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.
“We, of course, are curious if it’s any way related to the previous situation during dry-dock testing, but I don’t want to guess,” he said in an interview last week.
It would be unusual for all of a tunnel borer’s outer seals to breach so early in its journey, Preedy said.
