[grand music] ROB BELL (VOICEOVER): Extraordinary, iconic, lethal, these incredible ships have told our story for the past 400 years and defined what it means to be part of our island nation.

♪ ♪ I'm Rob Bell.

And in this series, I'll be exploring Britain's greatest ships.

♪ ♪ This time, I uncover the story behind perhaps the most famous ship in the world-- the Titanic.

The biggest ship ever built, she was a sensation before she even set sail.

This place is just epic.

ROB BELL (VOICEOVER): The Titanic boasted the very latest technology, but her maiden voyage ended in a catastrophic loss of life.

That's a disaster.

The whole thing was chaos, and it shouldn't have been.

ROB BELL (VOICEOVER): She was said to be unsinkable.

So how did Titanic become the most famous maritime disaster in history?

[music criscendos, fades] [waves crashing] At the beginning of the 20th century, shipbuilding was booming.

[chatter, hammering] Huge British ports like Belfast in Northern Ireland were hammering out ever bigger, better, and faster ships to move people and goods around the world on a scale never seen before.

The Harland & Wolff Shipyard lies in the heart of Belfast.

In 1908, they were commissioned by the White Star shipping line to build a game-changing passenger ship that would strike ore into anyone who saw it.

This new liner wasn't just going to be the most luxurious, it would also be the biggest ship the world had ever seen.

And they gave it a fitting name, the Titanic.

♪ ♪ ROB BELL (VOICEOVER): But its maiden voyage was to end in disaster.

The Titanic has been lying on the seabed for over 100 years.

It seemed we'd lost all connections to this legendary ship.

But in 2013, a piece of living history returned to Belfast docks.

♪ ♪ This is the SS Nomadic.

Now, you might be thinking that she looks vaguely familiar.

Well, she was the Titanic's original tender.

So she has the same lines and the same livery as her bigger sister.

The Nomadic is the only remaining White Star ship anywhere in the world, and her original job was ferrying passengers out to the Titanic for that first and last voyage across the Atlantic.

ROB BELL (VOICEOVER): Today, the Nomadic is the closest you can get to boarding the Titanic.

Walking along this very same deck that those passengers did over 100 years ago.

You can just imagine the levels of excitement and the buzz that there would have been on board.

Those passengers perhaps clinging onto this railing as they steam towards the great mass of the Titanic.

♪ ♪ It would have been an imposing sight.

At 14 stories high, it was the largest ship ever built and it would have towered above them.

ROB BELL (VOICEOVER): To give an idea of Titanic's size, its museum here on the docks where the ship was built is the same height as its hull.

But building the world's biggest ship created a problem for the White Star Line.

If nobody built the world's biggest ports, it would have nowhere to go.

The White Star Line took a monumental gamble.

Imagine that the jumbo jet doesn't exist, but somebody comes along and they have an idea to build the jumbo jet.

Well, no airport has a runway long enough.

That is exactly what the White Star Line did.

They went ahead and ordered Harland & Wolff to build the world's largest liners, when there was no docks capable of handling the vessel.

ROB BELL (VOICEOVER): White Star Line managed to persuade key ports to extend piers and dredge deeper channels.

But why did the Titanic need to be so big?

It was all part of a daring new business plan to carry as many of a profitable new type of customer as possible.

Titanic was essentially an immigrant ship.

Her official designation with the British government was the immigrant ship Titanic.

And so the prime reason really for building the Titanic was because of mass migration, that's third class passengers.

The second and the first class was really, if you like, the jam on top of the bread and butter.

But the bread and butter is the bit that actually paid for the Titanic to be built and paid for her to be operated.

ROB BELL (VOICEOVER): The Titanic's size meant there was room for each class to occupy their own zones, even with separate promenade decks.

It's most famous for its first class passengers, who traveled in incredible luxury.

At the Titanic museum, you can see for yourself how the ship was designed to give them a whole separate world on top of the immigrant masses below.

Passengers and crew alike had never seen a ship built on this scale before.

You can see here there were 10 deck levels in total, and in the top half of the ship you had these open, airy spaces for first class passengers, where the designers freed up whole sweeping areas to accommodate jaw-dropping features like glass roof staircases, long promenade decks.

ROB BELL (VOICEOVER): The Titanic was the biggest moveable, man-made object the world had ever seen.

