A look at deep-bore tunnel machine and launch pit

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by JOE FRYER / KING 5 News

KING5.com

Posted on October 31, 2012 at 10:22 PM

Updated Thursday, Nov 1 at 12:51 PM

SEATTLE -- The giant machine that will bore a tunnel beneath Seattle should be completely built by year's end and could arrive in Seattle as early as February or March, said the Washington State Department of Transportation (WSDOT).

The deep-bore tunnel will replace the aging Alaskan Way Viaduct, which will eventually be torn down.

For the past several months, constructions workers in Seattle have been preparing for the machine's arrival by building a launching pit directly south of the Viaduct.  Crews have been building walls and digging out soil for the pit, which will be 400 feet long and 80 feet deep. 

The 5-story-tall boring machine, which will be the largest ever built, is about 60 to 70 percent finished, said Matt Preedy, deputy program administrator for the Alaskan Way Viaduct.  WSDOT just released new images of the machine, which is under construction in Japan. 

Workers standing next to the machine almost look like "ants," said Mike Melanson, who viewed the pictures earlier this week. 

When the machine is finished and tested in December, crews will need to take it apart into 41 pieces, then place everything on a boat and ship it to Seattle. 

Once the machine arrives at Terminal 46 in Seattle, possibly in February or March, crews will lower each part into the pit and reassemble the machine there, a process that will likely take a few months, Preedy said. 

If everything stays on track, the massive machine will break ground by early to mid summer.

Some have questioned why the machine is not being built in the United States. WSDOT said six companies were qualified to tackle the massive project and only one of those was a U.S. company.  Price, delivery time frame and several other factors were taken into consideration when deciding which company would build it, Preedy said.

WSDOT is sponsoring a contest for students to name the machine.  For more information, check out the following link:

http://www.wsdot.wa.gov/projects/viaduct/TBMName

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