, unsurprisingly,

the whole concept has been under an enormous amount of public scrutiny.

Last week, the team had a visit from the city planners,

the people with the power to decide if the project can proceed.

At the moment, we're only lighting the deck from this side,

so the level is higher.

And they got their first look at the lights to make sure

they don't dazzle passers-by.

Why do they seem brighter at this end?

of this extraordinary project...

For 2,000 years, it has been the lifeblood of London,

nurturing the city that has grown along its banks.

And today, it is still very much a working river

with tens of millions of journeys over and along it every year.

But it's about to undergo a change like never before.

There is a plan for an audacious engineering project

the likes of which this city has never seen,

which promises to transform London's skyline for good.

The plan - to light the River Thames.

15 iconic bridges with a combined span of 2.5 miles

spread over five miles of river.

In this series, I will follow the ins and outs

I was going to say, this end... Well, because of the angle.

Charlie, tell me when you've got hands on.

...and see exactly what it takes

to get something this ambitious off the ground.

This has to work.

If you were to close the bridge, its £2 million for 20 minutes.

What?! £2 million for 20 minutes.

A project on this scale will be pitted with challenges,

from public scepticism...

...to unforeseen delays.

I don't care if somebody else's project

in another part of the world has to wait a bit.

You know, how will they prioritise us?

But like any construction project on this scale,

Right, just got a small loop now.

Are you still enjoying it? Yeah. Yeah?

Yeah. You look a little tired.

It's the first time I've seen you looking tired.

Yeah, it's been a long week,

but we've got a lot of details sorted out this week,

so, you know, from here on in,

there shouldn't be that many issues that we come across.

There, I said it.

You did, didn't you?

You'd better touch wood!

Well, I look forward to seeing it move forward.

Slowly.

issues are always around the corner.

The lights are almost all fitted and powered,

but the data cables which allow the computers to control the lights

need to be hooked up and working, too.

But they aren't.

One little snag that we're dealing with at the moment is

we're just having a bit of an issue with the data cable

running along the upstream light fittings.

We've got a bit of a break in the data cable somewhere,

so we're just running checks through at the moment.

The only man on site able to fix the fibre-optic cable

is electrical engineer Barry.

the brightness on London Bridge -

Each of the four bridges had one arch lit for inspection.

That's not good, is it?

But the test highlighted a serious issue.

We're being completely blinded by the lights under London Bridge.

It's not a pleasant experience, actually.

And the project needs the city planners' approval to continue.

So, erm...

How have we done?

At the Illuminated River Foundation's office,

project director Sarah Gaventa

has received some feedback from the inspection.

We've just had some kind of e-mailed comments saying that

Now, obviously, at the base of the bridge, you get horizontal thrust,

which none of us were comfortable with, it was far too bright

for any pedestrian walking underneath the bridge -

there were a few little tiny things that we need to tweak,

a few fittings that aren't quite working the way we hoped.

The city planners gave us eight out of ten,

which I'm kind of happy with, but it means that we can carry on

and complete the rest of the bridges.

The news couldn't come at a better time.

The big switch on is in just six weeks.

But before that, there's a race to get the bridges up and running

ready for Leo the lighting artist to take control

and he is due in from America any day.

for certain parts of it to be replaced as well.

that we would be hosting the Olympic rings,

but in addition to that, we got a fantastic lighting system.

But even though there was lots of talk then about the legacy

of the system and it would last for 25 years,

it's not been as robust as we would have liked,

and here we are now a number of years later

and there are regularly parts of the system that fail.

There are always... With the nature of LED lighting,

because they come in strips rather than single lights,

if one goes out, you'll notice 20 gone.

And then to replace those, to do works on that, is quite complicated.

We need road closures for certain elements to be replaced,

sometimes river closures and span closures on the bridge

And then just before the Olympics, we got some fantastic news

So what's to say the new lighting won't fail

and fall into disrepair like the current lights on Tower Bridge?

Well, as part of the strict planning permission,

the project has had to guarantee that they will repair

and maintain all their new lights for at least ten years.

Broken and missing lights should become a thing of the past.

Right. I have made my way right up to the very top

of the North Tower of Tower Bridge.

Very few people get to come up here, which is a shame,

because that is an incredible view.

I'm going to be honest with you for a second,

because I used to be slightly dismissive of Tower Bridge.

but was the biggest bascule bridge in the world.

The entire roof of this space hinges down.

The whole thing hinges down

as the bridge opens.

So that is the underside of the deck of the bridge.

And you can actually hear the rumble of traffic as it runs over the top.

And what's quite amazing is that at high tide,

the level of the Thames would be up well over my head,

yet this is pretty dry.

It's just engineering on a wonderfully grand scale.

Fantastic.

When originally built, it was steam power that lifted the road.

The bridge wasn't the first to do this,

I sort of thought it was a bit of Victorian flimflam.

From visitors to internet streaming cameras,

the world's eyes are on this bridge 24/7.

Manager Chris Earlie knows all too well

the difficulties the project may face

when trying to light one of the world's most famous bridges.

A lot of existing lighting on the bridge itself at the moment,

isn't there? The history of that -

it's a relatively recent installation, isn't it?

The majority of the artistic lighting. Yeah.

Prior to 2012, the bridge was lit with floodlights,

so it was a very basic lighting scheme.

It was to pick out the architectural features of the bridge.

It's quite satisfying, that!

We're not allowed to touch anything, we can't modify anything,

as you would imagine. Just a little bit, may be! Well, no.

No, we've behaved ourselves, despite wanting to on a few occasions.

