Rating is available when the video has been rented.
This feature is not available right now. Please try again later.
Published on Mar 13, 2014
In this March 5 video, crews dismantle the temporary concrete tunnel rings that Bertha, the SR 99 tunneling machine, used for leverage at the start of her two-mile journey beneath downtown Seattle. Each full ring consists of 10 segments of reinforced concrete that together weigh 360,000 pounds. After the ring segments are pulled to the ground, they are hoisted out of the launch pit for recycling. Removing the rings will give crews space to begin building the double-deck highway within the tunnel.