Original subtitles

The submarine's huge - it's 100 metres long,

it's three decks deep.

There is no inch of the submarine that's similar to another inch of it.

I would definitely put it in the same league as the Space Shuttle

or projects of that size.

To my mind, this is a 7,000-tonne Swiss watch.

There's an extraordinary amount of expertise

in putting one of these submarines together.

There are stages when it's like blacksmithing

and there are stages when it's like brain surgery.

The team I've got have been working together for over 20-odd years.

I mean, we're used to a lot heavier. This is a baby.

I'll be fully qualified in September 2010, which is really daunting -

being able to say, "I will be a qualified electrician."

I'm in charge of purchasing submarines

for the Ministry of Defence and it's my job to make sure

that the programmes that we're hearing from the company

are sensible and real and we're getting value for money out of them.

This is number one seagate.

At the moment, she's laying down in the recess.

We're unable to shut the gate and make this area non-tidal.

It's obviously quite a serious thing when a 380-tonne gate

has collapsed on the bottom.

It's a big, big engineering challenge.

Without that gate in place, this submarine will not leave Barrow.

This is a key point for the Royal Navy, bringing Astute out.

If I get that wrong, I'm certainly aware of the amount of scrutiny that will be coming down on me.

Anthony, my son, he said, "What do you do, Daddy?"

He said, "I build submarines for the Queen."

It's a wet and windy weekend in the middle of November.

And the first new British submarine to be built for ten years

is now preparing to sail out into the open sea

for the very first time.

Is my cap badge in the middle? Yes. You're perfect!

Good. Because often it's round there.

14 years in the making

and costing over £1 billion,

she is one of the most technologically advanced machines in the world.

She's a world-class submarine,

in her sense of technology underwater and above water,

the weapons she can carry to sea

that attack not only ships, but the land targets.

She's an awesome vessel.

Impressive as she is,

her final exit into the open sea is not going to be an easy one.

Much of Britain has experienced the worst storms of the year,

with strong winds and heavy rain

causing flooding and damage across the country.

We have very strict criteria for making sure we have a safe exit.

And the rain only affects the visibility on the day.

It's the wind that matters.

This is the story

of how one of the world's most complicated machines is built.

And the people that build it.

It's about five to seven and I'm going to work.

I've been in the Navy almost 30 years now

and I've spent probably, literally, about 15 years underwater in submarines.

It's the start of a typical working day

for the people who build Britain's nuclear submarines.

There is a lot of people that I know that work in the yard.

Obviously there's Ged, my husband. My sister-in-law works in there.

My brother-in-law works in there. My brother works in there.

I would say every family that I know,

at least one or two people actually work in the yard.

Barrow-in-Furness is a town of 62,000 people

on the edge of the English Lake District.

The town has an amazing history of building submarines,

launching its first in 1887.

It only takes me about ten minutes, if that, to get to work.

And generations of the same families from all around the area

still build them today.

I'm just swiping on.

This is electronic timekeeping to make sure we're in at the right time and not late.

The capability of our submarines is something that we want to keep to ourselves,

because if other countries, other organisations, know the capability of the units we operate,

then they can develop ways of defeating that capability.

So that's why we're very careful about who comes on this site

and also what information we're allowed to give as well.

The current owner of the shipyard is British defence company BAE Systems.

The business employs over 35,000 people across the UK,

with around 5,000 of them in Barrow alone.

BAE Systems is not without its critics.

But in this town, the company forms the very backbone of the local economy.

We have extraordinary numbers of people working here,

with all sorts of family relationships. And the business has

a real family feel to it as well. We play a vital part in the community.

A lot of salaries and money goes back into the community through our shipyard.

Britain's need for submarines splits opinion.

Some think they're critical for defence,

others that they're a waste of taxpayers' money.

But with a potential order book of seven Astute submarines,

Barrow depends on them to prosper into the next decade and beyond.

This is the only site in the UK where we design, build, test and commission

nuclear submarines for the Royal Navy.

Britain's current fleet of attack submarines are coming to the end of their working lives,

and the Royal Navy are desperate to get their hands on this new class.

One of the world's most technologically advanced machines,

they pack weaponry, life support and all the sensitive equipment

a submarine needs to operate -

including a nuclear reactor that will power its engine for 25 years

and never need refuelling.

At almost £1 billion, this submarine doesn't come cheaply.

Or quickly.

The submarines take years to manufacture. But what we do have

on-site here are four submarines in various stages of their build.

The first one is afloat, outside the Devonshire Dock Hall.

The second submarine is behind me. The third submarine is just about whole.

We've got a few more units to weld together.

And the fourth submarine is, at the moment,

in a series of units being outfitted.

