big bertha

Joe Mabel / Wikimedia Commons

If you've ridden a train to or from Seattle you have probably passed through the heart of the city via the Great Northern Tunnel.

This month, the tunnel turns 110 years old.

Back in the fall of 1904, when it was finished, the mile-long tunnel was the tallest and widest in the United States.

Local historian Michael Sullivan tells the story:

A tunnel machine is set to resume digging beneath the streets of Seattle in June. This machine isn't named Bertha.

SR 99 Tunnel Making Machine Bertha Blocked by Pipe

Jan 3, 2014
WADOT

Experts say a steel pipe is at least partly to blame for halting a massive tunnel-boring machine beneath downtown Seattle. The state Department of Transportation said today (Friday) that an 8-inch-diameter pipe was discovered protruding through an opening in the machine's cutter-head. Officials say the pipe is a well casing installed by the department in 2002 to monitor groundwater. Chris Dixon is the Seattle Tunnel Partners Project Manager.  “A cutter head won't line through and cut up steels.  Very good with clay and sands and boulders and gravels but …not good with metal.” He said.

"Big Bertha" should soon get back to work digging a nearly two mile tunnel to replace Seattle’s Alaskan Way Viaduct.