The second cycle of six pontoons for a replacement State Route 520 floating bridge were towed out of the Concrete Technology Corporation casting basin in Tacoma, Wash., from Jan. 28 to Jan. 31, 2013.
In this time-lapse video, crews maneuver a large T-pontoon into position to add the additional floatation needed to tow the supplemental stability pontoons out of the basin. Crews repeat this process three times to tow the six pontoons out of the basin so that work can begin on the third cycle.
Kiewit-General-Manson Joint Venture is building 44 pontoons in Tacoma, as well as the floating bridge on Lake Washington for the Washington State Department of Transportation. The new floating bridge requires 77 pontoons in all, with 33 to be built in Aberdeen, WA. – wsdot on YouTube