So you can look around the site here and see from first rolling the steel

to actually operating the systems and preparing to go to sea.

Building four boats with a staggered production schedule,

the range of skills needed on site is extraordinary.

The people here are unique - in not only what they do,

but how they do it.

I'm just changing into my overalls.

I have to wear them so you don't cut yourself or hurt yourself.

But they're not very flattering, to say the least.

I work on that boat. Boat two, Ambush.

This one closer to us is boat three.

We're going down there, to the toolbox talk.

That's Nige, the team leader.

Morning, Nige.

Erin Browne will be trained in the electrical systems

of the submarine and is one of only 300 electricians on the build.

When she's qualified, she'll be part of a very elite and highly-skilled club.

That was our toolbox talk. We have one every morning at half-past seven,

telling us any health and safety issues from the day before,

any communications - basically keeping us in touch with what's going on around the yard.

The whole site covers 169 acres,

making it Britain's biggest shipyard.

And as a hub of high technology,

nuclear submarines aren't just built in Barrow - they're designed here, too.

The submarine is designed to operate in a very hostile environment,

which is under the sea, at pressure.

It's a salty environment - it wants to corrode.

At the same time, it has to keep its crew of 97 crew safe

for about a three-month period without surfacing.

So it has to make its own air, its own water, carry its own food.

It has to operate as a war-fighting machine as well.

The submarine has to be able to withstand underwater strikes and explosions.

And so computer simulations put the hull through extreme testing,

to ensure it will keep its crew safe if attacked.

With around 600 people involved in the design process alone,

this is one of the largest concentrations of such expertise in the world.

This is the most complex submarine we've ever built.

It's got 250,000 miles' worth of cable onboard the boat.

It's got something like about 25,000 valves.

We have to produce more than 100,000 drawings,

so all the drawings originate from our computer-aided model.

It took four years to design the Astute,

which will contain more than a million individual components.

Designed on a computer,

but built by hand.

My job is steelwork team leader.

I started off as a shipwright in 1982

and worked my way up through the business.

I've been in this shop now for about 12 years.

This is the place where all the submarines start out life.

This is where the raw plates come in by road.

The wagons back into the shop,

the magnet crane removes them and puts them into the piles.

Using a plasma cutting machine,

each plate has carefully designed patterns burnt into them.

When each plate comes off the burning machine,

what we do, we leave a small stitch of metal,

which stops all the individual pieces falling out on the floor.

Peter, the burner, what he's doing now is cutting through all the little stitches

so the piece parts will fall out.

They all go where they need to be, to be built in the right time, just like a massive Airfix model.

The steel that makes the hull

is shaped and rolled until the massive sections are completed.

Peel away the special coating and the pressure hull is simply a watertight tube,

capped at both ends with tanks that fill with water,

to help it dive and surface.

And finally, there's a fin section on top.

The hull is made of eight separate steel sections,

each around 11 metres in diameter.

The boat is 97 metres long and when finished, weighs 7,400 tonnes.

The huge sections are made in a different part of the yard

and when completed, need to be transported down a public road

to the building where the vessel is actually put together.

At 260 metres long,

58 metres wide and 51 metres tall,

this building is one of Britain's biggest sheds.

This is the DDH, which stands for Devonshire Dock Hall.

The submarines are built in here because it's where all the top-secret stuff is,

where people can't see, so it's housed and it's hidden. It's where the magic happens, I suppose.

The Astute is the first class of British submarine

in which sections are worked on vertically.

This allows easy access for the team,

before the section is turned the right way up, or ship-wise.

Right. What we've got is a unit like this.

We'll lower it down

till it's on its two turning shoes at the far end there.

What we'll then do is rig Frank up to the shop crane up here.

He'll start turning it over like this,

so it's rolling on the two turning shoes.

My job is just a second set of eyes, just to make sure

that everything runs smoothly.

I'm the appointed person, if anything goes wrong,

it's me that gets it in the neck.

We're at a critical stage now in this turn

where we've transferred the weight of the unit onto the mobile crane.

The mobile crane is holding the load.

We're now going to derig the shop crane and

rerig it onto these eyeplates on this lower side of the unit.

It's a critical point now. If either of these two cranes fail...

Well, I wouldn't like to be standing here. I'll put it that way.

A submarine packs in three times more machinery and equipment than any surface ship.

But most of the back of the boat is taken up with the nuclear reactor,

the engine and all the different back-up systems.

We're now in the diesel generator space.

Should we lose a reactor at sea, then we would rely on these diesel engines to provide

the electrical power for running the minimum of equipment that we need to live as human beings.

If you really need them at sea, then it's a bad hair day and you've got some problems, yeah.