So how did Harland & Wolff meet the challenge of building such a gigantic ship?

[dramatic music] Ironically, the biggest problem wasn't in making it float.

It was building it on dry land.

Normally, a ship's hull took shape on a slipway supported by a gantry.

If the blocks under the keel were just half an inch out, the whole ship could break in two.

Engineers managed to balance its entire 882 feet to perfection.

The slipway where the Titanic was built is still here today, and it gives an idea of the sheer scale of the problem.

Even long established shipbuilding techniques would become fraught with new dangers.

Once the hull was watertight, the Titanic faced what should have been its most perilous journey, from land here out into the estuary.

ROB BELL (VOICEOVER): Titanic's slightly smaller sister ship, Olympic, was the first to launch, a dangerous feat never attempted on this scale before.

As soon as ships were released from the support of the gantry, they needed to slide into the water as quickly as possible to avoid keeling over.

Despite the high tech solutions like steam release mechanisms to help Titanic slide down the slipway, engineers hedged their bets with a method they've probably been using since before the Ark.

ROB BELL: To ease its path and reduce friction, shipbuilders used an age-old trick, 22 tons of rendered beef fat and soap were smeared all over the slipway, right down to the water's edge.

No doubt there are probably a few crossed fingers involved too.

ROB BELL (VOICEOVER): They had no guarantee it would work.

A crowd of 100,000 gathered to hold its breath, while the massive hull gently slid over beef dripping an inch thick into the estuary.

Once the hull had been successfully launched, the next step was to tow it into a dry dock.

With the gate closed, the surrounding water could be pumped out and construction of the vessel completed.

And of course, Titanic was going to need the world's biggest dry dock to be built.

This is the dry dock that Harland & Wolff had to build to fit out the hull.

It's almost impossible to take in the sheer scale of this place.

"Titanic" is definitely the word.

It's taken me almost three minutes to walk from one end to the other.

ROB BELL (VOICEOVER): With the dry dock drained of water, the empty hull of the Titanic could become a masterpiece in steel.

But these were the days before welding.

Thousands of steel plates up to an inch thick had to be hammered together by hand with three million rivets.

It took 15,000 men to build the Titanic.

And you can just imagine the noise and the industrial clamor that would have been echoing off of these walls.

This place is just epic.

ROB BELL (VOICEOVER): After a construction cost equivalent to hundreds of millions of pounds today, the Titanic set sail on its first Atlantic crossing to New York.

[triumphant music] [horn blows] For passengers in France, the tender ship Nomadic would herald this whole new way of traveling.

ROB BELL: Passengers boarded the Nomadic here to be ferried across to the Titanic.

And it was on board this vessel that they got their very first taste of the incredible ship they were about to experience.

But the story of the Titanic's maiden voyage was to become unforgettable for very different reasons.

How could a state-of-the-art ship, with so much money invested in it, come to such a catastrophic end?

ROB BELL (VOICEOVER): Belfast docks still bear the marks of building the biggest ship the world had ever seen.

And the Titanic is not just famous for its size.

Thousands of visitors flock here to the Titanic Museum to see the displays of opulent luxury, like the kind of first-class cabin which would have cost you thousands of pounds in today's money.

Previous transatlantic liners had offered sumptuous suites and fancy dining, but on board the Titanic everything was bigger and better.

The very finest cabins were decorated in historical styles.

They had their own private promenade deck, fireplaces, en suite bathrooms, electric lighting and heaters, and buttons to call valet service.

ROB BELL (VOICEOVER): The Titanic also had the first heated onboard pool, a Turkish steam room, squash court, gymnasium, and library.

This lost world now lies two miles beneath the waves, with one very special exception.

At a secret location in rural Derbyshire, retired engineer John Siggins has spent the last 25 years painstakingly rebuilding his own little corner of the Titanic.

[chuckles] John, what have you-- what have you got here?

This is-- I've just stepped into a completely different world.

Time capsule.

ROB BELL: An absolute time capsule.

It is, isn't it?

If you listen, you hear the engines.

[engines humming, clanging] Have you recreated that as well?

That's the engines, yeah, in the background.

And all this here?

JOHN SIGGINS: That's all original silverware, as would have been used on Titanic.

May I have a sit-down and just see what feels like to experience?

