All language subtitles for Britains.Greatest.Bridges.Series.1.5of6.The.Clifton.Suspension.Bridge.1080p.HDTV.x264.AAC.MVGroup.org.Eng

lands on the ground, and forms a stalagmite.

It was built without any water proofing over the top

so rainwater does percolate through.

And it's very damp and humid in here.

And over 180 years,

the water trickling through has allowed those stalactites to form.

It's basically lime being washed out of the lime mortar.

Amazing. Beautiful effect isn't it?

Yeah. I mean it's like... It really is.

It's very cathedral-like in here, isn't it? Yeah. That's right.

And of course the water drips off the ends of the stalactites

Yeah. Water percolates through.

Yeah...yeah. Amazing.

So, there are more chambers like this down here? There's 12 chambers altogether.

And they are all linked

with various little passageways and tunnels and shafts.

You'd have absolutely no idea walking across the bridge

that this was all down here.

That's correct.

Come through and have a look through here. The maze continues, David.

Here you go. So, this is vault number five of 12.

It's about 11 metres high, it's got a span of six metres across,

This arched chamber, built out of the steep limestone cliff,

is one of a network of 12 interconnecting vaults

that form the two-storey abutment.

It was Brunel's ingenious way

of distributing the weight of the bridge effectively,

keeping it strong and stable,

but at the same time, using less material,

which crucially kept costs down.

This is vault number four out of 12. David, this is incredible.

This is one of the better vaults we've got.

This is actually the largest vault of the lot. Amazing.

and the length of this one is nearly 20 metres

So quite impressive.

And of course what you are looking at here is the natural rock

going back up the slope of the gorge.

As you can see, they just built around it.

Over the decades, water has leaked through the limestone ceiling,

forming these beautiful stalactites,

some of which are up to four metres long.

These stalactites give it quite an awesome effect in here, don't they?

In October, 1831,

Does this change your kind of feelings about the bridge at all?

Or enhanced them in any way?

Well, both of those things, yeah.

The skill with which they built it...

..it's beautiful.

The intricate abutments

are a testament to Brunel's incredible design.

But, just four months after work began on the bridge,

the entire project was brought to a dramatic halt

by a decision made over 100 miles away in London.

The more you learn about this bridge the more impressed you are, I think.

a government U-turn on plans to give more people a right to vote,

led to anger on the streets.

Bristol was once again a city in crisis.

Building didn't start for five years due to yet more rioting in Bristol

as political unrest swept across the country.

Brunel himself was enlisted as a Special Constable.

While calm was eventually restored,

investor confidence had been shaken to the core.

When work on the bridge finally resumed in December, 1835,

In the heart of the abutment here. Yeah.

And we're right under the tower now.

So, the Leigh Wood's tower, basically straddles across the road.

The roadway runs along the top of the...of this chamber.

And the two legs of the tower sit on top of these walls.

These take the weight of the tower right down to the rock below us.

It's extraordinary, isn't it?

Right here, we are surrounded by the bridge.

We are in a vault, vault there, vault there,

vault there, vault there and a tower right above us.

It's absolutely beautiful.

This is the central vault.

And four more at this level and another five down below.

And the bricks are very... They're pretty rough, aren't they?

Well, Brunel didn't expect anybody to come in here

and admire the handicraft so...it's...

I wonder, are you sure about that? It's just left very rough ..

Look at the stonework around this little tunnel here. It's beautifully done..

It's built to last but it's not built for appearance.

You know, that little tunnel needed to last forever.

But the bridge that stands here today,

would be his greatest-ever challenge.

And prove to be more than a lifetime's work.

In June, 1831, groundwork began at the Avon Gorge

in preparation to build Brunel's masterpiece.

For the 24-year-old engineer,

the Clifton Suspension Bridge

would be his first major project in charge...

..and ultimately the most challenging of his entire career.

Of all the projects Isambard Kingdom Brunel was involved with,

the Clifton Suspension Bridge is probably the most well recognised.

But, little did Brunel know that completing the bridge,

is very different to the one Brunel originally wanted to build.

This early drawing clearly illustrates

how Brunel intended the bridge to look

when he first sketched out a design.

The roadway suspended by chains attached to the top of the cliff,

and accessed by tunnels carved out of the solid rock.

But the 299-metre span exceeded the length

deemed safe by suspension bridge expert Thomas Telford.