That's good. Carry on. Absolutely. Better get on with it.

I think you need to come and help us finish off. Yes.

Here comes another tube. Here comes another tube. Right.

The whole of the other side has been done and the whole of this side

has been done - there's literally just these last few units to go in.

I got it, there we go.

It's very satisfying to know

for ever more when I walk up this side,

this little light here, I put in place, I fitted it!

hasn't been a big... Unfortunately, no.

And dangling below, the last junction box has been placed.

Well done, mate. Well done.

Hopefully we won't come back to this one, because it'll work first time.

And the team can celebrate hitting their deadline.

Sort of get yourselves in between these two lamp posts.

Can we have some bums on the wall?

When it's all lit up properly,

it's going to be quite a sense of achievement by everyone.

Probably one of the most iconic jobs I'll ever be involved in.

OK, so everybody looking at me, please.

I've heard there's like 200 million people going to see these lights.

We better make sure it's wired up correctly, then.

The team of 180 men and women are on one final push

But now I've had a chance to really look around,

and I'm blown away by it.

It is the most incredible feat of 19th-century engineering.

But there is no denying the role that this bridge plays

in the global consciousness. Everybody knows it.

And therefore lighting it in a way that is beautiful, respectful,

and crucially, lasts - well, that?

That is a challenge.

It's almost three years

since work to light the Thames started in earnest,

and now the Illuminated River team

are closing in on their first big deadline.

hinge like that, and this is the curve.

to get the last of 8km of cables added

and the final set of the 69,000 light nodes installed,

a task that has taken over 9,000 work clays to complete.

When done, artist Leo can start the four-week job

of programming the lights to get them ready for the big switch-on.

But there is one bridge

that is proving far more tricky than the rest.

We all assumed that millennium Bridge was going to be

probably one of the easiest.

Unfortunately, that hasn't always been the case.

She's thrown a series of challenges at us from day one.

Nothing superfluous on this bridge. So the angle grinder

Leo, Sarah and the team have to hope

London is a glitzy, major city.

I think that's a lot of what people come to London for.

It's a place to work but it's also a place to visit and enjoy

and I think the lights are part of that investment.

What if I told you it was costing over £40 million to do?

Well, that seems ridiculous.

Can't really comment on the relative costs.

The figures are astronomical,

But it's something to look at and something that feels nice

in an exciting city, and it's probably a good idea, yes.

Now with four weeks to go

and publicity for the project gaining momentum,

and you don't really need to illuminate it any more at all.

that when they finally switch the lights on,

the public will not only like what they see but think it's worth it.

If I was to tell you it cost in excess of £40 million?

Quite.

I'd rather have the Garden Bridge.

In just five clays' time, Leo Villareal

will be arriving in the UK to start programming

the 69,000 light nodes

that will transform four of London's greatest bridges.

It will be a seminal moment in this epic project

which, when finished, will give night-time London a brand-new look.

With less than a week to go until the American artist

It's kind of like a clever sort of judo move of bringing the force

but you've got other arches pushing back to balance that.

Now, crucially, and the way that bridges like this

have worked for ever

is that everything is in compression.

The weight is here, it's pushing down into compression

which is pushing down the arch into the base of the pier

which is in compression down onto the base of the river,

into the bed of the river.

Because old materials couldn't take tension -

that is why the arch bridge has worked

for so many thousands of years.

It's all in compression.

touches down, work is flat out to get all the data cables installed

of the weight on the bridge down and across and into the ground.

There's something magic about this simple, efficient form.

The Illuminated River Project know

that if they're going to transform the capital's bridges,

they're going to have to win the hearts and minds

of the general public who use them.

Now, it may be privately funded,

but people still need to feel

that it's worth the £45 million price tag,

money that arguably could be spent elsewhere.

Well, my first thought was

that there's quite enough light in London at night

And who could forget David Beckham's joy

and not just the flourishes and details.

Its very shape, with the walkway and the two towers,

it is something like a giant stage set.

And over the past 100 years,

it has been used as exactly that

by a whole host of daredevils and performers.

From early parachute test jumps...

...motorbike flips...

...to height-defying pop stars...

...and Hollywood movies...

...the stars have been lining up

to perform with the iconic Tower Bridge backdrop.

There's something incredibly theatrical about this bridge,

as he kick-started the London Olympics?

But for me, what goes on inside the bridge is just as exciting.

Wow.

Look at this.

What an incredible...

What an incredible space.

Now, this is one of the bascule chambers

that sit right at the base of the two main towers of Tower Bridge.

Bascule is a funny word. It sort of roughly translates as seesaw,

from the French.

And you can actually understand how the bridge works.

It hinges from that point, and these giant sort of metal planks

were submitted.

and the bridges back to normal.

Last year, over 19 million tourists came to London.

And for many of those visitors,

a trip down the Thames was high on their to-do list.

And what better way to get a look at the most famous bridge of the lot,

and arguably the most iconic symbol of London?

In 1876, the City of London Corporation

held a competition for the design

of a much-needed new river crossing

downstream of London Bridge.

The Victorians didn't do things by halves,

and over 50 ambitious and sometimes outrageous designs

The River Thames is one of the world's great waterways.

But the design that won was this one.

And it has since become one of the most iconic

and recognisable bridges anywhere in the world.

Costing just over a million pounds -

that's roughly £132 million in today's money -

the bridge took eight years to build,

but became an instant London landmark.

The Illuminated River project is intending to leave Tower Bridge

until last, and for good reason.

They want to bring all their experience

from lighting all the other bridges

before they approach the most symbolic of them all.