Seattle Bridges

[andy3175]

Thought you would enjoy this article on Seattle's "gritty" bridges:

http://www.seattletimes.com/pacific-nw-magazine/seattles-gritty-bridges-are-built-for-function-not-beauty/

Seattle's George Washington Memorial Bridge, AKA the Aurora Bridge, opened to traffic in 1932, and features a striking cantilever and truss design that soars 167 feet above Lake Union and the Fremont neighborhood. ...

While we can't compete with Pittsburgh, which boasts 400 to 1,200 bridges depending on who's counting, Seattle owns and maintains some 150 bridges within its city limits. ...

Seattle boasts the two longest floating-bridge spans on Earth, the eastbound Mercer Island floating bridge and the Highway 520 bridge. Three, if you count the $4.65 billion replacement to the 520 bridge currently under construction across Lake Washington.

The Interstate 5 Ship Canal Bridge, a double-decker monster stretching 4,429 feet over Lake Union between Capitol Hill and the University District, doesn't just carry 256,000 vehicles each day, the most of any bridge in the region; it also serves as a critical continental trade link along the only interstate freeway in America that connects Mexico and Canada. ...

The Fremont Bridge, which has only a 30-foot clearance, connects the Queen Anne and Fremont neighborhoods and is one of the busiest drawbridges in the world. Completed in 1917, the bridge opens an average of 35 times a day, a yawning chasm at which stifled commuters have been shouting curses for years. ...

As part of the $930 million Move Seattle transportation levy that voters approved on Nov. 3, $140 million will be used to eliminate the backlog on spot repairs for the city's bridges; seismically reinforce 16 vulnerable bridges; and replace the city's last remaining timber vehicle bridge, which runs along Fairview Avenue over the southeastern shore of Lake Union, among other uses.

The ballot measure laid bare a core truth about our man-made ecosystem: It is startlingly fragile.

We learned this the hard way in 1990, when the floating Lacy V. Murrow Bridge linking Mercer Island and Seattle along Interstate 90, which was undergoing repairs, broke apart and sank during a heavy wind- and rainstorm.

A major rationale for replacing the 11,088-foot Alaskan Way Viaduct along State Route 99, which was completed in 1953, was concern about its ability to withstand a major earthquake.

In 2014, the collapse of an I-5 bridge over the Skagit River near Mount Vernon, which happened after a truck struck it, thrust bridge stability into the public's consciousness once more.

[Bruce]

Some of these functional bridges are actually quite beautiful. Seeing cars zip across the Ship Canal Bridge at sunset is a great sight from the UW campus.