Yeah sit in the-- that's a first-class dining room chair, that.

Original.

This is how the first class would have ate their meals.

This has all been sourced from Olympic?

JOHN SIGGINS: Yeah.

So it would have been, what, the exact same stuff on Titanic?

- Yeah.

This would have been used on board the ship, the same.

[ballroom music] The service and the experience that you were getting on board Titanic in first class, it was up there with the highest hotels in the world, the highest-- JOHN SIGGINS: It was like-- it was a five-star hotel on the sea.

ROB BELL: So those first-class passengers weren't necessarily bothered about going on board a ship.

They just wanted luxury around them?

Yeah, yeah.

ROB BELL (VOICEOVER): The whole point was for the upper classes to feel like they were either back in their stately homes or dining out in style.

ROB BELL: So what have you got here, John?

This looks like-- JOHN SIGGINS: This menu is what the first class would have eaten.

OK.

JOHN SIGGINS: That's the 14th, that one.

ROB BELL: Oh, so that's-- JOHN SIGGINS: So that's the day before the ship sank.

Yeah.

I mean, this gives you a bit of an example of-- JOHN SIGGINS: Example of what they ate, yeah.

Six, seven, eight-- JOHN SIGGINS: Nine courses.

There's nine courses on there.

JOHN SIGGINS: Yeah, yeah.

Dessert and coffee.

I mean, that's typical, is it, of a first-class meal?

JOHN SIGGINS: Yeah, it would have been, yeah.

ROB BELL: Can I have a look?

JOHN SIGGINS: Yeah, you're all right, yeah.

So this is a, what, teacup?

That's just a normal teacup, that is.

A normal teacup.

It'll have a date stamp on the bottom.

ROB BELL: Yeah, April 1909.

JOHN SIGGINS: 1909, yeah, yeah.

That's a teacup.

That's a coffee cup.

That's what they call a beef tea mug.

ROB BELL: There's even different mugs for different types of tea?

- Yeah, yeah.

Time of day, different-- Yeah, yeah, different types of stuff they used.

They used different patterns throughout the day.

ROB BELL: What are these for?

JOHN SIGGINS: They're grape scissors.

ROB BELL: Grape scissors?

JOHN SIGGINS: Yeah.

ROB BELL: Are you kidding?

JOHN SIGGINS: No.

You cut grapes with them.

ROB BELL: They've commissioned specifically-- JOHN SIGGINS: --for cutting grapes in half.

Well, can't you just-- No.

Not if-- no, posh people never did that.

That's a bit rough.

You had to have a pair of scissors to cut them.

Be civil.

ROB BELL: I mean, come on.

Yeah, that was very uncouth of me.

Where are my manners?

I'm so sorry.

JOHN SIGGINS: Yeah.

Do you ever feel that sometimes you might just take your meals in here just as a-- - We do.

- Do you?

Yeah, we have our meals at Christmas.

We sit in here and have our Christmas dinner in here.

Do you go to this extent?

Yeah, yeah, yeah.

Don't use those plates.

I don't use those plates.

You wouldn't-- you wouldn't want to put those in the dishwasher.

No, I don't use the plates.

I use-- I've got all the plates.

I've got some P&O ones.

[laughter] [rousing music] ROB BELL (VOICEOVER): While the privileged few enjoyed the top decks of the Titanic, the less wealthy majority occupied the spaces below.

Poor as some people were, it's a bit of a myth that third-class travel on the Titanic was something to be endured rather than enjoyed.

Admittedly, it was further down in the bowels of the ship, but there was separate accommodation for families and single men and women.

Freshly prepared hot meals were served four times a day, all part of the price of your ticket.

The food was even served by stewards in White Star Line livery.

ROB BELL (VOICEOVER): The luxury of first class on board Titanic is legendary, but even third class was said to be better than second class on rival ships.

It was all part of White Star Line's plan to attract repeat business from immigrants.

PAUL LOUDEN-BROWN: Most of those passengers would be traveling as what we call chain migration.

They would be going over to America to create a bridgehead.

Then they would send money back to the old country, and they would bring back other members of the family.

And gradually, the White Star Line would get even more profit from bringing further members of the family over.

And this meant that the White Star Line constantly had a tap of more migrants.

