The Engine That Powers the World Timeshift

Buried deep within this ship is a piece of technology that has

transformed the modern world.

We're about to fire up one of the biggest engines in the world!

Here it goes!

MEHANICAL WHIRRING Incredible!

That same technology is also in this train...

TRAIN HORN HONKS

HE LAUGHS

..this lorry,

this submarine...

You feel like you're in an engine walking through here.

..and this tractor.

I'm talking about the diesel engine.

Now, some may think the diesel

is what powers their sensible family car.

Well, I'm here to tell you that it's much, much more than that.

No other engine is so versatile or used in so many applications.

Oh, my God, it's genius, I love it.

The vast majority of the world's commercial, industrial,

agricultural, mining and military vehicles are powered by diesel.

Bring on the diesels!

Yeah!

My name is Mark Evans

and this is a story I've been wanting to tell for a long time.

I've had a lifelong love affair with diesels

ever since I learned to drive tractors on the farm as a lad.

Even to this day...

HE SNIFFS

..if I catch that heady whiff of diesel,

it brings back very happy memories.

Lovely!

This is the unlikely tale of how a 19th-century invention became

the 21st century's most important engine.

It's massive, it's everywhere, it's everything you do.

Engines like these are the unsung workhorse of the modern world!

ALARM BLARES

There are alarms going off everywhere!

The story of the diesel engine starts with a man and a mystery.

In 1913, a body was discovered in the North Sea by a Dutch steam ship.

Documents on the corpse revealed it to be a German man

who'd disappeared ten days earlier on a ferry

travelling between Antwerp and London.

His name was Rudolf Diesel and just years before,

he had invented the most efficient heat engine the world had ever seen.

He was rich, famous,

a friend to the great American inventor Thomas Edison.

So why would such a gifted, successful man

throw himself off a ferry?

The answer, for me, lies in the engine he created.

The diesel was patented in Germany in 1892.

It was one of several new engines

being developed in the late 19th century

to replace the ageing steam engine.

Steam power had run the factories, mills, trains and ships

that had driven the industrial era.

But steam engines were bulky, labour-intensive

and very inefficient.

For engineers like Diesel, the route to a replacement for steam

lay in a recent technological breakthrough,

a technology this museum in West Wales is dedicated to -

internal combustion.

-Mark, how are you?

-Hi.

'Here, curator Paul Evans has assembled an incredible collection

'of the internal combustion engines that were vying to replace steam.'

Steam engines had used external combustion, meaning the fuel, coal,

was burned in a separate chamber to the engine itself.

The new internal combustion engines aimed to be more efficient,

by burning their fuel inside the engine.

But there was something different about the one I'm here to see.

Its method of internal combustion would make it

the most important engine in the modern world and this is it -

the only functioning example in Britain of an original diesel.

-There she is.

-Look at that. And the only one that's working?

She's the only running in the UK.

Probably the oldest running in the world, we think.

Can we get a bit closer and kind of touch and smell this thing?

'This model is the same design Diesel first demonstrated in 1897

'while working for a German machineworks.'

It's an extraordinary piece of kit.

Just...

Just gorgeous.

The immediate advantage internal combustion engines

like the diesel had over steam was they only needed one man to operate.

So, listen, how do you start it?

-Nice, I bet that tastes good.

-1998.

MARK CHUCKLES

WHIRRING

AIR HISSES

It's like coming alive.

Just lovely! Ah!

Incredible! This is such a treat.

Compare that to what was before this, the steam engine.

Firing up a steam engine took so many people,

it was a right old fiasco

getting them started and keeping them running.

One man gets this engine running in a few minutes.

But what made Diesel's engine unique

compared to other internal combustion machines

was the way it burned the fuel inside its cylinder -

a process called compression ignition,

something Diesel found inspiration for

in a type of pneumatic cigar lighter, popular in the late 19th century.

-It's a bicycle pump with no outlet, isn't it?

-Yeah.

Essentially, so if you put it down here, so you've got the bottom here,

you'd have some tinder, and just a plunger piston.

So, let's see what happens when I push the plunger.

And look at that, you get fire.

That is the simple secret behind every diesel engine

that has ever been made.

If you compress air far enough, it gets hot enough to start a fire.

It's so simple, that's the beauty of it.

You take air, you compress it,

the more you compress it, the hotter it gets.

If you compress it enough,

when you squirt some fuel in it, that fuel will burn.

The expanding gas then pushes the piston down again. Dead simple.

What compression ignition gave Diesel's engine

was unparalleled efficiency which completely eclipsed steam power.

Steam engines were, at best, 10% efficient.

In Diesel's invention, 30% of the energy

was converted to useful power,

more than any other internal combustion engine.

In fact, it was the most efficient engine the world had ever seen.

You're talking about an engine that's three times as efficient,

so a third of the cost to run it. It's a huge thing.

-Three times more efficient?

-Nearly four.

Wow. This was a seismic shift...

-Yeah.

-..in terms of how you powered our world.

