The Workers' Coast 2 Coast

This is Coast.

We're celebrating the workers of our shores.

The east coast of Britain is dotted with industrious communities.

They strike out across the sea to earn a crust.

Men who know the price to be paid for landing fish.

But this harsh life on rolling seas

relies on the support of those back on land.

I'm in search of forgotten workers

who kept our biggest fishing fleet afloat.

We've arrived in Grimsby.

This harbour used to be crammed with trawlers.

At the high watermark of the North Sea Fleet,

some 300 fishing vessels worked out of Grimsby.

Magnificent vessels like this were a floating workplace,

doing business in the wild North Sea.

The crew scoured the seas for cod and haddock,

fish that had to be kept fresh for weeks.

They needed ice, lots of it.

A challenge the early trawler men had to crack.

This grand building houses a freezing machine

constructed on a massive scale.

This is an ice factory!

Built in 1901, the Grimsby Ice Factory

supplied the port's trawlers for nearly a century.

My guide is Mike Sonley,

who was the last man out when the factory closed its doors in 1990.

This precious film was shot just two weeks before production ceased.

Today, it looks very different.

This is Mike's first visit back to his old workplace.

Heartbreaking. I just can't believe it.

A lump comes in your throat, definitely.

A real shame. How did that finish up there?

It was immaculate. You could just eat your dinner off the floor.

It was spotless.

I suppose the ice factory was totally essential for the port, for the trawlers.

We'd come out here at 4:00am and there'd be 20 wagons out there

waiting for 20 tonnes of ice each.

It was a fantastic company to work for.

When this machinery sprang into action, the ice palace came alive.

These massive engines were used to compress ammonia gas.

How did that compressed gas produce up to a thousand tonnes of ice a day?

Chemist Mark Lorch has the answer.

The first step is really just to get a gas and compress it.

Now, you can feel that's cold.

As it comes out it expands and in the process cools down because all the molecules

are much further apart now. They're not able to bash into each other quite so much.

That chilling effect is the principle behind all sorts of refrigeration,

including your domestic fridge and freezer.

The next step then is to show you how we can make ice with this simple set-up.

Pour this briny water into here, and what we need to do is to squirt some of this pressurised liquid,

which will be very cold when it releases, through this coil here

and in so doing, this whole coil will cool down,

the salty water will cool down.

But salty water will go below zero degrees centigrade before it freezes.

So, if we then take our tube of fresh water,

put that in there, this tube will freeze.

Because the brine has a lower freezing point than fresh water,

it will cool this fresh water in here pretty quickly and that will turn to ice.

Yeah, that's the hope, yeah.

So we just need to wait for that to freeze.

We're minus two, heading for minus three degrees in there now.

-There you go.

-It's solid.

-There you go, ice on the dockside.

This cooling method, scaled up to an industrial process, powered the ice factory.

It started with piping in the fresh water to be frozen.

-That there came down.

-All these nozzles...

Came down all in one go, so they filled every pan with water.

-So the fresh water came out of these pipes, filled those pans...

-That's correct.

So these metal boxes was where the ice actually formed.

That's it. Just the same as when you put your ice cubes in a fridge.

But where was the brine that chilled this fresh water?

Below the pans. If you took all the pans out, it would be just one gigantic swimming pool.

So you've got hundreds of these metal pans full of fresh water,

they get filled up here and they get pushed by gigantic rams

through the brine from one end of this hall to the other.

And by the time the pans had got to the far end, the water's turned to ice.

It took 27 hours for the pans to reach the far side of the building,

gradually being chilled on their journey

through the super-cooled brine beneath the floorboards.

So the pans have travelled the full length of the hall, and they've emerged this end and turned into ice.

That's correct. Then the crane comes along with the hooks, picks it up,

drops it in the thaw tank, which is warm water.

As soon as your ice pops up out here in moulds, it's into the cradle then.

The cradle's balanced with seven and a half tonnes of ice.

It tips over, slides down, all on to the floor, like. You know.

Then you fed the ice on to the conveyor into this crusher in the far end here.

So for the ice factory this is the very end of the process,

because what's falling out the bottom of the crusher is crushed ice ready for the trawlers.

That's it, and it takes it up there and on to that conveyor out there and into the ships.

