Sellwood Bridge

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Sellwood Bridge
New Sellwood Bridge in March 2016.jpg
The new bridge in March 2016
Coordinates 45°27′51″N 122°39′56″W / 45.46429°N 122.66564°W / 45.46429; -122.66564Coordinates: 45°27′51″N 122°39′56″W / 45.46429°N 122.66564°W / 45.46429; -122.66564
Carries 2 traffic lanes, pedestrians, cyclists
Crosses Willamette River
Locale Portland, Oregon
Owner Multnomah County
Characteristics
Design Deck arch bridge
Total length 1,976 ft (602 m)
Width 64 ft (20 m)
Longest span 465 ft (142 m)
History
Construction cost $290 million (projected)
Opened February 29, 2016
Statistics
Daily traffic 30,000 (2005)[1]

The Sellwood Bridge is a deck arch bridge that spans the Willamette River in Portland, Oregon, in the United States. It was Portland's first fixed-span bridge and, being the only river crossing for miles in each direction, is the busiest two-lane bridge in Oregon.[1] It links the Sellwood and Westmoreland neighborhoods of Portland on the east side with Oregon Route 43/Macadam Avenue on the west side. At its east end it leads to Tacoma Street. The bridge is owned and operated by Multnomah County. The original steel truss span was completed in 1925, which was a replaced with the deck arch bridge that opened in 2016.[2]

History[edit]

Original Span
Sellwood Bridge - Portland, Oregon.jpg
The Sellwood Bridge in 2010
Locale Portland, Oregon
Characteristics
Design Truss bridge
Total length 1,971 ft (601 m)
Width 28 ft (8.5 m)
Longest span 300 ft (91 m)
Clearance below 75 ft (23 m)
History
Opened December 15, 1925
Closed February 25, 2016

Designed by Gustav Lindenthal, the first bridge opened on December 15, 1925, at a final cost of $541,000[3] (equivalent to $6.9 million in 2011). It was 1,971 feet (601 m) long with 75 feet (23 m) of vertical waterway clearance. It had four continuous spans, all of Warren type.[1] The two center spans were 300 feet (91 m) long, and the two outside spans were 246 feet (75 m) each. The girders from the old Burnside Bridge (built in 1894) were reused at each end. The two-lane roadway was 24 feet (7.3 m) wide. There was a sidewalk on the downstream side only, with a width of 4 feet 3 inches (1.30 m); however, the street light foundations shared space with the sidewalk, making the sidewalk's usable width at those points about 3 feet (36 inches, 91 cm).[4] Allowing for safety clearances, there was less than 2 feet (24 inches, 61 cm) of usable sidewalk. The Bicycle Transportation Alliance listed the Sellwood Bridge as one of the top ten priorities for improving Portland's bicycling.[5]

The bridge's condition had been deteriorating since the 1960s.[6] In an October 2011 study, the Department of Transportation wrote that the Sellwood Bridge must be replaced 'immediately'.[7] On December 15, 2011, the county received US federal funding sufficient to begin immediate work on a replacement.[8] On July 19, 2012, Multnomah County commissioners approved a $299 million design for a new bridge.[9] Upon discovery of cracks in both concrete approaches in January 2004, the weight limit on the bridge was lowered from 32 tons to 10 tons.[10] This has caused the diversion of about 1,400 daily truck and bus trips,[1] including 94 daily TriMet bus trips. Over the few years that followed, there was debate on whether the bridge should be replaced, repaired, closed altogether, or closed for automotive traffic (but left open for pedestrians and bicycles).[6] In April 2005, Bechtel gave Multnomah County an unsolicited plan to replace the bridge through a public-private partnership.[11]

In July 2007, the Multnomah County Board of Commissioners considered several options for a replacement bridge. At the time, the top option was a 75-foot-wide (23 m) bridge with two car lanes and two transit lanes, running just south of the current bridge, with a projected cost of $302 million.[12] In November 2008, however, the Sellwood Bridge team issued a draft Environmental Impact Statement containing details on five different finalist designs and alignments.[6] In February 2009, the Policy Advisory Group (PAG), based on recommendations provided by a Community Task Force and the public, selected a Locally Preferred Alternative (LPA). The LPA includes replacement of the existing bridge with a new bridge, alignment approximately 15 feet south of Tacoma Street, allowing continuous traffic flow at the crossing during construction, a pedestrian-actuated signal at Tacoma Street and SE 6th Avenue, and a signal at the west end interchange. The LPA is 64 feet (or less) wide and consists of two traffic lanes, two bike lanes, and two 12-foot (3.7 m) wide sidewalks.[13] A final Environmental Impact Statement was published in spring 2010, and it was approved by the Federal Highway Administration in July 2010.[14]

After evaluation in 2010 of several different possible designs, a two-lane steel deck arch bridge was chosen for the replacement bridge. This was approved by the Multnomah County Commission on January 27, 2011.[15][16] The new bridge is strong enough to carry streetcars and the design will include some provisions intended to make the potential installation of a streetcar line across the bridge easier, should city officials later decide to build such a line. Plans to include streetcar tracks were briefly considered in late 2010, but dropped in January 2011 to reduce costs.[17]