For a submarine to operate effectively, it has to be virtually undetectable.

To do this, machinery is isolated from shocks, noise and vibration.

This mounting here is an example of how you decouple the noise or the vibration

generated from the diesel engine here from a sensitive piece of equipment.

You can see here that this allows this piece of equipment to move.

We expect the Astute class to be one of the,

if not THE quietest submarine in the world.

One of the reasons for that is the technology we employ on here

to prevent the vibration being transmitted to the hull.

MUSIC: "The Blue Danube"

Today, boat three is taking shape as some of her biggest sections are moved into position.

Submarines take on water to help them dive.

And a lot of it comes into the streamlined 270 tonne forward end construction.

This unit also houses the submarine's sonar equipment.

Active sonar works by emitting a pulse of sound and then calculates

the amount of time it takes to hit an object and bounce back, which determines the distance.

But the Astute will normally use passive sonar,

which simply listens to the sea to detect and identify objects.

It's claimed this technology is sensitive enough to hear a boat

leaving New York harbour from Southampton.

The other end of the submarine is capped with the after-end construction.

Weighing in at around 230 tonnes, this also takes on water when the submarine dives and

houses the mechanisms that control the submarine's rudder and propeller shaft.

My name is Derek Parker and I work for Production Services team.

We're in charge of all major movements in the DDH.

Do all the heavy lifting, do all the shipping of modules

and moving all the units.

We're setting up now ready to move the aft-end construction

up to the after dome.

There's four transfer cars.

They can actually pick up up to 250 tonnes per car.

We're moving 39 metres

and it's a metre a minute it travels.

Everything's away, so...

we're ready for this. We're ready to go then, boys.

Green button. Let's go. Thank you.

The team I've got have been working together

for over 20-odd years,

so they know the system inside out.

I mean, we're used to a lot heavier.

We're used to something like 600 tonne,

putting it together against another unit. This is a baby.

This is a little baby!

As we get six foot off the unit, we have to put people inside.

So we bring more people in cos we've got to watch as we go up towards the dome,

so that we don't hit that unit.

As you can see, we've only got three inches to go now.

Now we're going to go on an inch button, where we can do it an inch at a time.

Inch it up, Tony. That's right, mate.

Just the last inch, now, boys.

That's it. Thank you.

We can't do more with the transfer system, that's as close as we get it.

And it's within half an inch.

It's gone well.

One of the biggest and most complicated areas of the submarine

is the command deck - the nerve centre of the boat,

built as a separate module in another part of the shipyard.

The command deck module is 22 metres long and weighs 180 tonnes.

It contains the navigational controls, sonar, communications and weapons systems.

The captain's cabin is on the top deck, while the second deck

is where food is prepared and the crew eat, sleep and relax.

We put all the the combat system together here,

make it talk to each other and then the boat, the CDM, gets fleeted from here

down to the submarine, then set back in the submarine.

This is called the sonar cab space.

Various equipment in here - the processing for the sonar,

for the networks, for the command systems.

I'll show you the sound room.

This is where the sonar sets up.

This is all the command system.

All the sonars and all the other equipment on board

pass all their information across to these desks.

OK, carrying on aft, this is the commanding officer's cabin.

Again, at the moment, it's pretty bare.

The captain is the only man onboard who has a cabin to himself.

He's the sole occupant of this one.

This is the lower deck of the CDM, which is mainly accommodation.

There's 19 bunks in this space - quite cramped.

But nothing different to what submariners are used to and have been used to for many years.

When I was in the Navy, all we had was a bunk light.

Nowadays, they have iPod chargers, they have all sorts.

OK, coming to the after-end of the command deck now,

we have both the junior rates' and the senior rates' messes.

This is where they live when they're off watch as well.

And the final compartment is the galley.

Or the kitchen.

It's got every possible modern convenience.

Everything. I don't know - it's got more than my kitchen has!

There's a little bit of finishing off still to do,

but we're not far off completion, whereby this will then be transported

down to the DDH and slotted into the submarine.

Once the units are fully fitted out, they can be joined together.

We're going right through this unit into the next unit, and we're going to go down the tank.

A job for the welding team.

There's always one squad on nights, one squad on days.

We will be on the job until it's finished.

It's hard work. I'm on my second T-shirt now. I'm sweating.

I'm tired. I'm going to be here till about 7 o'clock tonight. So...

We all have a section each. Start at the same time, finish at the same time, more or less.

Hopefully, the results are all the same - the welding's good.

Compared to some of the spaces on this submarine, this space is big.

This is my job down here.

I've got to crawl down this gap on this ladder to get down.

The job will take over two kilometres of welding to complete,

so the team will have to work in unison,

with accuracy being key to ensure the units are in perfect alignment.

