Denver Ave. / Columbia Blvd. bridge

Several years ago, this humble blog featured a lot of posts about bridges. It was a good subject for an ongoing project: They photgraph well, they often have interesting history to dig up, and esoteric engineering details to nerd out over, and there's a limited supply of them, enough to sustain an interesting project, but few enough that you'll eventually run out and you can call it done. That is, unless you're willing to go further and further afield, or write about increasingly small and esoteric bridges that nobody in their right mind would possibly be interested in. Or you can do what I did, which is call it done, but continue on down the rabbit hole anyway.

You can probably guess where this is going: I outdid myself and found a really super esoteric bridge and wrote an entire blog post about it, and I feel like I need to apologize in advance for just how esoteric it is. This one may actually look vaguely familiar, in the unlikely event you've been following the ongoing bridge project all this time. We covered the Denver Avenue bridge over the Columbia Slough back in 2014, along with the Vanport Bridge next door that's used by the MAX Yellow Line. This time we're looking at the Denver Ave. bridge/viaduct over Columbia Boulevard & a Union Pacific rail line, a bit south of the slough bridge. I suppose I just assumed this was all one structure, and the Columbia Blvd. part was just the southern approach to the slough bridge, but there's actually a short bit of road separating them. The state's 2013 Historic Bridge Inventory assures that although the two structures look identical, structurally and legally they are two separate bridges. From the bridge inventory:

In the late 1920s, increased traffic on the West Side Highway led to a major revision in how the highway approached the Interstate Bridge, then the only Portland area crossing into Washington State. Prior to this redesignation, the West Side Highway ended at downtown Portland, with only the Pacific Highway continuing over the bridge. These new bridges were designed to match those on the Pacific Highway, and continued to be a major part of the approach until the construction of I-5. They both feature a unique baluster railing, which is now mostly hidden behind protective wooden paneling.

In a couple of these photos you can sort of see the "unique" baluster, which is somewhat less distinctive than it sounds, unfortunately. Since these photos were taken, ODOT performed a major renovation on this bridge as well as the slough one, and both now sport modern, safe, and non-distinctive railings. As far as I know, ODOT didn't bother saving a chunk of the old one for posterity; it's just gone. In any case, the bridge inventory also includes a few dry stats, in case Obscure Portland Bridges is ever a pub trivia category:

Bridge Number: 04518
Lat/Long: 45 35 09, -122 41 13
Description: Thirteen 71-ft reinforced concrete girder and floorbeam system spans with curved haunches

In case you were curious, "curved haunches" is a technical term in bridge engineering, and was not intended as an insult. The state's 2012 Bridge Condition Report notes that that the slough bridge proper (bridge number 04517, if you were wondering) dates to 1916, with steel construction, while the Columbia/Union Pacific part dates to 1929, with concrete construction. So I suppose there would have been a surface level intersection & railroad crossing here before the current bridge. I'm not sure why this would be useful information, unless possibly you need to date an old photo or it's part of a trivia question, but hey.

Ochoco St. Bridge

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The next installment in the ongoing bridge project is yet another really obscure one. SE Ochoco St. runs right along the Sellwood-Milwaukie border, and it crosses Johnson Creek on the little bridge you see here. This isn't something that I would normally care about, but it got a mention in the state's 2013 historic bridge inventory, so I figured it might be worth a quick peek. Here's what they had to say about it:

Bridge Number	25B58
Year Built	1947
Location:	Near 21st Street in southeast Portland
Lat/Long:	45 27 31, -122 38 31
Description:	One 40-ft reinforced concrete rigid frame span
Designer:	Geary Kimbrell for Portland City Engineer Ben S. Morrow
Builder:	Johnson-Sterner Corporation
Significance:	This bridge is significant as an intact example of a slabtype rigid frame structure, which is a rare type in Oregon. Designed by the city, it improved access to the Kellogg Park Housing Project, which had housed soldiers during WWII. As is common with Portland structures, the bridge features an unusual railing that adds to the appeal of the visually simple structure.
Character Defining Features:	Decorative railing, Structure type

The only other photos I've found of this little bridge are in a big Word document full of photos of the area, focusing on the grounds of the giant Oregon Liquor Control Commission warehouse just east & south of here. Apparently they were involved in a late 1990s watershed restoration project for the bit of Johnson Creek that fronts on their property. I suppose pasting images into a Word document was the convenient way to share photos back then. Truly, it was a dark and primitive time.

