Evergreen Point Floating Bridge

Evergreen Floating Bridge

The Evergreen Point Floating Bridge, also known as the 520 Bridge and officially the Governor Albert D. Rosellini Bridge, carries Washington State Route 520 across Lake Washington from Seattle to its eastern suburbs. The 2,350 m floating span is the longest floating bridge in the world, as well as the world’s widest measuring 35 m at its midpoint.

This bridge is made up of pontoons. Pontoons for marine industrial uses are usually fabricated from steel plate and sheet. Pontoons as parts of watercraft and aircraft are more typically molded in glass-reinforced plastic. Before the 1970s, glass-reinforced plastic was rare; older techniques include those of traditional wooden boatbuilding as well as plywood over wooden ribs or metal sheets over metal ribs (

Pontoons for marine industrial uses are usually fabricated from steel plate and sheet. Pontoons as parts of watercraft and aircraft are more typically molded in glass-reinforced plastic. Before the 1970s, glass-reinforced plastic was rare; older techniques include those of traditional wooden boatbuilding as well as plywood over wooden ribs or metal sheets over metal ribs (aluminum or steel), reflecting the prevailing practice in aircraft and boats. In model building, floats can easily be carved out of solid blocks or laminated sheets of foam.

The bridge opened in April 2016 and replaced another floating bridge of the same name at the site, which was 40 m shorter.

Planning of the replacement bridge started in 1997 with a cross-lake study conducted by the state Department of Transportation. The study followed several others in the late 20th century to find solutions to traffic on the SR 520 floating bridge, with most proposals rejected after heavy opposition from communities on both ends of the bridge.

The final environmental impact statement for the project was issued in 2011, allowing for construction of the pontoons to begin the following year.

Facts

  • The bridge has six lanes and a bicycle path.
  • It is made up of 77 pontoons and each pontoon weighs around 11,000 tons, which is the equivalent of 23 Boeing 747 jets
  • The bridge costs $4.65 billion.

Watch a Video

Leave a Reply

Your email address will not be published. Required fields are marked *