0:00:05 > 0:00:08# If you've got a question and you don't know where to go
0:00:08 > 0:00:11# Ask Nina for some help cos she's got a science show
0:00:11 > 0:00:14# She makes sense of her senses while helping all her fans
0:00:14 > 0:00:17# By doing her experiments with potions and with bangs
0:00:17 > 0:00:19# Touch your tongue
0:00:19 > 0:00:20# Fingers
0:00:20 > 0:00:23# Eyes, ears, nose
0:00:23 > 0:00:26# Nina and the Neurons find out what you need to know
0:00:26 > 0:00:29# Nina and the Neurons find out what you need to know
0:00:29 > 0:00:32# Luke, he helps us with our eyes and Felix with our touch
0:00:32 > 0:00:35# Ollie sniffs out smells and scents And Belle, she hears so much
0:00:35 > 0:00:38# Bud is Ollie's brother He helps us with our taste
0:00:38 > 0:00:41# They're Nina's little Neurons And they're coming to your place!
0:00:41 > 0:00:43# Touch your tongue
0:00:43 > 0:00:44# Fingers
0:00:44 > 0:00:47# Eyes, ears, nose
0:00:47 > 0:00:50# Nina and the Neurons find out what you need to know
0:00:50 > 0:00:53# Nina and the Neurons find out what you need to know
0:00:53 > 0:00:54# Oh, yeah! #
0:00:57 > 0:01:01Oh, nearly there. Just a little bit more.
0:01:01 > 0:01:03Done it! Oh, hello, there.
0:01:03 > 0:01:07I'm just taking the core out of my apple. Look!
0:01:07 > 0:01:09I can see right through the middle now.
0:01:09 > 0:01:12BEEPING
0:01:12 > 0:01:15I hear a beep, I see a flash, I wonder what they're going to ask.
0:01:20 > 0:01:24- ALL: Hi, Nina.- Hi, guys. - We've got a question for you.
0:01:24 > 0:01:28- How are tunnels made?- That's a great question. How are tunnels made?
0:01:28 > 0:01:31Well, tunnels use lots of clever engineering,
0:01:31 > 0:01:35so why don't you come down to my workshop and we'll investigate?
0:01:35 > 0:01:39ALL: See you soon, Nina! Bye!
0:01:39 > 0:01:42Well, I'm going to need some help to answer this one,
0:01:42 > 0:01:46and I know just who to ask. OK, Neurons, time to get to work.
0:02:01 > 0:02:02ALL: Neurons at the ready, Nina.
0:02:04 > 0:02:07OK, today's question is, how are tunnels made?
0:02:07 > 0:02:09Which Neuron do you think
0:02:09 > 0:02:11will be most useful in helping find the answer?
0:02:11 > 0:02:14ALL: Me! Me! Me!
0:02:14 > 0:02:17Will it be fabulous Felix?
0:02:17 > 0:02:21I can help so very much if you need the sense of touch.
0:02:21 > 0:02:24- Will it be beautiful Belle? - I send messages to brain from ear.
0:02:24 > 0:02:27If there's a sound, I'll help you hear.
0:02:27 > 0:02:29Will it be lovely Luke?
0:02:29 > 0:02:32For looking and seeing day or night,
0:02:32 > 0:02:34I'll help you with your sense of sight.
0:02:34 > 0:02:36Will it be awesome Ollie?
0:02:36 > 0:02:38If it's pongy or whiffy but you can't tell,
0:02:38 > 0:02:42- my messages help your sense of smell.- Or will it be baby Bud?
0:02:42 > 0:02:47Sour, salty, bitter or sweet, I'm your taste buddy whenever you eat.
0:02:52 > 0:02:53It's Luke.
0:02:53 > 0:02:57ALL CHANT: Go, Luke. Go, Luke. Go, Luke.
0:02:57 > 0:03:02Go, Luke. Go, Luke. Go, Luke. Go, Luke!
0:03:02 > 0:03:06Cool, Nina. I'll be looking out to help you.
0:03:06 > 0:03:09Today's question is, how are tunnels made?
