Tunnel Boring Machine by Natalie

Hello, my name is Natalie and I will be telling you about tunnel boring machines.  The tunnel boring machine is a really big machine that has drills in the front.  The tunnel boring machine is used for making tunnels for the subway.  It can break through giant rocks.  The front of the tunnel boring machine used to be yellow, but it is not yellow anymore because it got too dirty!

This is a Tunnel Boring Machine underground.
It is yellow because it's clean.

How big is a TBM? by Ante

This is a tunnel boring machine turning its front
which is used to dig the hole.

The TBM weighs 200 tons.

The front of the TBM is 25 feet long.

When they are done with the TBM, they pull it out of the ground with a crane.  Then they break the TBM into pieces and they put it on a boat.  Then it goes to a different place so it can dig a new tunnel.