Damaged beams force weight limits on historic OC bridge
TriMet will reroute buses onto I-205; the arch bridge will close for repairs late this year
Oregon's Department of Transportation has slapped a new weight restriction on the Oregon City arch bridge connecting Oregon City and West Linn, a change that will force TriMet buses to take a different route on the south side of the Willamette River.
Effective immediately, new load limits will restrict commercial vehicles, large trucks and other vehicles weighing more than 14 tons from using the historic bridge. Passenger vehicles weighing less than 14 tons can still use the bridge. The bridge will be closed again later in March.
Recent bridge inspections found damage on a few of the structure's floor beams. Limiting the weight of vehicles that can cross the bridge will allow the bridge to remain open for most motorists, according to ODOT.
TriMet buses will no longer use the arch bridge. TriMet has rerouted routes No. 35-Macadam and No. 154-Willamette to the Interstate 205 George Abernethy Bridge.
TriMet has also closed the north- and southbound bus stops on the west side of the arch bridge.
Emergency vehicles and school buses that use the Abernethy Bridge should not be impacted by the new arch bridge weight restriction.
ODOT spokesperson Christine Miles said damage was found during inspections leading up to a major bridge renovation project coming later this year.
'We do more and more inspections as they get closer to digging into the rehab,' she said. 'For the average car and truck you'll be fine. We know it's an inconvenience but we want to keep it open as long as we can to the majority of the traffic.'
ODOT originally planned to keep the arch bridge open during the projected 18-24 month renovation project, but Miles said it will now be closed completely. The closure will begin this fall or winter after ODOT finishes a repaving project on the I-205 Abernethy Bridge, which is slated to take place over 10 weeks this summer.
The arch bridge also closed last weekend for preparatory work for the major renovation. Contractors need to determine the best way to remove the concrete from the bridge, which is actually a steel structure that's wrapped in concrete, making it a 'one-of-a-kind' bridge along the West Coast, Miles said.
'Our bridge engineer said this is like remodeling a 1922 home - it's one of a kind,' Miles said. 'You kind of have an idea of what you'll find inside but until you take off all of that concrete you don't know.'
The bridge was built in 1922 and named to the historic register in 2005. Miles said ODOT intends to restore the bridge to its 1922 state. It will not be widened or changed.
The bridge received a 'structurally deficient' rating during a 2007 inspection. That's the same rating given to the Minnesota Highway bridge that collapsed in 2007, killing 13 people. At the time, ODOT officials pointed out that several bridges across the state received the same rating.
'Suppose you've got a house and it needs a new roof - that would be structurally deficient,' ODOT communications director Dave Thompson said after the 2007 bridge report was released. 'It's still safe, it just needs some work.'
The bridge will close again later in March to move utility wires under the span. Electronic signs near the bridge will notify motorists of the closures this weekend and later in March.
The new load restriction might be lifted once the rehabilitation project is complete in 2011.