Connecting two pits
Crews continue work on the SR 99 tunnel’s south portal operations building in April 2014. The west wall of the pit (at the center of this image) is where crews will make a large hole to connect the basement of the future building to the adjacent tunnel launch pit, where the SR 99 tunneling machine was launched in July 2013. This hole will connect the operations building’s four large ventilation stacks to the tunnel and provide an access point for maintenance workers. Learn more about the Alaskan Way Viaduct Replacement Program at www.alaskanwayviaduct.org or follow Bertha on Twitter @BerthaDigsSR99.