The following is a release from the Washington State Department of Transportation:

Crews building the new State Route 520 floating bridge on Lake Washington reached a significant milestone today as they moved the bridge’s last three massive concrete pontoons into final position. The pontoons form the structural spine of the world’s longest floating bridge.

Crews today towed pontoons B, C and D from an east-end moorage near Medina to their permanent location at the new bridge’s west end, near Seattle.  Bolted together, the three pontoons gave the appearance of a giant barge – more than 1,000 feet long.  With tall columns and new roadway deck already built atop them, pontoons B, C and D together form most of the new floating bridge’s west high-rise.

“With the final three longitudinal pontoons now in their permanent location, you can actually see this great new bridge stretching end to end across the lake,” said Julie Meredith, the Washington State Department of Transportation’s administrator of the SR 520 Bridge Replacement and HOV Program. “It’s an exciting day for everyone involved in the project.”

Within a few weeks, crews will tow Pontoon A back into position and connect it to Pontoon B. Pontoon A is one of two “cross” pontoons that bookend the new floating highway. In between are the bridge’s 21 longitudinal pontoons – each 11,000 tons and 360 feet long. Fifty-four smaller, supplemental pontoons flank the jumbo pontoons to give the bridge added support and stability.

When it opens to traffic in spring 2016, the new floating bridge will have two general-purpose lanes and one transit-carpool lane in each direction.  Built to withstand stronger windstorms and wave action, the bridge also will have wide shoulders for disabled vehicles and a 14-foot-wide bicycle and pedestrian path.