Other side of that bulkhead is the nuclear reactor.

To the right, the command deck module goes in this side.

This is my gun. Press the trigger and the gas comes out first.

Then you let go of the trigger.

The wire obviously feeds out with the power going through it.

If you get too hot or get too dry a mouth or lose too much fluid, you've got to come out.

Heat-wise, it's the same everywhere.

It's extremely hot wherever you are, as you can see.

It is hot. It's hard work, it is a hard job to do.

It will take eight welders working day and night shifts

three weeks to join just two parts of the submarine together.

And the tanks they work in can reach temperatures of up to 130 degrees.

On a job like this, we'll be doing miles of welding.

Absolutely.

We used coils of wire and I think they hold about about 10lb of wire.

We can put one or two of them in in a shift, easy.

So...there's a lot of welding involved.

I take pride in my work. I think a lot of the welders do.

It's a bit of a challenge now and again, so, yeah.

Bit of a challenge with each other as well.

When you're welding, it's got to be right.

We have a bit of a laugh over it -

bit of a dig at each other - so you take pride in your work that way.

Ged's worked in the yard

for about 25 years now.

He left school when he was 16 and went straight into the yard.

Left in the June and went in the September.

I like it because I think it's permanent, it's stable.

You know, he's got a good job there

and he's home from work within five minutes.

A welder's a very, very manual job. Very dirty.

And he has to get into some sort of tight spots that I certainly couldn't get into, so...

Once the welding is finished inside, the team move to the outside of the hull to complete the job.

It's quite an important job.

If anything goes wrong with the job,

it goes on my record. I did my first one of these aged 18.

I think I'm the youngest one to do one.

Quite proud of it as well, really.

This is finished now. They'll crack-detect it.

Then it'll get ultrasonic tested,

which is just like a baby scan, really.

You put jelly on it, put a probe over it.

Just to make sure there's no muck or defects in the metal.

Then they'll X-ray it just to further check it again. Just to make sure.

There's lives at risk, so it's got to be right.

Where there is a join,

there is usually a weakness.

But in the case of the Astute,

the metal used by the welders is actually stronger than the hull.

This innovative work is done on-site by a team of scientists and engineers.

In the mechanical test area,

there are various pieces of equipment and techniques

which allow us to characterise the way materials behave,

such as tensile testing, which we use to pull material apart.

Or impact testing.

When two sections of the submarine are joined together,

we will have specified the materials that have been joined together.

We will have developed the process which joins the material together.

And we will have assessed the suitability of the material that goes into joining the two pieces together.

Boat two is ready to be outfitted.

The vessel will eventually contain over one million components,

which includes 23,000 pipes and over 100 kilometres of electrical cabling.

Just going to go into the workshop now -

go see Carl and see what the plan of action is for today.

With a maximum of 290 people allowed onboard boat two at any one time,

the different teams need to work together.

They will literally build her by hand.

The job that we're doing today is going to be in the captain's cabin,

so it's quite a small compartment.

Just been to the PAM cabin to get our PAMs - personal air monitors.

We need them for gases or if there's a gas leak, such as argon.

Argon's really dangerous. They say two lungfuls and it kills you straightaway. So, nasty!

Before we go onboard, the last thing we've got to do is swipe on with our passes.

That's just so they know how many people are onboard,

so that if there's a fire, they know how many people to get off-board. Things like that.

Erin is one of 500 apprentices and graduates working in the shipyard.

Apprentice schemes all over Britain are now being reintroduced,

to stop the decline of traditional skills.

And this is especially essential for the survival of Barrow.

This is the captain's cabin space. Ooh!

This is a call signal station.

So if the power goes down on the boat and you can't contact other areas,

this will have a handset on it.

So it's like a wind-up phone.

Apprentices always work with someone already qualified,

known as a journeyman.

I basically get a step-by-step guide through how to do something

until I've learned - until I'm confident I can do it myself,

and then I do them on my own. But I've never done one of these before, so Carl'll tell me what to do.

These cables are going to be going into the tops of the terminals,

which are connected to the bottoms of the terminals.

All these colours go up the side and then they're all connected in there.

We've got blue and black, red and black, then there's three white and black ones.

We'll be able to work out on the drawing which one goes where. So just them ones?

Yeah.

What next? Three and four.

These are the first submarines we've built for ten years and a lot of the skills have been lost.

We had a spell with no apprentices coming through. We've had to start it up again.

If you didn't have apprentices, you'd be struggling in the future.

This is the big employer of the town.

We need this to keep going.

Good? All right. Yeah.

Sorted.

Erin did well. She looked at it, she did well.

