Steel Bridge
Template:Short description Template:About Template:Use mdy dates Template:Use American English Template:Infobox Bridge
The Steel Bridge is a through truss, double-deck vertical-lift bridge across the Willamette River in Portland, Oregon, United States, opened in 1912. Its lower deck carries railroad and bicycle/pedestrian traffic, while the upper deck carries road traffic (on the Pacific Highway West No. 1W, former Oregon Route 99W), and light rail (MAX), making the bridge one of the most multimodal in the world. It is the only double-deck bridge with independent lifts in the world<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and the second oldest vertical-lift bridge in North America, after the nearby Hawthorne Bridge. The bridge links the Rose Quarter and Lloyd District in the east to Old Town Chinatown neighborhood in the west.
HistoryEdit
The bridge was completed in 1912 and replaced the previous Steel Bridge built in 1888 as a double-deck swing-span bridge. The 1888 structure was the first railroad bridge across the Willamette River in Portland. Its name originated because steel, instead of wrought iron, was used in the original bridge's construction, which was very unusual for the time.<ref>Template:Cite book</ref> When the current Steel Bridge opened, it was simply given its predecessor's name.
The bridge was designed by the engineering firm of Waddell & Harrington,<ref name="wood-wortman-p180">Wood Wortman (2006), pp. 5, 39, 42, 180.</ref> which was based in Kansas City, Missouri, but also had an office in Portland.<ref name="steel over">Template:Cite book</ref>Template:Rp The structure was built by Union Pacific Railroad and the Oregon-Washington Railroad and Navigation Company (OWR&N)<ref name="steel over"/><ref name=bottenberg>Template:Cite book</ref> at a cost of $1.7 million<ref>Template:Cite book</ref> (equivalent to $Template:Inflation million in Template:Inflation-yearTemplate:Inflation-fn). It opened in July 1912 to rail traffic and on August 9, 1912, to automobiles.<ref name="wood-wortman-p180"/>
The 1888 Steel Bridge (upper deck) had been crossed by horse-drawn streetcars from the time of its opening and then by the city's first electric streetcar line starting in November 1889.<ref name="steel over"/>Template:Rp When the present Steel Bridge opened in 1912, the streetcar lines (all electric by then) moved to it, starting on September 8, 1912.<ref name="oreg1912sep9">"New Bridge Used: Streetcars Take New Route for First Time" (September 9, 1912). The Morning Oregonian, p. 10.</ref><ref name="steel over"/>Template:Rp Streetcar service across the Steel continued until August 1, 1948, when the last car lines using it, the Alberta and Broadway Lines, were abandoned. A single line of Portland's once-extensive trolley bus system also used the bridge; the Williams Avenue line crossed the Steel Bridge from 1937 until October 9, 1949.<ref name="steel over"/>Template:Rp<ref name="thompson2010">Template:Cite book</ref> (Many years later, in 1986, electric transit vehicles returned to the bridge in the form of MAX Light Rail and later the Portland Vintage Trolley.)<ref name="steel over"/><ref name="thompson2010">Template:Cite book</ref>
The lower deck of the bridge was threatened by major floods in 1948, 1964, and 1996.<ref name="wood-wortman-p180"/>Template:Rp The bridge was closed for three days because of the danger during the February 1996 floods.<ref name="PRN-1996apr">Template:Cite magazine</ref>
In 1950, the Steel Bridge and its newly reconstructed approaches became part of a new U.S. 99W highway<ref name="steel over"/>Template:Rp connecting Harbor Drive and Interstate Avenue.
In the 1960s, the bridge was sought for use by Interstate 5, which was later moved to the Marquam Bridge. Construction of the freeway instead brought the addition to the Steel Bridge of a new viaduct leading onto I-84 from the bridge's eastbound lanes.<ref>Template:Cite news</ref>
In 1972, the bridge became part of Route 99W, replacing the US 99W designation. Harbor Drive, and by extension the ramps onto it from the bridge, was demolished from 1972 to 1974. It was replaced by Tom McCall Waterfront Park.
