March 23 project update: Third piece of tunneling machine lifted to the surface
Seattle Tunnel Partners has successfully lifted the third piece of the SR 99 tunneling machine to the surface for repairs. Crews lifted the machine’s 90-ton right side body from the pit Monday afternoon. Like the previous two pieces removed from the pit, the right side body is part of the machine's exterior shield.
The first lift, which occurred last week, can be seen from the perspective of the crane operator in this time-lapse video (links to YouTube).
With the machine's upper shield removed, STP will turn their attention to the final lift: Bertha's massive cutterhead and main drive unit. Crews will use the giant red crane, called a modular lift tower, to make the 2,000-ton lift. This narrated video (links to YouTube) explains the repair plan in detail.
Crews lifted Bertha’s 90-ton right side body from the pit on Monday.
Three pieces of Bertha's shield have been brought to the surface for repairs.