http://dcsfilms.com/Site_4/DCS_Website_41.html

In 1930, the city of Seattle and King County granted a franchise to the Seattle Toll Bridge Co. to build the Seward Park span, but financiers failed to step forward with bridge funds, and the plan fell through.

King County took over the project in 1935 with plans to build a steel truss cantilever from Seward Park for an estimated $3.5 million. Still, financing was a problem.

The state created the Washington Toll Bridge Authority to get federal grant money. The toll bridge authority was charged with locating, designing, financing and building both the Lake Washington and the Tacoma Narrows bridges.
In June of 1937 Lacey V. Murrow, a member of the toll authority and director of the state Highway Department, listened to Hadley’s plan for a bridge made of concrete pontoons. The idea stuck.

Pontoons seemed ideal. Concrete would be less expensive, and a seven-foot immersion in the water would be enough to stabilize the bridge during rough water.

Murrow was satisfied that enough motorists would use the bridge, at 25 cents per car, to repay the revenue bonds to finance more than half of the $8 million it would cost to build it. A $3.7 million federal grant would pay for the rest.

Work began on the Lake Washington Floating Bridge on Dec. 31, 1938. For the next 18 months, more than 3,000 men were employed on the bridge construction.

The four-lane concrete highway consisted of 25 floating pontoons bolted together end-to-end and attached to fixed approach spans.

The bridge was anchored with steel cables to resist wind and waves, and hydraulic jacks to let out or take up the slack.

It was the first floating draw span in the world, with a 200-foot section designed to allow vessels to pass through. Two 75-horsepower motors were used to open the span in 90 seconds. The bridge opened on July 2, 1940 as a crowd of 2,000 watched the christening of the 6,620-foot floating span.

Fifty years after it was built, water from a heavy rainstorm filled the pontoons and the floating bridge sank into Lake Washington on Nov. 25, 1990. Right away, efforts began to replace it with $88 million in emergency highway funds.

According to WSDOT:

Washington State is the floating bridge capitol of the world with the four longest and heaviest floating bridges. They are the SR 520 Evergreen Point Bridge, the I-90 Lacey V. Murrow Bridge, the I-90 Homer M. Hadley Bridge, and the SR 104 Hood Canal Bridge.

In 1957, a concrete floating bridge was built across Lake Okanagan at Kelowna in south central British Columbia, Canada. Its floating length is 2,100 feet (640 meters) and its design is very similar to the Lacey V. Murrow Bridge.

The Demerara Harbor Bridge in Georgetown, Guyana is another floating bridge. It is made of steel pontoon units and extends 6,074 feet (1851 meters).

Norway has two large floating bridges – the Bergsoeysund Floating Bridge in Kristiansund, More og Romsdal and the Nordhordland Floating Bridge.

Another long-time floating bridge site is the Golden Horn at Istanbul, Turkey.

Want to add one of these pics to the wikipedia entry, Ben? We also need a new picture of you, unless you are indeed eyeless:

http://en.wikipedia.org/wiki/Image:Seattle-meetup-4_11.jpg

Cliffe