New Rails at McCullough's Cape Creek Bridge

Conde McCullough, Oregon’s prolific State Bridge Engineer, was responsible for something on the order of 900 bridges constructed over the first decades of the Oregon State Highway Department’s effort to “Get Oregon out of the Mud!” that began in 1913.  McCullough has achieved near iconic status in Oregon, and in fact nationwide, for the combination of beauty and function that he brought to the task.  Many of Oregon’s most scenic places, at river crossings and canyons, benefit from his skill.  Nowhere is McCullough’s impact more noticeable than on the Oregon Coast, where what is now US 101 wouldn’t exist without the many McCullough-designed spans that cross the rivers and creeks draining into the Ocean.

Last week I was at the Cape Creek Bridge, at Heceta Head, just north of Florence.  While not as dazzling or well-known as the famed “Coastal Bridges” that span major rivers, Cape Creek is still a pretty spectacular design.  It’s probably fair to assume that some of the lessons learned here in 1931-32 helped guide the design of the landmark bridges that were to follow.  Cape Creek is also important for its recent history, being the first bridge in Oregon to benefit from “cathodic protection,” a nifty system where a low-wattage (900w) electrical charge is run through the all the reinforcing steel inside the concrete, providing protection against the salt-spray intrusion that doomed the Alsea Bay Bridge.

Unfortunately when that system was installed at Cape Creek in 1991, the bridge rail wasn’t included (it was likely already damaged).  Years earlier, in 1978, a standard “flex-beam” or w-rail had been installed to keep an errant vehicle from crashing through (lovely, isn’t it?).  Last week it was obvious that major elements of the starburst pattern railing (it looks really cool when the light comes through…sort of a shadow-picture) are literally crumbling away.

This week, through HERITAGE,  I am working on findings for OBEC Consulting Engineers, of Eugene, to document a project that will remove the damage and replace it with new, pre-cast, rail sections that will look almost exactly the same as the originals.  They will just be stronger.  And the reinforcement steel will be “tied” together electrically, so that ODOT can connect the rail to the cathodic system and assure it doesn’t crumble away.  AND, because the new rail and sidewalk are stronger, and meet code, we get to remove the lovely flex-beam!

Bridges, bridges, and more bridges

This Friday the State Advisory Committee on Historic Preservation will review the Willamette River Highway Bridges multiple property submittal.  This is a document on the significance of the ten major spans across the river in Multnomah County and includes the formal nomination of four bridges; Hawthorne, Morrison, Burnside and Broadway.  I started working on this project almost two years ago and in the process found a new appreciation for each of these amazing spans.  Almost every Oregonian knows the bridges in downtown Portland, from the “erector set” Marquam, to the soaring Fremont and most of us, I like to think, have our favorites.  They are an amazing group of spans, probably unmatched anywhere in the country, certainly on the West Coast, if only for their diversity.  From the Hawthorne, which is the oldest vertical lift bridge in the nation, to the St. Johns, the longest suspension bridge in the world when it was completed, to the Morrison, the first bascule bridge designed with open  piers to allow water to flow directly through them, Portland does bridges with panache.  It was fun to study these works, and honor to be able to document them for much-deserved recognition on the National Register of Historic Places.

If the Willamette Bridges are the pinnacle of bridge technology in the middle of Oregon (vying with McCullough’s coastal bridges for State-wide honors as a group), they surely are not the only spectacular spans in Oregon.  As I wrote many years ago, getting around the state Oregon, a state replete with creeks, rivers and crevices, without bridges would be darn near impossible.  And Oregon has always taken its roads, and its bridges, seriously.  We still do.  Covered Bridges, those comfortable, quaint, roofs over rivers were a popular form in Oregon where wood, just like rivers, can be easily found.  For years I have worked on the rehabilitation of numerous covered bridges, usually as a part of a team headed by the great guys at OBEC Consulting Engineers.  Together we’ve been involved with the rehab of award-winning projects like the Lowell Covered Bridge or, more recently, the Chambers Covered Railroad Bridge.

This week, on my way up to Portland, I will swing through north central Lane County, where the Deadwood Covered Bridge is soon to get a new shake roof and some other minor but much needed attention.  Deadwood, like so many of Oregon’s 50+ surviving covered bridges, has been bypassed by a typical slab, beam and girder (i.e. pretty boring) concrete span.  Thankfully the good people of Lane County had the vision, and the continued willingness, to retain the Deadwood, and a bunch of other covered bridges, for their history and charm.  Lane County has the largest collection of covered spans in Oregon, which as the largest collection of such spans in America west of the Mississippi River. 