In the 1900s, internal combustion engines, like the diesel,

started replacing steam engines in mills and factories

across the industrial world.

Diesel's first designs ran on peanut oil

but soon the standard fuel became a form of crude oil.

His design was licensed internationally and he made

a small fortune, but Diesel had higher hopes for his invention.

He was a utopian thinker who published books on social reform.

He believed his engine could release workers from wage slavery

and break corporate monopolies.

He wrote of his hopes that his machine would change the world.

But the gap between Diesel's ambitions for his engine

and the grubby realities of business soon widened.

Just because he was a brilliant engineer didn't make him

a brilliant businessman and as a result of battles about patents

and some poor business decisions,

he saw his wealth quite literally slip through his fingers.

By the time he stepped aboard the ferry in September 1913,

he had already lost 10 million Deutsche Marks.

Was that the reason he threw himself overboard?

Maybe.

But I have a feeling it wasn't just

because he was losing control of his wealth,

but because he was losing control of the destiny of his invention.

Rudolf Diesel, the pacifist and utopian thinker,

had become distraught by a new application of his invention,

an application that was going to change the face

of 20th-century warfare - the world's first-ever stealth weapon,

the submarine.

Exactly what drove Rudolf Diesel to suicide will perhaps never be known.

But what is certain is the submarine would be a turning point

in the development of the diesel engine.

As war approached in 1913, European nations had been

striving for decades to perfect submarine technology.

The problem was how to power them.

Steam engines were totally impractical.

The internal combustion engine seemed to be the solution.

The only question was

whether that would mean Diesel's engine or one of its competitors.

Diesel's compression ignition engine was one of two

major types of internal combustion engine being developed.

The other was this, the petrol engine.

The petrol and diesel engines functioned in very similar ways,

save one key aspect.

The fundamental difference between a diesel

and a petrol engine is the way you start the fire inside them.

Whereas the diesel engine ignites fuel by compressing air,

the petrol engine ignites

with electrically-produced sparks from a spark plug.

Spark ignition helped give the petrol engine a crucial advantage

over the diesel - it produced a more powerful combustion.

So, when the Royal Navy commissioned this, its first-ever submarine,

the vessel was equipped with a petrol engine.

The Royal Navy's top brass believed that the superior power

and performance of the early petrol engines would be the key to finally

making a submersible warship possible but trials soon proved them wrong.

And the reason these petrol submarines were about to run

into trouble lay in the engine's spark ignition system.

For a spark ignition engine like a petrol engine to work,

it needs a fuel that's flammable, it'll burn, but it's also volatile.

And you can demonstrate the difference between diesel

and petrol very easily, but I'm just going to try

and light the diesel in this container here.

And it goes out straightaway because that will burn

but it's less refined

so it won't set on fire just by putting a match in it.

Compare that with petrol.

And there you have the difference -

petrol is volatile, even at room temperature, it lets off fumes,

that's why you can smell it so easily and the vapour is flammable.

That is a very dangerous fuel to be around.

Early petrol engines leaked flammable fuel and fumes from every pore,

which made the Navy's petrol submarines so prone to fire

that white mice were kept onboard.

If the mice became overwhelmed by petrol fumes, then the crew

knew it might be a good idea to shut the engines down

and open a porthole which...

is easier said than done...

in one of these.

You can get a sense of what being stuck next to a petrol engine

in a submerged tin can was like by starting one up...

Ignition on. Here we go, wish us luck.

..which with a 100-year-old engine is no picnic.

Happy your end?

I'm not at the right point, am I?

If you get it set in the right place...

What? Do you think I'm too near me?

'I guess this is what you get

'when you try starting up a petrol engine

'in a documentary about the diesel.'

-Not enough effort.

-Is that what it is? No, tell me.

Literally, more effort needed.

HE GROANS

When did they invent the starter motor?

ENGINE WHIRS

Yes!

Finally!

Oh, my God, I'm knackered!

What a beast!

There is petrol literally dripping and oozing out of this engine.

Would you want to be in a submarine powered by one of these?

While the Royal Navy persisted with petrol-powered submarines,

the French and Germans were experimenting

with diesel-powered subs.

Diesel oil wasn't prone to fire like petrol

and the diesel engine's remarkable efficiency

gave the submarine something the petrol engine could not -

its most vital attribute,

the range to reach the enemy's vulnerable shipping lanes.

Britain would eventually commission its own diesel submarines

like this one, HMS Alliance.

Charlie Haywood and Leo Hubbard both worked on vessels such as these.

Charlie, Leo, I've never been in a submarine before

and you feel like you're in an engine walking through here.

Yes, they called me Piston.

THEY CHUCKLE

So, you, Charlie, you were a crew onboard.

On HMS Artful which is identical to this, basically,

and so I would have been on my first submarine

as Chief of the Watch in the engine room here.

How much of your life did you spend essentially living right next

to big diesel engines?

Eh, probably about...

-..ten years.

-So, ten years of your life, literally, feet from...

-Well, I used to go to shore sometimes.