Denver Ave. Bridge

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The next Columbia Slough bridge on our little tour is the one that carries N. Denver Ave. over the slough. Like the MLK and N. Portland Road bridges, this is an ODOT-owned bridge, since this stretch of Denver Ave. doubles as a chunk of highway OR 99W. At one time, 99W (a.k.a. the "West Side Highway") continued through downtown Portland, from SW Barbur to Front Avenue, then along Harbor Drive to the Steel Bridge, then up Interstate Avenue to Kenton, where it jogged over to become Denver Avenue, and then headed across the Columbia Slough north to the Interstate Bridge. Most of that stretch is no longer a state highway, but the stretch of Denver Ave. north of Argyle St. still is for some reason.

The Portland stretch of 99W was a late addition to the state highway system. At the time the Interstate Bridge went in, there was a great deal of infighting about which street would be the main approach to the bridge: Union Avenue (now MLK) or Vancouver Avenue, which Union Ave. finally won after a few years of rival booster clubs duking it out. Interstate (then known as Patton Avenue) wasn't in the running, because a steep bluff at the south end meant it didn't actually connect directly to downtown back then. It was a major local street, and was platted out as a wide street in case it became a major arterial later (which was a huge help when the MAX Yellow Line went in), but in 1916 it dead ended somewhere around today's Overlook Park. So a small wooden bridge was built, giving local traffic access to the Interstate Bridge.

A decade later, a major roadcut project finally connected Patton Avenue to the Steel Bridge and downtown Portland, and the widened street was rededicated as Interstate Avenue in September 1928, though a lot of references I've seen give 1929 as the actual project completion date. The bridge over the Columbia Slough was reconstructed at that point to handle the additional traffic. The Oregonian's "Year in Review" article on Jan 1. 1930 portrayed the Interstate Ave. project as one of the year's major news stories. A 1947 aerial photo shows the bridge here, along with an area of commercial development along the Kenton stretch of Interstate, but you can see that parts of the surrounding area were still semi-rural even then. A couple of interesting Cafe Unknown posts have more about the history of Interstate Avenue, with all its ups and downs, from potholed neighborhood street to neon wonderland, to blighted backwater after I-5 opened, and now to a rapidly gentrifying neighborhood with its own MAX line.

ODOT's 2012 bridge condition report says the slough bridge dates to 1916, while the adjacent viaduct over Columbia Blvd and the Union Pacific railroad is circa 1929. So it's possible there was a surface level intersection and railroad crossing here until the bridge upgrade project, in which case the original slough bridge was probably lower than the current one. That's my guess, anyway.

The 2013 state historic bridge inventory describes the bridge and viaduct:

In the late 1920s, increased traffic on the West Side Highway led to a major revision in how the highway approached the Interstate Bridge, then the only Portland area crossing into Washington State. Prior to this redesignation, the West Side Highway ended at downtown Portland, with only the Pacific Highway continuing over the bridge. These new bridges were designed to match those on the Pacific Highway, and continued to be a major part of the approach until the construction of I-5. They both feature a unique baluster railing, which is now mostly hidden behind protective wooden paneling.

Unfortunately I don't think you can see the unique bridge railing very well in any of these photos. The inventory PDF has a better photo, showing it really doesn't look all that different from other ODOT bridges of that era. The inventory goes on to mention that the slough bridge consists of "Three 78-ft steel girder and floorbeam system spans with reinforced concrete deck girder approach spans", while the viaduct is "Thirteen 71-ft reinforced concrete girder and floorbeam system spans with curved haunches.. ODOT researched the history of the Denver Ave viaduct over the railroad for the MAX Yellow Line project. The study determined it was ineligible for the National Register of Historic Places, and mentioned the slough bridge as similarly utilitarian & ineligible. The city's historical research for the Vancouver Ave. bridge replacement also mentions the Denver Ave. bridge briefly, but doesn't have much to say about it.

No discussion I've seen of the bridge mentions who designed it, and they usually do if a bridge is by someone well-known or historically important. The Union Ave./MLK, N. Portland Road, BNSF railroad, and (original) Vancouver Ave. bridges turned out to be minor designs by rather famous bridge engineers, but as far as I can tell that's not the case here. Perhaps as a result, it doesn't have a BridgeHunter or Structurae page of its own, but it does at least have an UglyBriges.com entry. That page tells us the bridge has an ODOT sufficiency rating of 51.7 out of 100 (as of April 2013), and it's described as being in "fair" condition and "functionally obsolete". It received an underwater inspection in 2011, which noted that the underwater portion of the bridge pilings are not entirely steel and concrete, which is a little surprising: "The part of this structure across the slough consists of 3 steel girder spans of 78 ft. each. Each pier is supported on two concrete columns with a webwall in between, that are supported by two individual concrete footings founded on untreated timber piling."

