Tunnel boring machine in pieces for voyage to Seattle

Tunnel boring machine in pieces for voyage to Seattle

Credit: WSDOT

Workers stand in the shadow of what will become the world’s largest-diameter tunnel boring machine. Currently being assembled in Japan, the machine will dig the SR 99 tunnel beneath downtown Seattle starting in summer 2013. Scheduled to open to traffic in late 2015, the tunnel will replace the central waterfront section of the Alaskan Way Viaduct.

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by KING 5 News

NWCN.com

Posted on March 7, 2013 at 5:51 PM

Bertha, the world record 5-story-tall boring machine, will begin work in Seattle soon. But first, Bertha’s 41 pieces – the largest weighing up to 900 tons – are being loaded on a single ship.

The ship will leave Japan in mid-March and arrive in Seattle later this month, if the weather cooperates.

Bertha's deep-bore tunnel will replace the aging Alaskan Way Viaduct, which will eventually be torn down. She should begin digging next summer.

“We’re entering an exciting stage of this project,” said Linea Laird, WSDOT’s administrator for the Alaskan Way Viaduct Replacement Program. “While we have a lot of work to do once Bertha arrives, we can’t wait to introduce her to the people of Washington.”

You can follow Bertha's journey through her Twitter account (@BerthaDigsSR99).

Crews in Seattle are 80 percent finished with a 400-feet-long, 80-feet-deep pit directly south of the viaduct where Bertha will begin her digging.

Once the machine arrives at Terminal 46 in Seattle, expected to be in late 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.

The Washington State Department of Transportation is holding an open house Thursday to talk about Bertha and give people a sneak peek at the support facilities near the launch pit, which include a soil-removing conveyor belt that will stretch two miles by the end of construction.

WSDOT will host a presentation about Bertha’s arrival at 6 p.m. Thursday at Milepost 31 in Pioneer Square.

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

Bertha the machine was handed over to Seattle Tunnel Partners, the project's contractor, at a ceremony in Japan on December 20, 2012.  As Bertha’s owner, STP is responsible for ensuring she functions properly at all times.

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.

Hitachi Zosen, a company that specializes in massive tunneling equipment, built the machine.

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