-Did you?

-They let you ashore?

-Yes.

-So, yeah.

-So you must have quite a love affair with these things?

I wouldn't say that, I have a respect, a healthy respect.

They can go wrong very quickly if you don't look after them.

HMS Alliance was designed for service in the vast expanse

of the Pacific during the Second World War,

which is where the diesel engine's 30% fuel efficiency

became invaluable.

The petrol engine had efficiency of around 12%,

less than half of the diesel.

This meant, for the same volume of fuel,

a diesel submarine could travel much further than a petrol vessel.

How important was the distance you could travel in a submarine?

The range was important.

By the time you got on patrol, it'd be time to come back

if you didn't have a long range.

How long a range? How far could you go?

10,500 miles before you'd need to refuel,

on the surface at an economical cruising speed of 11 knots.

-10,500...

-10,500 nautical...

-That's a very long way.

-Yeah.

Would you have ever achieved that on a petrol engine

-in terms of efficiency?

-No.

-No.

-Couldn't.

Absolutely impossible.

No, you wouldn't and you wouldn't be able to store enough fuel.

The First World War was the submarine's proving ground.

The Royal Navy's first petrol-powered submarines had a range of 280 miles.

By the end of the war, the Germans were building diesel U-boats

with a range of over 11,000 miles.

With sufficient range to attack Allied shipping

in the Atlantic, Germany's submarines sank over 5,000 ships.

The diesel had won its first battle against the petrol engine.

The diesel engine gave the submarine the range,

safety and reliability it needed to become one of the iconic weapons

of the 20th century,

not a use that Rudolf Diesel would have wanted for his invention.

But the submarine also gave the diesel engine something,

a unique application,

a proving ground for its unique properties

and properties that, after the First World War,

would be in greater demand than ever before.

Despite the diesel engine's success in submarines,

the rest of the First World War was a victory for the petrol engine.

Most of the conflict's new vehicle developments were petrol-powered -

aircraft, tanks, trucks.

The diesel engine was too big, too heavy and too slow-running

to be of use in these new technologies

so when peace time saw an explosion in mass-produced road transport,

these vehicles were almost all petrol-powered too.

By the late 1920s,

there didn't seem to be a future for the diesel engine in road vehicles

but in the early 1930s, that was all about to change

as a result of one of the greatest untold stories

in the history of British engineering

and the key to that story is under the bonnet of this -

the Citroen Rosalie, built in 1934,

and the first commercially available diesel car the world had ever seen.

CAR HORN HONKS

What a beautiful car!

Now, buried deep inside here is one of the most important

technological innovations in the history of the diesel engine.

It's this, a Comet swirl chamber.

Now, it looks pretty unassuming, doesn't it, but it had

a seismic impact on the story of diesel-powered road transport.

The Comet swirl chamber was the key to making diesel engines small enough

yet still powerful enough to be used in road vehicles.

It was the brainchild of the man who established this cutting-edge

engine development company, Harry Ricardo.

Harry Ricardo was born in 1885

and designed his first engine as a schoolboy.

During the war, he developed engines for tanks

and used the profits to build his company.

In the 1920s, Harry set about cracking the puzzle of making

diesel engines usable in road vehicles.

For ex-Ricardo engineer Dave Morrison,

who worked with Harry, it was a passion for efficiency

that drove Ricardo towards diesel technology.

To give you an example, in his house,

he was so obsessed with not wasting water, and in those days,

they had no showers, they used to have baths,

and he had three daughters so there were five of them in the house.

All this hot water was just being wasted.

He couldn't bear this, so what he invented was a channel system

where the waste water from the bath went into his greenhouse,

provided a heat exchanger in the greenhouse,

and it enabled him to grow nectarines in Sussex.

MARK CHUCKLES

That's so brilliant.

Harry could see that the key to improving the performance

of diesel engines lay in the way they burned their fuel.

Because diesel is a heavier oil than petrol, it is less volatile

and harder to make burn.

The key was, how can I burn this fuel efficiently?

Mix up the air and the fuel?

Diesel, it's not volatile and you've got to try and sheer the fuel,

break it down into tiny, tiny droplets.

Harry's solution was the Comet - a pre-chamber that the fuel

entered before hitting the combustion chamber.

This ingenious component helped mix the air and the fuel

so that the combustion was improved.

Unique slow-motion footage shot in the 1970s

shows the incredible swirling of fuel and air created by the Comet chamber.

The imaging is utterly beautiful, isn't it?

On the left is the Comet pre-chamber, on the right, the combustion chamber.

So now here's the pre-chamber, the swirling pre-chamber for the Comet.

The fuel's injected, it burns, straight out of the throat

and forms two contra-rotating vortices...

-Oh, OK.

-..to complete combustion.

Having a Comet chamber is what allows, essentially,

the perfect burn and the perfect burn gives you the most power.

And that, in terms of its application in road-going vehicles

particularly, that would have been utterly critical.

That's right.

It's mesmerising.

The Comet pre-chamber was patented in 1931.