An upcoming ODOT project will redesign the intersection of Denver Ave. & Schmeer Road, directly north of the bridge. At present the north end of the bridge crosses an underpass that routes southbound traffic onto Schmeer Rd. The redesign will move the intersection north, and turn the underpass into a stretch of the Columbia Slough Trail instead. In Spring 2015 they'll also start work on the bridge and viaduct, resurfacing them and replacing the current bridge railings and adding crash barriers. Schematics of the new design indicate there will be a crash barrier separating the sidewalk from street traffic, and the redesigned bridge will include separate bike lanes, which it doesn't currently have. It will still only have a sidewalk on one side of the bridge, I suppose because extending the bridge out to add one on the other side would be too expensive. Still, it seems like a positive step, in an area that's only going to have more bike and pedestrian traffic as the Columbia Slough Trail keeps being extended.

SW Barbur/Multnomah Viaduct

I recently ran across ODOT's 2013 Historic Bridge Field Guide, which lists bridges the state thinks are "significant" somehow, broken down by county. Part 4 covers Multnomah County, and it includes a number of obscure structures I wasn't familiar with or had never paid any attention to. Case in point, SW Barbur crosses over Multnomah Boulevard on a kinda-historic overpass, built in 1935. I've driven over it countless times but never gave it a second thought until now. The state's description of it:

Description: Three span continuous reinforced concrete deck girder bridge with a 70-ft maximum span on a 47-degree skew. The bridge originally crossed over the Oregon Electric Railway.
Alterations: The railway was replaced by Multnomah Blvd, changing the context of the bridge.

The pdf also includes a photo of a plaque on the viaduct, which reads:

OREGON ELECTRIC RAILWAY OVERCROSSING

Built under co-operative agreement by
The United States Bureau of Public Roads
Oregon State Highway Commission

C.J. Montag
Contractor
1935

The old Oregon Electric Railway tracks were removed to make room for Multnomah Boulevard not long after the bridge here was built. A news article from October 1948 indicates the road was being built at that time, so rail service must have ended at some point before that. Further west, a long stretch of the former Oregon Electric line was reused as part of the westside MAX Blue Line, and another stretch of track now carries the WES commuter train.

The Oregon Electric system was an entirely different system than the competing Southern Pacific Red Electric, which crossed the West Hills just south of Beaverton-Hillsdale Hwy. The Red Electric right-of-way wasn't replaced by a new road after service ended, and in recent years parts of it have ended up as much-needed neighborhood hiking trails.

NW Melinda & Maywood

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Today's installment in the ongoing bridge project takes us to Portland's West Hills, at the hairpin intersection of NW Melinda Ave. & Maywood Drive, not far from NW 23rd. We're here because of an unusual arched concrete structure that supports Maywood as it climbs sharply from the intersection. I ran across it in the 2013 Oregon's Historic Bridge Field Guide, Part 4 -- the guide's alphabetical by county, and Multnomah County falls in part 4 -- which calls it the "NW Maywood Dr Semi-Viaduct" and describes it:

Description:
Nine 13-ft reinforced concrete frame spans with an arched façade
Significance:
The significant aspect of this relatively simple structure is the arched façade on the frame spans which give the bridge the appearance of a Roman aqueduct. It is unknown why this sort of bridge would have been constructed in this neighborhood. Along the road underneath the viaduct is a large amount of stone masonry that may be the remnants of the previous bridge or roadway.

Thanks to the library's Oregonian database, we can answer some of the open questions in the state's description of this sorta-bridge. The aforementioned stone masonry was likely part of an early 20th Century retaining wall, which collapsed on December 21st, 1932. The article says the wall had been there for nearly 20 years. A pair of photos in the next day's paper show it really was an enormous landslide, and it's surprising that no deaths or injuries were reported. Melinda Ave. was reopened the day of the slide, but Maywood was out of commission for an extended period of time. A full year later the city still hadn't gotten around to repairing it despite residents' repeated pleas. The city eventually had to appropriate an extra $8000 for the replacement viaduct; budgets must have been very tight during the Depression. I assume that money went to build the present structure, which was completed in 1934. I don't have references for why it looks the way it does; I imagine that after all the delays and handwringing they felt they should build something that looked (and was) solid and reassuring. Or maybe it was just the contemporary style at the time. I'm not really sure about that part.

As for the present structure, it's 80 years old this year, vastly outliving its predecessor. The city's 2011 bridge inventory gives it a sufficiency rating of 59.6 out of 100, meaning "not deficient", but also notes it has a posted weight limit, gives its condition as "poor", and says it ought to be replaced at some point.

There's one other detail here, something I only realized after I looked at the map for a while and couldn't figure out what looked wrong. Melinda Avenue is apparently one of the very few roads in the city that runs east-west but is designated an avenue. There are quite a few avenues that aren't straight, but this is the only one I know of that is basically straight and runs east-west. I'm only asserting "one of the very few", though, because I haven't looked for other examples, and looking for them seems like it would be incredibly tedious. Tedious even by my usual standards, which is saying a lot.