The heavy rotators at the heart of Bertha’s front end
This Aug. 10, 2015, photo shows two of the big rotating pieces at the front end of the SR 99 tunneling machine. The largest circle is Bertha’s main bearing and bull gear, which rotates the cutterhead. The smaller circle is the center pipe, part of the agitator that mixes excavated material in the chamber behind the cutterhead. Learn more about the Alaskan Way Viaduct Replacement Program at www.alaskanwayviaduct.org or follow Bertha, the SR 99 tunneling machine, on Twitter @BerthaDigsSR99.
The heavy rotators at the heart of Bertha’s front end
This Aug. 10, 2015, photo shows two of the big rotating pieces at the front end of the SR 99 tunneling machine. The largest circle is Bertha’s main bearing and bull gear, which rotates the cutterhead. The smaller circle is the center pipe, part of the agitator that mixes excavated material in the chamber behind the cutterhead. Learn more about the Alaskan Way Viaduct Replacement Program at www.alaskanwayviaduct.org or follow Bertha, the SR 99 tunneling machine, on Twitter @BerthaDigsSR99.