ROB BELL (VOICEOVER): The White Star Line wanted immigrant passengers to recommend the Titanic to everyone they knew, so they were handled with a respect that many had never even seen at home.

It wasn't treating people as just a one-way quick fix, get them on the ship and get them off the other way, because a bad experience for that migrant meant the potential of losing 5, 6, 7, 10, 20 more migrants in the future.

Steerage on the Titanic was like a whole neighborhood, with families living, eating, and socializing together, whilst right beneath their feet was the incessant throb of the mighty engines powering the liner across the Atlantic.

ROB BELL (VOICEOVER): Titanic's engines needed to produce enough raw power to push over 52,000 tons across the Atlantic at up to 21 knots, about 25 miles an hour.

At the Titanic Museum, immersive computer graphics give you an awe-inspiring sense of what it took to fire up the biggest mobile power plant in the world.

[engines churning] This just gives you a bit of an idea of the scale of what was on board Titanic.

We're down here in the engine rooms.

With all the mechanics moving, you can imagine the noise this would have been making all around.

Everything's just enormous.

ROB BELL (VOICEOVER): Titanic's engines produced 46,000 horsepower and enough electricity to light up a town.

Back in the real world, locomotives are the last surviving machines where you can see the raw power of steam for yourself.

[train whistles] The boilers on board the Titanic were roughly four times the size as the one on this locomotive, and there were 29 of them lined up along the bottom of the ship.

They generated the steam to power the enormous propellers.

ROB BELL (VOICEOVER): The Titanic had three propellers.

The two on either side for maneuvering weighed 38 tons each.

The central propeller in front of the rudder was brought in for top speed cruising.

This colossal pile of coal here weighs in at about 120 tons.

But to feed the insatiable appetite of the fires raging in its furnace, the Titanic needed 600 tons of coal every day.

That's five piles like this every day for six days.

[train whistles] ROB BELL (VOICEOVER): The Titanic had over 150 stokers shoveling coal around the clock in the bowels of the ship.

At full steam, she had 162 furnaces lit.

The furious energy from all that steam powered four reciprocating engines, a bit like pistons moving in and out of cylinders on a car engine.

But these were the biggest ever built, each one the size of a three-story house.

ROB BELL (VOICEOVER): For efficiency at high speed, the Titanic also deployed the very latest military technology, a turbine engine powered by the low-pressure steam leaving the pistons.

Everything about the Titanic was the last word in high tech-- electric lights, remote-controlled safety systems, and a new-fangled invention that could keep ships in touch with each other across large distances-- radio.

ROB BELL (VOICEOVER): But how effective were the first radios?

John Siggins' 100-year-old wireless set is still ready for action.

Goodness me!

What have you got here, John?

That's your Marconi spark gap transmitter.

That spark, then, is transformed into a radio signal, which is then broadcast-- Broadcast outwardly.

How old is this machine here?

Do we know?

That one's gonna be about 120-year-old.

- Really?

- Somewhere around there, yeah.

And so something like this was on Titanic, was it?

JOHN SIGGINS: Yeah, very similar.

ROB BELL: This was state-of-the-art technology at the time.

JOHN SIGGINS: It was at the time.

ROB BELL (VOICEOVER): In 1912, communication between ships at night still relied on coded sequences of rockets fired from the deck.

But at nighttime, powerful radio signals bounced off the upper atmosphere to reach other radios beyond the curvature of the Earth.

Can I have a go and try and tap out the old SOS?

Yeah, have a go.

Off you go.

Dot, dot, dot, dash, dash, dash, dot, dot, dot?

- Yeah.

- SOS.

ROB BELL: Let's try it then.

SOS.

[taps, sparks buzzing] ROB BELL: That's it.

That's simple.

During the day, they weren't so good, but at night time, they could travel up to 500 miles.

ROB BELL: That's how powerful the signal in this is?

JOHN SIGGINS: Yeah.

If I connected that to an aerial, it might affect the police headquarters up here.

ROB BELL (VOICEOVER): As powerful as this new technology was, the Titanic's radio operators were mainly kept busy making money from it as a plaything of the wealthy.

Radio was also an exciting innovation, enabling passengers to send messages back to people on shore, if they could afford the cost of it, that was.

In today's money, a 10-word message would have cost around 40 pounds, so they tended to be kept quite short and succinct, messages like this one-- "Fine voyage.