Its unprecedented power was showcased in 1933 when Britain's George Eyston

broke the world diesel land speed record in a Comet-powered car.

-VINTAGE RECORDING:

-Today, I have driven it on Brooklands track

and it has achieved a speed of over 106mph.

Incidentally, the fuel oil engine is the most economical one to run.

The fuel consumption is so low that on my record run

today at Brooklands, it only cost me thruppence.

The Ricardo Comet's first customer was AEC,

the company that built London's buses.

It was a staggering success.

The London General Omnibus Company were overwhelmed with

the smoothness of the engines

and they were, above all, very clean,

they were smoke-free, it was a revelation for the time.

And, of course, extremely economical, it was saving them a lot

of money in terms of running costs, that was the drive for doing it.

Within a few decades,

London's entire bus fleet had converted to diesel engines.

Because of the success of the London bus application, everybody wanted

to license these engines and they ended up in many different vehicles.

As the '30s rolled on, taxi, bus, coach

and road haulage operators across Britain

and the world were converting their fleets to diesel engines.

Almost all of these were powered by Ricardo Comet pre-chambers

or others like it.

The only failure for Harry Ricardo's Comet was the car I'm driving -

the Citroen Rosalie.

So why didn't it take off in the passenger car, then?

Petrol engines are more refined, they're smoother.

Diesel had a bit of a reputation for being a bit rough in taxis,

it hadn't been properly refined, there wasn't the need.

Even though the lighter, more powerful petrol engine

still dominated the car market in the 1930s,

thanks to the Comet, diesel's takeover of the roads had begun.

The Comet chamber is a true piece of British engineering genius.

It put Britain at the forefront

of high-speed diesel road vehicle engineering.

Today, driving along the road,

pretty much every vehicle you see bigger than a family car

is powered by a diesel engine and it all started right here.

By the end of the 1930s, Europe had returned to war once again.

In Germany, Rudolf Diesel became a propaganda hero

when the Nazi film ministry produced a biopic in 1942.

The film spotlighted his engine's contribution to the Nazi war effort,

something I suspect would have mortified Rudolf.

Tellingly, the film doesn't deal with the subject of Diesel's death

but a key montage did hint at the next stage

in the story of his engine.

Among the submarines and trucks were these - tractors.

The war would leave most of Europe facing food shortages

and in the '50s, Britain began a programme

to increase its self-sufficiency in food production.

It's places like this vintage vehicles rally in Cheshire where you

can trace the role the diesel engine would play in what was to come.

Mechanisation of British farming had started before the war with

steam engines like these.

I'll tell you what, they are beautiful, aren't they?

Utterly magnificent machines.

I mean, they're kind of like a crossover between the days

of the working horse with all the regalia they wore

and it was about showmanship.

They are works of art.

But in terms of practicality...

It's just never going to work, steam, is it?

Steam tractors were still in use on British farms in the 1950s.

One man who can attest to that is lifetime farmer Dick Walker.

-Dick, how old are you?

-84.

-Are you really?

-Yeah.

You don't look a day over...57.

-I was driving a steam engine when I was 15 years old.

-Really?

-Yeah.

-A big one?

-A big one. Full-size steam engine.

It must be so much work getting a steam engine going...

Oh, you had to be there an hour before you were

ready in the morning to light the fire and get steam up.

And then keeping it going all day long?

Keep stoking it up about every half hour all day

and filling it with water, hosepipe and coal all day long.

Britain's self-sufficiency plan meant upgrading the country's agriculture

with modern farm machinery.

Initially, this was done with petrol-powered tractors

like these, the famous Little Grey Fergie.

But in 1953, the UK's first mass-produced diesel-powered

tractor arrived - the Fordson Diesel Major.

And this would change everything.

Farmers are notorious for being quite conservative when it comes to

decision-making but it was these tractors, Fordson Majors, the classic

blue and orange, that convinced farmers that diesel was the future.

'Dick was one of the farmers who soon traded his petrol machine

'for a Fordson diesel.'

So, you've had a love affair with these your whole life, really?

I've got 17 at home, tractors, all vintage.

Here, just down the road, I only live two mile away.

I started collecting them 40 years ago.

The attraction of diesel tractors over petrol began with

their efficiency and lower running costs, but it didn't end there.

Petrol engines weren't ideal for outdoor conditions.

In cold weather, they had to use both petrol and paraffin fuel to operate.

And the petrol engine's spark plugs could malfunction

in the damp and rain.

Were farmers difficult to convince that actually diesel was the future?

Well, the diesel was a lot easier cos there was no petrol,

starting on petrol and getting it warm and turning it on paraffin

and once you started it on diesel, you could go all day, like.

And cheaper to run.

Just get it on, press the starter and go.

But the diesel engine had another attribute that made it better suited

to the rigours of agriculture than the petrol engine.

And I'm in a good place to demonstrate what this was.

Welcome to the brilliantly bonkers world of competitive tractor pulling.

So, the big question in the '50s was diesel versus petrol,

so we're going to put it to the test.

