As one of the major East-West traffic corridors into downtown Seattle, WA, the SR520 Floating Bridge and Landings (SR520 FB&L) spans Lake Washington. The pontoon design for the floating span was discussed in the October 2016 issue of STRUCTURE magazine. The floating span is dynamic, moving with fluctuations in the water level of the lake as well as wind and wave action. As a result, each end of the bridge requires a transition span from the floating bridge portion to the fixed, land-based approaches. …