Brunel's solution was to build two platforms called abutments

Convinced, Gilbert conceded,

But despite the judge's recommendations,

he wasn't given the job, and so, returned to Birmingham

where he went on to enjoy a career designing postboxes.

So, what led to the committee's change of heart?

Well, in what was nothing short of an audacious move

by the young engineer,

Brunel confronted Gilbert, the competition judge,

discrediting the winning entry

by revealing what he considered to be serious design flaws

and insisting that his was the only workable design.

out of the jagged cliff.

and after agreeing to make a series of adjustments,

Brunel was declared the winner.

The young engineer had never built a bridge before,

and perhaps it was Brunel's sheer confidence in his design

that led to him winning the contract.

So, was the cocky engineer right

to have so much faith in his own design?

Experts today, believe

he got the all-important length of the chains spot on.

Fantastic. It was a long way round, otherwise.

It's a fantastic view.

Today, we're heading deep into the very foundations

of this incredible structure.

Our guide is Bridge Master David Anderson.

This little wall here, was that part of the transportation system

during the construction?

That's right. Yeah.

That was the abutment for the iron bar that Brunel put across the gorge,

for the transporting men and materials across the gorge

when the two towers and abutments were being built.

I've been on the bridge many times, but, never inside the vaults.

Exactly.

This steel door now covers the entrance to the vaults

which were sealed off and forgotten about for more than 150 years.

Oh, wow.. Look at this.

What do you think of that, Isambard? It's quite stunning.

It's quite a surprise. (CHUCKLES)

It's sort of really not what I was expecting at all.

It's actually quite like a bridge arch, isn't it? Indeed.

It's just like a... In fact it is a bridge with water on the side of it.

I've been given special permission

These would form the foundations for two large towers,

from which the chains would be draped,

reducing the free suspended span of the bridge to 194 metres,

much more in line with Telford's recommendations.

Until recently, it was assumed

the abutments at either end of the bridge, were solid.

But, in 2002,

the maintenance team discovered a hidden shaft,

leading to a series of underground tunnels and vaults.

a grand ceremony was held to mark the laying of the foundation stone,

to explore the bridge's best kept secret,

a secret which is key to the entire structure's success.

Isambard, hi. Hi. How are you doing?

And joining me is a man called Isambard Thomas,

Brunel's great-great-great grandson

How was the journey? Easy.

So, we're going down in the vaults

up here in the suspension bridge today.

Have you been down there before? I've never been down.

led to Hawkshaw and Barlow redesigning some parts of the bridge.

Work on Brunel's "darling" began once more.

Hawkshaw and Barlow may not be the names

that most people associate with the Clifton Suspension Bridge,

but they were absolutely key

in masterminding the structure we see today.

They acquired Brunel's initial plans, but times had changed

in the 30 years since work had first started on the bridge.

Engineers had learnt a great deal about bridge building

and how dangerous strong winds can be to a suspension bridge like this one.

These new discoveries

of completing a new Clifton Suspension Bridge.

Brunel had originally intended

that the bridge be held up by two chains on each side,

one on top of the other,

but Hawkshaw and Barlow increased that to three on each side,

making the bridge stronger.

Brunel had also intended to use wooden struts

to support the road deck,

but again, these were deemed to be too weak.

So Hawkshaw and Barlow changed the design,

It was demolished to make way for a new railway bridge

and on either side of that, a pair of pedestrian bridges,

the Golden Jubilee Bridges.

But there are actually remnants of a fourth bridge here too.

The brick buttresses of what's now the railway bridge

are actually the original foundations of another Brunel bridge,

the original Hungerford Bridge,

which stood here until 1862, when work began to knock it down.

Brunel's footbridge only lasted 14 years

and featured a pier for steamers to dock.

It was the only suspension bridge that Brunel completed in his lifetime.

swapping wood for the wrought iron lattice work structure we see today.

into Charing Cross Station.

The engineer in charge of building the new Thames Bridge

was John Hawkshaw, an admirer of Brunel's,

and together with his colleague, William Barlow,

the pair came up with a radical idea.

Why not use the chains and saddles from the old Hungerford Bridge,

to finish off the Clifton Bridge as a fitting memorial to Brunel?

The idea took off, and three years after Brunel's death,

Hawkshaw and Barlow were put in charge

Some people think so, they point out

The Clifton Suspension Bridge Trust now oversees its day-to-day running,

and the works program that ensures that the bridge remains

in the condition that Brunel intended.

For over 150 years, the Clifton Suspension bridge

has swayed majestically high above the Avon Gorge.

