SEATTLE - Bertha, the world's largest tunneling machine, is just about ready to get to work on two miles of Seattle soil.

On Saturday, Gov. Jay Inslee and the Washington State Department of Transportation hosted a public celebration at Bertha's launch site, west of CenturyLink Field.

This is a historic day, Gov. Inslee told guests, before participating in a short ceremony to christen the machine. When I look down into this pit, I don't just see a big machine. I see determination, I see innovation, I see teamwork, I see a symbol of a community that worked together to move us forward.

Bertha is five stories tall, longer than a football field and her face alone weights nearly 900 tons.

Bertha will move slowly, averaging 36 feet a day, grinding away at the soil beneath Seattle at one revolution per minute.

We want to make sure this machine has every fail-safe mechanism available to make sure we control the ground effectively, said operator Jerry Roberge.

Visitors on Saturday got to sign their names on the concrete pieces that will form the tunnel.

Tunneling starts at the end of July after final testing is complete. The tunnel is scheduled to open to drivers in late 2015. For more information about the SR 99 Tunnel Project, visit

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