The first Morrison Bridge lift-span deck over Portland’s Willamette River lasted 53 years. Sure, it wasn’t without its detractors, with its slick open steel grate design and all, but still, it lasted 53 years. Version two couldn’t even sniff that timeline, making it just over two years before Multnomah County announced a decision to rip it out and start fresh.
Ever since the county spent $4.2 million in 2012 on installing a fiber-reinforced polymer lift-span deck, Morrison has proven strife with issues. And they aren’t good issues.
Nearly immediately after installation the lift-span deck showed “signs of failure,” according to Multnomah County, and an investigation confirmed that panels were deteriorating and loosening to the point of flapping as cars drove over the deck.
Designed by North Carolina-based ZellComp and installed by Conway Construction of Ridgefield, Washington, both locked in multiple lawsuits over the project, when Multnomah County announced plans in July to replace the decking they didn’t mince words over the reason, calling the polymer “defective” and saying it “cannot be effectively repaired.” Of course, part of the legal dispute rages over if the decking was faulty upon delivery or if installation made it so.
Either way, the county wants nothing more to do with the polymer—which it also installed full of issues on the same river’s Broadway Bridge—that brought trouble even before it was installed since some pieces allegedly arrived on site already cracked, forcing the county to ask for a discount.
While the lawsuits and blame surrounding the polymer will continue, the county wants to forge ahead with a $7.3 million project to clear away the lightweight polymer. The county has hired David Evans & Associates to design either a return to the open steel grating deck the county so often decried as dangerous and slippery or a solid aluminum deck. The final decision on the material will come in late 2014 with the replacement a 2015 project.
It appears Multnomah County won’t experiment with the Morrison Bridge again. It can’t afford to.
Tim Newcomb is Engineering News-Record’s Pacific Northwest contributor. He also writes for Popular Mechanics, Sports Illustrated and more. You can follow him on Twitter at @tdnewcomb or visit his website here.