Nice and neat. So, good job. We opened it and there's

loads of terminals and I thought, "Looks complicated."

But once I read the drawing and understood it, it was pretty easy.

While the teams continue to finish the inside,

a very special process is beginning on the outside.

The surface of the boat is covered with around 40,000 rubber tiles,

designed to make the boat almost invisible.

The rubber absorbs and then breaks up enemy sonar waves,

stopping the signal returning and giving the Astute's position away.

This rubber blanket also gives added sound insulation,

making the submarine even quieter.

Each submarine will spend around five years inside the Devonshire Dock Hall,

before being removed and lowered into the dock outside by a massive ship lift,

capable of handling vessels weighing more than 16,000 tonnes.

Once in the Wet Dock,

the submarine can be fine-tuned and finished.

Coming on!

Stop! Unlocked.

The weapons storage department,

or torpedo room, is where weapons are loaded, stored and fired from.

The Astute is armed with Spearfish torpedoes, that have

a range of over 65 kilometres and weigh two tonnes each,

and Tomahawk cruise missiles,

able to accurately hit targets more than 1,000 kilometres inland.

However, as an attack submarine, the Astute is not built to carry

the controversial Trident missile system.

Today, the crew are engaging in a war-game exercise,

to test that all the equipment is talking to each other correctly.

The plan today is to run three scenarios.

These scenarios will test all aspects of the system,

both, er, physically

and the crew as well. It will test them as well.

OK, listen up, guys. This is your brief. Your task.

You've been allocated a patrol area in the Norwegian Sea

with an assigned role of surveillance and intelligence gathering.

Patrol the area and attempt to covertly trail

any deploying submarines which you detect and classify.

You are to maintain a fire control solution at all times whilst on the trail.

If you detect the Delta Four preparing for a weapon firing,

you are to conduct a simulated Spearfish engagement,

including water shots to ensure counter-detection.

You have two hours and 30 minutes to save the world.

Dangerous submarine contact.

The control room up here is where we prepare the fire control solution for firing a weapon

and then down below in the weapon stowage compartment, or bomb shop,

that's where we actually fire the weapons from.

It's simulating the submarine being used for what it's intended.

Classified Oscar.

'Stand by Spearfish attack, track 35 is targeting Classified Oscar.

'From two tube.'

Valid active contact.

Valid active contact. Weapon two.

DISTORTED SPEECH OVER RADIO

The command system uses its various algorithms

to work out where we think the target's going to be.

And then once we've got a good fire control solution on the target,

we'll try and fire a weapon at it.

Valid active contact bearing 146, range 10,700 yards.

That is the target. Continue the attack. Roger. Continue the attack.

Starboard fire. Track 35.

Starboard fire. Track 35.

Weapon is in weapon mode.

It's gone very well. I think the crew were very impressed

and certainly, our team were very impressed.

We all worked very hard. It's been a very long day. I think we've all got something out of this.

With the command deck fully operational,

the last major engineering feat to overcome is also the most difficult.

The submarine's nuclear reactor will need to be switched on.

Safety is the first priority.

And the people of Barrow need to be prepared for the unlikely event of a nuclear accident.

SIREN WAILS

This is the first time in ten years since we've last operated a nuclear reactor.

There are plans that have been put in place by the civil authorities that we've signed up to.

There's a lot of eyes watching how we do our business here.

There's a lot of auditing done on a very regular basis.

So, yes, we're watched and very open in what we do here.

Doesn't bother me. It's just part of the town and part of my growing up.

If there's an emergency, they will sound that buzzer.

If you hear that buzzer going, you know there's something wrong.

The shipyard send out leaflets -

what to do in an emergency.

An innocuous looking packet of tablets.

These tablets are there to protect your thyroid.

But we've never had a nuclear emergency in all those years,

so, why worry? I think what people worry about round here

is where the next shilling's coming from to buy the tea.

STEEL DRUMS PLAY "In The Mood"

For a town that's been building nuclear submarines for 50 years,

testing the warning systems is just a routine event and doesn't interrupt everyday life.

Usually I'm wearing big blue overalls, nice and baggy.

But you can't have a carnival without all the sparkles.

This is obviously a lot sparklier and a lot more colourful!

It's nice to be able to come out of work and have a different life.

You have to have a different personality to be able to get on with the guys.

But it's good to come and have a little break from it.

I don't miss out on any of the girlie stuff,

because I see these twice a week.

What do you think about me working in the yard? I think it's cool!

Why is it cool? Because you can fix my plugs.

That's all I'm good for, is it? Fixing your plugs!

Landing is fine, land at your discretion.

The wind 180, four knots.

'Roger that.'