0:03:09 > 0:03:10We SEE inside tunnels,
0:03:10 > 0:03:13so Luke, our sight Neuron, will be helping us.
0:03:13 > 0:03:15But standby, Neurons,
0:03:15 > 0:03:17I have a feeling I may need help from all of you.
0:03:17 > 0:03:21I need to get the workshop ready before the engineers arrive.
0:03:23 > 0:03:25Connor loves playing on the trampoline.
0:03:25 > 0:03:29Emily loves her goldfish. Ferdia likes climbing each trees.
0:03:29 > 0:03:34- Some tunnels are really long. - A tunnel can go underwater.
0:03:34 > 0:03:36I've been through a tunnel in my car.
0:03:36 > 0:03:41For one day only, Connor, Emily and Ferdia become the engineers.
0:03:45 > 0:03:48- Hi, guys.- Hi, Nina!
0:03:48 > 0:03:51Welcome to my workshop, and thanks for your great question.
0:03:51 > 0:03:53How are tunnels made?
0:03:53 > 0:03:57To find out the answer, we're going to start by using our senses.
0:03:57 > 0:04:01ALL: Woop-woo! A senses experiment! We're ready, Nina!
0:04:01 > 0:04:05So, what is a tunnel and why do we need them?
0:04:05 > 0:04:08Well, a tunnel is a long hole under the ground that we use
0:04:08 > 0:04:10to get from one place to another.
0:04:10 > 0:04:13They can help us go under things, like rivers and seas.
0:04:13 > 0:04:18This is a model that shows us how a tunnel can go under the water,
0:04:18 > 0:04:22but the tunnel doesn't get wet inside.
0:04:22 > 0:04:24- LUKE:- Looks dry to me, Nina!
0:04:24 > 0:04:27It is, Luke. So when it's too difficult to build a bridge
0:04:27 > 0:04:29to cross a river or the sea,
0:04:29 > 0:04:32engineers make a tunnel that goes under the water.
0:04:32 > 0:04:36People go into the tunnel at one end... Whee!
0:04:36 > 0:04:38..and out the other end.
0:04:38 > 0:04:41Tunnels are really good for trains, because trains aren't very good
0:04:41 > 0:04:44at going over hills, so trains often go through tunnels.
0:04:44 > 0:04:50I wish I was a train! They go really fast and they make lots of noise!
0:04:50 > 0:04:52Choo-choo!
0:04:53 > 0:04:57I'm going to try and make a pretend tunnel using this clay,
0:04:57 > 0:05:01and this tunnel is going to be under the sea,
0:05:01 > 0:05:05so we're going to pretend that this blue block is this sea.
0:05:05 > 0:05:10- Oh! Ugh! That feels very heavy, Nina!- It is, Felix.
0:05:10 > 0:05:14Water gets very heavy when there's a lot of it in one place,
0:05:14 > 0:05:16like the sea.
0:05:16 > 0:05:20So let's sit the blue block on top of the clay
0:05:20 > 0:05:23just like water sits on top of the ground.
0:05:23 > 0:05:26And I'm going to make the tunnel using this,
0:05:26 > 0:05:28which I used on my apple earlier.
0:05:36 > 0:05:40Now, that's our tunnel started. It's still quite small.
0:05:40 > 0:05:43We need to make it bigger so cars and trains can go through.
0:06:04 > 0:06:07- OLLIE:- Nina, your tunnel's going droopy.
0:06:07 > 0:06:10That's because a tunnel is made by taking away the soil,
0:06:10 > 0:06:12and when you take away the soil,
0:06:12 > 0:06:16you're taking away what's holding up the heavy water above.
0:06:16 > 0:06:20Some tunnels go underneath cities with heavy buildings,
0:06:20 > 0:06:23or under big mountains which are made of heavy rock,
0:06:23 > 0:06:26so engineers had to work out how to make tunnels strong enough
0:06:26 > 0:06:31so they could hold up water or buildings or even mountings.
0:06:31 > 0:06:34How do they make the tunnels so strong, Nina?
0:06:34 > 0:06:38I know an amazing place where we can find out. Let's go, engineers!
0:06:38 > 0:06:40Yeah!
