Bertha chugging along, more than half way to rescue pit

SEATTLE (AP) — Seattle's troubled tunnel machine named Bertha has made it more than half way toward its goal of reaching a rescue pit where it can be repaired.

On Wednesday, Bertha drilled 6 feet through the south wall of the access pit and on Thursday morning, she had made it 14 feet. The wall is 20 feet thick.

State transportation officials say as the machine moved forward, it built two concrete tunnel rings. The tunnel, once completed, will replace the Alaskan Way viaduct, damaged in a 2001 earthquake.

Once Bertha reaches the pit, crews plan to remove the front of the machine and pull it out of the pit so it can be repaired.

Seattle Tunnel Partners, the builders, are following strict protocols to prevent overheating that could further damage the machine.