How it Works -
-Solar Panels
-Bananas
-Axes
-Platinum Rings
-Solar Panels
-Bananas
-Axes
-Platinum Rings
Category
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TVTranscript
00:00The show that reveals how extraordinary items in our world are designed, constructed and produced.
00:06See the engineering, the technology and big ideas that make the world go round.
00:11Find out how it works.
00:30Coming up, how do British supermarkets ship green bananas all the way from Costa Rica and get them onto the shelves just as they start to ripen?
00:46Swedish Vikings were famous for their love of the axe and today we'll learn about one of the oldest tools in man's toolbox.
00:52And turning junk into jewellery. We'll see how the platinum from recycled computers is turned into an A-list as accessories.
01:05But first, when you think of sun and sand, holidays in the Caribbean are usually what spring to mind.
01:12But have you ever thought about solar panels instead?
01:15The main ingredient that makes them work is silicon or sand which comes from rocks found in a quarry like this.
01:22It's out of the quarry and into the fire.
01:28The first stage is to get the silicon out of the rocks and that's done in this enormous furnace.
01:34Temperatures reach well over 2000 degrees Celsius.
01:38This is unbelievably hot and also quite dangerous.
01:42To keep their eyebrows safe, the men work the oar using long poles.
01:46Silicon is used to make everything from window glass to the processors in your home computer.
01:51And without it, a solar panel just wouldn't work.
01:57Huge barrels are used to carry it around the factory.
02:01Nothing else could withstand the immense heat involved.
02:04In this form, it is liquid molten silicon.
02:07But to make solar panels, certain chemicals need to be added to it.
02:11First, the ore needs to be crystallized which occurs here in this cooling machine.
02:15The silicon is so hot it could melt right through it.
02:21But the boffins have come up with a solution.
02:24Cold water is pumped round it as it works, which acts like watery air conditioning.
02:29The super-hot crystallized silicon emerges from the machine.
02:33But how will this help to harness energy from the sun?
02:38Solar panels are made using thin slices of silicon which have two unique layers in them.
02:44These are created using two chemical processes which affect the silicon at different times during production.
02:49Time for stage one. This is where the first chemical is added. It will help make the silicon more conductive.
03:05To get the two combined properly, the tank is sealed into a large furnace and left for two days.
03:10It's like cooking a big stew and the chef keeps a close eye on his recipe.
03:18When the buzzer rings, the cooking is complete.
03:21The furnace is opened and the silicon block emerges.
03:26This block would be far too big to put on your roof, which is where solar panels usually go.
03:31The average roof wouldn't support it, so now it needs to be cut down to size.
03:35Cutting solid crystal isn't like cutting butter.
03:38It can be very dangerous, so a protective shield is raised to keep workers safe.
03:44Diamond-tipped blades then slice through it, cutting individual panel-sized columns ready for the next stage.
03:54The columns are now the right size, but they are still far too thick to convert the sun's energy into electricity.
04:00So they need to be cut down even further by this machine.
04:03It has hundreds of spinning wires which slice their way slowly through each column.
04:06What they leave behind is wafer-thin sheets of silicon crystal, perfect for solar panels.
04:13The slices must be separated to be cleaned, but no machine exists that's sensitive enough to do it without breaking them.
04:26It must be done by hand, because the panels are barely fingernail width and incredibly fragile.
04:37Wherever humans are part of a process, contamination follows, because we release millions of dust particles.
04:43The freshly cut slices must now be thoroughly washed before they can be treated with the second chemical.
04:50Once the treatment is in place, the panels are returned to the furnace and baked to create the two separate layers.
04:56No, this isn't a pattern for a new kind of urban camouflage. It's the basic unit that makes up a larger solar panel.
05:08It comes in two different colors, but this isn't a fashion statement.
05:11The blue shade is added so the panel can absorb more light and make more energy.
05:20The panels are also treated with an anti-reflective coating, which is painted on and then baked into place.
