From JPCL January 2024
Photo: xiao zhou / Getty Images
Last summer, crews on the Morrison Bridge in Portland, Oregon, finished a two-year-long repainting project, which included around 2,000 gallons of paint and roughly 5,000 hours of work. The completed project reportedly marks the first time the bridge has been painted since its construction 66 years ago. According to a report from the Multnomah County Transportation Division, the $26 million project gives a new, “fresh” look to the bridge, while also providing a safer crossing for the local community.
The bridge had not been painted since its original construction, and the steel and coatings were showing signs of deterioration. Photos: courtesy of Multnomah County Transportation Division
The Morrison Bridge, which stretches over the Willamette River, acts as a gateway to downtown Portland and replaced two previous Morrison bridges, constructed in 1887 and 1905, respectively. Completed in May 1958, the current Chicago-type double-leaf bascule bridge now connects to interstates, making it a major transportation corridor.
Designed by Sverdrup/Parcel of St. Louis, and Moffatt, Nichol and Taylor of Portland, the main river truss spans and draw spans were constructed by the American Bridge Division of the U.S. Steel Co., Manson Construction and Engineering. The structure includes six lanes of traffic, carrying 50,000 vehicles daily.
The bridge consists of two 237-foot, nine-inch steel deck truss side spans and a 284-foot, six-inch double-leaf bascule draw span, for a total bridge length over the river of 760 feet. The bascule span reportedly only requires opening about 30 times per month.
The most recent modifications before the latest project took place in 2011, with the replacing of the lift span deck, as well as adding a shared use path on the south side and overlaying the east approaches.
The steel was abrasive blast-cleaned to a Near White Metal finish before being coated with a three-coat system. Photo: courtesy of Multnomah County Transportation Division
The project was initially estimated to cost $20 million, with 90% being financed by the federal government and county taxpayers paying the remainder.
In July 2021, Multnomah County selected a Florida-based protective coatings contractor to be the general contractor for the project. According to reports, the contractor submitted the lowest responsive bid of six contractors at a bid of $18,243,777.
The project started at the beginning of 2022, with the closure of an on-ramp to allow space for equipment and installation of a platform for painters working beneath the six-lane span. Work was reportedly focused on the underside of the five river spans on the structure, primarily below the deck. These spans include the center movable span, two flanking truss spans and two girder spans above the river to the east, with the easternmost gird span partially over land.
The bridge deck itself would reportedly not be repainted, except for metal parapets and curbs near the movable span. Additional work would also reportedly include replacement of the sidewalk panels on the lift span, and cleaning of the canopies, handrails and exterior of the operator towers.
The blasting and coating application work took place under containment to encapsulate the existing lead-based coatings and any potential overspray. Photo: courtesy of Multnomah County Transportation Division
In October 2022, the bridge was officially closed for the multiyear painting project. The steel on five river spans was to be repainted throughout the project, as well as any additional repairs and lead paint removal.
From Oct. 14 to 17 of that year, the bridge was closed to allow the contractor to paint the east side of the bridge, in addition to removing, inspecting and replacing steel beams. Existing paint was reportedly peeling and had to be removed to avoid corrosion of the structural steel members.
The bridge’s old paint was reportedly lead-based, leading each section of the bridge to be fully encased to prevent the removal process from harming the surrounding environment. After the old paint was removed, existing corroded steel was then reportedly replaced before the span was repainted. The newly painted spans are now reportedly lead-free.
According to the report, crews had to work on safety platforms roughly 50 feet in the air to paint the structure, while also wearing “extensive” protective gear. Three coats of paint were reportedly applied to the bridge, including a zinc primer coat, an intermediate coat for added protection and then a final finish coat.
“Because the old paint contains lead, crews must follow rigorous environmental protocols, which includes using a large industrial vacuum to prevent the paint from falling into the river,” said Project Manager Kenneth Huntley.
The engineering and contracting teams celebrated successful completion of the project. Photo: courtesy of Multnomah County Transportation Division
The newly applied protective coating system now has an aluminum grey finish, meant to honor the bridge’s original color and its history, beginning with its construction in 1957.
As a part of the project, crews had reportedly performed a structural analysis on the bridge’s steel members, identifying and repairing damaged steel sections and increasing the life of the bridge by several years. Crews were reportedly able to make over 20 steel repairs to strengthen to bridge, while also repainting the sign structures over it and replacing all the old signs to make traffic and safety messaging more visible.
In addition to painting the Morrison Bridge, several repairs to steel members were identified and included as part of the project along with other improvements. During the blasting and cleaning of the old paint, several locations on the bascule spans were discovered to have much more severe section loss in critical steel truss members than originally thought. This discovery led to change orders to implement repairs, ensuring the structural integrity of the bridge. Even with all the field issues on the project, the contractor was on time and on budget, and the painting was completed in July 2023.
“After more than 60 years, the Morrison Bridge was in desperate need of a new coat of paint,” Huntley said.
“We were able to not only repaint the bridge, but we also found several seriously damaged steel sections through inspections that we were able to fix. These repairs extended the life of the bridge significantly.”
According to the report, the project had also provided thousands of hours of learning opportunities, as three separate apprenticeships worked with the contractor to total around 3,600 hours of training.
Additionally, three different Disadvantaged Business Enterprise (DBE) organizations also reportedly worked on the project as subcontractors.
As work on the exterior of the bridge is finished, the County is reportedly beginning to work on another project on the same structure.
The Morrison Bridge Strengthening Project will reportedly improve the southeast Morrison Street and the southeast Belmont Street ramps to the bridge to reduce weight restrictions, currently preventing heavy trucks from using the bridge. The project will also include the replacement of the motors and brakes in the movable span, which helps open and close the bridge.
Construction for that project is reportedly expected to run from spring 2024 to fall 2025.
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