The Morrison Bridge is a

bascule bridge A bascule bridge (also referred to as a drawbridge or a lifting bridge) is a moveable bridge with a counterweight that continuously balances a span, or leaf, throughout its upward swing to provide clearance for boat traffic. It may be single- o ...

that spans the

Willamette River The Willamette River ( ) is a major tributary of the Columbia River, accounting for 12 to 15 percent of the Columbia's flow. The Willamette's main stem is long, lying entirely in northwestern Oregon in the United States. Flowing northward ...

Portland, Oregon Portland ( ) is the List of cities in Oregon, most populous city in the U.S. state of Oregon, located in the Pacific Northwest region. Situated close to northwest Oregon at the confluence of the Willamette River, Willamette and Columbia River, ...

. Completed in 1958, it is the third bridge at approximately the same site to carry that name. It is one of the most heavily used bridges in Portland. It was added to the

National Register of Historic Places The National Register of Historic Places (NRHP) is the Federal government of the United States, United States federal government's official United States National Register of Historic Places listings, list of sites, buildings, structures, Hist ...

in November 2012.

Predecessors

The original Morrison Bridge (or Morrison Street Bridge) was a wooden truss swing-span bridge that opened to the public on April 9, 1887 (with a formal opening three days later), as the first Willamette River bridge in Portland and the longest bridge west of the

Mississippi River The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...

. It was named for the street it carried, which had been named for John L. Morrison, a

Scottish Scottish usually refers to something of, from, or related to Scotland, including: *Scottish Gaelic, a Celtic Goidelic language of the Indo-European language family native to Scotland *Scottish English *Scottish national identity, the Scottish ide ...

immigrant Immigration is the international movement of people to a destination country of which they are not usual residents or where they do not possess nationality in order to settle as permanent residents. Commuters, tourists, and other short- ...

who built the first home on Morrison Street. It was first a

toll bridge A toll bridge is a bridge where a monetary charge (or '' toll'') is required to pass over. Generally the private or public owner, builder and maintainer of the bridge uses the toll to recoup their investment, in much the same way as a toll road ...

(rates: horse-drawn rig -

US$ The United States dollar (Currency symbol, symbol: Dollar sign, $; ISO 4217, currency code: USD) is the official currency of the United States and International use of the U.S. dollar, several other countries. The Coinage Act of 1792 introdu ...

0.15, team of horses - $0.20, pedestrian - $0.05) but went toll-free in 1895. The second Morrison was another swing bridge that was built in 1905. It was not designed for automobiles and the 1958 replacement was long overdue. The first Morrison Bridge carried

horsecar A horsecar, horse-drawn tram, horse-drawn streetcar (U.S.), or horse-drawn railway (historical), is a tram or streetcar pulled by a horse. Summary The horse-drawn tram (horsecar) was an early form of public transport, public rail transport, ...

s starting in March 1888, about a year after the bridge opened. Electric

streetcars A tram (also known as a streetcar or trolley in Canada and the United States) is an urban rail transit in which Rolling stock, vehicles, whether individual railcars or multiple-unit trains, run on tramway tracks on urban public streets; some ...

, introduced in Portland in November 1889, replaced horsecar service on the bridge in stages starting in 1890.. Streetcars also crossed the second (1905) Morrison bridge, but not the third (1958), as the last lines of Portland's past streetcar system had been abandoned by the time it opened.

History of present bridge

The present bridge was built by

Multnomah County Multnomah County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the county's population was 815,428. Multnomah County is part of the Portland metropolitan area. The state's smallest and most populous county, it ...

. It was completed on May 24, 1958, at a cost of $12.9 million. In 1961,

Interstate 5 Interstate 5 (I-5) is the main north–south Interstate Highway System, Interstate Highway on the West Coast of the United States, running largely parallel to the Pacific coast of the contiguous U.S. from Mexico to Canada. It travels thro ...

and Interstate 84 ramps were added. In 1987, the Morrison Bridge became the first bridge illuminated by the Willamette Light Brigade. In 2007, the original 16 colored floodlamps illuminating the concrete piers were replaced by energy-efficient and computer-controlled

LED A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresp ...

s. Different colors may be selected for each of eight zones of the piers. Static and animated patterns may be requested for a fee which ranges from $100 per night to $1200 per month (as of 2009). Access for bicycles and pedestrians was improved in a $1.9 million project which began construction in March 2009 and added a barrier-separated path on the south side. Previously, there were only narrow sidewalks. In 2011–12, the steel grating on the bascule deck was replaced with fiber-reinforced polymer panels to provide better traction for vehicles. The work was completed in March 2012, but problems with the new deck panels began to be reported in fall 2013. Multnomah County anticipates a major seismic upgrade around 2020. The bridge was added to the

in November 2012.

Description and statistics

The bridge is the largest mechanical device in

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

. gears drive 940-

ton Ton is any of several units of measure of mass, volume or force. It has a long history and has acquired several meanings and uses. As a unit of mass, ''ton'' can mean: * the '' long ton'', which is * the ''tonne'', also called the ''metric ...

counterweights located inside each of the piers. The clearance is sufficient for most river traffic, requiring bridge openings only about 30 times a month. The bridge currently carries 50,000 vehicles daily in six lanes. The canted windows of the control tower give the distinctive look of

air traffic control Air traffic control (ATC) is a service provided by ground-based air traffic controllers who direct aircraft on the ground and through a given section of controlled airspace, and can provide advisory services to aircraft in non-controlled air ...

towers. The current bridge does not connect to Morrison Street at its west end because the second bridge was left in operation while the latest version was built, necessitating that the replacement bridge be on a different alignment. In 2005, the bridge opened for river traffic an average of 33 times a month.

References

External links

Morrison Bridge
page on Multnomah County website

* {{Tom McCall Waterfront Park Bascule bridges in the United States Bridges completed in 1887 Bridges completed in 1905 Bridges completed in 1958 Bridges in Portland, Oregon Bridges over the Willamette River Swing bridges in Oregon Historic American Engineering Record in Oregon National Register of Historic Places in Portland, Oregon Road bridges on the National Register of Historic Places in Oregon 1887 establishments in Oregon Buckman, Portland, Oregon Drawbridges on the National Register of Historic Places Southwest Portland, Oregon Former toll bridges in Oregon Tom McCall Waterfront Park Metal bridges in the United States

Predecessors

History of present bridge

Description and statistics

See also

References

External links