Tuesday, November 29, 2011

the Lake Washington Floating Bridge, Seattle

Now known as the Lacey V. Murrow Memorial Bridge, this is a floating bridge that was built on concrete pontoons, and at the time of opening in 1940 was the world's longest such bridge at 6,620 ft (2,020 metres). It is now the world's second longest: the longest is the Evergreen Point Floating Bridge, a few miles to the north on the same lake, built 23 years later.

This photo looks to have been taken within 10 years of the opening. It included a movable span that could be retracted into a pocket in the center of the fixed span to permit large boats to pass. This design resulted in a roadway "bulge" that required vehicles to swerve twice across polished steel joints as they passed the bulge. Today it carries the eastbound lanes of Interstate 90 across Lake Washington from Seattle to Mercer Island, Washington. In 1989 another similar slightly shorter bridge, the Homer M. Hadley Memorial Bridge, was built next to the original bridge to carry the Interstate 90 westbound lanes.

As on the Auckland Harbour Bridge, a reversible lane system is used to cater for the different volume traffic flows in each direction at different times of day.

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