0:06:44 > 0:06:47Hmm! Where do you think we're going today?
0:06:47 > 0:06:53- Nina said it's an amazing place! - Maybe it's a maze at a playground.
0:06:53 > 0:06:56I have a nose for finding the right way to go in a maze.
0:06:56 > 0:07:00We'll soon find out, Neurons. We've arrived.
0:07:00 > 0:07:04OK, engineers, you asked, how are tunnels made?
0:07:04 > 0:07:06And we've come to the Channel Tunnel.
0:07:06 > 0:07:08This tunnel goes under the sea,
0:07:08 > 0:07:11just like the little tunnel back at the workshop.
0:07:11 > 0:07:15The Channel Tunnel is one of the longest tunnels in the world.
0:07:15 > 0:07:18It's so long that it goes all the way
0:07:18 > 0:07:21to another country - France. Look!
0:07:22 > 0:07:26We've got special permission to go inside, engineers.
0:07:26 > 0:07:32- Well, engineers, how far can you see?- A long way, Nina.
0:07:32 > 0:07:35This tunnel's so long, I can't see the end, Nina.
0:07:35 > 0:07:38Now, what shape is this tunnel?
0:07:38 > 0:07:40It's round, Nina.
0:07:40 > 0:07:43That's right, it's round, just like a circle.
0:07:43 > 0:07:48Engineers make tunnels round because it makes the walls stronger,
0:07:48 > 0:07:50so this means they stay up,
0:07:50 > 0:07:53even though there's lots of heavy water above them.
0:07:53 > 0:07:57This gives me an idea for another experiment. Let's go, engineers.
0:07:58 > 0:08:03OK, engineers, we're going to pretend these are two tunnels.
0:08:03 > 0:08:06One is round. And one is square.
0:08:06 > 0:08:09And we know that the sea is heavy,
0:08:09 > 0:08:13so we're going to make these heavy bolts our sea.
0:08:13 > 0:08:16But which one of the tunnels will stay up under the heavy weight?
0:08:16 > 0:08:18Let's find out.
0:08:34 > 0:08:36Keep going, engineers!
0:08:48 > 0:08:51Wow. The round tunnel was far better
0:08:51 > 0:08:55- at holding up our heavy sea, wasn't it?- Yes!
0:08:55 > 0:08:59So we've proved that a circular shape makes a stronger tunnel
0:08:59 > 0:09:02than a square shape. Circles are strong
0:09:02 > 0:09:06because their shape spreads weight evenly around their sides.
0:09:06 > 0:09:09And this makes circles the perfect shape for a tunnel.
0:09:09 > 0:09:13- How did they get all the soil out, Nina?- That's a great question.
0:09:13 > 0:09:17To find out the answer, we need to go back to my workshop.
0:09:19 > 0:09:22So your question was, how are tunnels made?
0:09:22 > 0:09:25So far, we've discovered that engineers make tunnels
0:09:25 > 0:09:27that are shaped like circles
0:09:27 > 0:09:30because they are better at holding things up than square tunnels,
0:09:30 > 0:09:35but we still need to find out how all the soil gets out of a tunnel.
0:09:35 > 0:09:39And I have the perfect experiment to show us.
0:09:39 > 0:09:44We're going to pretend this is a tunnel we're making
0:09:44 > 0:09:47and inside it are these foam blocks.
0:09:47 > 0:09:51And Ferdia, Emily, you guys are going to be the diggers.
0:09:51 > 0:09:54You'll dig out the soil, making the tunnel,
0:09:54 > 0:09:58and Connor, you are going to collect the soil from the diggers.
0:09:58 > 0:10:02- Are you ready for some digging?- Yes!
0:10:02 > 0:10:05OK, let's dig! Go! Go!
0:10:05 > 0:10:06Go, Emily, you're first.
0:10:09 > 0:10:10Brilliant, excellent.
0:10:13 > 0:10:15Give it to Connor. Brilliant! Swap round.
0:10:19 > 0:10:20Brilliant!
0:10:22 > 0:10:24Oh, go on, Ferdia, you can do it!
0:10:33 > 0:10:35The tunnel looks nearly empty, Nina.