05:26Any light the panel reflects would simply be wasted energy.
05:29Now, the panels are clean, properly treated and wearing this season's colors.
05:38They're ready to make electricity, but how do you get power out of them?
05:43High-tech computers align the panels and the next machine paints a layer of this grey gunge onto them.
05:49It looks like bad school custard, but it's actually semi-liquid metal.
05:52It helps conduct energy from the panel into the electricity grid and through a plug into whatever appliance you're using.
06:10We can now assemble a full-sized solar panel.
06:14Each wafer acts like a battery that generates its own electricity.
06:17But to get power out, the panels are assembled in rows connected by metallic pathways.
06:27With neat rows all hooked up, the machine can put all the pieces together.
06:32It's like making a gigantic chip butty, only the chips are made of silicon.
06:38A large slice of glass makes the base, followed by layers of adhesive paper, the silicon panels, and more adhesive to hold it in place.
06:48The final layer is the frame to hold it all together.
06:51Even though English weather isn't always sunny, solar panels can work in our cloudy conditions.
06:56They just need to be cleaned, installed, and plugged in.
07:03So, as Britain's summers get sunnier, solar panels will work to help us cut down our harmful carbon emissions.
07:09It's official. Bananas are the most popular fruit in the UK, and we scoffed almost one billion of them last year.
07:31But unlike apples or pears, we import our bananas from far-off places.
07:36Here in Costa Rica, this plantation is the size of 324 football pitches.
07:42The workers use a pulley system to get themselves around.
07:46It's meant to transport the fruit, but catching a lift saves them from walking.
07:49Modern bananas are sterile, so each new plant must be taken from an old cutting.
07:56This is pretty tough work, as the plants can grow several meters tall.
08:00If the workers didn't replant each year, the plantation would stop producing.
08:04Once the fruit begins to emerge, the plants must be pruned.
08:09The large purple flowers at the base divert energy that would produce bigger, tastier bananas, so the workers remove it.
08:17The remaining bunches are put into bags coated with insecticides to protect them from being eaten.
08:22To keep the insects at bay, the crops are also sprayed, but not by an aeroplane.
08:35They use a high-tech chopper, which is more agile.
08:38It's controlled by satellite technology, which stops local workers being covered with pesticides in their own homes.
08:44These bananas have a radius of 3 cm, and although they're not ripe yet, now is the perfect time to collect them.
08:56When the fruit has reached this ideal size, these guys have the job of preparing them for the packing plant.
09:03Their protective bags are removed, and foam inserts are placed between the bunches.
09:08If the fruit have even the tiniest bruises, UK customers leave them on the shelf, so they're protected right from the start.
09:20Enormous bunches are loaded onto the pulley system, and join a long traffic jam of other fruit heading for the processing plant.
09:29Now you'd need an enormous trolley to buy a bunch of 60 bananas with your weekly shopping, so now they're separated into smaller ones before being sent for a bath.
09:53Tough EU laws legislate for bananas' size, shape, and even their curve, so the workers must be sure there are no slip-ups with any fruit that aren't up to scratch.
10:09Any that fail are thrown onto the waste conveyor, but they aren't discarded.
10:16They'll be used to feed local livestock or sent to be processed into baby food.
10:20The remaining bananas are then sent off for another bath, which kills off any spiders who may be trying to hitch a ride to a supermarket near you.
10:33The fruit is given its trademark branding, and boxes are built to store them for their long journey across the Atlantic.
10:39This plantation has produced over 270,000 boxes of bananas. They're packed up and sent by the lorry load to the docks.
10:52Here, they're put on board ships in specially cooled containers for the journey to Europe.
11:00They won't be enjoying any sun on the deck, though. It's an 11-day journey, and being in the sun would ripen them too early.
11:06When they're finally unloaded, the bananas are still green. This means they can be stored until the shops need them.
11:19They're stacked in sealed ripening rooms. When the stores need them, these rooms will be flooded with ethylene gas.
