Book 3, Question 24 · Video
Why Do Tunnels Go Through Mountains?
Going over a mountain costs time, fuel, and steep roads. A tunnel cuts a nearly flat path through the rock. A tunnel is a shortcut through the mountain, instead of over it!
Read the full answer →What Crafty Clover says in this video
Intro
Hey there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why do tunnels go through mountains?
The Big Idea
Going over a mountain costs time, fuel, and steep roads. A tunnel cuts a nearly flat path through the rock. A tunnel is a shortcut through the mountain, instead of over it! Engineers plan every part carefully, so it is safe.
Step 1
Step one: pick a path, and dig in. Surveyors map the shortest safe line through the mountain. Then machines chew through the rock, or controlled blasts open a hole. That is a lot of rock to move, sometimes many truckloads!
Step 2
Step two: haul the rock out. All the broken stone has to go somewhere. It rides out of the tunnel on conveyor belts. The tunnel is a dry tube through wet or hard ground.
Step 3
Step three: line the walls, and add lights and fans. Concrete rings hold the mountain back so it cannot cave in. Lights help drivers see, and fans keep the air fresh inside. Trains, subways, water pipes, and even animals like moles use tunnels.
A Closer Look
Let's take a closer look at a tunnel! Solid rock surrounds the tunnel tube. The concrete lining keeps the mountain from caving in. And vent fans keep the air fresh. Rock outside, safe roadway inside! Every layer of the tunnel has a job.
Quick Facts
Quick facts! Ancient Romans were already digging road tunnels through hills. Japan's Seikan Tunnel is more than 50 kilometers long. Some tunnels even go under rivers and under the sea. And always follow the tunnel lights, and never stop inside unless told. Tunnels have been helping people travel for thousands of years.
Think Like a Scientist
Now, think like a scientist! With a grown-up nearby, build two paths in sand. One goes over a hill of cups. The other goes through a paper tube tunnel. Which toy car gets there faster? Compare the two paths.
Outro
Tunnels are shortcuts through the mountain. Now you know why we dig them! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!