We have a 1950s diesel here, we have a 1950s petrol over here.

They are both going to compete on the pull. We have a crowd.

What we need is a driver.

If you've never seen tractor pulling,

let me give you a sense of what it is.

This is just like an Arctic Truck trailer

which has got a great big weight on the back of it here.

The weight at the back of the trailer moves towards the front

the further the tractor pulls.

The trailer has a sled at the front that digs into the ground.

This basically means the longer you pull,

the more load is put on your engine and, eventually, the tractor stalls.

I've never done this before, I have to say.

I've driven a lot of tractors, but I've never done a tractor pull.

Our demonstration will start with this intimidating beast -

a 1950s petrol-powered tractor.

Let's see how far this one gets.

Just like tractors working the field, in a pull, you have to keep

your engine in low gear until, as the load increases, the engine stalls.

So that is how far the petrol managed to pull the sled, so we're taking it

all the way back to the start and now we'll hook up the diesel.

Dick's kindly lending me his very own 1950s diesel-powered Fordson.

Now, this isn't exactly science,

but let's put diesel's pulling power to the test.

It's a while since I drove a tractor.

Hey!

But by some minor miracle...

..I get further than the petrol tractor did.

-Did I beat it?

-Yeah.

-Yes! By about ten feet, that's good enough!

Bring on the diesels!

What we've just seen in action is another of the diesel engine's USPs -

the fact that in low gears and with heavy loads,

the diesel engine is less prone to stalling than a petrol engine.

This made the diesel perfect for agricultural work.

Well, there you go, there wasn't a lot in it,

but these were the very early diesel engines.

It just got better and better from here on in.

With lower revving, torque-ier engines

that could just haul and work all day long,

the diesel engine had become the farmers' friend.

'The Fordson Diesel Major led a breakthrough for the diesel

'engine in British agriculture.

'By the end of the '50s,

'the market for petrol tractors in the UK had all but disappeared.

'Today, you'd be lucky to find any agricultural machinery in this

'country that's not diesel.

'Across the world, the picture has been the same.

'Between the '50s and the '80s, the world's population almost doubled.

'Diesel engine helped feed these new mouths.

'From tractors to harvesters, forklifts to forestry machines,

'global agriculture is now almost completely

'reliant on the diesel engine.

'But while the diesel was feeding an increasingly populous world,

'there was still the matter of how that population got around.

'For the best part of 150 years,

'the most efficient way of doing that had been rail transport.

'Rudolf Diesel himself had overseen early trials of diesel powered

'locomotives in Germany.

'And by the 1950s,

'diesel trains were well established in countries like the US.

'Here, however, things took longer'

because countries like Britain that had vast reserves of coal

found it much harder to wean themselves off steam power.

As far as rail was concerned,

Britain remained hooked on steam far longer than it should have.

'In 1955, for the first time ever,

'the largely steam driven British rail network was running at a loss.

'Increased competition from road transport,

'much of it now running on diesel, was eating away at rail profits.

'And when British Railways published its 1955 modernisation plan,

'it recommended that much of the network convert to diesel power.

'To understand why, I'm at Britain's last remaining working railway

'roundhouse in Derbyshire.

'Its manager is Mervyn Allcock.'

Mervyn.

-Hello.

-Hello.

-Mark.

-Good to meet you, Mark.

-Nice to see you.

'It was in these roundhouses that the earliest British experiments

'with diesel engines in trains were made.

'And these were the subjects.

'The humble shunters, the workhorses of the rail yards.'

-So that's this kind of locomotive?

-Yes.

It's the first train you always had on your kid's train set, isn't it?

-It is, yes.

-When you couldn't afford the really, really expensive,

-like the Flying Scotsman.

-That's right, you bought a little shunter.

-You bought a little shunter, didn't you?

-Yeah.

-What a treat!

-This is my kind of cockpit, Merv!

-It's fabulous.

It's fabulous, isn't it? It's basic engineering, but fabulous.

-Proper dials, big levers. What's not to love about that?

-Yeah! Indeed.

-So, can we fire this one up?

-We can, yes.

'It didn't take long for the diesel engine to win over those who

-'had to work with it.'

-Push the master switch on.

-OK.

-And then, if you want to press the starter button.

-Here we go.

There you go.

ENGINE STARTS

There it goes, that's it.

My God! What a difference...

Instantly, what a difference to if you were running a steam engine.

Oh, quite. You would have to get up many hours earlier,

starting the fire,

waiting for the steam pressure to build up.

So, you'd have a team of blokes who would have to get up

at like four o'clock or something to get the whole thing going...

That's exactly it.

'And now comes the realisation of a childhood dream, to drive a train.'

-Your hand on the brake.

-Yeah.

And if you just toot the horn, to say we're moving.

-Press it downwards.

-HORN TOOTS

-Ha-ha!

-And then take the brake off.

-OK, yeah.

Right.

-Give it a little bit of throttle.

-So, a little bit of throttle there.

-Yeah.