As the summer turns into the autumn,

boat one is nearing the end of its testing phase

and closer to having its reactor switched on.

So it's now coming under close scrutiny by the man charged with

ensuring the vessel is safe and ready to be delivered to the Royal Navy.

It's all kind of coming together. Right. Thank you.

We're going to test everything.

Cooking a curry and lasagne.

We're going to serve it to an admiral in about an hour's time.

Um, passes first.

I've been on two different types of submarines

and this is the biggest galley I've ever been on. It's absolutely massive.

The admiral has come to hear first-hand how close they are to switching the nuclear reactor on

and taking the submarine to sea.

Hello. How do you do? Hello, Coxswain.

Generally, just a normal working environment, it's not bad at all.

It's not so hot that you can't work in it.

Where are we having lunch? Here? In here, sir. Good.

Him having a bit of dinner is a bit of a bonus for him. I'm keen to hear what it's like at grassroots level.

The main priority is just to make sure everything works and we can actually work in here.

Which other defects have emerged that give you a sense that we're going to have a tricky month ahead of us?

I'm in charge of purchasing submarines for the Ministry of Defence.

It's my job to make sure that the purchasing operation

is well-founded

and that we're...

That the programmes that we're hearing from the company

are sensible and real and we're getting value for money out of them.

And wrestling the boat from the dock, that sounds like an negative thing,

but wrestling the boat out of the hands of the dockyard that have loved it is what we do.

After his inspection and discussions with the crew,

Admiral Lister needs to take his findings to the managers of the shipyard.

We have meetings with Admiral Lister at least once a fortnight.

We had originally hoped to be ready to go to sea late summer.

We're a little bit later than that now.

We've had no fundamental issues, but we have had some minor teething problems and difficulties.

Nothing major, but a few obstacles that we've had to overcome.

The meeting will last late into the night.

Obviously, we're interested in your reflections on the visit on the boat we've just done.

Then I wouldn't mind quickly going through the agenda for tomorrow, to make sure we've got that done.

Right. In terms of technical progress,

where you've handed over compartments, they're impressive.

The wardroom and the junior rates are very good indeed.

The people who've fitted them out should be congratulated.

Overall, though, I'd have expected you to make more progress in handover.

My quiz to Alan and Paul as they showed me round was,

"Why haven't you moved on more than this?"

And they were telling me they've been clearing defects like nobody's business.

Yeah, the word "defects" is something we've debated.

In the construction industry, I think they use the word "snagging".

I know in the US, they use the word "unsats" - unsatisfactories.

We use the word defects. Anything that doesn't comply with the requirements or the specification.

So the vast majority of defects are pretty modest. They're things like paint spills,

tally plates missing, chips in varnish. Those sorts of things.

That's my challenge to you. Is this going at the pace that we need it?

We need this submarine. We absolutely need this submarine.

It's hugely frustrating - not just for me, but for the whole company.

We really do want to see Astute go to sea. We want to show what a capable submarine it is.

The Astute is almost four years late on its delivery

and estimated to be overspent by around £800 million.

BAE Systems inherited some of these problems back in the 1990s,

before they owned the company.

Design and contractual issues hampered the early stages of the project

and apprentice schemes had been stopped, which meant skills were being lost from an aging workforce.

In 1999, when they took over the shipyard,

BAE Systems had to implement new design technology and reintroduce the apprentice scheme.

Only now is the first of seven vessels about to be delivered to the Royal Navy.

What drew me to the submarine service,

particularly as an engineer, was the nuclear aspect.

I find it quite fascinating that we can produce so much energy

for a submarine all in such a small tube,

going around the world for months at a time.

Doing things that people don't necessarily know about.

I'm a keen biker. It's a beautiful ride in.

The Lake District is my favourite place in the country.

And living in Bardsey, it's a beautiful little village as well,

with some special attractions.

Commander Paul Knight is overseeing the nuclear reactor being switched on -

the last job before the boat can leave the dock.

The design of our reactor is confidential.

We don't want to let the design out

because it does give indications of the performance of the submarine.

And also, the technology that's behind it is obviously valuable to the nation,

and we wouldn't want to share it with other nations.

You take the reactor critical by taking the control rods out of the reactor core.

It starts off very low power,

producing a power which you can barely light a light bulb with,

all the way up to full power, which is obviously a confidential figure.

I can't tell you.

But is enough really to power a city the size of Southampton, really,

is the comparison we make.

It's the first time in ten years

a nuclear reactor has been switched on anywhere in the UK.

But the people of Barrow take it in their stride -

including former shipbuilders who've seen it all before.

It's just an everyday occurrence for us.

Not that it happens every day or every week.

It only happens at the tail-end of the build of a submarine.