On July 19, 2012, a final design was approved by Multnomah County commissioners. The design is a steel deck arch bridge with pedestrian and bicycle lanes on both sides. Construction was funded with $136 million from the county (raised from a $17 annual vehicle registration fee), $33 million from the federal government, $35 million from the state, and $84.5 million from the city of Portland.[9] Clackamas County was originally to provide some funding due to the bridge’s use by many residents of that county, but that plan was later rejected by voters.[18]

On January 19, 2013, the 6.8-million pound bridge was moved onto temporary steel supports by contractor Omega Morgan.[19] The moved bridge, known as a shoofly bridge,[20] served as a temporary span until the new crossing opened in early 2016. The old bridge closed to traffic permanently on February 25, 2016, and the new bridge opened to traffic on February 29, 2016.[2] In between, on February 27, an opening celebration event took place on the new span with access to pedestrians and cyclists only. Crews began demolishing the original railings and bridge deck once the old span closed, with the process completed in May 2016. The steel trusses will be removed and the temporary supports will be dismantled in the summer of 2016.[19]

Design[edit]

The Sellwood Bridge stretches a total of 1,976 feet (602 m) across the Willamette River. The deck arch design’s longest span is 465 feet (142 m) long and rests on a total of two piers in the water. There are a total of three arches carrying the 64-foot (20 m) wide span. The deck carries two lanes of traffic, bicycle lanes in both directions, and sidewalks on both sides.

See also[edit]

References[edit]

  1. ^ a b c d Wood Wortman, Sharon; Wortman, Ed (2006). The Portland Bridge Book (3rd ed.). Urban Adventure Press. pp. 83–88. ISBN 0-9787365-1-6. 
  2. ^ a b KATU staff (February 29, 2016). "New Sellwood Bridge open for pedestrians and drivers". KATU. Retrieved 2016-02-29. 
  3. ^ Wood, Sharon (2001). The Portland Bridge Book. Oregon Historical Society. ISBN 0-87595-211-9. 
  4. ^ "Sellwood Bridge". Multnomah County. Retrieved 2006-11-06. 
  5. ^ Bicycle Transportation Alliance. "Blueprint for Better Biking: Sellwood Bridge" (PDF). Retrieved 2006-11-06. 
  6. ^ a b c Dylan Rivera (November 26, 2008). "Region weighs options on cracked Sellwood Bridge". The Oregonian. Retrieved April 17, 2011. 
  7. ^ http://www.kptv.com/story/15736104/survey-deems-80-portland-bridges-structurally-deficient
  8. ^ "The Sellwood Bridge: A New Milestone". Sellwood Bridge Project website. Multnomah County. December 16, 2011. Retrieved January 31, 2013. 
  9. ^ a b Mayer, James (July 19, 2012). "Sellwood Bridge final design approved". The Oregonian. Retrieved July 23, 2012. 
  10. ^ Hamilton, Don (June 24, 2004). "Sellwood span has new limits". Portland Tribune. Archived from the original on February 11, 2012. Retrieved May 7, 2015. 
  11. ^ Jacklet, Ben (May 13, 2005). "The Sellwood solution?". Portland Tribune. Archived from the original on February 11, 2012. Retrieved May 7, 2015. 
  12. ^ Arthur Gregg Sulzberger Holly Danks Jessica Bruder Steve Mayes Jessica Riffel (July 13, 2007). "Portland New, wider Sellwood span favored". The Oregonian. (registration required (help)). 
  13. ^ "Previous phases". Multnomah County. Retrieved April 17, 2011. 
  14. ^ "Notice of Final Federal Agency Actions on the Sellwood Bridge Project, SE Tacoma Street and Oregon Highway 43, Multnomah County, OR". Federal Highway Administration via the Federal Register. April 13, 2011. Retrieved April 17, 2011. 
  15. ^ Vorenberg, Sue (January 27, 2011). "Sellwood Bridge design approved by county". Daily Journal of Commerce. Retrieved April 17, 2011. 
  16. ^ Hannah-Jones, Nikole (January 27, 2011). "Multnomah County board approves Sellwood Bridge design". The Oregonian. Retrieved April 17, 2011. 
  17. ^ Schmidt, Brad (January 20, 2011). "Sellwood Bridge design won't include $13 million for streetcar tracks or on-ramp". The Oregonian. Retrieved April 17, 2011. 
  18. ^ Law, Steve (June 14, 2011). "County pushes ahead on Sellwood Bridge plan". Portland Tribune. Retrieved May 7, 2015. 
  19. ^ a b Tims, Dana (January 19, 2013). "Sellwood Bridge move comes off without a hitch, amazing hundreds of onlookers". The Oregonian. Retrieved January 31, 2013. 
  20. ^ "The Sellwood Bridge Project, accessed January 22, 2013

External links[edit]