Yet, despite the passage of time,

few other bridges on the planet have come close to rivalling it

in terms of ambition and sheer engineering brilliance.

So, is this really Hawkshaw and Barlow's bridge,

just a monument to Brunel?

to fund its upkeep.

it's just the towers and some of the chains that were Brunel's.

The rest of the structure,

and the fact that it still stands today, are down to others.

But had it not been for the genius,

the vision and the dogged determination of one man,

it simply wouldn't have been here at all.

For me, Brunel deserves his credit,

as the father of Clifton Suspension Bridge.

Captions by Red Bee Media (c) SBS Australia 2019

But after years of waiting, Bristol had its bridge across the gorge,

Now, some engineers say these design changes have been crucial

in keeping the bridge safe and stable over the last 150 years.

And had it been built to Brunel's original design,

it may have come crashing down into the gorge below long, long ago.

On the 8th of December, 1864,

Hawkshaw and Barlow's reworking of Brunel's original design, was complete.

Almost 30 years after construction began,

the Clifton Suspension Bridge was finally declared open.

Tellingly, none of Brunel's family attended the ceremony.

In the middle, the Charing Cross Bridge, the railway bridge,

offering road access between Clifton Down and Leigh Woods

for the first time.

The bridge is Grade I listed

and still has 99% of its original parts.

They do take some looking after, though.

You can see the tower at the far side,

is currently undergoing a vital maintenance program.

Since the day it opened,

the bridge has relied upon the support of the people who use it

And on her maiden voyage

cutting the journey time by 13 hours to just four.

Brunel would design every aspect of the railway,

including three viaducts, seven tunnels and four major bridges.

If this wasn't enough of a distraction

from his barely-started bridge at Clifton,

Brunel had also developed an interest in ship building.

This is the SS Great Britain,

the second of Brunel's massive liners,

and the first iron ship ever to cross the Atlantic.

She was built right here, in Bristol in the 1840s.

between London and Bristol,

she sailed right past the unfinished towers at Clifton.

By 1843, the towers were finally finished

and most of the iron work for the crossing had been delivered.

But, money for the bridge had now completely dried up

and construction work came to a halt.

In a letter to the local paper

one man referred to them as "unsightly piers"

and suggested they be left uncompleted

"as monuments to our folly".

Sadly, all of this was considered too expensive.

and reignite faded interest.

But it wasn't long before the enormity of the project was realised.

The huge abutments and two 26 metre-tall towers

took six years to build, almost three years longer than planned,

crippling the already-overstretched budget.

A rethink to Brunel's flamboyant design was urgently needed.

The stonework on the towers here

was supposed to be covered with stylised iron panels,

illustrating the story of the construction of the bridge.

The plans even showed two sphinxes one atop each of the towers.

The future of the Clifton Suspension Bridge lay in tatters,

As various cost-cutting solutions were offered, and rejected,

doubts were raised as to whether the bridge would ever be finished,

one local predicting a completion date of 1987.

As progress on the bridge slowed to a crawl,

Brunel turned his attention to other projects.

By now, Brunel was not only in charge of the Clifton Suspension Bridge,

he was also Chief Engineer on another massively ambitious build,

The Great Western Railway.

This 116-mile track would provide a high-speed link

..the only part of the bridge that had been built

the Clifton Suspension Bridge has dominated the Avon Gorge.

Brunel's mesmerising design

has become the symbol of the city of Bristol

and there is no better place to appreciate it than from up here.

What an amazing view.

For many, this bridge, the Clifton Suspension Bridge,

is the crowning glory of Isambard Kingdom Brunel's career.

For 30 years, Brunel tried to get the bridge finished

but the project was crippled by bad luck and lack of money.

When he died, in 1859...

For over a century and a half,

were the so-called "monuments of failure", the towers.

The road deck was nonexistent

and the suspension chains had been sold off.

But just when many thought that the bridge would never be finished...

..another suspension bridge came to its rescue...

..this one, the Hungerford Bridge across the River Thames

where the Charing Cross Bridge now stands.

If you look closely behind me,

you'll see there are actually a number of bridges here.

broken and frail.

but Brunel's numerous other projects remained on track.

In 1858, Brunel was photographed

at the launch of the largest of his steamers,

the SS Great Eastern.

He looks every inch the powerful Victorian engineer.

But the incredible workload of numerous projects

was about to take its toll.

This photo, taken less than two years later,

shows a very different man -

So, it was Mr Hawkes' design that was considered first class.