There's never been an accident. The things are totally safe.

Hopefully. Touch wood.

It is a bit of a strange thing to be used to, obviously.

It's summat you grow up with in the town. Yeah, I-I-I can't see...

There's nothing to be frightened of.

We're all doomed, sir!

It's Saturday morning,

September 5th, and we're starting power range testing today.

Good morning.

It's just a day like any other in Barrow.

But inside the shipyard, the reactor is carefully being switched on and monitored by nuclear engineers.

OK.

We've started. That's good.

That's the first time we've taken a new design of a reactor critical

on a submarine for ten years as well, so it's a very big milestone -

not only for the Astute project, but also for the UK as a whole.

The design of the reactor is top secret,

but there are some elements that are unclassified.

It's protected by special shielding

that weighs around 100 tonnes and protects the crew from radiation.

It's fuelled with an incredibly radioactive substance, enriched uranium.

When the reactor is started up for the first time, a neutron is fired at a uranium atom.

That uranium atom splits, or fissions,

releasing energy and freeing more neutrons

that trigger the same process of splitting in surrounding uranium atoms.

Once this chain reaction becomes self-sustaining,

the reactor is said to be critical and is generating an enormous amount of heat.

Once we've ensured the design is correct, the instrumentation is correct,

we then move up in power in gradual steps,

resulting in, in two weeks' time, full power operations.

The huge amount of energy the reactor is creating is used to heat water.

The water, under extremely high pressure,

which prevents it from boiling, passes a heat exchanger,

which contains another circuit of water at a much lower pressure.

This water DOES boil and creates steam.

The steam drives turbines and the turbines generate all the power the submarine needs.

The Astute is, in part, an old-fashioned steam engine -

though coupled with 21st-century nuclear technology.

Yeah, it's been not just a tough week - it's been a tough few months, really, getting here.

Yeah, definitely. It's a relief, I guess, for a lot of people who've worked very, very hard.

And fingers crossed, it should all go smoothly

and we're one step closer to exiting Barrow

and taking the submarine to sea and handing it over to the Royal Navy.

But as that moment gets closer,

an unexpected and unforeseen obstacle appears from nowhere.

And this one could stop the submarine leaving Barrow altogether.

This is number one seagate, a flap gate by design. It's rather like a drawbridge.

At the moment, she's laying down in the recess.

We're unable to shut the gate and make this area non-tidal.

The submarine only has a certain amount of time to get from the dock to the deep water.

And without the gate, this timing is next to impossible to control,

meaning the Astute's exit would become a huge gamble.

The only way we can take the submarine out now, with one gate out of operation,

is to time it precisely such that we're in the lock

at the right height of tide and then take her straight out to sea.

You then have to accelerate the exit speed through the channel.

You'd be doing handbrake spins round the corner. It's just not something we would consider.

With the risk of grounding the submarine a serious one,

the only choice is to raise the lock gate from the seabed -

and although the gate is actually owned by Barrow's Port Authority,

everybody agrees to work together to find out why it isn't working.

And then hopefully fix it.

With daylight, the fault is clearly evident.

This is the side one where you can see a crack on the north side.

On the far side, this actually sheered off completely.

It's a big pain, yes. It's a lot of work.

It's a mammoth task - the gate is over 20 years old -

but a team of engineers will have to figure out a way to fix it.

We do want the nuclear submarine going out and so we have a very vested interest

in getting this gate up and running and operable.

It's been a few weeks now since you guys have been in town.

The gate has moved on significantly from where we were three weeks ago.

The main issue we had was the fact that this bracket here had failed.

When we recovered the gate,

we weren't given an awful lot of surprise in terms of

the extent of the work. We have fitted initial brackets to the structure,

basically just to make the structure a bit more integral.

The gate may be fixed, but the job isn't over.

It's no easy task to re-install the 324-tonne piece of steel.

It's about the same position it was in when we took it out about two and a half months ago.

It's a drawbridge-action gate.

Four times a day, it's cycled - on each tide.

It's operated from the winch-house, which is located just behind.

For the next two days, divers and engineers will work around the clock to hit their deadline...

Without that gate in place, this submarine will not leave Barrow.

..until it's back where it belongs.

It's gone very close to programme and most programmes slip quite a lot.

But this one hasn't slipped too much and today's the big day. It is a big sigh of relief.

With the gate back in place and the dock fully functional,

there's nothing left to stop the Astute from finally leaving Barrow.

Except the weather. And the events of the last few months mean the warm summer is a distant memory.

She will be sailing in November.

Commander Andy Coles, the captain of the boat, is preparing his crew for the exit.

We're just doing the final preparations and final checks, ready to sail tomorrow.

