Feb. 19 afternoon update: Bertha reaches daylight

Posted on Feb 19 2015 12:17 PM

At midday Thursday, the top portion of the SR 99 tunneling machine’s cutterhead broke through (links to YouTube) the southern wall of the access pit. Crews will continue to mine an additional two feet before stopping to build another concrete tunnel ring.

This is just the beginning of the repair effort being led by Seattle Tunnel Partners and manufacturer Hitachi Zosen. The machine will continue to move forward in 6 ½ foot increments, stopping to build rings on its way into the pit. When the front end of the machine is fully exposed, crews will begin the disassembly process. STP has told us that taking the machine apart and lifting it to the surface will take significant time and effort.

We recognize that the public has great interest in STP’s repair effort. We will continue to provide photos, video and regular updates about their progress as they work to resume tunneling. 

Repair plan resources:


Previous updates

Feb. 19, 2015 morning update - Bertha approaching the pit

Feb. 18, 2015 afternoon update - Bertha digs on

Feb. 18, 2015 project update - Bertha on the move

Feb. 13, 2015 project update - Safety at the forefront

Feb. 13, 2015 project update - Long-term traffic impacts on SR 99: lane closure begins March 7 through late May

Feb. 12, 2015 - Incident at tunnel's north portal work zone

Feb. 9, 2015 project update - Cradle awaits Bertha's front end

Archive of previous updates