11:27This gas ripens the bananas at a regular, measurable pace, which means the stores know exactly when they are ready for the shelves.
11:38So, from the exotic fields of a Costa Rican plantation to the supermarket trolley in the UK, the Brits are certainly bananas about their bananas.
11:51Still to come, the wood axe is forged in the flames of a Swedish furnace. We'll find out just how that works, and you'd need a platinum credit card to buy a platinum ring, but we'll find out how scientists can turn junk into jewelry.
12:19Whether you think of roaring log fires in the outdoors way of life, or a scene from your favorite horror film, the wood axe is one of the oldest tools used by man.
12:42This Swedish axe master can make a new axe head using solid steel, a blast furnace, and a few wax from his industrial hammer.
12:53To get the steel soft enough to shape it, he feeds solid bars of it into the heart of his forge.
12:59He has to use pincers because it burns at an incredible 1200 degrees Celsius.
13:06Once it's red hot, he can slice through it like soft toffee.
13:09A lump the size of a fist will be enough to make an axe head, but he knows he can't hang around.
13:14By the tenth whack, his axe is already starting to take shape. Successive blows help to finish it off and compress the metal for strength.
13:31Now, even the toughest of Vikings needed a handle to wield an axe, so the blacksmith has got to include a hole for one, but he's working against the clock here because the metal is cooling fast.
13:41He inserts a steel peg, which is hammered into place. It'll press the hole wide enough for the handle. The same is done from the other side to ensure the hole goes all the way through.
13:54As the blade head cools, the red glow dies and it's becoming harder to shape it, but the last blow doesn't need much power.
14:01The final whack puts his personal stamp on the axe, and his work is done.
14:12Over 50,000 axes are made here every year, and that means the company has a reputation to uphold.
14:18So as well as making strong axes, there's the small matter of making them sharp too.
14:24Using his full body weight, the sharpener leans each blade into the grinding wheel, giving it a razor-sharp edge.
14:31Conveniently, it also shines up the blade, so it'll glitter nicely in the sun.
14:38Once the sharpening is complete, the blade must be hardened. Steel may feel tough, but depending on its carbon content, it can be quite soft.
14:47The axe head is passed through a machine which heats it up, and then it's dropped into a bath of cold water.
14:53This process doubles the hardness of the steel, which will help it last longer.
14:56All this activity has excited the metal. It's not jumping up and down and shouting a lot, but the molecules in the metal are now very active.
15:07When this happens, the blade can become fragile, so they're now placed in what's called a relaxing furnace.
15:12Here they are heated for an hour at 195 degrees Celsius.
15:19Once the blades are cool, calm and collected, they're ready to face the double tap safety test.
15:24Before they're ready to chop some trunks, though, they need a quick makeover. A quick shine helps to enhance that powerful menacing look.
15:37Here you can see the difference it can make. The first blade is the raw metal. The second one has been ground down and sharpened.
15:52And the final one here has been polished, and it's ready to chop some firewood.
15:55Finally, the blades are oiled. This protects them from rust and corrosion.
16:07All that's missing is something to hold it with. Funnily enough, the axe that will cut down trees ends up with a wooden handle.
16:14It's strong, but also flexible enough to withstand the impacts it experiences.
16:20The handle guy inserts a steel collar into the blade. The wood has been cut to fit this, but he still needs to use an air compressor to get the two together.
16:28A quick test makes sure it's seated properly, and then a wedge of wood will be glued into the end.
16:45This looks quite simple, but it spreads the handle out and stops it from slipping free.
16:51A tough woodsman wouldn't look so tough if his blade was to fly off and hit someone.
16:55It's just time for the final trim to remove the excess wood and a quick visit to the sander before a brand new chopper is ready for action.
17:13So like the actor wielding it in a horror film, the woodsman's axe has been very well pampered to get it ready for its close-up.
17:21If you want to show her you love her, an engagement ring is a nice touch, but they'll be fooled by cheap imitations like ordinary gold.