-Oh, my God! I'm driving a train.

I'm actually driving a train.

TOOTS HORN

-Get into second?

-Yeah. Drop the throttle off, change to second.

And again. That's it.

Ho-ho! Gear change! In a train!

'The stock in trade of the shunter

'was moving other trains about the yard.'

So we're going to hook up to the yellow one on the right, are we?

Yeah.

A little bit of brake.

Slowing us down.

And...that's it, we're on.

That close manoeuvring there, it's very subtle for a big, heavy thing.

-Absolutely, yeah.

-In a steam, what would you have to

do to be able to do this kind of close manoeuvring?

-You'd have to be very skilled.

-How heavy is what we're going to pull?

It's over 100 tonnes.

-You can really feel it there.

-You feel you've got it now, don't you?

Oh, my God!

'This is one of the most easy to use vehicles I've ever driven.'

That is actually so easy. Even an idiot can do it.

Honestly. I mean, having never driven a train, I've just shunted 12 tonnes.

And I tell you what really gets you is the subtlety of that.

-For something so heavy, you can... The fine...

-The control is there.

The control is incredible.

-Yeah.

-Absolutely incredible.

-It is.

Just ten minutes in here and you can see why the diesel shunter

completely revolutionised this kind of work.

'In the years following British Railways' modernisation plan,

'it wasn't just the network shunters that got diesel engines,

'but locomotives of all kinds.

'By the early 1960s, most of the fleet had been converted to diesel.

'But among the lines that hadn't was the East Coast Mainline.'

This was the prestigious line between London and Edinburgh,

the domain of the Flying Scotsman.

It was, if you like, the racetrack of the rail network.

Long, straight and flat, it cried out for a racehorse of an engine.

Something that would put Britain at the forefront of diesel train power.

The Deltic.

'The Deltic is one of the most incredible

'stories in the history of British Rail.

'This is the home of the Deltic Preservation Society,

'which has been safeguarding these locomotives for nearly 40 years.

'What makes these trains so special are their diesel engines,

'which is where I can find technician Alex Williams at work.'

-Alex.

-Hello, Mark.

-They don't leave much space for humans!

Mind your head as you're coming down.

-This is such a beast. It's huge.

-Welcome to the heart of the machine.

So, you're already into a job then here. What's going on?

We're pressure testing this unit

because it's had some coolant issues.

'The Deltic engine is a diesel like no other.'

This all looks a bit odd to me,

a bit upside down, cos I'm looking down into the underside

of a piston here, but I'm also looking at a piston here.

And it's just the same underneath and on the other side.

'What I can't see in this engine compartment is that the Deltic

'engine takes its name from its triangular shape,

'derived from the Greek letter Delta.'

Is that unique?

The idea of having them in a triangle is very much unique.

It's kind of like the Formula 1 engine of diesel trains.

Very much so.

'This very special engine has a story with a very unlikely beginning.

'In the mid 1930s, the German Luftwaffe was experimenting

'with a diesel engine powerful enough to use in its JU86 Bomber aircraft.

'The design was acquired by the British engineering company Napier

'in 1939. And after the war,

'the Royal Navy installed these diesels in motor torpedo boats.

'Alan Vessey was an engineer who worked for the Navy

'on the Deltic project.'

-So you know them inside out.

-Well, yes. I hope I know more than most.

So, what did it feel like to be part of a team,

working on something that was so state of the art?

It was remarkably complex at first.

And it was also top secret for the Admiralty.

Therefore, you couldn't openly discuss it in the engineering

world until the first engines had been successful in the first ships.

So you couldn't go down the pub and start bragging with your mates...

Not really, no.

'What made the original Luftwaffe engine

'so unique was something called opposing pistons.

'In any normal diesel engine, a single piston ignites

'fuel by compressing air against the top of the cylinder.

'With opposing pistons, there are two pistons in each cylinder

'and they ignite the fuel by compressing air against one another.'

So you're getting double the bang for your buck, if you like.

-You're getting twice the amount of power out of this thing?

-Yes.

'But Napier took the opposing pistons concept to another level

'when it created the Deltic engine.

'They put three sets of opposing pistons

'together in the inverted triangle shape.

'Each Deltic engine comprised six of these triangular

'arrays for a total of 36 pistons in a remarkably small space.'

So at 1,500 revs, with six banks operating,

you get 25 combustions in these cylinders per second.

That is the lower speed.

'So, when it came to choosing an engine to replace

'the Flying Scotsman, there was only one contender.

'When the first Deltic took to the tracks in 1961,

'it was the most powerful train in the world.

'It shaved an hour off the time from London to Edinburgh.

'The Deltic was to rail transport what Concorde was to aviation -

'the most advanced, most powerful technology of its kind.'

In its day, it was the world's fastest locomotive.

You might say the Luftwaffe had a hand in the greatest

story in British Rail's history.

In 1960, British Railways built its last steam locomotive,

but it wasn't just the age of steam trains that was ending.

On the global scale,

it was the great era of steam itself that was finally closing.

