What repairs are needed?
Remarkably, the bridge has not needed any major renovation since it was built. During an inspection a few years ago, ODOT found some damage to the structural steel under the Gunite (concrete) coating which could weaken the structure over time if not repaired. Also, the Gunite coating has cracked with age and portions of it have been adversely affected by water.
Repairs being made are:
• The existing Gunite on the arches will be removed. The steel structure underneath will be examined for corrosion or damage and repairs will be made.
• The Gunite will be replaced with a new coating of Shotcrete to protect the steel underneath.
• Several support beams on the roadway deck have corrosion damage and need to be repaired and replaced.
• The bridge deck/roadway will be resurfaced.
• The approach on the Oregon City side of the bridge will be repaired and improved.
• The ornate bridge railings will be replaced with railings that appear nearly identical, but are composed of structural steel hidden within the concrete.
• New roadway lighting will be installed including replicas of the original lights.
What kinds of repairs are allowed?
This bridge is listed on the National Register of Historic Places. Because of this historic designation, ODOT must follow the Secretary of Interior’s standards for rehabilitation. Visually, the bridge must look as close as possible to original, while providing safe use by the public.
Will the bridge be widened?
No, the arch ribs cannot be moved to fit a wider roadway. Adding lanes to the outside of the bridge cannot be supported by the existing structure. Widening the road would, also, adversely affect adjacent buildings in Oregon City. Since the bridge is historic, these changes would not be allowed.
Is the bridge made of solid concrete?
The main arch span over the river may look like a concrete bridge but it is really made of steel. To protect the steel from corrosion, portions were either encased in concrete or were covered with Gunite. Gunite was a relatively new product in 1922 and it was a mix of cement and sand that was sprayed on the bridge using high air pressure.
The Gunite is being removed by hydroblasting. This process uses high pressure water to break up the Gunite. The byproducts of the process are water, steam and debris. ODOT is capturing all the water and debris that is removed to dispose of it in an environmentally approved manner.
Will the weight restriction be lifted?
ODOT has a weight restriction on the bridge and it is currently closed to all commercial motor vehicles and all vehicles weighing more than 14 tons. When the rehabilitation project is complete, ODOT expects to lift the weight restriction.
Who is the Contractor?
The contractor for this project is Wildish Standard Paving Co., headquartered in Eugene. Wildish was selected based on its experience with other historic bridge rehabilitation projects and a demonstrated ability to get the job done safely, economically and quickly--with a sharp eye on quality.
T.C. Wildish started the company in 1935 with a single truck in which he hauled gravel. Today, second, third and fourth generation family members continue to own the business which supports family wage jobs for 400+ employees. The company performs well over $100M of work annually throughout Oregon. Project leadership for the Arch Bridge project is provided by Scott Vogl and Josh Smith. The company is managed by 35-year Wildish employee, Tim Hendrix.
Who is involved in the project?
ODOT has worked closely with the cities of Oregon City and West Linn, Clackamas County and Downtown Oregon City throughout the development of this project. A Bicycle/Pedestrian Task Force advised ODOT on how to accommodate cyclists and walkers during the closure of the bridge. The Task Force was composed of representatives of the Cities, County, Bicycle Transportation Alliance and Downtown Oregon City.
What is the project cost?
Construction Contract: $14.6 million
Sources: Federal Funds 89.7%; State funds 10.3%