Bertha’s big troubles started in Japan

The Seattle TimesFebruary 25, 2014 

Chris Dixon, project manager for Seattle Tunnel Partners, earlier this month points out the outer seal assembly of Bertha’s main drive unit in photos taken before drilling work began. Dixon said there are indications that all seven outer seals may have been breached.

MARK HARRISON — The Seattle Times

Long before tunnel-boring machine Bertha stalled underneath Seattle because of leaky seals, it experienced a problem involving the same seals back in Japan.

When workers tested the mammoth $80 million machine before it was shipped here last April, they discovered damage to the seal system and ended up taking Bertha apart for repairs.

Now Bertha is again having problems with seals. There are indications that all seven of the machine’s outer seals may have been breached, according to the state Department of Transportation and the tunnel contractor.

Repairs will take several months in a 120-foot-deep pit that must be dug in front of the machine in wet soil along Elliott Bay.

While Bertha is having trouble with the same seals that had to be fixed in Japan, it’s unknown whether the cause of the problem is the same, said Matt Preedy, deputy administrator for the Alaskan Way Viaduct Replacement Program with the state Department of Transportation.


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