Steam Makes Things Spin

Over the years I have been involved with many projects that generate electricity, mostly hydro projects, but also Oregon’s only nuclear project, the Trojan Plant, near St. Helens.  In general there are only a few basic forms of making electricity.  You can use nature in the form of water or wind to spin a turbine (which spins the generator), in recent years you can use the sun to directly create electricity through photo voltaics, or you can generate steam to turn the generators.  There are lots of ways to create steam; you can tap it geothermally or you can create heat, which boils water.  HOW you create the heat is the main difference between most forms of generation other than solar, wind, or hydro.  At root most generation is centered around what amounts to a big tea kettle...the boiler, than can be fired by coal, by wood waste or hog fuel, by natural gas, or by a nuclear reaction.  At its core even the Trojan Plant, which people somehow envision as using some primal natural force (an atomic reaction) to create massive amounts of power was far more mundane....it was using all the heat generated by that reaction to create high pressure steam to spin a generator.  Exactly the same process as burning coal, or wood, just far more efficient and on a far larger scale (and yes, with a more complex waste product...but that isn’t the point of this little discourse). 

The more common way to create steam power for electric generation is to burn coal, and that is what most of America, without the plentiful waterways of the Pacific Northwest, does to power its computers and recharge its IPODs.  Coal is abundant, but it’s not generally considered green, and most steam plants in the Northwest now burn natural gas. 

Last month I toured one of Oregon’s few remaining steam plants of any sort, one built in 1930 to burn bunker oil, added to in the 1940s and 1950s to burn sawdust and wood-chips, and today burning natural gas.  EWEB’s Standby Steam Plant, located right in downtown Eugene, is also interesting that while it was designed to produce electricity (burning material to raise the temperature of water to turn one of its three generators), it was later converted (in 1962) to actually create, well, steam, that was directly transmitted around the downtown to heat various private and public buildings.  For the moment, the newest unit at the plant still does just that but all the earlier units remain in place, just as they were designed, and so the plant functions as something of a textbook of steam plant generation technology between 1930 and 1950.  I am enjoying researching, and documenting, the operation of this historic facility as part of EWEB’s decommissioning the facility.  It sure makes for some great images...the interiors of mid-20^th century industrial facilities are nothing if not photogenic!

Chambers Covered Bridge

Sometime ago I became part of a team working on the process of reconstructing the Chambers Covered Bridge, located in Cottage Grove, Oregon. The Chambers Covered Bridge, unique among Oregon's remaining covered spans, was designed not to carry automobiles, but a logging railroad. Built in 1925 at the edge of the J. H. Chambers Mill, it served a small logging railroad that went out to the west and brought the huge trees, and the locomotive that pulled them, over the Coast Fork of the Willamette River, just south of downtown Cottage Grove.

As often happens, the mill burned (twice) and the rail line was scraped.  Eventually the land was sold for residential development but the old bridge remained, disconnected from its track, its purpose, but still too interesting (and large) to remove. After a complex legal process, it ended up in the ownership of the City, who have great plans to transform the bridge into a pedestrian and bike crossing, leading to the local high school and the Cottage Grove Campus of Lane Community College, located nearby. When the project started, the Chambers Covered Bridge was in pretty sorry shape, but the engineers thought it could stand until we got all the paperwork done.  Then we'd take the bridge apart, salvage the larger members for re-use, and mill new wood to replicate the damaged areas as part of  a full, comprehensive, reconstruction based upon the original design.

All was going swimmingly until that big wind storm a few weeks ago. Old covered bridge, with siding, are sort of like sails and can only take so much.  The wind storm, and the bridge's decaying bottom chords, must have been Chambers' limit, forcing the entire structure to lean, or rack, toward the south.  Last week the bridge was out of plumb almost 2" in four feet.  That's a pretty noticeable lean, especially in a tall, narrow, structure, designed to fit a steam-powered locomotive. When I was on site last week  I commented if there is any more wind, it sure as heck better come from the south because the bridge can't take much more from the north.

Quick action by Cottage Grove, by OBEC (the engineering firm in charge of designing the new project), ODOT and Oregon SHPO resulted in the Chambers Bridge being determined an emergency.  That let us skip some of the paperwork (we'll do it later) and begin working immediately.  Careful deconstruction will begin early next week, with the goal of saving the bridge before it falls over, so we can begin to reconstruct it using as much of the original timbers as possible. Let's all hope there are no huge windstorms (or even little windstorms) in Cottage Grove before then.

Parvin Covered Bridge Rehab, Lane County

Today I am writing a "baseline" report for the area surrounding the Parvin Covered Bridge, in Lane County. This bridge, built in 1921, is one of about 50 surviving examples of the 450 or more covered bridges that once carried traffic over Oregon's rivers and streams. Like most covered bridges, Parvin has legions of supporters who treasure these examples of the wooden bridge builders art in Oregon. Parvin is somewhat unusual in that it still carries vechicular traffic over Lost Creek (many covered bridges are pedestrian only).

Just west of the bridge, which connects Parvin Road to Lost Creek Road, sits the circa 1865 house of James and Selenia Parvin, along with two early barns that were also built by the family. On the west of the bridge is another house, built and long occupied by James' son.

None of these resources will be impacted by the current project, which will rehab the Parvin Bridge to assure it survives for a long long time, it's just interesting that this little neighborhood, centered on this bridge (and the one that stood here before it) has changed so little in the past century and half of Oregon's history.