It's a tradition at Fat Pencil Studio for new staff to take a deep dive into our beloved city's engineering history with a digital recreation of one of Portland's many landmark bridges. This provides a means to familiarize ourselves with Trimble SketchUp 3D modeling software, its associated tools, and the digital ecosystem at large. The project also flexes many technical muscles so to speak, in terms of researching a bridge's history, managing map data, and making site visits to see how everything fits together. I chose the Broadway Bridge as my assignment. You can find a few of photos from my trip below.
From the moment I started the project, I was drawn to the mechanical complexities of the Broadway Bridge and its striking hue of amber. I needed to know how exactly such a marvel moves all the pieces in synchronization so effortlessly.
To say the bridge simply hinges open to the marine transit below would be a grand understatement. The bridge's general structure was designed by acclaimed civil engineer and senior bridge designer, Ralph Modjeski, and the center bascule span was designed by the Strobel Engineering Company of Chicago, holder of the Rall-type bascule system patent.
The Broadway Bridge is a Rall-type bascule bridge spanning over the Willamette River in Portland, Oregon, United States at a total distance of 1,742 feet with a width of 70 feet. A bascule bridge, also commonly 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 aquatic traffic. It may be single or double-leafed lift. The name comes from the French term for balance, seesaw, or scale, which operates on the similar principles. More specifically on Rall type bascule systems, each leaf and its counterweight roll back and forth on giant bull wheels to allow maximum river clearance. This feature swings the leaf up and recessing back ever so slightly, allowing to bridge to open quickly and require relatively little energy to operate, with Broadway opening on average, about 25 times a month, while providing the possibility for unlimited vertical clearance for marine traffic. Although bascule-type bridges are the most common type of movable span, only three Rall-bascule highway bridges still exist in the U.S., the other two being much smaller than the Broadway. The bridge's draw span is unusually long. Each leaf measures about 140 feet, weighing more than 2,000 tons, making Broadway the seventh-longest bascule bridge in the world.
Broadway's Early Years
Opening on April 22, 1913, at a cost of $1.6 million, Broadway Bridge was the world's longest double-leaf bascule bridge at the time. The bridge's name derives from the street it carries, Broadway, but at the time of the bridge's construction that street name was in use only east of the river. The westside portion of what is now Broadway had been named 7th Avenue, but was renamed Broadway once the bridge opened and joined the two streets.
Modifications, Rebuilds, and The Lovejoy Columns
Since its debut, Broadway has made many updates to keep up with the times.
The new road for a modern world
What what was once planks of wood, The City of Portland takes the bridge under major development to line the roads with asphalt in 1970.
A bright new coat of paint
At its debut, the bridge was originally painted black akin to neighboring bridges, Portland architect Lewis Crutcher suggested that each have its own distinct color and Broadway was repainted to “Golden Gate Red” in 1963.
Going west
In 1927, the 2,000-foot long viaduct, the Lovejoy Ramp, was built from the bridge's west deck, extending over Lovejoy Street to 14th Avenue, providing access to and from the bridge that had previously been sectioned off by the local railroad yards. An additional, shorter ramp, from the intersection of 10th Avenue at Irving Street and connecting to the easternmost portion of the new Lovejoy viaduct, but due to delays to the start of work, did not open until October 1928 with an official opening in December 1928. Ultimately the approach was torn down by the City of Portland in 1999 and re-opened as a shorter approach in 2002 in order to allow for development of the new River District residential area.
The Lovejoy Columns
Supported the Lovejoy Ramp, a viaduct that from 1927 to 1999 carried the western approach to the Broadway Bridge over the freight tracks in what is now the Pearl District. Painted by Athanasios Efthimiou Stefopoulos from 1948 to 1952. A talented artist and at the time, worked nearby as a watchman in the northwest Portland rail yards for the SP&S Railroad Company. In his downtime at the train yard, he climbed atop the boxcars and painted the Broadway Bridge Lovejoy overpass columns with whimsical images of doves, owls, lions, anthropomorphic trees, Greek mythical gods, biblical figures, and Americana. Although his murals were not commissioned, his art was appreciated and allowed to remain for decades.
In 1999, when urban redevelopment began to sweep through the area the 40-acre railyard and Lovejoy overpass were set to be demolished. Thanks to extensive lobbying by Rigga, a group of insurgent Portland architects and artists (led by public installation artist and James Harrison), ten of the painted columns were cut down and saved. For the next five years, attempts to restore the columns were unsuccessful as all but 2 columns remain in storage beneath the Fremont Bridge as of 2022. Two of the original columns were relocated to NW 10 ave, between Everett and Flanders Street, where they were restored in 2005 using photographs and documentations for reference material.
Broadway Bridge Today
Today, it still stands strong as ever as one of the few surviving Rall mechanisms in operation, hosting four lanes of vehicle traffic, two 11-foot wide sidewalks and being a prominent bike route between east and west.
As of November 2012, Broadway was added to the National Register of Historic Places.
References
- https://www.loc.gov/resource/hhh.or0292.sheet?st=gallery
- https://www.multco.us/bridges/broadway-bridge
- https://en.wikipedia.org/wiki/Broadway_Bridge_%28Portland,_Oregon%29
- https://historicbridges.org/bridges/browser/?bridgebrowser=oregon/broadwaybridge/
- https://bridgehunter.com/or/multnomah/6757000000000/