Fine ship."

But around 9:30 PM on the 14th of April, as the Titanic neared the sub-arctic waters off Newfoundland, the messages she started receiving from other ships nearby took an ominous turn-- warnings of an ice field ahead.

[dramatic music] After four days at sea, the Titanic was 400 miles from land when it entered an ice field several miles wide.

Nearby, ships like the Californian had stopped for the night, waiting for daylight to pick their way through the ice floes.

But on the Titanic, Captain Smith didn't even order a reduction in speed.

♪ ♪ It was a very cold night.

In fact, the day had been so cold, they'd canceled lifeboat practice, not perhaps a sensible thing to do in the circumstances with benefit of hindsight.

But she was going fast, even in these icy conditions.

This wasn't unusual at the time.

It was thought that the lookouts would be able to spot bergs in time, and so it wasn't anything special.

But in the event, it turned out to be extremely dangerous.

ROB BELL (VOICEOVER): To spot an iceberg on a dark night, lookouts would usually search for large silhouettes against the horizon or white waves breaking around the base of a berg.

But a low, dark shape was suddenly spotted only a ship's length ahead.

It would appear that atmospheric conditions prevented the lookouts in the foremast seeing the iceberg in time.

But eventually they did see it, and they called upon the ship to turn to try and avoid it.

And the tragedy of it is, she almost did, but not quite.

And so she scrapes along the side of the iceberg.

And the iceberg under the water punches holes, takes off rivets, and punctures a whole series of small openings in the right-hand starboard side of the ship.

And this causes water to cascade inside.

ROB BELL (VOICEOVER): The iceberg gouged thin slits in the hull no wider than a hand's width.

But crucially, they were dotted along the whole front third of the ship.

But how could ice have ruptured solid steel in the first place?

It seems crazy that ice could cut through mild steel an inch thick.

But the colossal forces involved in this phenomenal collision are all about sheer scale.

So, of course, the ice here is softer than metal.

You can see, in this battle, it's the metal wins, as the ice is breaking up.

That means the metal is harder than the ice.

ROB BELL (VOICEOVER): But the berg that sank the Titanic is estimated to have been at least 20,000 tons of solid ice.

They weren't going to just bounce off each other.

If sheer mass holds the ice in one place, it pushes back against the metal.

But with the ice firmly in my vise here, if I now take my metal plate, which represents the hull of the Titanic, and if I run that along the top of the ice.

There's maybe a bit of smoothing off of the surface of that ice there, but this metal plate is getting dented and bent right up.

Now, when metal is continuously bent or stretched, it reaches something called its tensile strength.

That's the point where it breaks or tears or cracks open.

And on the Titanic, there's also a possibility that those forces started to pop the rivets out of the joints.

♪ ♪ ROB BELL (VOICEOVER): Up on deck, even people who'd noticed the impact didn't seem alarmed.

Why did they find it so hard to believe they were in danger?

The Titanic's reputation was built on safety features that were designed to cope with all known threats to shipping.

Like other ships, it was divided vertically into sections by bulkheads, walls running from the bottom to the top of a ship.

Each of the resulting compartments had watertight doors to stop a leak from spreading the length of the ship.

To make space for the large rooms on top, the Titanic's bulkheads stopped here, beneath the first-class facilities.

But this wasn't a compromise on safety from the designers-- quite the opposite.

ROB BELL (VOICEOVER): Regulations of the time demanded that ships had to be able to stay afloat with any one of these compartments flooded.

Titanic had 16 watertight compartments and could survive up to four of them flooding.

She also had a barrage of steam-powered pumps to slow down any rising water in the engine rooms.

The Titanic had more of the latest safety features than any other civilian ship of its time.

That's why the buzz surrounding its construction earned it the reputation of being the unsinkable ship.

[water lapping] ROB BELL (VOICEOVER): When the Titanic steamed into the iceberg, Captain Smith ordered an immediate stop to assess the damage.

The radio operator, Jack Phillips, started transmitting alerts to any nearby ships to come with assistance.

Whilst they waited, Captain Smith tried to find the answers to two main questions.

Were they sinking?

And if so, how long would it take?

ROB BELL (VOICEOVER): The Titanic was built to remain afloat with up to four of its watertight compartments flooded.