In 1964, the share of the world's power generated from coal

fell below 50% for the first time.

We had entered a new epoch of energy production,

an age increasingly powered by the diesel engine.

By the early 1970s,

the diesel engine was winning the race against the petrol engine in

almost all modes of land transport, with one notable exception - cars.

But that was about to change.

In 1973, the Arab nations announced an oil embargo,

following war with Israel.

The price of petrol skyrocketed.

With the spotlight on fuel efficiency, the quest was on to

design diesel engines that could replace their more inefficient

petrol cousins.

And the story of how this happened can be best told from a company

that was at its heart.

When we want a new diesel, we go to a car dealership, but when a car

manufacturer wants a new diesel engine,

they come to places like this - Delphi, one of the world's most

advanced diesel engine fuel

injection research and development centres.

'Ken Smith is a senior engineer at Delphi, who can help me

'understand how the diesel engine hijacked the car market.'

Until the oil crisis,

diesels had been more or less sidelined as work vehicles only.

And then in the '70s, the oil crisis comes along, everyone realises

we've really got to worry about the fuel economy of these things.

'The problem facing diesel engine designers was how to compete

'with petrol's power and performance.

'Initially, the answer appeared to be the Comet swirl chamber

'technology Harry Ricardo had trailblazed back in the '30s.'

Companies like Volkswagen, Peugeot, Citroen,

they started to develop very efficient engines...

The same system that Harry Ricardo came up with that

-went into the early diesel mass produced cars.

-Yes.

'But the Comet pre-chamber had its limitations and 1970s diesels

'were still underpowered, compared to their petrol counterparts.

'The answer was to do away with the pre-chamber and instead,

'inject the fuel directly into the combustion chamber.

'This had previously been impossible to perfect in small engines,

'until Delphi put a direct injection fuel pump into a 1984 Ford Transit.'

So the Transit, one of the most iconic vehicles of all time,

was that a pivotal moment, in terms of the development

-of the diesel engine that ultimately would come into cars?

-Yes.

That was a very efficient small commercial vehicle

and it was the first one that introduced a 4,000 RPM diesel

engine with direct injection systems,

the same concept that is now applied across everything today.

'Powered by direct injection technology,

'sales of diesels soared in Europe in the '80s and '90s.

'Environmental concerns helped fuel this demand,

'as diesel engines emitted much less carbon dioxide than petrol.

'By the end of the '90s,

'the diesel engine's assault on Europe's car market

'was in full swing, something that would have delighted Rudolf Diesel.

'He had written that his life's work would be complete

'when his engine was powering motor cars.

'It may be a little behind schedule, but today,

'half the new cars in Europe are diesel.

'But perhaps Rudolf wasn't setting his sights high enough

'when it came to what his engine might eventually achieve

'because the diesel engine's biggest contribution to the modern world

'hasn't been on the roads, but out at sea,

'something I've come to Felixstowe, Britain's busiest port, to witness.'

It's when you visit a container ship port like this that the extent of the

diesel engine's role in the modern global economy becomes very apparent.

'Today's world of intercontinental global trade depends on ocean

'transport to move billions of tonnes of resources and goods each year.

'The engine that has made this feasible is the ultra large

'Marine Diesel Engine.'

And I'm about to see one of the most modern examples.

It powers this hulking great container ship.

'In 1982, the first giant marine engines with over 50% efficiency

'were introduced to power container ships like these.'

The scale of this thing is absolutely mind-blowing.

'This is the Ever Lunar,

'the newest vessel in Taiwanese shipping company, Evergreen's fleet.

'It's a dedicated container ship carrying thousands

'of the now-standardised 20-foot containers.

'Melvin Lin is the company's chief captain

'and has served over 30 years at sea.'

-Captain Melvin?

-Glad to meet you.

Hello. Mark. Nice to see you.

-This is an amazing ship.

-Thank you.

-So, how big is it?

We can carry about 8,500 20-foot containers.

-So, these kind of containers that we're looking at now?

-Yes.

That's a lot of containers.

'The efficiency of the diesel engine on this ship

'gives it astonishing range.'

The vessel's maximum range will be

around 55,000 nautical miles,

which is more than 100,000 kilometres.

-That's twice the way around the Earth.

-That's right.

-Before we can refuel it.

-That's extraordinary.

And how many crew are needed to manage the ship?

Around 14 to 16, it depends.

-14 to 16?

-It's fully computerised.

'These controls hook up to an engine

'on a scale I've never before witnessed.

'Even getting to the engine room can induce vertigo.'

So, from the bridge, how many floors down to the engine room?

From the top to the bottom, there's one, two, three, four, five,

six, seven, eight, nine, ten.

-Ten.

-That's to the bottom. But now, we're only here.

-OK.

-So nine floors we've got to go down in the lift?

-That's right.

OK. So this is the control room?

Main engine control room.

'The engine room itself is like a cathedral of power.'

So this is the top, how far does it go down?

-We have to go down four floors.

-Four floors?

