World's largest tunneling machine heading to Seattle

World's largest tunneling machine heading to Seattle
(WSDOT photo)
SEATTLE (AP) - The world's largest-diameter tunnel boring machine is being loaded in 41 pieces onto a ship in Japan for a trip to Seattle.

The Seattle Daily Journal of Commerce reports the $80 million machine named Bertha was built at a factory in Osaka and is expected to arrive by the end of the month.

Bertha will be reassembled in a pit to tunnel a new Highway 99 route under downtown Seattle to replace the Alaskan Way Viaduct.

The tunnel will have a diameter of nearly 58 feet and is set to start boring this summer. The tunnel is scheduled to open in late 2015.

The tunnel borer was named Bertha in honor of Bertha Knight Landes, who was elected mayor of Seattle in 1926. The name was submitted by both a second-grade student at Lincoln Elementary School in Hoquiam and a fifth-grade class at Poulsbo Elementary School.