Water was now rushing in to at least five of them.

But with the rest of the compartments remaining intact, they were estimated to keep the ship afloat long enough for help to arrive.

25 minutes after hitting the iceberg, Captain Smith ordered the lifeboats to be prepared and the band to start playing to raise spirits.

But passengers were slow to muster on the freezing cold deck.

Why did the crew and passengers alike seem to feel like they were in so little danger?

The belief at all levels that Titanic was unsinkable meant that, on this very cold night, that if you were a rich American lady or a rich British duchess or something, were you really going to get into a lifeboat on a cold evening when all this beautifully lit ship, with the orchestra still playing, was giving you a great sense of security?

Of course you weren't.

ROB BELL (VOICEOVER): The majority of people on board were on the lower decks.

Those scrambling to escape the rising water were met by a maze of corridors, locked gates, and stairs.

They had never rehearsed boat drill.

That's a disaster.

Therefore, people had no idea where to go.

The first-class passengers were closest to the boats, and they could virtually all speak English, so could the second-class passengers.

The third-class passengers, steerage, were immigrants.

Many of them couldn't speak English at all.

ROB BELL (VOICEOVER): There are no photographs of the Titanic's final hours.

But this model in the Ulster Transport Museum is based on survivors' accounts, when confusion was turning to panic.

Even an hour after the impact, Captain Smith hadn't instructed the officers to evacuate the passengers.

Up on deck, everything now depended on the lifeboats.

With the ship leaning dangerously forward, the crew started launching, women and children first.

But why were there only 20 boats to accommodate less than half the passengers on board?

In their minds, the Titanic, if it did get into any form of distress, there were so many vessels traveling from the West to the East that, at any one time, you could guarantee there would be a vessel within hailing distance of your particular ship.

ROB BELL: And it took some time between the strike of the iceberg, the collision, and it actually sinking.

If a vessel had come to the assistance of the Titanic, then you and I wouldn't be here talking today.

ROB BELL (VOICEOVER): Why did no one come to the aid of the Titanic before she sank?

There were five other ships navigating the ice field.

When Titanic fired off rocket flares to attract attention, they were seen by the Californian.

But why didn't it take action?

Back then, there was some ambiguity about what these rockets represented.

Was it distress, or was it a vessel signaling to another vessel at sea?

That was the way that we communicate to see if that vessel didn't carry wireless.

Nowadays, if you see any pyrotechnics at sea, immediately we know that's distress.

ROB BELL (VOICEOVER): With the rockets being ignored, it was down to the wireless operator to get a distress call through to any ship that had a radio.

The Carpathia responded, but it was almost 60 miles away across the ice field.

Again, the closest ship, the Californian, didn't respond.

ERIC GROVE: The problem with other radio operators, though-- infamously in the Californian-- is that they close down.

You weren't supposed to keep radio watch on a 24-hour basis.

And this meant that not all ships in the vicinity picked up the signals.

With the ship now dipping precariously forwards, the lifeboats' state-of-the-art winches were becoming trapped and tangled.

Two of the lifeboats were yet to be launched, when, at 1:45 AM, the Titanic's final message was received.

"Come quick.

Engine room nearly full."

The nearest ship was still more than two hours away.

♪ ♪ By 1:40 AM, water had been gushing into the front six compartments of the Titanic for 2 and 1/2 hours.

The situation was now critical.

The bow was so heavy, it tilted the stern clean out of the water.

And without the water around it to support the weight of the massive engines near the back, the keel started to bend, and the steel plates of the hull were torn apart.

ROB BELL (VOICEOVER): The Titanic had managed to stay afloat thanks to its remaining watertight compartments.

But when the bow of the Titanic finally went under, it only took minutes for the whole ship to disappear.

Why did the safest ship on the sea come to such a swift and catastrophic end?

This plastic box represents the Titanic.

And you can see I've got it divided into these watertight compartments.

Now, you also see at the front here, I've drilled some holes.

Now, they represent the compromise to the Titanic's hull when it struck the iceberg.

But I've got those taped up for the minute.

So if I pop this into the water, unsurprisingly, it floats.

To make this model more representative, we need to add a little bit of weight, a bit of ship's ballast so that it sits down in the water like the hull of a ship would.

There we go.