An engine that's four floors. For this, five floors.

That's bigger than my house.

'It's the size of these nine cylinders

'that gives the engine its huge power.

'The space inside the cylinders, the displacement, is measured in litres.

'And together, these nine cylinders displace 18,500 litres.

'Your car at home probably has two litres.'

So, how many horsepower? What's the power of this?

75,190 horsepower.

OK. Hang on a minute, then. 70...

Hold on, I'm going to do some maths now.

75,190. Right, I'm going to divide that by...

-Say 150 horsepower is a reasonably-powerful car?

-Yeah.

That's, like, 501 cars.

500 BMW 250 injection.

That's a lot of power.

It's a big, big ship.

All large commercial ships use diesel engines like these.

Not just all the container ships,

but the tankers and bulk carriers, too.

It's incredibly hard to give you a sense

of just how massive this diesel engine is.

But if you think behind the end wall there

is the propeller for this ship,

that if it was in this engine room,

it would fill it from a width point of view and more.

But it's driven by a prop shaft

that runs through these bearings all the way to the engine.

So the engine is the big green thing here you can see.

The flywheel is behind this arch.

But there are nine cylinders down here.

One, two, three, four, five, six,

seven, eight, nine cylinders.

Now we're going up. On this level, we have

turbo one...

..turbo two...

..and turbo three.

And the top floor of the engine, here you go.

This is the top of the cylinders.

It's a colossally huge engine, this.

I mean, it's just massive!

The numbers themselves just speak volumes.

It weighs 1,800 tonnes.

It's 75,000 horsepower.

It's 18,000 litres.

But what's perhaps most extraordinary is that in essence,

this is the same machine as Rudolf Diesel's original design.

100 years on, one man's invention

is powering the biggest ships in the world.

'I've only got a few minutes left before the Ever Lunar leaves port.

'So just time enough to see something very special.'

We're about to fire up one of the biggest engines in the world.

It starts with compressed air,

so some engines behind you will kick in first.

Really tense, this.

Here it goes. Here it goes now!

18,000 litres is now alive!

Look at that! Incredible!

Engines like these are the unsung workhorse of the modern world.

ALARM WAILS

There's alarms going off everywhere.

'Ultra-large marine diesels have transformed modern shipping.'

These vessels are so vast,

they look like they'd be painfully slow, but not true.

Today, the largest diesel-powered cargo ships

rock along at a staggering 50km an hour.

And that, with the greatest fuel efficiency

of any engine in the world.

50km an hour, is fast enough to water-ski behind.

The very first container ship in 1956 could handle 210 containers.

The increasing power of marine diesels has allowed

a 50-fold increase in the size of these vessels.

Today, the largest can handle over 15,000 containers.

If you loaded all those on a train,

it would be 91km long.

'The impact on shipping costs of all this

'has turned global economics on its head.'

The incredible power

and efficiency of 21st-century diesel-powered ships

means that it's cheaper to ship something from Shanghai to Felixstowe

than it is to deliver it from your local shop to your house.

'Around 99% of modern cargo ships of all sizes use diesel engines,

'forming the backbone of a diesel-powered

'network of global trade.'

Imagine a crop grown in Africa or Latin America

that's irrigated by a diesel-powered pump

and it's cultivated by diesel-powered tractors.

When the crop's harvested, it's taken to a canning factory,

probably in a diesel-powered truck,

and the canning factory is powered by a diesel generator.

The cans are then put in containers like these

and taken by road or rail, diesel, again, to a port,

where a diesel crane loads them

onto a diesel-powered ship that brings them here.

When they arrive, more diesel-powered cranes unload the containers

and put them on more diesel-powered lorries

and then they're distributed around the country on more trains,

trucks and vans, all powered by diesel.

The true extent of the diesel engine's role

in the modern globalised economy is simply astonishing.

Measured in the distance that goods have to travel from their manufacture

to their point of sale, about 94% of global trade is diesel-powered.

Today, the diesel is the most indispensible engine in the world.

It's not just powering cargo ships, but pleasure boats and ferries, too.

Not just agricultural machinery, but construction machines, as well.

Not just almost all commercial vehicles,

but almost all military vehicles.

The only notable area of transport it has not touched is aviation.

But like all engines that burn fossil fuels,

the diesel's future is unclear.

Having promoted it for its environmental friendliness,

we've now learned it emits gases

and particulates that are harmful to human health.

Rudolf Diesel would, no doubt, be reminding us

how his original engines ran on peanut oil,

and suggesting that biofuels could be a way forward.

But whatever the diesel's fate,

its importance to the modern world is clear.

Whether you like diesel engines or you loathe them,

I hope I've managed to convince you that the way we live

today would be very, very different without them.

Just as steam engines powered the Industrial Revolution,

the diesel engine has been the driving force

behind the globalisation of our 21st-century world.

Now, whatever the future for the compression-ignition engine,

I for one think it's high time we doffed our caps to Rudolf Diesel

and gave his simple, but brilliant invention a little more love.