"Who says only those standing in the light are heroes?" Approaching the "underground dragon" - China's giant shield aircraft

When it comes to major national weapons

What can you think of?

Aircraft carrier, manned spacecraft, nuclear submarine?

That's right

These high-tech technologies have always made us proud

But the first thing that came to my mind was

Shield! Structure! Machine!

February 26

The super-large diameter tunnel boring machine "Yongzhou" rolled off the production line in Changsha, Hunan

The shield machine will be sent to and used in

The world's longest undersea high-speed railway tunnel

Jintang Subsea Tunnel of Ningbo-Zhoushan Railway in Zhejiang

This behemoth is several stories high and weighs thousands of tons.

It has long served in underground space

But silently making great contributions to my country's tunnel construction

Who says only those who stand in the light are heroes?

01 What is a shield machine? It builds roads through mountains and bridges over rivers

This is commonplace for road builders.

But if you want to cross mountains and valleys, dive into rivers and seas

Want to dig a hole underwater

The world's deepest submarine high-speed rail tunnel

What to do?

China's shield machine has become

A capable man in tunnel engineering

The full name of the shield machine is the full-section tunnel boring machine

It is a truly "national" heavy weapon

What does this “capable general” look like?

The length of a shield machine is usually more than 100 meters.

Weighing thousands of tons

It consists of cutter head, main drive, shield, and pipe segment.

It consists of assembly system, control room, propulsion system and other parts.

(Photo source: China Railway Construction)

02 Is the shield machine used to dig tunnels? There is Shenzhou in the sky and Jiaolong in the sea

There are high-speed railways to chase the wind and shield tunnels to go underground

The shield machine is like a "steel earthworm"

The head has a large rotatable blade

Many sharp knives are installed on the knife disc

Driven by hydraulic jack

The shield machine moves forward slowly

While spinning your head

While "eating" rocks and soil

Slowly opening up an underground passage for people

But as the subway tunnels get deeper, a lot of soil will be produced.

The cutterhead rotates continuously to cut the soil and rocks

Most of the soil and stones cut off

It will be transported out by the "conveyor belt" inside the shield machine

A small part was squeezed into the inner wall of the tunnel by the shield machine.

The shield machine moves forward

Assembling prefabricated concrete segments

Achieve one-step tunnel forming

Shield machine is the core equipment in infrastructure

In the field of rail transit construction in my country

Plays an important role

So the shield machine is called

The crown jewel of mechanical manufacturing