Digging starts for stalled Seattle tunnel machine

AP News
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Posted: Oct 21, 2014 2:32 PM

SEATTLE (AP) — Contractors building a new highway tunnel under downtown Seattle have started digging a 120-foot pit to rescue a stalled boring machine named Bertha.

Seattle Tunnel Partners also is pumping out groundwater as it digs the 80-foot-wide pit near the Seattle waterfront.

The $80 million, five-story-tall boring machine overheated and came to a stop last December after digging about 1,000 feet, or about 10 percent of the planned Highway 99 tunnel route. An investigation found seals in the cutting head were damaged.

A crane will lift the cutting head from the pit for repair. Tunneling could resume in March.

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Information from: Seattle Daily Journal of Commerce, http://www.djc.com/