That's more like it.

And you can see that these divisions between the watertight compartments on the Titanic didn't go all the way to the top of the ship.

Instead, they only came up about halfway, to allow for those large, open spaces in the first-class accommodation.

So if I now take this tape off and open up the holes to the water in the front compartment here, so that goes in.

It floats still.

But we need to get our ballast weight back in the middle.

Let's carefully pop those back in.

[suspenseful music] So it doesn't take long for water to start pouring in, because those holes were all beneath the waterline.

So water floods into that first compartment of the ship.

Water keeps coming in slowly now.

The water starts to tip over the top of that bulkhead and enters into the second part of the ship.

And once that starts to happen, the ship goes down very, very quickly.

[gurgling] And that's what happened on the Titanic.

ROB BELL (VOICEOVER): Because it only took a shallow angle for water to spill over the top of the bulkheads, the Titanic was engulfed in a lethal chain reaction.

But why wasn't she built to withstand such a long gouge in the hull?

There's a common misconception about the Titanic that she was badly built, that she wasn't built to withstand that collision with the iceberg.

And that is just not fair.

It's not true, in fact, and it's not fair on the builders and on the White Star Line, because the Titanic was built in excess of the legal requirements of shipbuilding in 1912.

It was the finest quality craftsmanship that went into that vessel.

And they always said at the time, if it's Belfast built, it's well built.

But nobody contemplated that amount of underwater damage.

Any other vessel wouldn't have remained afloat for a fraction of the time.

ROB BELL (VOICEOVER): The Titanic was built to be one of the safest ships of its day.

Its sister ship, the Olympic, survived another 21 years.

Olympic had a very successful career.

She became known as "Old Reliable."

She actually rams and sinks a German submarine.

And so it demonstrates that the basic design of the Titanic was fine, as long as you didn't drive it at high speed into icebergs.

[somber music] ROB BELL (VOICEOVER): The Titanic sank because no steel ship had ever experienced this kind of damage.

But many lifeboats left with empty spaces, so could more have been done to save lives?

PAUL LOUDEN-BROWN: Really, most of the criticisms should fall with Captain Smith, because Captain Smith's responsibility is to every man, woman, and child on board the ship.

Not in living memory for those men in 1912 had a disaster befallen a ship on such a scale.

They could not contemplate such a catastrophe.

And I firmly believe that Captain Smith has a form of mental breakdown.

And that freeze in command, you can see going all the way through, right down to junior officers and ratings lowering the boats.

They didn't realize the importance and magnitude of the coming disaster.

ROB BELL: Until it was too late?

PAUL LOUDEN-BROWN: Until it was too late.

There are undoubtedly 700 unnecessary deaths.

ROB BELL (VOICEOVER): Human error is ultimately responsible for the loss of life on board the Titanic.

But there were many people who, by their own acts of heroism, saved lives, too.

After the impact, the engineers returned to the flooding compartments to keep the power going and prevent the ship from plunging into darkness.

Most had likely drowned before a single lifeboat had been launched.

And when Captain Smith finally ordered the crew to abandon ship, not everyone obeyed.

ERIC GROVE: Captain Smith, eventually, he says to the crew, it's every man for himself.

And he tries to get Phillips, the radio operator, to leave his post.

But the great professional that he was, he wouldn't.

He kept on signaling until finally the water came in, and that was the end of him.

ROB BELL (VOICEOVER): Following naval tradition, Captain Smith also went down with the ship.

Five years earlier, he'd claimed that modern shipbuilding had eliminated any possible threats that could cause a liner to sink.

There are three lessons which were quite rapidly accepted after the Titanic disaster.

The first was, you had to have a 24-hour radio watch.

Secondly, you've got to have enough lifeboats.

They were not just there to transfer part of the passengers to another ship.

You had to have enough lifeboats for everybody to be able to get in and wait for rescue.

Thirdly, there was the International Iceberg Organization which gave ships due warning of ice.

So those three were the great lessons, and they made the high seas and the North Atlantic in particular a great deal safer.

The tragedy of a so-called unsinkable ship suffering such a catastrophic loss of life still grips our imaginations over 100 years on.

But perhaps, thanks to the lessons learned that we should never be so complacent to blindly put all our faith in structures and machines, there has never been another Titanic.

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