I'll show you as much as I can within the bounds of legality.

Welcome onboard.

Just come this way, please.

We're in the centre of the control room

and in front of me, I've got ship control.

To the left, I've got the sonar and to the right, the combat system.

This is where I sit and when I'm not here, where the officer of the watch sits.

And this is my cabin. This is where I sleep and work.

So I spend my time between the control room and here.

I have screens here which show me the tactical picture and I can see what's going on on the periscope.

I'm now converting my chair into the bunk, where I sleep at night.

I've got communications right next to me and everything's been aligned up so it's above the level of the bunk,

so in bed when they call me, I can see everything from bed. So it's quite good.

You can tell what day of the week it is by the food.

For example, you always have fish and chips on a Friday.

And you get to look forward to those nights as well.

Get all the ugly ones out. This is the senior rates' mess.

If you'd like to follow me.

OK. This is the senior rates' mess.

This is one of the three messes we have onboard.

On the other side of the corridor, the junior rates' mess -

exactly the same, but this is for the junior rates.

It's a little more homely now.

We've gone nice chairs and more comfortable living arrangements.

It's got a PlayStation, Xbox, big telly, media centre,

and it's just coming together now, so we're all ready to go to sea in all respects.

I think you have to have a certain temperament to be a submariner.

You have to be able to get on with people and work in a very small space.

We don't tend to be quite so clipped and so formal as other areas of the Navy.

It's just a matter of the environment we live in. The senior rates live in two different mess decks.

This is one of them. We utilise the maximum amount of space,

using three racks on either side.

Each man has at least one locker,

and underneath each bunk is stowage as well.

But we're experts at living on the minimum amount of clothing.

We're up on the forward navigation position, commonly known as the bridge on the submarine.

As you can see, we get a very good view from here.

It's even more precise, I think, than being on the bridge of a ship

because you can feel the elements working with you or against you.

You're able to take action against them quickly.

Tomorrow represents a really key point for us,

which is the move away from this dock down to Ramsden Dock and so

therefore with the tugs' assistance, we'll be going through that bridge and down to Ramsden Dock tomorrow.

Clearly trying to sail in mid November is a risk with the weather.

And the weather forecast over the next two days is not ideal.

We've already got a freshening wind which we can feel in our hair now.

It's going to get stronger over the next 24 hours.

But everybody's attention is on us at the moment. This is a key point for the Royal Navy, bringing Astute out.

I get that wrong, I'm certainly aware of the amount of scrutiny that will be coming down on me.

It's November the 14th, 2009.

And the first new British submarine for 10 years

is about to sail out into the open sea for the very first time.

Originally planned for the summer, the submarine's last hurdle to exit

is the uncertainty of the British weather.

Submarines manoeuvre extremely well underwater.

But on the surface, they're not quite so good at manoeuvring, so we need some tug assistance.

They're going to bring alongside four very powerful tugs

and then we will manoeuvre the submarine through the lock system,

under the Michaelson Road Bridge, round to Ramsden Dock in preparation for exit.

There has been a lot of effort from everyone involved here.

It's been fraught with interesting conversations and emotions that have come out.

The crew are ready, the tugs are ready.

The wind has finally dropped. So we've got one window of opportunity before it starts getting dark.

So, it's a good day.

It's quite narrow here -

it's 28 metres wide - so it is quite a challenging thing.

You can see the challenge to be able to get through this narrow gap.

We've been eating, drinking, breathing the submarine

and getting it ready for this moment.

Now that we can step back and watch it go through,

it's really a great moment, actually.

It's something that the country should be really proud of.

The first time that we've launched a new submarine out of here for ten years.

It's a hell of an achievement, actually.

The whole process will take two days,

but at 9:15 on Sunday 15th November,

the gate holding back the sea has been safely lowered

and the submarine leaves Barrow for the first time.

She'll never return.

Once free of shallow water,

the tugs will depart and her reactor will take over,

silently powering the Astute through the ocean.

Started off as a team leader on the Astute that's just gone out.

Fantastic pride.

That's what I felt. We want to see more of these.

And not with ten-year gaps, either.

I work on boat two. We need to make sure we knuckle down and we can have a day like this in years to come.

It was built slowly and carefully by a lot of dedicated people.

It's a wonderful thing to see it go.

I was surprised, actually, to see how fast it was cruising along there.

It's taken 14 years to get to this moment.

But for almost 5,000 people in the shipyard,

tomorrow is another working day.

They'll clock on as usual and continue building the next Astute submarine -

one of the world's most complicated and secretive machines.

In the next programme,

we go to Derby and meet some of the 11,000 people that build jet engines

for one of the world's most famous companies - Rolls Royce.

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