0:10:47 > 0:10:50You've finished, engineers. Well done.
0:10:50 > 0:10:52You got all of the soil out of the pretend tunnel.
0:10:52 > 0:10:55You dug right through to the other side.
0:10:55 > 0:11:00- But did the digging get easier or harder as you were doing it?- Harder.
0:11:00 > 0:11:03Yes, and that's because the longer a tunnel gets,
0:11:03 > 0:11:06the further you have to go back to move the soil away.
0:11:06 > 0:11:10Engineers had a clever idea to solve that problem.
0:11:10 > 0:11:12Instead of digging from just one end,
0:11:12 > 0:11:16dig the tunnel from both ends at the same time.
0:11:16 > 0:11:18Let's try it. Go!
0:11:22 > 0:11:24You're doing really well, guys!
0:11:30 > 0:11:34Wow! Because you were digging from both ends,
0:11:34 > 0:11:37you only had to carry the soil through your half of the tunnel.
0:11:37 > 0:11:41And that meant the job was finished much, much faster.
0:11:41 > 0:11:43And that's how lots of tunnels are built.
0:11:48 > 0:11:52So, your question was, how are tunnels made?
0:11:52 > 0:11:53And I think we've answered it.
0:11:53 > 0:11:57We discovered that tunnels are holes in the ground that help us
0:11:57 > 0:12:00go underwater or through big hills or mountains.
0:12:00 > 0:12:04Engineers make tunnels shaped like circles
0:12:04 > 0:12:06because they are strong and hold their shape.
0:12:06 > 0:12:09We also found out that digging a tunnel
0:12:09 > 0:12:12from both ends at the same time is faster,
0:12:12 > 0:12:15because you only have to carry the soil half as far.
0:12:15 > 0:12:21- I hope that's answered your question.- Thanks, Nina! Bye!
0:12:21 > 0:12:22You're welcome. Bye.
0:12:25 > 0:12:28If you want to know more about the science and engineering
0:12:28 > 0:12:32that's all around us, go to the Nina section on the CBeebies website.
0:12:32 > 0:12:33Have fun!
0:12:33 > 0:12:34- # Boring - Pushing
0:12:34 > 0:12:35- # Twisting - Mixing
0:12:35 > 0:12:37- # Drilling - Squeezing
0:12:37 > 0:12:38# Floating
0:12:38 > 0:12:39# Go engineering
0:12:39 > 0:12:43# Go engineering!
0:12:43 > 0:12:47# When you need to fly it make it, shape it
0:12:47 > 0:12:52- # Go engineering - Go engineering!
0:12:52 > 0:12:55# When you want to build go engineering
0:12:55 > 0:12:56# Engineering!
0:12:56 > 0:13:01# When you've got to solve a problem but you don't know how to do it
0:13:01 > 0:13:04# It's time to go engineering
0:13:04 > 0:13:05# Engineering!
0:13:05 > 0:13:10# When you want to lift it stick it, pop it, bend it
0:13:10 > 0:13:13# It's time to go engineering
0:13:13 > 0:13:14# Engineering!
0:13:14 > 0:13:19- # Go engineering - Go engineering!
0:13:19 > 0:13:22# When you need to fly it make it, shape it
0:13:22 > 0:13:24# Engineering!
0:13:24 > 0:13:29- # Go engineering - Go engineering!
0:13:29 > 0:13:31# When you want to build go engineering
0:13:33 > 0:13:35# Go engineering! #
0:13:35 > 0:13:38It's been such a great day, man.
0:13:38 > 0:13:42Seeing inside the big tunnel was so cool.
0:13:42 > 0:13:44I've had a brilliant day.
0:13:44 > 0:13:49Hearing why tunnels are circular was amazing!
0:13:49 > 0:13:51I've had a fabby day!
0:13:51 > 0:13:56Digging out the pretend tunnel was lots of fun!
0:13:56 > 0:13:59And remember, engineers help to build the world around us.
0:13:59 > 0:14:02They make things work and use science to solve problems.
0:14:02 > 0:14:04See you again soon. Bye!
0:14:04 > 0:14:06ALL: Bye!