Bridge drivers will see first signs of replacement taking shape
If you drive across Lake Washington this week on the SR-520 floating bridge, you may notice some construction in the water. That’s the first step in building a new floating bridge across the lake--running parallel to and just north of the existing floating bridge.
This week, a large crane will move into place, along with some barges. Then, steel piles will get pushed into the soft soils in the lake-bed, just off-shore of Medina.
That’s just setting the stage for the main action, which is bolting together massive pontoons and sections of bridge deck says Jeff Switzer of the Washington State Department of Transportation.
The biggest of those sections are as long as a football field, and half the width. They’ve been manufactured in Aberdeen and Tacoma. They’ll arrive this summer, towed by tug-boats, after squeezing through the Ballard locks.
One by one, each pontoon will get bolted together at the staging area that’s being created this week. Then each one gets tied by steel cables to anchors down in the muck at the bottom of the lake.
It’ll take about two years to assemble the entire bridge deck.
The new bridge is both wider and taller than the old one, which was built back in 1963. However, design of the non-floating portion on the Seattle side of the lake is still in a legal dispute and hasn’t been funded.