17:42If you really want to sweep someone off their feet, only platinum will do.
17:47It's expensive stuff, worth twice as much per kilo as gold is, so it's kept under lock and key.
17:53But because it's also quite rare, workers recycle and reuse it wherever possible, and that's where this box of industrial waste comes in.
18:01Contained within this waste is pure platinum, and the brainiacs at this chemical plant are going to separate it out from the other metals.
18:10All the debris is put into this enormous glass flask.
18:13The glass is important because it resists the chemicals they are about to use.
18:17Yes, this is the fun bit of chemistry. Mitric acid and hydrochloric acid are poured in, then the flask is sealed.
18:26Over the next two days, the metals will dissolve until all you're left with is this acidic black soup.
18:31Platinum recovery is like a big experiment, only the scientists know what the outcome is going to be.
18:41The next stage is to separate the platinum from the other metals, and that's done with this powder.
18:46The powder is added at the top of the flask, and as it filters down, the platinum particles stick to it, leaving the other, cheaper metals behind.
18:57Slowly, it settles to the bottom, and once the scientists are happy, all the liquid will be drained off, leaving them with a big bucket of sand-like grit.
19:10Now, you might have a hard time convincing anyone that this is the most valuable metal in the world, so the grit is then placed into trays and incinerated.
19:22At 950 degrees Celsius, everything but the metal is burned off, and when the boffins open up the furnace, what's left looks like…
19:41asphalt.
19:42It's actually platinum, but it's been filled with air bubbles from the furnace.
19:47To turn it into the shiny metal that's so sought after for making jewelry, it needs to be reheated in an airtight furnace.
19:53This powerful oven can reach 2,000 degrees Celsius, and can be kept airtight while it does this.
20:03The platinum slag is added in, the heat is turned up, and the aerated metal is melted down.
20:08The lid is then closed, and all the air extracted. Even the terminator wouldn't survive in here.
20:21What emerges has to be the most expensive brick in the world.
20:42Just one kilo of this precious metal is worth over 20,000 pounds.
20:46In this form, it would be a bit awkward to wear, so specialists at the factory turn the blocks into tubes.
20:59Jewelers can use them to make rings or any other jewelry your girlfriend might want.
21:03Slicers are cut off the tube in a sealed environment to ensure nothing is lost.
21:07And this is what you end up with.
21:11Gold and silver are weak, so they're mixed with other metals to strengthen them, but this reduces their value.
21:18Platinum is strong enough to be worked alone, which is another reason it's so valuable.
21:24Sizing is quite a simple process, but if the customer prefers a thinner style, more metal must be carved away.
21:31Using a lathe lubricated with high-quality oil, micro-fine slivers of the ring are carved away.
21:38Again, nothing is wasted, and the jeweler and the computer both keep a very close eye on what's going on.
21:46Because it's so rare, and your girlfriend isn't going to want any old ring, platinum jewelry is often made to order.
22:05Only experts get to work with this precious metal, and they have to know what they're doing.
22:10Heat is the most common tool. Melting the metal makes it pliable, but if he keeps the flame on too long, the ring will collapse into an expensive, but ugly, blob.
22:25Another tool that can be used to create a mount for jewels is this saw.
22:30Tiny quantities of the ring are carved away to create the setting for the gemstone to fit into it.
22:34Now, you could try this with your Black & Decker workmate, but we really wouldn't advise it.
22:41Alternatively, smaller stones can be placed into ready-made settings like this one.
22:47An electric hammer gently closes the metal around the stone, which will hold it in place.
22:52And finally, the ring is polished, ready to be worn.
22:56Gold and silver change colour as they age, but because of its purity, platinum doesn't.
23:03So like the credit card you've always dreamed of, this is platinum, and it's worth twice its weight in gold.
23:10I hope you go Yoon, hooke and gold.
23:17Once geworden is gold.
23:21Bye.
23:24Well see you then!
23:30We see you then.
23:36Joanne P up.
23:38.