S01E02 Fire Engine Hose and Reflective Strips

Fire Engine Hose and Reflective Strips | Maddie's Do You Know? Series 1, Episode 2 - Full Episode! 👩 - YouTube
【纪录片】你知道吗第二集.消防水龙和反光带【720p】【双语特效字幕】【纪录片之家字幕组】_哔哩哔哩_bilibili

Hello, I'm Maddie and today I'm at a fire station. Sometimes accidents happen which could cause a building to catch fire. If this happens, someone will call the fire brigade who will rush to the fire, put out the flames, and make sure things are safe for everyone.

But do you know how firefighters put out a fire? Let's find out. How does it work?

This is a special fire tower, and it's used by firefighters so they can practice putting out flames. Now, you should never play with fire; it can be very dangerous. But can you see something coming out of the middle? That is smoke, and it's been put there especially so the firefighters can practice putting it out as if it were a real fire. But how do you think they're going to do it?

That's right, they're going to pour water on it. Trouble is, it's a really long way away, so we need to find a way to get the water up there to put the fire out.

So how do you think the firemen are going to put out the fire? Let's watch and see.

They're pulling out a long ladder, and that will mean they can get right up to the top where we can see the smoke on the fire tower. This fireman has a giant hose, and just look how much water is coming out at the end of that. The water is coming out so fast and it's so powerful that it's able to reach all the way up to the top where the smoke is coming out of the fire tower. Listen to the sound of the water. All of that water's spraying up into the smoke.

The practice has ended and the firefighters can now turn the water off. But do you know how a fire hose works?

Inside the fire engine is a big tank of water. At the back of the fire engine, there are some levers and switches; this is called the pump panel. This controls how much water will flow out of the engine to be used on the fire. Next to this is a large pump and a wheel called a rotor. When the lever is pulled, the rotor spins around very fast. The water flows into the spinning rotor, which creates something called water pressure, which pushes the water out of the hose really fast.

Isn't that interesting? Let's go to the back of the fire engine to see all of that happening. And the firefighters have given me special permission to use the fire hose. And remember, you should never try this yourself. I can only give it a go because I'm with specially trained firefighters to make sure I'm safe. I need some protective clothing.

All of the hoses are kept rolled up neatly in the side of the engine. Here they go. Wow, they are really heavy. When they're needed, the hoses are unwound and then they're attached to the back of the fire engine.

The end of the hose is attached to this metal tap; it's called a valve. And the valve is connected to the water tank inside the engine and the pump. This here is the pump panel, and this is where the firefighters can control the water and turn it on and off. Clever, isn't it?

That hose is 25 meters long. That's the same length as a swimming pool. I've got my special little camera with me. We can attach it to the end of the fire hose so we can see just how fast the water shoots out the end. And if you look, there's some more smoke coming out the fire tower. That can only mean the firefighters are about to start another practice.

And this time, it's my turn to have a go at using the fire hose. They're about to... water! It easily reaches the smoke high up the building. I can't believe all of that water is coming from inside the fire engine. I am soaked!

I loved seeing the fire hose in action. What was your favorite bit about seeing how a fire hose works? Do you remember the name of the special taps that the hose is connected to on the fire engine? That's right, they're called the valves. Did you hear the sound the water made when it rushed out of the hose? And did you see how fast the water came out of the hose to put the fire out? Wow.

The fire engines are really important because they take firefighters and all of their equipment to a fire so they can put it out really quickly. But when they're driving fast to the scene of a fire, a fire engine needs to be seen and heard so the other drivers on the road know that they're there. And that's why a fire engine has a big blue light, a siren, and special markings on the side so that everybody can see it.

Police cars, ambulances, and of course fire engines are covered in these special stickers. They're called reflective strips, and the really clever thing about them is that they can be seen in the dark. You might have some reflective strips on your clothes or maybe on a bag so that you can be seen better at nighttime. But do you know how reflective strips are made? Let's find out. How is it made? Strips.

Today I'm going to show you how this turns into this. Come with me.

The outside of a police car starts off like an ordinary white car. If it wasn't for the blue light on top, you wouldn't even know this was a police car. But all that's about to change with lots of these. These are huge rolls of reflective material, and the team here is going to cut the yellow, blue, and red rolls into different shapes to turn the white car into a police car.

The different shapes and sizes are designed on this computer, and that information is sent to a machine. And here, the reflective material is cut into all the stickers that are needed for the police car. The machine uses a special cutter. It moves really fast.

Jake is popping out all of the different pieces from the sheet of material, and then he's going to take them over to be stuck on the car. But how do you think he's going to stick them on? Well, all of those different shapes and strips have a sticky back; they're just like giant stickers. Do you like stickers?

Steve first makes sure the stickers are in the right position, and then when it's ready, he very carefully peels off the sticky back. It's a great sound, isn't it? And then he just presses down the sticker using this tool; it's called a squeegee. And the squeegee rubs the sticker down onto the car and makes sure there aren't any air bubbles which would cause it to lift off the car.

It's looking really bright, isn't it? But do you know how these reflective strips are made?

Reflective stickers are made in layers. The first layer is made of a shiny clear plastic called acrylic. A stamp is used to press pyramid shapes called prisms into the acrylic. The layer of prisms is laid upside down onto another piece of acrylic. In just one centimeter, there are five thousand prisms.

Next, another layer of acrylic is fixed on top of the prisms. It can be clear or a bright colour like blue or yellow. A layer of glue is then fit on the underneath of the tape to make it sticky, followed by a peel-off strip.

When light hits the sticker, it bounces off all the little prisms inside and reflects back. It looks as if the sticker has lit up, which makes it really bright, especially in the dark.

So reflective strips are made in layers. But if we use my special camera, the microscope, we might be able to see the prisms close up. So you can just about make out the different shapes of the prisms on the yellow reflective strip. But to really see them, we need to shine some light onto the tape. Look, now it's really bright. And that's because the light is hitting the tape, bouncing around the prisms, and then shining back out again. What do you think it looks like? I think it looks a bit like honeycomb.

The blue and yellow reflective stickers are being stuck on our police car in a special pattern, and that pattern has a funny name: Battenberg. Battenberg is the name of the pattern used on all emergency vehicles. But emergency services use different colors. So police cars are blue and yellow, ambulances are green and yellow, and fire engines are red and yellow.

Back to our car, it takes a few hours and now it looks like a police car. But why is the word "police" backwards? It's for the car driver in front so they can read it in their mirror. So when the word is reflected in a mirror, you read it the right way round: police. It's clever, isn't it? And at the back, the word police is the right way round so people driving behind the car can read it too.

But there is one last sticker to go on, and it goes on the roof. If a helicopter is flying overhead, these big letters on the roof will let them know exactly which police car it is, who's driving it, and where it's going.

The police car is finished, and that was a lot of stickers.

I loved seeing how a plain white car was turned into a police car. What was your favorite bit? Do you remember what the name of the pattern of stickers is called? That's right, it's called Battenberg. Did you hear the sound the strips made as the back was peeled off? And did you see the way the strip looked close up when I used my special camera?

So the next time you see an emergency vehicle, you'll know all about the reflective strips: about how they were put on, how they're made, and what the different colors mean. And the next time you see a fire engine, you'll know how it works to pump water through the hose.

Well, I think it's time to hand in my firefighter's helmet. I'll see you next time.