But as Grimsby's fishing fleet dwindled,

fewer workers were waiting at the end of the line for ice.

The factory doors closed in 1990.

And what was it like that day that you left here,

the last man to be in here and lock the door for the last time?

Well, I can't explain it.

It was like if you'd lost somebody you know in your family really.

And it was heartbreaking.

And now to see it like this.

There's not much market for ice these days in Grimsby harbour,

but it's still doing brisk business.

The busiest boats now are those coming and going to service offshore wind farms in the North Sea.

Workers adapting to our changing coast.

New technology driving new opportunities.

It's an old, old story around our shores.

The Royal Navy has often been at the vanguard of innovation.

Fine ships have always needed skilled workers.

Those backroom boffins have given our sailors the edge in battle

since the days of wooden warships.

Back then, the Navy's cannonballs flew truer than those of our enemies.

Their deadly accuracy was largely due to a secret ingredient

we used to make our shot perfectly round.

A rare mineral used to manufacture precision cannonballs

was mined near Whitehaven.

Tessa is on the mineworkers' trail.

I'm going back over 200 years to the time of Nelson's Navy.

At the Battle of Trafalgar, HMS Victory alone

fired over 2,500 rounds of heavy iron shot.

At war with Napoleon, the Navy needed lots of ammunition.

Maritime historian Gareth Cole knows the numbers.

I have here a couple of receipts which show just how many cannonballs

were sent to the ordnance by various companies.

-We've got one here for 100,000 cannonballs.

-100,000?

100,000 in one delivery, which cost about £8,500.

Considerable amounts of cash are being parted.

It was. Over the course of about a 30-year period,

over the French Revolution and Napoleonic wars, the ordnance spent about £10 million on the Navy,

which is about £1 billion in today's money.

Foundries could make a mint from Government contracts.

But they had their work cut out.

The Navy wasn't easy to please.

There's more to cannonballs than meets the eye.

To fly true and hit the intended target,

they have to be as round and as smooth and as perfect as possible.

To appreciate why the plumbago miners were so important,

we need to find out what plumbago actually is

and how it helped cast cannonballs.

So we're going to make our own. Old-style!

The trade secrets of cannonball casting were lost as the industry dwindled.

But foundry man Andrew Laing is trying to turn back time.

The plumbago was a secret process.

You coat the mould with the plumbago to make it nice and smooth

when the casting is removed, and this is what we call casting strip

and so there's no sand sticking to the actual casting.

The effect it has in the mould is a bit like buttering a baking tray.

It slips out at the end.

Plumbago powder stopped the cast iron cannonballs sticking, even when red-hot.

Nothing else was such a good lubricant, and only we had the best.

You're smoothing it in with your finger there.

-Yeah, we're just sleeking it up.

-And that's to help it ease out.

And again to make the ball as smooth as possible.

When it's being fired. So will I have a go at doing that? Fill in the gouge.

Plumbago is common today. We know it as graphite or pencil lead.

But some 200 years ago, high-grade plumbago was rare.

Whitehaven was close to the only mine for the precious element.

Plumbago was hard to get, and working with it was a closely guarded commercial secret.

We haven't a manual for casting cannonballs and we're nowhere near a foundry.

Can we manage it on the quayside?

-Which one have we got?

-Any one.

-Go on. Go on.

That's it.

So, the moment of truth.

Will our graphite lining, in other words the plumbago,

have delivered a perfectly formed smooth cannonball? No pressure.

Oh, it's a disaster! There isn't one.

It's not run. The metal's chilled.

The sea breeze cooled my molten iron so quickly, it didn't flow into the mould.

Of course, you did cast it!

But these wily lads have left nothing to chance.

They've brought cannonballs cast in their foundry.

Half the mould with plumbago, half without.

You can see the surface finish on that one, the effects of the plumbago.

Yeah, you can immediately. I mean, this is smooth,

and on this side it's a very sandy feeling.

A real magic ingredient,

and quite sobering to think we didn't even get off step one today.

Clearly, I wouldn't make a living from cannonballs.

But then, the bottom fell out of the market a while ago.

Early in the 19th century, plumbago from near here

started to fall in value as other sources were discovered overseas.

Local miners had to find new uses for their graphite, in other words plumbago,

and turned it into pencil leads.

Swords into plough shares.

Cannonballs into pencils.