And just minutes after this was taken, Brunel suffered a stroke.

He died 10 days later

at the age of just 53.

Despite years of trying, Brunel never saw his bridge completed.

At the time of his death, most of the bridge was still unfinished,

the decks were missing,

the chains and numerous other parts had been sold off.

So, the question is who on earth would want to take up the challenge

of completing Brunel's most iconic design?

building the bridge across the gorge would take more than three decades

incorporating factories, a chapel, granaries,

two built-in windmills and even a naval school.

But his stone design was dated

and the cost of building it would have been well over £10,000,

a figure William Vick's initial investment

was still a long way from reaching.

Sadly, nothing ever came of William Bridges' design

and it would be another four decades

before plans for a new bridge were seriously considered.

But even when a design was chosen,

that would have dominated the gorge,

and prove to be THE greatest challenge

for the most famous British engineer of all time.

For many people, the Clifton Suspension Bridge

spanning the vertigo-inducing Avon Gorge in Somerset

is THE most beautiful bridge in the world...

..a 214 metre-long engineering marvel

that has dominated this incredible landscape

for over a century and a half.

Today, it is widely regarded

where high-masted ships could easily sail below.

The answer can be found here

at Merchant Hall in Clifton Down just metres from the bridge.

This copy of a will dated 1754,

is that of one William Vick, a major wine merchant in Bristol.

According to its terms, he left a sum of £1,000

for a bridge over the River Avon

from Clifton Town to the opposite side on Leigh Town

which he hoped would be of great public utility.

Vick requested that when that money had matured to £10,000

a bridge was to be built at Clifton

as the crowning glory of Isambard Kingdom Brunel,

So, there was money on the table but there was a problem.

The gorge at its narrowest was over 200 metres wide

and nearly 100 metres high.

No-one had built a bridge that long or that high before,

but it didn't stop people from trying.

In 1793, over 40 years after Vick's death

the appropriately named William Bridges, a local Bristol engineer,

submitted this extraordinary design.

Bridges' vision was for a five-storey arch

At almost 400 metres in length,

pivotal to the city's economy.

Brunel's solution was not a bridge but the Thames Tunnel,

the so-called eighth wonder of the world.

This was Brunel's grand entrance hall

which led down to the first-ever tunnel beneath the Thames.

In fact it was the first tunnel

beneath any river anywhere in the world.

It connected Rotherhithe here on the south side of the river

across to Wapping on the north bank

without blocking any shipping in and out of London.

which sailed up the Thames every day laden with trade,

20 metres below the surface of the river,

the construction of the Thames Tunnel was a mammoth undertaking.

At the time, it was THE most ambitious engineering project

anywhere in the world.

Perhaps even more amazing

was that Mark Brunel entrusted most of the day-to-day work

to his deputy engineer, his son Isambard,

who was aged just 20 when he was appointed the role.

The grand entrance, or sinking shaft as it became known,

in a hole in the ground,

one of the greatest engineers of the 19th century.

Walking up here alongside the bridge, stood 250 feet above the river below,

you can't help but feel a bit small,

a bit insignificant maybe.

And not just because of the enormity of the bridge itself,

but because of the enormity of the man behind it.

Isambard Kingdom Brunel's Clifton Suspension Bridge

might never have happened, though...

..were it not for an event that occurred here,

but where was the money going to come from?

over 100 miles from Bristol in south-east London.

It was a disaster that killed six men,

but that led directly to Brunel's involvement at Clifton.

At this very spot, in February, 1825,

50 metres from the banks of the River Thames

an engineer by the name of Mark Brunel, Isambard's father,

began a monumental endeavour.

His challenge was to link the north and south banks of the River Thames

without disrupting the flow of the 3,000 tall-masted ships

was a monumental task...

and they'll probably say Isambard Kingdom Brunel,

ask them what he built and they'll probably say this.

The Clifton Suspension Bridge was Brunel's lifelong passion,

a work of art, that would make him

one of the most famous engineers in history.

Brunel called it his "darling", his first child.

And you can see why he loved it so much.

It seems to hang in the sky.

But back in 1830,

the challenge of designing a bridge to span this vast chasm

Ask anyone in England to name a famous engineer

..one that would result in great rivalries

and push engineering to new heights.

For over 150 years,

this great bridge has stood as a testament

to Brunel's engineering brilliance.

But this bridge was almost never completed.

And questions still remain

as to whether Brunel was the true designer at all.