In the mid-1980s, the bridge underwent a $10 million renovation, including construction of the MAX light rail line of TriMet. Beginning in June 1984, the span was closed to all traffic for two years.<ref name="oreg-1984-jun12">"Steel Bridge shut down for light rail" (June 12, 1984). The Oregonian, p. B1.</ref> It reopened on May 31, 1986.<ref name="oreg-1986may30">Federman, Stan (May 30, 1986). "Bridge party trumpets reopening". The Oregonian, p. E2.</ref> Completion and testing of the light-rail tracks and overhead wires across the bridge took place during the next three months and the light rail line opened for service on September 5, 1986.<ref name="steel over"/>Template:Rp The renovation also saw the crossing gates blocking the roadway and sidewalks during raising of the upper-deck lift replaced and automated. For the current bridge's first 72 years, the gates had been manually operated, rotated horizontally across the roadway by two "gate tenders", one on each side of the lift span.<ref name="steel over"/>Template:Rp Small shacks for the gatekeepers were positioned on the roadway deck, between the inner and outer traffic lanes, but these were removed during the 1980s rebuilding and replaced by a new gate tender house positioned above the roadway, in the west lift tower.<ref name="steel over"/>Template:Rp Powered crossing gates replaced the manual ones, and operation of the gates is now controlled remotely, by the bridge operator.<ref name="steel over"/>Template:Rp
A single-lane viaduct that connected the bridge's east approach to another viaduct (still in existence) that takes traffic from southbound Interstate 5 to Interstate 84 was closed in 1988 and was demolished in 1989, as part of roadway changes intended to improve traffic flow around the Oregon Convention Center.<ref name="oreg-1989jan18">Federman, Stan (January 18, 1989). "Major road repairs this summer could snarl Portland-area traffic". The Oregonian, p. B2.</ref> The center was under construction at that time and opened in 1990.
In 2001,<ref name="steel over"/>Template:Rp a Template:Convert and Template:Convert cantilevered walkway was installed on the southern side of the bridge's lower deck as part of the Eastbank Esplanade construction, raising to three the number of publicly accessible walkways across the bridge, including the two narrow sidewalks on the upper deck. The bridge is owned by Union Pacific with the upper deck leased to Oregon Department of Transportation, and subleased to TriMet, while the City of Portland is responsible for the approaches.<ref>Template:Cite news</ref>
The average daily traffic in 2000 was 23,100 vehicles (including many TriMet buses), 200 MAX trains, 40 freight and Amtrak trains, and 500 bicycles. The construction of the lower-deck walkway connected to the Eastbank Esplanade resulted in a sharp increase in bicycle traffic, with over 2,100 daily bicycle crossings in 2005.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> MAX traffic has tripled since 2000, when only the Gresham–Hillsboro line (now the Blue Line) was using the bridge, to 605 daily crossings (weekdays) as of 2012.<ref name="steel over"/>Template:Rp This resulted from the addition of three more MAX lines during that period: the Red, Yellow, Green Lines.
In the summer of 2008, the upper deck was closed for three weeks to allow a junction to be built at the west end connecting the existing MAX tracks with a new MAX line on the Portland Transit Mall. A change made at that time was that the two inner lanes became restricted to MAX trains only, with cars, buses and other motorized traffic permitted only in the two outer lanes.<ref name=trib-2008aug>Template:Cite news</ref>
In 2012, the Steel Bridge celebrated its 100th birthday. The Oregonian called it the "hardest-working" bridge on the Willamette River: "Cars, trucks, freight trains, buses, Amtrak, MAX, pedestrians, bicycles — you carry it all."<ref>Template:Cite news</ref>
Structure and lift operationEdit
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The lift span of the bridge is Template:Convert long. At low river levels, the lower deck is Template:Convert above the water, and Template:Convert of vertical clearance is provided when both decks are raised. Because of the independent lifts, the lower deck can be raised to Template:Convert, telescoping into the upper deck but not disturbing it. Each deck has its own counterweights, two for the upper and eight for the lower, totaling Template:Convert.
The machinery house sits atop the upper-deck lift truss. The operator's room is suspended from the top of the lift-span truss, directly below the machinery house, so that the operator can view river traffic as well as the upper deck. After the 2001 addition of a pedestrian walkway on the lower deck, cameras and closed-circuit television monitors were added to allow the operator to view the lower-deck walkway.<ref name="steel over"/>Template:Rp
See alsoEdit
- List of bridges documented by the Historic American Engineering Record in Oregon
- List of crossings of the Willamette River
- Steel Bridge Skatepark
ReferencesEdit
- General
- Specific
External linksEdit
Template:Bridges of Portland, Oregon Template:Crossings navbox
Template:Kerns, Portland, Oregon Template:Lloyd District, Portland, Oregon Template:Old Town Chinatown, Portland, Oregon Template:Authority control