Historic Bridges of Bridgetown
By George Kramer
Portland’s Willamette River bridges are world-class. From the soon-to-be replaced Sellwood to the graceful St. Johns, ten major spans in 10.7 river miles include examples of multiple bridge technologies. Many are the oldest or longest examples of type ever built.
Portland’s first Willamette bridge, the Morrison, was completed in 1887 and was key in knitting Portland, East Portland and Albina into the modern city four years later. Those early, mostly wooden, swing spans relied upon a pivot point in the middle of the river channel. The slow process of opening, turning the center span 90-degrees to allow river traffic to pass, was problematic as the Port traffic grew. Portland’s leadership turned to a radical new technology, the vertical lift bridge. A vertical lift has one long span that rises to create a single open channel; much better for shipping. The Hawthorne, opened in 1910, is the oldest vertical lift in the world. A year later the Steel Bridge was completed, with a complex double-lift mechanism that allowed trolley and rail traffic, as well as river passage. It’s the only double vertical lift bridge in the world. Both were designed by Waddell and Herrington, the firm that invented the technology.
Portland continued to experiment. The Broadway is a bascule bridge, better known as a draw bridge. There were four major types of bascules, the most famous designed by Joseph Strauss, the engineer best remembered for the Golden Gate Bridge. Portland’s oldest bascule, the Broadway (1913) relies on a Rawl bascule, a very complicated mechanism that never really caught on. The Broadway, designed by Ralph Modjeski, is not only the nation’s oldest Rawl, it’s the largest ever built. Strauss got his chance, with the Burnside (1926).
The Ross Island and the Sellwood were Portland’s first “fixed” spans, built so high above the water that ships pass below. Both were designed by Gustav Lindenthal. The St. Johns (1931, David Steinman) was the longest suspension bridge in the world when it was completed, and remained so until Strauss’ Golden Gate opened. The Morrison (1958) is an early example of hydraulic design to minimize turbidity in the river. What the Marquam, blasted as the “Erector Set” when it opened in 1966, lacks in aesthetics, it makes up in utility; it carries more traffic than any other bridge in Oregon. And finally, the Fremont was the largest orthotropic deck truss in the world when it was lifted into place in one single motion in 1973.
Portland’s Willamette River Bridges have recently been documented and listed in the National Register of Historic Places. It’s a fitting honor for an amazing collection of long spans, spans that help connect, and characterize what is affectionately, and appropriately, known as “Bridgetown.”
George Kramer is a historic preservation consultant and prepared the Willamette River Highway Bridges of Portland Multiple Property Document and National Register nominations for the Broadway, Burnside, Hawthorne, and Morrison Bridges.