The breathtaking Avon Gorge,

Stopping traffic.

have not only linked our island, but, made it great.

These are the bridges that are known around the world,

built by visionaries like Stevenson and Brunel

who are famous even today.

Look at this!

From the banks of the Tyne to the mighty Thames,

from the Firth of Forth to the Menai Strait...

..I'm on a journey to discover how those great bridges were built...

Here we go.

..and the sweat and sacrifice that went into their constructions.

which marks the boundary between north Somerset and Bristol

I'll uncover the huge egos, flawed geniuses and jealous rivalries

behind their creation.

It's as if he'd been airbrushed from the whole story.

These are Britain's greatest bridges.

1,500 tons of wrought iron, 75 metres high,

stretching gracefully for over 200 metres

across the dramatic Avon Gorge in Somerset,

the Clifton Suspension Bridge

is nothing short of an engineering masterpiece.

The new bridge was supposed to ease congestion, but it didn't.

and these tides even made it as far as Bath.

But at low tide, ships could find themselves grounded on the riverbed,

and in the worst cases, that could cause them to break apart.

The passage through the Avon Gorge was undoubtedly hazardous,

but the profits made the journey a risk worth taking.

As a result the city grew in both wealth and size.

But, there was only one bridge across the river Avon in Bristol

and by 1750 it had become massively congested.

The first stone bridge which stood for over 500 years

was covered in houses and even shops until it was replaced in 1768.

The rising river could help the ships in towards Bristol

And worse still for the people of Bristol,

there was now a toll to use it.

For years, the locals campaigned to have the hefty charges scrapped.

For a while it looked like the protesters would win

but the tolls were just too lucrative.

And in 1793, the city decided to extend them instead.

This resulted in a massive riot.

At least 11 people were killed, and another 45 were injured.

There was no doubt the city needed another bridge

But back in the 18th century, one of the port's most profitable activities

dates to the last ice age.

It was formed when the original River Avon became blocked by ice

and was diverted, cutting its way through the soft limestone.

Looking at it now, it's hard to believe

but this narrow stretch of the River Avon,

was once one of the most important waterways in the whole of Britain.

It linked the bustling city of Bristol,

the second-largest port in England,

with the Bristol Channel, that's six miles in that direction.

was the elaborate way into the subterranean tunnel.

was the trading of slaves...

..its ships sailing to Africa to take on a human cargo bound for America,

and returning with their holds full of sugar.

It was an inhumane trade

but nevertheless made Bristol one of the richest cities in the land.

Navigating this stretch of the river wasn't easy.

The tides at the mouth of the river Avon

can vary the water levels by up to 12 metres,

that's the second-largest tidal range of anywhere in the world.

proved for the first time

Have it too loose,

and the bridge can easily sway back and forth.

And that's not what you want when you're 75 metres up in the air.

The fact that Brunel's, and so many of the other 22 designs submitted

were for suspension bridges,

had a lot to do with this,

the Menai Bridge across the Menai Strait

from the Welsh mainland to Anglesey.

This revolutionary bridge,

with a record-breaking single span of 177 metres,

But you'd be wrong.

that it was possible for the heavy-duty suspension bridge

to cover vast distances.

And, importantly,

given the limited budget available to span the Avon Gorge,

the suspension bridge used far less materials than other bridge designs,

so they were cheaper to build.

The Menai Suspension Bridge, completed in 1826,

was built by Thomas Telford,

one of the greatest engineers in the country.

Now, if I shorten the chain,

that the chain supports.

And on either end I've got my anchor points holding the chain in place.

And finally, here,

built into my piece of string

I've got a little device

which tells me how tight the chain is being pulled.

It's kind of like the device you use

when you weigh your luggage

when you go on holiday.

The pull on the cables is currently only about half a kilogram.

And the man the city of Bristol turned to to judge their competition.

immediately you see the dip in the middle is much smaller,

and my device here is giving me a reading of 1.5 kilograms.

So this is now quite tight.

You can see that's not giving very much at all.

Have it too tight

and you risk that the anchors get pulled clean out of the ground,

and the whole bridge just comes crashing down.

You might think that a loose chain is the way to go -

less risk of the chains pulling themselves out from the ground.

After scrutinising designs

Eventually, the committee decided a second competition was needed,

with both Telford and Brunel entering.

Brunel sketched out four new designs,

this time, for a bridge with a span of 194 metres.

