Reconnecting Bertha’s inner cylinder
Crane crews lower the SR 99 tunneling machine’s inner cylinder into place in this Aug. 13, 2015 photo. The inner cylinder houses the machine’s agitator, which mixes excavated material, and the inner seal ring, which protects the main bearing. Learn more about the Alaskan Way Viaduct Replacement Program at www.alaskanwayviaduct.org or follow Bertha, the SR 99 tunneling machine, on Twitter @BerthaDigsSR99.
Reconnecting Bertha’s inner cylinder
Crane crews lower the SR 99 tunneling machine’s inner cylinder into place in this Aug. 13, 2015 photo. The inner cylinder houses the machine’s agitator, which mixes excavated material, and the inner seal ring, which protects the main bearing. Learn more about the Alaskan Way Viaduct Replacement Program at www.alaskanwayviaduct.org or follow Bertha, the SR 99 tunneling machine, on Twitter @BerthaDigsSR99.