By Sarah Aitchison, June 5, 2015
Seattle Tunnel Partners began attaching a new and redesigned seal system to Bertha this week.
It’s the first step in repairing the massive tunnel-boring machine (nicknamed Bertha, after the Bertha Knight Landes, the first woman mayor of Seattle) so it can go back underground and resume digging.
Hitachi Zosen, the company that built the massive tunnel-boring machine, sent the inner part of the new seal system from Japan in October. Last week, the outer portion of the seal system arrived and installation began Friday.
After Bertha was shut down in December 2013, crews discovered the seals that keep out dirt and grit had been damaged. Then, they had to dig a 120-foot-deep access pit to get the parts out to be replaced.
The new seal system should be easier to access in case things go wrong again.
STP is supposed to announce a new timeline and estimated completion date for the Alaskan Way Viaduct Replacement Program sometime this month.
The $3.1 billion project is almost two years behind schedule. Because the machine shut down after traveling fewer than 1,500 feet into the nearly 2-mile-long tunnel, Hitachi Zosen is still on the hook for replacing the parts and making sure the machine can function properly.