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Contributed by the Oregon Department of Transportation

Nearly 50 years ago, the Oregon Department of Transportation (ODOT) solved a major mobility issue with construction of the original Interstate 5 Willamette River Bridge in Eugene, Ore. Before this link in the nation’s north-south interstate highway system on the West Coast was complete, drivers through this area had to exit the unfinished interstate and navigate local streets before reconnecting with the interstate system — adding additional time and miles to a road trip.

After two years of construction, completion of this bridge in 1961 marked a significant milestone in Oregon’s transportation history, making travel through the area easier and safer for drivers and freight haulers by cutting 12 miles and nearly 90 minutes from the drive to Portland from Eugene.

Now through 2013, as crews work to replace this aging bridge as part of ODOT’s Oregon Transportation Investment Act (OTIA) III State Bridge Delivery Program, the following photos show how construction of the original bridge compares with what’s going on today.

Past: Before the Willamette River Bridge was built, I-5 ran to the north and south of Eugene and Springfield, but did not cross the river. Here, the trees of Alton Baker Park are seen on either side of the river. Toward the right, the outline of a crane can be seen as construction crews prepare to set a bent form.

Past: Although the technology and tools used in 1961 were suitable for the time, preparing for construction over a strong, flowing river is never an easy task. Looking toward the north side of the Willamette River, the center of this image shows where crews started forming and building falsework around Pier 3, one of the five piers of the original bridge that touched down in the middle of the river. Early on in construction, crews diverted river flow to the north to allow for work on the southern portion of the bridge. A diversion dam can be seen to the right of the photo off the southern bank. Pier 5 is visible in the foreground, and the staging progress on the northern half of the bridge can be seen in the background.

Present: Unlike the original box girder bridge — which touched the water in five locations — the new deck arch bridge will have only a single touch point in the middle of the river. Taken in May 2010, this photo shows the early stages of construction for the bridge’s arch ribs. The steel bents used to support the arch ribs rest on a massive, 120,000-square-foot work bridge used to support the people and machines building the new structure.

Standing at 10 feet above the ordinary high-water mark, the work bridge is built on 263 steel pilings driven into the riverbed and serves as a catch-all for debris to help keep the river beneath it clean and undisturbed. Rather than build a workbridge, crews on the construction site of the original bridge worked from the soil of the diversion dam seen in the previous photo.

To comply with current Oregon Department of Fish and Wildlife in-water work windows, the new bridge’s construction team had to build the work bridge in a tightly constrained time period of less than three months.

Past: The Willamette River Bridge not only serves as an important interstate crossing over the river, but also over Franklin Boulevard, one of Eugene’s main thoroughfares. The photo above shows the scaffolding system around one of the columns that eventually supported this section of the bridge over Franklin Boulevard. The Willamette River is visible in the background.

Present: The arches of the bridge meet in the center of the Willamette River on a natural island, connected by shaft caps placed on top of custom-designed, poured-concrete drilled shafts. The caps connecting each point are unique, created to perfectly match with the ribs and vertical supports. Located at the single touch point in the middle (known as Bent 3 or “the icebreaker”), the shaft cap’s unique shape and size — 8 feet wide, 12 feet tall and 6 feet thick — make it a challenging piece for crews to work with. It is shown here with rebar cages coming out of the top to frame the vertical supports and the arch rib connection points sprouting from its sides.

Past: Falsework for the original Willamette River Bridge is built on the southern half of the box girder structure. Pier 2 is already built and can be seen mid-stream. Upon completion of the southern half, crews built another diversion dam under it and built the north half, which allowed crews to work directly from soil on the river instead of building from the type of work bridge typically used today.

Present: This aerial photo shows the temporary Willamette River Bridge, built as an intermediate solution in 2004, next to the current work bridge and arch rib construction. The location of the new bridge will allow for the same level of access to pedestrian and bicycle paths as before, and ODOT is upgrading the quality of these paths for easier navigation and use.

Past: The profile of the original box girder bridge is starting to take place in the photo above, which shows the completed falsework for the northern half of the bridge. As with construction on the southern half, the river below was diverted to allow crews and equipment access to the work site.

Present: The new bridge arches, which may appear decorative to the casual observer, are actually highly technical, carefully engineered supports. Here, the wooden framework for the two northbound arches are seen with the beginnings of a rebar cage climbing up. These cages will eventually help form the concrete arches.

Past: The original Willamette River Bridge opened to traffic in December 1961, connecting the existing stretches of I-5 and making travel along the interstate easier and faster. The 67-foot-wide, 1,800-foot-long structure stood for nearly 50 years until safety concerns led to its demolition in 2009 for construction of the new Willamette River Bridge.

The new Willamette River Bridge, scheduled for completion in winter of 2013, will feature two graceful, parallel deck-arch bridges that stand approximately 63 feet above the water. The northbound structure will measure nearly 2,000 feet long, while the southbound will come in at 1,760 feet. Both the north- and southbound bridges will be about 67.5 feet wide to accommodate three lanes of traffic with shoulders — doubling the highway space for potential commuters for years to come.