Better still, he added a price tag of just £42,000,

10,000 less than Telford's,

and yet neither of them won.

The new judge brought in to replace Telford was Davies Gilbert,

a mathematician and theorist

who'd helped mastermind the record-breaking Menai Bridge.

would ruin the natural beauty of the gorge.

by entrants including Brunel and Telford,

along with engineers Samuel Brown, and William Hawkes

from the Eagle Foundry in Birmingham,

Gilbert recorded his conclusions.

"I would place them in the following order,

"first, Mr Hawkes, second, Mr Brunel.

"Third, Mr Brown."

Unfortunately, Telford's design was placed to one side

on the grounds of being too expensive.

a three-span suspension bridge supported by two huge gothic towers.

Unfortunately, Telford rejected all the designs,

saying of Brunel's bridges

that they would certainly tumble down in a strong wind.

His key point was that it was impossible

for anyone to build a suspension bridge longer than 183 metres,

roughly the length of his own bridge across the Menai Strait.

But, Telford kindly offered to save the day.

In what some felt was a cunning move,

Telford submitted his own design,

is the weight of the bridge decks

These helped reduce the central span to just 110 metres,

almost a third of the length of Brunel's first design.

To the bemusement of many, Telford was awarded the contract.

After losing, it's said Brunel lit up one of his famous cigars,

and smoked away his anger.

But Brunel's disappointment was short lived.

Telford's bridge would cost £52,000 to build,

over six times the budget,

and many thought the monstrous pillars

to design and build the long-awaited bridge across the gorge.

Needing to convalesce, Brunel was sent to Bristol

and it was this that led to his involvement

in the Clifton Suspension Bridge.

By now, William Vick's initial investments

for a new bridge across the gorge

had risen from £1,000 to £8,000.

And the city was keen to spend it.

Additional funding was still needed

but Bristol just couldn't wait any longer

so the city announced a competition to find an engineer

before he'd finished his first project.

Never one to doubt his own abilities,

the 23-year-old Brunel leapt at the chance.

In seven weeks, he produced

not one but four separate designs for the bridge.

These weren't just plans for any old bridge,

they were plans for THE highest and THE longest bridge

that had ever been built.

Now, plans are one thing, but if he won,

Brunel would also have the mammoth task of actually building it.

carrying thousands of commuters beneath the Thames every day.

The tunnel itself runs right beneath my feet,

and you can see up on the walls here

where the old stairways would run all the way down.

When the tunnel was opened to the public in 1843,

on the first day alone, 50,000 people passed through these walls.

After three months, one million people had visited

all desperate to experience the world's first river tunnel.

These days, the tunnel is used by trains

on the London Overground network

Brunel, though, was not fazed and submitted his drawings.

But while 21st century commuters

might well take the tunnel for granted,

back in the 1820s, the construction process was a Herculean challenge

that was fraught with danger.

On the 12th of January, 1828,

the roof gave way and the freezing water burst through.

Six workers were killed,

and Isambard himself was carried out unconscious but alive.

Britain had almost lost one of its greatest-ever engineers

In every suspension bridge ever built,

Now, you might think that when those chains reach here,

that weight they're holding is transferred down through the towers

and into the cliffs below.

Well, some of it is.

But a lot of the weight is actually taken by the anchor points

at the very ends of the chains, buried deep down into the cliffside.

And one of the key decisions

anyone designing a suspension bridge has to make

is how long these chains should be,

ie, how much of a dip you get between the two towers.

that run the whole length from one side to the other.

the engineers have had to find a compromise

between the tightness of the cables,

and the stiffness of the bridge.

So, here is my model

of a suspension bridge.

I've got the towers here

on either end,

the string represents the chain,

the weight hanging off of the string

primitive suspension bridges have been used to cross rivers.

The city of Bristol would now have to decide

which of a total of 22 designs

received from well-established and budding engineers

would be the winner.

And it was clear that one type of structure was considered the key

to spanning the 200 metre-wide gorge,

the suspension bridge, which by 1828,

had successfully been used to span rivers up to 175 metres wide.

For thousands of years,

Britain's iconic bridges, spanning our most dramatic landscapes,

The genius of their design lies in their simplicity -

a single span supported entirely from anchors at each end.

The result is a strong yet flexible structure

that requires no central supports

built into the often-treacherous rivers below.

(CHUCKLES) Alright.

Now, this is a great place to see how a suspension bridge really works.

The entire weight of the bridge, all 1,500 tons of it,

is supported by these huge, big chains