For the first time, cameras go inside the Port of Miami Tunnel to show how the project is coming along.
The tunnel boring machine, nicknamed "Harriet," is more than a football field and a half long and weighs 6.5 million pounds. The machine is several stories high.
"Instead of looking at this like a machine, this is a complete factory," said Herrenknecht Project Manager Aaron Scarfia.
The machine is made up of 150 smaller machines that work at the same time to create the tunnel.
"This is the piece that actually is going to scrape against the ground," said Scarfia, referring to the machine's cutter head.
The cutter head will drill through rock with the help of 266 cutting knives and 34 cutter discs.
"As you're cutting through the ground, these [cutter discs] will rotate and cut the dirt," said Scarfia.
Crews use foam to turn the soil they dig up into putty, which is carted off on the conveyor belt above the MacArthur Causeway. The belt can remove 2,000 tons of material per hour.
"It's just fascinating that you can stand in one place and see what's functioning on the entire machine," Scarfia said of the control room.
The tunnel itself is made up of rings, which are placed one at a time. Each ring is made up of eight concrete segments. Those segments weigh 25,000 pounds, and measure 14-feet long, 5-feet wide and 2-feet deep.
The construction crews plan on using 12,000 concrete segments.
Thrust cylinders propel the machine forward, and brushes leave grease to seal the edges of the concrete.
During an emergency, the 16 person crew takes refuge in a small bunker. Inside, communication devices give them access to the outside world to call for help.
Next week, crews will begin drilling underwater from the MacArthur Causeway side to the Port of Miami, making up the eastbound and westbound lanes of the tunnel.